WorldWideScience

Sample records for arsenite oxidase gene

  1. Multiple controls affect arsenite oxidase gene expression in Herminiimonas arsenicoxydans

    Directory of Open Access Journals (Sweden)

    Coppée Jean-Yves

    2010-02-01

    Full Text Available Abstract Background Both the speciation and toxicity of arsenic are affected by bacterial transformations, i.e. oxidation, reduction or methylation. These transformations have a major impact on environmental contamination and more particularly on arsenic contamination of drinking water. Herminiimonas arsenicoxydans has been isolated from an arsenic- contaminated environment and has developed various mechanisms for coping with arsenic, including the oxidation of As(III to As(V as a detoxification mechanism. Results In the present study, a differential transcriptome analysis was used to identify genes, including arsenite oxidase encoding genes, involved in the response of H. arsenicoxydans to As(III. To get insight into the molecular mechanisms of this enzyme activity, a Tn5 transposon mutagenesis was performed. Transposon insertions resulting in a lack of arsenite oxidase activity disrupted aoxR and aoxS genes, showing that the aox operon transcription is regulated by the AoxRS two-component system. Remarkably, transposon insertions were also identified in rpoN coding for the alternative N sigma factor (σ54 of RNA polymerase and in dnaJ coding for the Hsp70 co-chaperone. Western blotting with anti-AoxB antibodies and quantitative RT-PCR experiments allowed us to demonstrate that the rpoN and dnaJ gene products are involved in the control of arsenite oxidase gene expression. Finally, the transcriptional start site of the aoxAB operon was determined using rapid amplification of cDNA ends (RACE and a putative -12/-24 σ54-dependent promoter motif was identified upstream of aoxAB coding sequences. Conclusion These results reveal the existence of novel molecular regulatory processes governing arsenite oxidase expression in H. arsenicoxydans. These data are summarized in a model that functionally integrates arsenite oxidation in the adaptive response to As(III in this microorganism.

  2. Linking microbial oxidation of arsenic with detection and phylogenetic analysis of arsenite oxidase genes in diverse geothermal environments.

    Science.gov (United States)

    Hamamura, N; Macur, R E; Korf, S; Ackerman, G; Taylor, W P; Kozubal, M; Reysenbach, A-L; Inskeep, W P

    2009-02-01

    The identification and characterization of genes involved in the microbial oxidation of arsenite will contribute to our understanding of factors controlling As cycling in natural systems. Towards this goal, we recently characterized the widespread occurrence of aerobic arsenite oxidase genes (aroA-like) from pure-culture bacterial isolates, soils, sediments and geothermal mats, but were unable to detect these genes in all geothermal systems where we have observed microbial arsenite oxidation. Consequently, the objectives of the current study were to measure arsenite-oxidation rates in geochemically diverse thermal habitats in Yellowstone National Park (YNP) ranging in pH from 2.6 to 8, and to identify corresponding 16S rRNA and aroA genotypes associated with these arsenite-oxidizing environments. Geochemical analyses, including measurement of arsenite-oxidation rates within geothermal outflow channels, were combined with 16S rRNA gene and aroA functional gene analysis using newly designed primers to capture previously undescribed aroA-like arsenite oxidase gene diversity. The majority of bacterial 16S rRNA gene sequences found in acidic (pH 2.6-3.6) Fe-oxyhydroxide microbial mats were closely related to Hydrogenobaculum spp. (members of the bacterial order Aquificales), while the predominant sequences from near-neutral (pH 6.2-8) springs were affiliated with other Aquificales including Sulfurihydrogenibium spp., Thermocrinis spp. and Hydrogenobacter spp., as well as members of the Deinococci, Thermodesulfobacteria and beta-Proteobacteria. Modified primers designed around previously characterized and newly identified aroA-like genes successfully amplified new lineages of aroA-like genes associated with members of the Aquificales across all geothermal systems examined. The expression of Aquificales aroA-like genes was also confirmed in situ, and the resultant cDNA sequences were consistent with aroA genotypes identified in the same environments. The aroA sequences

  3. Diversity and abundance of the arsenite oxidase gene aioA in geothermal areas of Tengchong, Yunnan, China.

    Science.gov (United States)

    Jiang, Zhou; Li, Ping; Jiang, Dawei; Wu, Geng; Dong, Hailiang; Wang, Yanhong; Li, Bing; Wang, Yanxin; Guo, Qinghai

    2014-01-01

    A total of 12 samples were collected from the Tengchong geothermal areas of Yunnan, China, with the goal to assess the arsenite (AsIII) oxidation potential of the extant microbial communities as inferred by the abundance and diversity of the AsIII oxidase large subunit gene aioA relative to geochemical context. Arsenic concentrations were higher (on average 251.68 μg/L) in neutral or alkaline springs than in acidic springs (on average 30.88 μg/L). aioA abundance ranged from 1.63 × 10(1) to 7.08 × 10(3) per ng of DNA and positively correlated with sulfide and the ratios of arsenate (AsV):total dissolved arsenic (AsTot). Based on qPCR estimates of bacterial and archaeal 16S rRNA gene abundance, aioA-harboring organisms comprised as much as ~15% of the total community. Phylogenetically, the major aioA sequences (270 total) in the acidic hot springs (pH 3.3-4.4) were affiliated with Aquificales and Rhizobiales, while those in neutral or alkaline springs (pH 6.6-9.1) were inferred to be primarily bacteria related to Thermales and Burkholderiales. Interestingly, aioA abundance at one site greatly exceeded bacterial 16S rRNA gene abundance, suggesting these aioA genes were archaeal even though phylogenetically these aioA sequences were most similar to the Aquificales. In summary, this study described novel aioA sequences in geothermal features geographically far removed from those in the heavily studied Yellowstone geothermal complex.

  4. Constitutive arsenite oxidase expression detected in arsenic-hypertolerant Pseudomonas xanthomarina S11.

    Science.gov (United States)

    Koechler, Sandrine; Arsène-Ploetze, Florence; Brochier-Armanet, Céline; Goulhen-Chollet, Florence; Heinrich-Salmeron, Audrey; Jost, Bernard; Lièvremont, Didier; Philipps, Muriel; Plewniak, Frédéric; Bertin, Philippe N; Lett, Marie-Claire

    2015-04-01

    Pseudomonas xanthomarina S11 is an arsenite-oxidizing bacterium isolated from an arsenic-contaminated former gold mine in Salsigne, France. This bacterium showed high resistance to arsenite and was able to oxidize arsenite to arsenate at concentrations up to 42.72 mM As[III]. The genome of this strain was sequenced and revealed the presence of three ars clusters. One of them is located on a plasmid and is organized as an "arsenic island" harbouring an aio operon and genes involved in phosphorous metabolism, in addition to the ars genes. Neither the aioXRS genes nor a specific sigma-54-dependent promoter located upstream of aioBA genes, both involved in regulation of arsenite oxidase expression in other arsenite-oxidizing bacteria, could be identified in the genome. This observation is in accordance with the fact that no difference was observed in expression of arsenite oxidase in P. xanthomarina S11, whether or not the strain was grown in the presence of As[III].

  5. ArxA, a new clade of arsenite oxidase within the DMSO reductase family of molybdenum oxidoreductases

    Science.gov (United States)

    Zargar, Kamrun; Conrad, Alison; Bernick, David L.; Lowe, Todd M.; Stolc, Viktor; Hoeft, Shelley; Oremland, Ronald S.; Stolz, John; Saltikov, Chad W.

    2012-01-01

    Arsenotrophy, growth coupled to autotrophic arsenite oxidation or arsenate respiratory reduction, occurs only in the prokaryotic domain of life. The enzymes responsible for arsenotrophy belong to distinct clades within the DMSO reductase family of molybdenum-containing oxidoreductases: specifically arsenate respiratory reductase, ArrA, and arsenite oxidase, AioA (formerly referred to as AroA and AoxB). A new arsenite oxidase clade, ArxA, represented by the haloalkaliphilic bacterium Alkalilimnicola ehrlichii strain MLHE-1 was also identified in the photosynthetic purple sulfur bacterium Ectothiorhodospira sp. strain PHS-1. A draft genome sequence of PHS-1 was completed and an arx operon similar to MLHE-1 was identified. Gene expression studies showed that arxA was strongly induced with arsenite. Microbial ecology investigation led to the identification of additional arxA-like sequences in Mono Lake and Hot Creek sediments, both arsenic-rich environments in California. Phylogenetic analyses placed these sequences as distinct members of the ArxA clade of arsenite oxidases. ArxA-like sequences were also identified in metagenome sequences of several alkaline microbial mat environments of Yellowstone National Park hot springs. These results suggest that ArxA-type arsenite oxidases appear to be widely distributed in the environment presenting an opportunity for further investigations of the contribution of Arx-dependent arsenotrophy to the arsenic biogeochemical cycle.

  6. Organization and regulation of the arsenite oxidase operon of the moderately acidophilic and facultative chemoautotrophic Thiomonas arsenitoxydans.

    Science.gov (United States)

    Slyemi, Djamila; Moinier, Danielle; Talla, Emmanuel; Bonnefoy, Violaine

    2013-11-01

    Thiomonas arsenitoxydans is an acidophilic and facultatively autotrophic bacterium that can grow by oxidizing arsenite to arsenate. A comparative genomic analysis showed that the T. arsenitoxydans aioBA cluster encoding the two subunits of arsenite oxidase is distinct from the other clusters, with two specific genes encoding a cytochrome c and a metalloregulator belonging to the ArsR/SmtB family. These genes are cotranscribed with aioBA, suggesting that these cytochromes c are involved in arsenite oxidation and that this operon is controlled by the metalloregulator. The growth of T. arsenitoxydans in the presence of thiosulfate and arsenite, or arsenate, is biphasic. Real-time PCR experiments showed that the operon is transcribed during the second growth phase in the presence of arsenite or arsenate, whereas antimonite had no effect. These results suggest that the expression of the aioBA operon of T. arsenitoxydans is regulated by the electron donor present in the medium, i.e., is induced in the presence of arsenic but is repressed by more energetic substrates. Our data indicate that the genetic organization and regulation of the aioBA operon of T. arsenitoxydans differ from those of the other arsenite oxidizers.

  7. 三价砷氧化细菌Acidovorax sp.GW2中As(Ⅲ)氧化酶基因和调控序列的克隆鉴定%Isolation and identification of arsenite oxidase gene and regulatory sequences in an arsenite-oxidizing bacterium Acidovorax sp. GW2

    Institute of Scientific and Technical Information of China (English)

    赵凯; 黄银燕; 王倩; 王革娇

    2011-01-01

    Using reverse transcriptase PCR method and a bacterial fosmid library screening, an arsenite oxidase gene cluster were isolated from an arsenite-oxidizing bacterium Acidovorax sp. GW2. There are seven genes including aoxRSXABCD putatively encoding the transcriptional regulator AoxR of a two-component signal transduction system (68% identity), a periplasmic sensor histidine kinase AoxS (55 % identity), a periplasmic binding protein AoxX (55 % identity), arsenite oxidase AoxAB(74 % and 71% identity, respectively), nitroreductase AoxC (46 % identity) and cytochrome c AoxD (63 % identity) respectively. According to the reverse transcriptase PCR experiments,aoxR and aoxS encoding for a two-component system proteins are co-transcribed and located in opposite to structural genes aoxABCD.aoxX and aoxRS are not in the same operon. Functional analyses through gene knock-out of aoxS, aoxX and aoxD showed that aoxS and aoxX are the essential genes in arsenite oxidation of GW2, and the loss of aoxD did not show significant effects on arsenite oxidation.%通过反向PCR和细菌Fosmid文库筛选,克隆得到1株二三价砷[As(Ⅲ)]氧化细菌Acidovorax sp.GW2的As(Ⅲ)氧化酶Aox基因簇,包括aoxRSXABCD 7个基因,分别预测编码双组分信号传导系统转录调控子AoxR(同源性68%),周质感应组氨酸激酶AoxS(同源性55%),周质结合蛋白AoxX(同源性55%),砷氧化酶AoxAB(同源性分别为74%和71%),硝基还原酶AoxC(同源性46%),细胞色素C AoxD(同源性63%).反转录PCR结果显示,编码双组分系统的aoxRS基因共转录,而与之转录方向相反的结构基因aoxABCD处于同一操纵子中,aoxX基因和aoxRS基因不在同一操纵子中.通过对aoxS、aoxX、aoxD的基因敲除功能研究发现aoxS和aoxX基因为GW2三价砷氧化的必需基因,aoxD的功能丧失减慢了三价砷的氧化速率,但非关键基因.

  8. Spatio-temporal detection of the Thiomonas population and the Thiomonas arsenite oxidase involved in natural arsenite attenuation processes in the Carnoulès Acid Mine Drainage

    Directory of Open Access Journals (Sweden)

    Agnès eHovasse

    2016-02-01

    Full Text Available The acid mine drainage (AMD impacted creek of the Carnoulès mine (Southern France is characterized by acid waters with a high heavy metal content. The microbial community inhabiting this AMD was extensively studied using isolation, metagenomic and metaproteomic methods, and the results showed that a natural arsenic (and iron attenuation process involving the arsenite oxidase activity of several Thiomonas strains occurs at this site. A sensitive quantitative Selected Reaction Monitoring (SRM-based proteomic approach was developed for detecting and quantifying the two subunits of the arsenite oxidase and RpoA of two different Thiomonas groups. Using this approach combined with 16S rRNA gene sequence analysis based on pyrosequencing and FISH, it was established here for the first time that these Thiomonas strains are ubiquitously present in minor proportions in this AMD and that they express the key enzymes involved in natural remediation processes at various locations and time points. In addition to these findings, this study also confirms that targeted proteomics applied at the community level can be used to detect weakly abundant proteins in situ.

  9. The Respiratory Arsenite Oxidase: Structure and the Role of Residues Surrounding the Rieske Cluster

    Science.gov (United States)

    Warelow, Thomas P.; Oke, Muse; Schoepp-Cothenet, Barbara; Dahl, Jan U.; Bruselat, Nicole; Sivalingam, Ganesh N.; Leimkühler, Silke; Thalassinos, Konstantinos; Kappler, Ulrike; Naismith, James H.; Santini, Joanne M.

    2013-01-01

    The arsenite oxidase (Aio) from the facultative autotrophic Alphaproteobacterium Rhizobium sp. NT-26 is a bioenergetic enzyme involved in the oxidation of arsenite to arsenate. The enzyme from the distantly related heterotroph, Alcaligenes faecalis, which is thought to oxidise arsenite for detoxification, consists of a large α subunit (AioA) with bis-molybdopterin guanine dinucleotide at its active site and a 3Fe-4S cluster, and a small β subunit (AioB) which contains a Rieske 2Fe-2S cluster. The successful heterologous expression of the NT-26 Aio in Escherichia coli has resulted in the solution of its crystal structure. The NT-26 Aio, a heterotetramer, shares high overall similarity to the heterodimeric arsenite oxidase from A. faecalis but there are striking differences in the structure surrounding the Rieske 2Fe-2S cluster which we demonstrate explains the difference in the observed redox potentials (+225 mV vs. +130/160 mV, respectively). A combination of site-directed mutagenesis and electron paramagnetic resonance was used to explore the differences observed in the structure and redox properties of the Rieske cluster. In the NT-26 AioB the substitution of a serine (S126 in NT-26) for a threonine as in the A. faecalis AioB explains a −20 mV decrease in redox potential. The disulphide bridge in the A. faecalis AioB which is conserved in other betaproteobacterial AioB subunits and the Rieske subunit of the cytochrome bc1 complex is absent in the NT-26 AioB subunit. The introduction of a disulphide bridge had no effect on Aio activity or protein stability but resulted in a decrease in the redox potential of the cluster. These results are in conflict with previous data on the betaproteobacterial AioB subunit and the Rieske of the bc1 complex where removal of the disulphide bridge had no effect on the redox potential of the former but a decrease in cluster stability was observed in the latter. PMID:24023621

  10. The respiratory arsenite oxidase: structure and the role of residues surrounding the rieske cluster.

    Directory of Open Access Journals (Sweden)

    Thomas P Warelow

    Full Text Available The arsenite oxidase (Aio from the facultative autotrophic Alphaproteobacterium Rhizobium sp. NT-26 is a bioenergetic enzyme involved in the oxidation of arsenite to arsenate. The enzyme from the distantly related heterotroph, Alcaligenes faecalis, which is thought to oxidise arsenite for detoxification, consists of a large α subunit (AioA with bis-molybdopterin guanine dinucleotide at its active site and a 3Fe-4S cluster, and a small β subunit (AioB which contains a Rieske 2Fe-2S cluster. The successful heterologous expression of the NT-26 Aio in Escherichia coli has resulted in the solution of its crystal structure. The NT-26 Aio, a heterotetramer, shares high overall similarity to the heterodimeric arsenite oxidase from A. faecalis but there are striking differences in the structure surrounding the Rieske 2Fe-2S cluster which we demonstrate explains the difference in the observed redox potentials (+225 mV vs. +130/160 mV, respectively. A combination of site-directed mutagenesis and electron paramagnetic resonance was used to explore the differences observed in the structure and redox properties of the Rieske cluster. In the NT-26 AioB the substitution of a serine (S126 in NT-26 for a threonine as in the A. faecalis AioB explains a -20 mV decrease in redox potential. The disulphide bridge in the A. faecalis AioB which is conserved in other betaproteobacterial AioB subunits and the Rieske subunit of the cytochrome bc 1 complex is absent in the NT-26 AioB subunit. The introduction of a disulphide bridge had no effect on Aio activity or protein stability but resulted in a decrease in the redox potential of the cluster. These results are in conflict with previous data on the betaproteobacterial AioB subunit and the Rieske of the bc 1 complex where removal of the disulphide bridge had no effect on the redox potential of the former but a decrease in cluster stability was observed in the latter.

  11. An ArsR/SmtB family member is involved in the regulation by arsenic of the arsenite oxidase operon in Thiomonas arsenitoxydans.

    Science.gov (United States)

    Moinier, Danielle; Slyemi, Djamila; Byrne, Deborah; Lignon, Sabrina; Lebrun, Régine; Talla, Emmanuel; Bonnefoy, Violaine

    2014-10-01

    The genetic organization of the aioBA operon, encoding the arsenite oxidase of the moderately acidophilic and facultative chemoautotrophic bacterium Thiomonas arsenitoxydans, is different from that of the aioBA operon in the other arsenite oxidizers, in that it encodes AioF, a metalloprotein belonging to the ArsR/SmtB family. AioF is stabilized by arsenite, arsenate, or antimonite but not molybdate. Arsenic is tightly attached to AioF, likely by cysteine residues. When loaded with arsenite or arsenate, AioF is able to bind specifically to the regulatory region of the aio operon at two distinct positions. In Thiomonas arsenitoxydans, the promoters of aioX and aioB are convergent, suggesting that transcriptional interference occurs. These results indicate that the regulation of the aioBA operon is more complex in Thiomonas arsenitoxydans than in the other aioBA containing arsenite oxidizers and that the arsenic binding protein AioF is involved in this regulation. On the basis of these data, a model to explain the tight control of aioBA expression by arsenic in Thiomonas arsenitoxydans is proposed.

  12. X-ray crystal structure of arsenite-inhibited xanthine oxidase: μ-sulfido,μ-oxo double bridge between molybdenum and arsenic in the active site.

    Science.gov (United States)

    Cao, Hongnan; Hall, James; Hille, Russ

    2011-08-17

    Xanthine oxidoreductase is a molybdenum-containing enzyme that catalyzes the hydroxylation reaction of sp(2)-hybridized carbon centers of a variety of substrates, including purines, aldehydes, and other heterocyclic compounds. The complex of arsenite-inhibited xanthine oxidase has been characterized previously by UV-vis, electron paramagnetic resonance, and X-ray absorption spectroscopy (XAS), and the catalytically essential sulfido ligand of the square-pyrimidal molybdenum center has been suggested to be involved in arsenite binding through either a μ-sulfido,μ-oxo double bridge or a single μ-sulfido bridge. However, this is contrary to the crystallographically observed single μ-oxo bridge between molybdenum and arsenic in the desulfo form of aldehyde oxidoreductase from Desulfovibrio gigas (an enzyme closely related to xanthine oxidase), whose molybdenum center has an oxo ligand replacing the catalytically essential sulfur, as seen in the functional form of xanthine oxidase. Here we use X-ray crystallography to characterize the molybdenum center of arsenite-inhibited xanthine oxidase and solve the structures of the oxidized and reduced inhibition complexes at 1.82 and 2.11 Å resolution, respectively. We observe μ-sulfido,μ-oxo double bridges between molybdenum and arsenic in the active sites of both complexes. Arsenic is four-coordinate with a distorted trigonal-pyramidal geometry in the oxidized complex and three-coordinate with a distorted trigonal-planar geometry in the reduced complex. The doubly bridged binding mode is in agreement with previous XAS data indicating that the catalytically essential sulfur is also essential for the high affinity of reduced xanthine oxidoreductase for arsenite.

  13. The genetic basis of anoxygenic photosynthetic arsenite oxidation

    Science.gov (United States)

    Hernandez-Maldonado, Jamie; Sanchez-Sedillo, Benjamin; Stoneburner, Brendon; Boren, Alison; Miller, Laurence G.; McCann, Shelley; Rosen, Michael R.; Oremland, Ronald S.; Saltikov, Chad W.

    2017-01-01

    “Photoarsenotrophy”, the use of arsenite as an electron donor for anoxygenic photosynthesis, is thought to be an ancient form of phototrophy along with the photosynthetic oxidation of Fe(II), H2S, H2, and NO2-. Photoarsenotrophy was recently identified from Paoha Island's (Mono Lake, CA) arsenic-rich hot springs. The genomes of several photoarsenotrophs revealed a gene cluster, arxB2AB1CD, where arxA is predicted to encode for the sole arsenite oxidase. The role of arxA in photosynthetic arsenite oxidation was confirmed by disrupting the gene in a representative photoarsenotrophic bacterium, resulting in the loss of light-dependent arsenite oxidation. In situ evidence of active photoarsenotrophic microbes was supported by arxA mRNA detection for the first time, in red-pigmented microbial mats within the hot springs of Paoha Island. This work expands on the genetics for photosynthesis coupled to new electron donors and elaborates on known mechanisms for arsenic metabolism, thereby highlighting the complexities of arsenic biogeochemical cycling.

  14. Effects of Arsenite Resistance on the Growth and Functional Gene Expression of Leptospirillum ferriphilum and Acidithiobacillus thiooxidans in Pure Culture and Coculture.

    Science.gov (United States)

    Jiang, Huidan; Liang, Yili; Yin, Huaqun; Xiao, Yunhua; Guo, Xue; Xu, Ying; Hu, Qi; Liu, Hongwei; Liu, Xueduan

    2015-01-01

    The response of iron-oxidizing Leptospirillum ferriphilum YSK and sulfur-oxidizing Acidithiobacillus thiooxidans A01 to arsenite under pure culture and coculture was investigated based on biochemical characterization (concentration of iron ion and pH value) and related gene expression. L. ferriphilum YSK and At. thiooxidans A01 in pure culture could adapt up to 400 mM and 800 mM As(III) after domestication, respectively, although arsenite showed a negative effect on both strains. The coculture showed a stronger sulfur and ferrous ion oxidation activity when exposed to arsenite. In coculture, the pH value showed no significant difference when under 500 mM arsenite stress, and the cell number of At. thiooxidans was higher than that in pure culture benefiting from the interaction with L. ferriphilum. The expression profile showed that the arsenic efflux system in the coculture was more active than that in pure culture, indicating that there is a synergetic interaction between At. thiooxidans A01 and L. ferriphilum YSK. In addition, a model was proposed to illustrate the interaction between arsenite and the ars operon in L. ferriphilum YSK and At. thiooxidans A01. This study will facilitate the effective application of coculture in the bioleaching process by taking advantage of strain-strain communication and coordination.

  15. Effects of Arsenite Resistance on the Growth and Functional Gene Expression of Leptospirillum ferriphilum and Acidithiobacillus thiooxidans in Pure Culture and Coculture

    Directory of Open Access Journals (Sweden)

    Huidan Jiang

    2015-01-01

    Full Text Available The response of iron-oxidizing Leptospirillum ferriphilum YSK and sulfur-oxidizing Acidithiobacillus thiooxidans A01 to arsenite under pure culture and coculture was investigated based on biochemical characterization (concentration of iron ion and pH value and related gene expression. L. ferriphilum YSK and At. thiooxidans A01 in pure culture could adapt up to 400 mM and 800 mM As(III after domestication, respectively, although arsenite showed a negative effect on both strains. The coculture showed a stronger sulfur and ferrous ion oxidation activity when exposed to arsenite. In coculture, the pH value showed no significant difference when under 500 mM arsenite stress, and the cell number of At. thiooxidans was higher than that in pure culture benefiting from the interaction with L. ferriphilum. The expression profile showed that the arsenic efflux system in the coculture was more active than that in pure culture, indicating that there is a synergetic interaction between At. thiooxidans A01 and L. ferriphilum YSK. In addition, a model was proposed to illustrate the interaction between arsenite and the ars operon in L. ferriphilum YSK and At. thiooxidans A01. This study will facilitate the effective application of coculture in the bioleaching process by taking advantage of strain-strain communication and coordination.

  16. Short-term exposure of arsenite disrupted thyroid endocrine system and altered gene transcription in the HPT axis in zebrafish.

    Science.gov (United States)

    Sun, Hong-Jie; Li, Hong-Bo; Xiang, Ping; Zhang, Xiaowei; Ma, Lena Q

    2015-10-01

    Arsenic (As) pollution in aquatic environment may adversely impact fish health by disrupting their thyroid hormone homeostasis. In this study, we explored the effect of short-term exposure of arsenite (AsIII) on thyroid endocrine system in zebrafish. We measured As concentrations, As speciation, and thyroid hormone thyroxine levels in whole zebrafish, oxidative stress (H2O2) and damage (MDA) in the liver, and gene transcription in hypothalamic-pituitary-thyroid (HPT) axis in the brain and liver tissues of zebrafish after exposing to different AsIII concentrations for 48 h. Result indicated that exposure to AsIII increased inorganic As in zebrafish to 0.46-0.72 mg kg(-1), induced oxidative stress with H2O2 being increased by 1.4-2.5 times and caused oxidative damage with MDA being augmented by 1.6 times. AsIII exposure increased thyroxine levels by 1.3-1.4 times and modulated gene transcription in HPT axis. Our study showed AsIII caused oxidative damage, affected thyroid endocrine system and altered gene transcription in HPT axis in zebrafish.

  17. Molecular evolution of the polyamine oxidase gene family in Metazoa

    Directory of Open Access Journals (Sweden)

    Polticelli Fabio

    2012-06-01

    Full Text Available Abstract Background Polyamine oxidase enzymes catalyze the oxidation of polyamines and acetylpolyamines. Since polyamines are basic regulators of cell growth and proliferation, their homeostasis is crucial for cell life. Members of the polyamine oxidase gene family have been identified in a wide variety of animals, including vertebrates, arthropodes, nematodes, placozoa, as well as in plants and fungi. Polyamine oxidases (PAOs from yeast can oxidize spermine, N1-acetylspermine, and N1-acetylspermidine, however, in vertebrates two different enzymes, namely spermine oxidase (SMO and acetylpolyamine oxidase (APAO, specifically catalyze the oxidation of spermine, and N1-acetylspermine/N1-acetylspermidine, respectively. Little is known about the molecular evolutionary history of these enzymes. However, since the yeast PAO is able to catalyze the oxidation of both acetylated and non acetylated polyamines, and in vertebrates these functions are addressed by two specialized polyamine oxidase subfamilies (APAO and SMO, it can be hypothesized an ancestral reference for the former enzyme from which the latter would have been derived. Results We analysed 36 SMO, 26 APAO, and 14 PAO homologue protein sequences from 54 taxa including various vertebrates and invertebrates. The analysis of the full-length sequences and the principal domains of vertebrate and invertebrate PAOs yielded consensus primary protein sequences for vertebrate SMOs and APAOs, and invertebrate PAOs. This analysis, coupled to molecular modeling techniques, also unveiled sequence regions that confer specific structural and functional properties, including substrate specificity, by the different PAO subfamilies. Molecular phylogenetic trees revealed a basal position of all the invertebrates PAO enzymes relative to vertebrate SMOs and APAOs. PAOs from insects constitute a monophyletic clade. Two PAO variants sampled in the amphioxus are basal to the dichotomy between two well supported

  18. Genes involved in arsenic transformation and resistance associated with different levels of arsenic-contaminated soils

    Directory of Open Access Journals (Sweden)

    Wang Gejiao

    2009-01-01

    Full Text Available Abstract Background Arsenic is known as a toxic metalloid, which primarily exists in inorganic form [As(III and As(V] and can be transformed by microbial redox processes in the natural environment. As(III is much more toxic and mobile than As(V, hence microbial arsenic redox transformation has a major impact on arsenic toxicity and mobility which can greatly influence the human health. Our main purpose was to investigate the distribution and diversity of microbial arsenite-resistant species in three different arsenic-contaminated soils, and further study the As(III resistance levels and related functional genes of these species. Results A total of 58 arsenite-resistant bacteria were identified from soils with three different arsenic-contaminated levels. Highly arsenite-resistant bacteria (MIC > 20 mM were only isolated from the highly arsenic-contaminated site and belonged to Acinetobacter, Agrobacterium, Arthrobacter, Comamonas, Rhodococcus, Stenotrophomonas and Pseudomonas. Five arsenite-oxidizing bacteria that belonged to Achromobacter, Agrobacterium and Pseudomonas were identified and displayed a higher average arsenite resistance level than the non-arsenite oxidizers. 5 aoxB genes encoding arsenite oxidase and 51 arsenite transporter genes [18 arsB, 12 ACR3(1 and 21 ACR3(2] were successfully amplified from these strains using PCR with degenerate primers. The aoxB genes were specific for the arsenite-oxidizing bacteria. Strains containing both an arsenite oxidase gene (aoxB and an arsenite transporter gene (ACR3 or arsB displayed a higher average arsenite resistance level than those possessing an arsenite transporter gene only. Horizontal transfer of ACR3(2 and arsB appeared to have occurred in strains that were primarily isolated from the highly arsenic-contaminated soil. Conclusion Soils with long-term arsenic contamination may result in the evolution of highly diverse arsenite-resistant bacteria and such diversity was probably caused in

  19. Biotransformation of arsenite and bacterial aox activity in drinking water produced from surface water of floating houses: Arsenic contamination in Cambodia.

    Science.gov (United States)

    Chang, Jin-Soo

    2015-11-01

    The potential arsenite bioteansformation activity of arsenic was investigated by examining bacterial arsenic arsenite-oxidizing gene such as aoxS, aoxR, aoxA, aoxB, aoxC, and aoxD in high arsenic-contaminated drinking water produced from the surface water of floating houses. There is a biogeochemical cycle of activity involving arsenite oxidase aox system and the ars (arsenic resistance system) gene operon and aoxR leader gene activity in Alcaligenes faecalis SRR-11 and aoxS leader gene activity in Achromobacter xylosoxidans TSL-66. Batch experiments showed that SRR-11 and TSL-66 completely oxidized 1 mM of As (III) to As (V) within 35-40 h. The leaders of aoxS and aoxR are important for gene activity, and their effects in arsenic bioremediation and mobility in natural water has a significant ecological role because it allows arsenite oxidase in bacteria to control the biogeochemical cycle of arsenic-contaminated drinking water produced from surface water of floating houses.

  20. Arsenic and phosphate rock impacted the abundance and diversity of bacterial arsenic oxidase and reductase genes in rhizosphere of As-hyperaccumulator Pteris vittata.

    Science.gov (United States)

    Han, Yong-He; Fu, Jing-Wei; Xiang, Ping; Cao, Yue; Rathinasabapathi, Bala; Chen, Yanshan; Ma, Lena Q

    2017-01-05

    Microbially-mediated arsenic (As) transformation in soils affects As speciation and plant uptake. However, little is known about the impacts of As on bacterial communities and their functional genes in the rhizosphere of As-hyperaccumulator Pteris vittata. In this study, arsenite (AsIII) oxidase genes (aroA-like) and arsenate (AsV) reductase genes (arsC) were amplified from three soils, which were amended with 50mgkg(-1) As and/or 1.5% phosphate rock (PR) and grew P. vittata for 90 d. The aroA-like genes in the rhizosphere were 50 times more abundant than arsC genes, consistent with the dominance of AsV in soils. According to functional gene alignment, most bacteria belonged to α-, β- and γ-Proteobacteria. Moreover, aroA-like genes showed a higher biodiversity than arsC genes based on clone library analysis and could be grouped into nine clusters based on terminal restriction fragment length polymorphism (T-RFLP) analysis. Besides, AsV amendment elevated aroA-like gene diversity, but decreased arsC gene diversity. Redundancy analysis indicated that soil pH, available Ca and P, and AsV concentration were key factors driving diverse compositions in aroA-like gene community. This work identified new opportunities to screen for As-oxidizing and/or -reducing bacteria to aid phytoremediation of As-contaminated soils.

  1. The pea gene NA encodes ent-kaurenoic acid oxidase.

    Science.gov (United States)

    Davidson, Sandra E; Elliott, Robert C; Helliwell, Chris A; Poole, Andrew T; Reid, James B

    2003-01-01

    The gibberellin (GA)-deficient dwarf na mutant in pea (Pisum sativum) has severely reduced internode elongation, reduced root growth, and decreased leaflet size. However, the seeds develop normally. Two genes, PsKAO1 and PsKAO2, encoding cytochrome P450 monooxygenases of the subfamily CYP88A were isolated. Both PsKAO1 and PsKAO2 had ent-kaurenoic acid oxidase (KAO) activity, catalyzing the three steps of the GA biosynthetic pathway from ent-kaurenoic acid to GA(12) when expressed in yeast (Saccharomyces cerevisiae). In addition to the intermediates ent-7alpha-hydroxykaurenoic acid and GA(12)-aldehyde, some additional products of the pea KAO activity were detected, including ent-6alpha,7alpha-dihydroxykaurenoic acid and 7beta-hydroxykaurenolide. The NA gene encodes PsKAO1, because in two independent mutant alleles, na-1 and na-2, PsKAO1 had altered sequences and the five-base deletion in PsKAO1 associated with the na-1 allele cosegregated with the dwarf na phenotype. PsKAO1 was expressed in the stem, apical bud, leaf, pod, and root, organs in which GA levels have previously been shown to be reduced in na plants. PsKAO2 was expressed only in seeds and this may explain the normal seed development and normal GA biosynthesis in seeds of na plants.

  2. Isolation and analysis of the genes for cytochrome c oxidase in Paracoccus denitrificans

    OpenAIRE

    Raitio, Mirja; Jalli, Tuulikki; Saraste, Matti

    1987-01-01

    Synthetic oligonucleotide probes were used to clone two loci from the chromosomal DNA of Paracoccus denitrificans that contain the genes for cytochrome c oxidase (cytochrome aa3). One locus seems to contain four or five genes probably forming an operon. Two of these code for the oxidase subunits II and III. Three open reading frames are found between the COII and COIII genes. The other locus codes for the subunit I. A short open reading frame is found upstream of this gene. All three subunits...

  3. Diversity of arsenite oxidizing bacterial communities in arsenic-rich deltaic aquifers in West Bengal, India

    Directory of Open Access Journals (Sweden)

    Devanita eGhosh

    2014-11-01

    Full Text Available High arsenic (As concentration in groundwater has affected human health, particularly in South-East Asia putting millions of people at risk. Biogeochemical cycling of As carried out by different bacterial groups are suggested to control the As fluxes in aquifers. A functional diversity approach in link with As precipitation was adopted to study bacterial community structures and their variation within the As contaminated Bengal Delta Plain (BDP aquifers of India. Groundwater samples collected from two shallow aquifers in Karimpur II (West Bengal, India, during years 2010 and 2011, were investigated to trace the effects of inter-annual variability in precipitation on community structure and diversity of bacterial assemblages. The study focused on amplification, clone library generation and sequencing of the arsenite oxidase large sub-unit gene aioA and 16S rRNA marker, with respect to changes in elemental concentrations. New set of primers were designed to amplify the aioA gene as a phylogenetic marker to study taxonomically diverse arsenite oxidizing bacterial groups in these aquifers. Overall narrow distribution of bacterial communities based on aioA and 16S rRNA sequences observed was due to poor nutrient status and anoxic conditions in these As contaminated aquifers. Proteobacteria was the dominant phylum detected, within which Acidovorax, Hydrogenophaga, Albidiferax, Bosea and Polymorphum were the major arsenite oxidizing bacterial genera. The structure of bacterial assemblages including those of arsenite oxidizing bacteria were affected by an increase in major elemental concentrations (e.g., As, iron, sulfur, and silica within two sampling sessions, which was supported by PCA analysis. One of the significant findings of this study is detection of novel lineages of 16S rRNA-like bacterial sequences indicating presence of indigenous bacterial communities across both wells of BDP that can play important role in biogeochemical cycling of

  4. Hippocampal mitochondrial cytochrome C oxidase activity and gene expression in a rat model of chronic cerebral ischemia

    Institute of Scientific and Technical Information of China (English)

    Qing Zhao; Yingli Zhang; Mingming Zhao; Yu Wang; Ming Ma; Xinquan Gu; Xia Cao

    2011-01-01

    The present study established a rat model of chronic cerebral ischemia using bilateral common carotid artery permanent ligation to analyze cytochrome C oxidase activity and mRNA expression in hippocampal mitochondria.Results showed significantly decreased cytochrome C oxidase activity and cytochrome C oxidase II mRNA expression with prolonged ischemia time.Further analysis revealed five mitochondrial cytochrome C oxidase II gene mutations, two newly generated mutations, and four absent mutational sites at 1 month after cerebral ischemia, as well as three mitochondrial cytochrome C oxidase III gene mutations, including two newly generating mutations, and one disappeared mutational site at 1 month after cerebral ischemia.Results demonstrated that decreased cytochrome C oxidase gene expression and mutations, as well as decreased cytochrome C oxidase activity, resulting in energy dysmetabolism, which has been shown to be involved in the pathological process of ischemic brain injury.

  5. Arsenite transport in plants.

    Science.gov (United States)

    Ali, Waqar; Isayenkov, Stanislav V; Zhao, Fang-Jie; Maathuis, Frans J M

    2009-07-01

    Arsenic is a metalloid which is toxic to living organisms. Natural occurrence of arsenic and human activities have led to widespread contamination in many areas of the world, exposing a large section of the human population to potential arsenic poisoning. Arsenic intake can occur through consumption of contaminated crops and it is therefore important to understand the mechanisms of transport, metabolism and tolerance that plants display in response to arsenic. Plants are mainly exposed to the inorganic forms of arsenic, arsenate and arsenite. Recently, significant progress has been made in the identification and characterisation of proteins responsible for movement of arsenite into and within plants. Aquaporins of the NIP (nodulin26-like intrinsic protein) subfamily were shown to transport arsenite in planta and in heterologous systems. In this review, we will evaluate the implications of these new findings and assess how this may help in developing safer and more tolerant crops.

  6. Molecular cloning and expression analysis of multiple polyphenol oxidase genes in developing wheat (Triticum aestivum) kernels

    Science.gov (United States)

    Polyphenol oxidase (PPO, EC 1.10.31) is a major cause of discoloring in raw dough containing wheat flour. Minimization of PPO activity has proven difficult because bread wheat is genetically complex, composed of the genomes of three grass species. The PPO-A1 and PPO-D1 genes, on chromosomes 2A and...

  7. Monoamine Oxidase a Promoter Gene Associated with Problem Behavior in Adults with Intellectual/Developmental Disabilities

    Science.gov (United States)

    May, Michael E.; Srour, Ali; Hedges, Lora K.; Lightfoot, David A.; Phillips, John A., III; Blakely, Randy D.; Kennedy, Craig H.

    2009-01-01

    A functional polymorphism in the promoter of the gene encoding monoamine oxidase A has been associated with problem behavior in various populations. We examined the association of MAOA alleles in adult males with intellectual/developmental disabilities with and without established histories of problem behavior. These data were compared with a…

  8. The four aldehyde oxidases of Drosophila melanogaster have different gene expression patterns and enzyme substrate specificities.

    Science.gov (United States)

    Marelja, Zvonimir; Dambowsky, Miriam; Bolis, Marco; Georgiou, Marina L; Garattini, Enrico; Missirlis, Fanis; Leimkühler, Silke

    2014-06-15

    In the genome of Drosophila melanogaster, four genes coding for aldehyde oxidases (AOX1-4) were identified on chromosome 3. Phylogenetic analysis showed that the AOX gene cluster evolved via independent duplication events in the vertebrate and invertebrate lineages. The functional role and the substrate specificity of the distinct Drosophila AOX enzymes is unknown. Two loss-of-function mutant alleles in this gene region, low pyridoxal oxidase (Po(lpo)) and aldehyde oxidase-1 (Aldox-1(n1)) are associated with a phenotype characterized by undetectable AOX enzymatic activity. However, the genes involved and the corresponding mutations have not yet been identified. In this study we characterized the activities, substrate specificities and expression profiles of the four AOX enzymes in D. melanogaster. We show that the Po(lpo)-associated phenotype is the consequence of a structural alteration of the AOX1 gene. We identified an 11-bp deletion in the Po(lpo) allele, resulting in a frame-shift event, which removes the molybdenum cofactor domain of the encoded enzyme. Furthermore, we show that AOX2 activity is detectable only during metamorphosis and characterize a Minos-AOX2 insertion in this developmental gene that disrupts its activity. We demonstrate that the Aldox-1(n1) phenotype maps to the AOX3 gene and AOX4 activity is not detectable in our assays.

  9. Effects upon metabolic pathways and energy production by Sb(III) and As(III)/Sb(III)-oxidase gene aioA in Agrobacterium tumefaciens GW4.

    Science.gov (United States)

    Li, Jingxin; Yang, Birong; Shi, Manman; Yuan, Kai; Guo, Wei; Li, Mingshun; Wang, Gejiao

    2017-01-01

    Agrobacterium tumefaciens GW4 is a heterotrophic arsenite [As(III)]/antimonite [Sb(III)]-oxidizing strain. The As(III) oxidase AioAB is responsible for As(III) oxidation in the periplasm and it is also involved in Sb(III) oxidation in Agrobacterium tumefaciens 5A. In addition, Sb(III) oxidase AnoA and cellular H2O2 are also responsible for Sb(III) oxidation in strain GW4. However, the deletion of aioA increased the Sb(III) oxidation efficiency in strain GW4. In the present study, we found that the cell mobility to Sb(III), ATP and NADH contents and heat release were also increased by Sb(III) and more significantly in the aioA mutant. Proteomics and transcriptional analyses showed that proteins/genes involved in Sb(III) oxidation and resistance, stress responses, carbon metabolism, cell mobility, phosphonate and phosphinate metabolism, and amino acid and nucleotide metabolism were induced by Sb(III) and were more significantly induced in the aioA mutant. The results suggested that Sb(III) oxidation may produce energy. In addition, without periplasmic AioAB, more Sb(III) would enter bacterial cells, however, the cytoplasmic AnoA and the oxidative stress response proteins were significantly up-regulated, which may contribute to the increased Sb(III) oxidation efficiency. Moreover, the carbon metabolism was also activated to generate more energy against Sb(III) stress. The generated energy may be used in Sb transportation, DNA repair, amino acid synthesis, and cell mobility, and may be released in the form of heat.

  10. Arsenite suppression of BMP signaling in human keratinocytes

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, Marjorie A.; Qin, Qin [Department of Environmental Toxicology, University of California, Davis, CA 95616-8588 (United States); Hu, Qin; Zhao, Bin [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Rice, Robert H., E-mail: rhrice@ucdavis.edu [Department of Environmental Toxicology, University of California, Davis, CA 95616-8588 (United States)

    2013-06-15

    Arsenic, a human skin carcinogen, suppresses differentiation of cultured keratinocytes. Exploring the mechanism of this suppression revealed that BMP-6 greatly increased levels of mRNA for keratins 1 and 10, two of the earliest differentiation markers expressed, a process prevented by co-treatment with arsenite. BMP also stimulated, and arsenite suppressed, mRNA for FOXN1, an important transcription factor driving early keratinocyte differentiation. Keratin mRNAs increased slowly after BMP-6 addition, suggesting they are indirect transcriptional targets. Inhibition of Notch1 activation blocked BMP induction of keratins 1 and 10, while FOXN1 induction was largely unaffected. Supporting a requirement for Notch1 signaling in keratin induction, BMP increased levels of activated Notch1, which was blocked by arsenite. BMP also greatly decreased active ERK, while co-treatment with arsenite maintained active ERK. Inhibition of ERK signaling mimicked BMP by inducing keratin and FOXN1 mRNAs and by increasing active Notch1, effects blocked by arsenite. Of 6 dual-specificity phosphatases (DUSPs) targeting ERK, two were induced by BMP unless prevented by simultaneous exposure to arsenite and EGF. Knockdown of DUSP2 or DUSP14 using shRNAs greatly reduced FOXN1 and keratins 1 and 10 mRNA levels and their induction by BMP. Knockdown also decreased activated Notch1, keratin 1 and keratin 10 protein levels, both in the presence and absence of BMP. Thus, one of the earliest effects of BMP is induction of DUSPs, which increases FOXN1 transcription factor and activates Notch1, both required for keratin gene expression. Arsenite prevents this cascade by maintaining ERK signaling, at least in part by suppressing DUSP expression. - Highlights: • BMP induces FOXN1 transcription. • BMP induces DUSP2 and DUSP14, suppressing ERK activation. • Arsenite suppresses levels of phosphorylated Smad1/5 and FOXN1 and DUSP mRNA. • These actions rationalize arsenite suppression of keratinocyte

  11. Biological Effects of Potato Plants Transformation with Glucose Oxidase Gene and their Resistance to Hyperthermia

    Directory of Open Access Journals (Sweden)

    O.I. Grabelnych

    2017-02-01

    Full Text Available It is known that regulation of plant tolerance to adverse environmental factors is connected with short term increase of the concentration of endogenous reactive oxygen species (ROS, which are signalling molecules for the induction of protective mechanisms. Introduction and expression of heterologous gox gene, which encodes glucose oxidase enzyme in plant genome, induce constantly higher content of hydrogen peroxide in plant tissues. It is not known how the introduction of native or modified gox gene affects the plant resistance to high-temperature stress, one of the most commonly used model for the study of stress response and thermal tolerance. In this study, we investigated biological effects of transformation and evaluated the resistance to temperature stress of potato plants with altered levels of glucose oxidase expression. Transformation of potato plants by gox gene led to the more early coming out from tuber dormancy of transformed plants and slower growth rate. Transformants containing the glucose oxidase gene were more sensitive to lethal thermal shock (50 °C, 90 min than the transformant with the empty vector (pBI or untransformed plants (CK. Pre-heating of plants at 37 °C significantly weakened the damaging effect of lethal thermal shock. This attenuation was more significant in the non-transformed plants.

  12. Disruption of the CYTOCHROME C OXIDASE DEFICIENT1 gene leads to cytochrome c oxidase depletion and reorchestrated respiratory metabolism in Arabidopsis.

    Science.gov (United States)

    Dahan, Jennifer; Tcherkez, Guillaume; Macherel, David; Benamar, Abdelilah; Belcram, Katia; Quadrado, Martine; Arnal, Nadège; Mireau, Hakim

    2014-12-01

    Cytochrome c oxidase is the last respiratory complex of the electron transfer chain in mitochondria and is responsible for transferring electrons to oxygen, the final acceptor, in the classical respiratory pathway. The essentiality of this step makes it that depletion in complex IV leads to lethality, thereby impeding studies on complex IV assembly and respiration plasticity in plants. Here, we characterized Arabidopsis (Arabidopsis thaliana) embryo-lethal mutant lines impaired in the expression of the CYTOCHROME C OXIDASE DEFICIENT1 (COD1) gene, which encodes a mitochondria-localized PentatricoPeptide Repeat protein. Although unable to germinate under usual conditions, cod1 homozygous embryos could be rescued from immature seeds and developed in vitro into slow-growing bush-like plantlets devoid of a root system. cod1 mutants were defective in C-to-U editing events in cytochrome oxidase subunit2 and NADH dehydrogenase subunit4 transcripts, encoding subunits of respiratory complex IV and I, respectively, and consequently lacked cytochrome c oxidase activity. We further show that respiratory oxygen consumption by cod1 plantlets is exclusively associated with alternative oxidase activity and that alternative NADH dehydrogenases are also up-regulated in these plants. The metabolomics pattern of cod1 mutants was also deeply altered, suggesting that alternative metabolic pathways compensated for the probable resulting restriction in NADH oxidation. Being the first complex IV-deficient mutants described in higher plants, cod1 lines should be instrumental to future studies on respiration homeostasis.

  13. Identification and analysis of the Shewanella oneidensis major oxygen-independent coproporphyrinogen III oxidase gene.

    Science.gov (United States)

    Al-Sheboul, Suhaila; Saffarini, Daad

    2011-12-01

    Shewanella oneidenesis MR-1 is a facultative anaerobe that can use a large number of electron acceptors including metal oxides. During anaerobic respiration, S. oneidensis MR-1 synthesizes a large number of c cytochromes that give the organism its characteristic orange color. Using a modified mariner transposon, a number of S. oneidensis mutants deficient in anaerobic respiration were generated. One mutant, BG163, exhibited reduced pigmentation and was deficient in c cytochromes normally synthesized under anaerobic condition. The deficiencies in BG163 were due to insertional inactivation of hemN1, which exhibits a high degree of similarity to genes encoding anaerobic coproporphyrinogen III oxidases that are involved in heme biosynthesis. The ability of BG163 to synthesize c cytochromes under anaerobic conditions, and to grow anaerobically with different electron acceptors was restored by the introduction of hemN1 on a plasmid. Complementation of the mutant was also achieved by the addition of hemin to the growth medium. The genome sequence of S. oneidensis contains three putative anaerobic coproporphyrinogen III oxidase genes. The protein encoded by hemN1 appears to be the major enzyme that is involved in anaerobic heme synthesis of S. oneidensis. The other two putative anaerobic coproporphyrinogen III oxidase genes may play a minor role in this process.

  14. Correlation of oxygen consumption, cytochrome c oxidase, and cytochrome c oxidase subunit I gene expression in the termination of larval diapause in the bamboo borer, Omphisa fuscidentalis.

    Science.gov (United States)

    Singtripop, Tippawan; Saeangsakda, Manasawan; Tatun, Nujira; Kaneko, Yu; Sakurai, Sho

    2007-09-01

    The moth Omphisa fuscidentalis (Lepidoptera, Pyralidae) is a univoltine insect with a larval diapause period lasting up to 9 months. We studied changes in O(2) consumption in conjunction with cytochrome c oxidase activity and cytochrome c oxidase subunit I (cox1) gene expression. O(2) consumption changed within a day, showing a supradian rhythm with a ca.12-h cycle at 25 degrees C. During the first two-thirds of the diapause period, from October to March, O(2) consumption was constant until January and then increased by March. Topical application of methoprene, a juvenile hormone analog (JHA), to diapausing larvae terminated the diapause and was associated with an increase in O(2) consumption rate at diapause termination. In JHA-treated larvae, cytochrome c oxidase activity in fat bodies was high at the beginning of the prepupal period and highest at pupation. cox1 expression in fat bodies displayed a transient peak 8 days after JHA application and peaked in the prepupal period. Taken together, our results show that the break of diapause by JHA is associated with the activation of cox1, bringing about an increase in cytochrome c oxidase activity, followed by an increase in O(2) consumption rate.

  15. Molecular characterization and expression pattern of tobacco (Nicotiana tabacum ascorbate oxidase gene

    Directory of Open Access Journals (Sweden)

    Zhihua Li

    2016-11-01

    Full Text Available The complete coding sequence of one tobacco (Nicotiana tabacum gene, ascorbate oxidase (AO, was isolated by the application of reverse transcription-polymerase chain reaction. The tobacco AO gene consists of a 1722-bp open reading frame and encodes a protein of 573 amino acids. Sequence comparison analysis revealed that the tobacco AO protein shares high homology with the AO proteins of Lycopersicon esculentum (89%, Populus trichocarpa (75%, soybean (74%, castor bean (73% and peach (73%. The prediction of transmembrane helices showed that tobacco AO might be a transmembrane protein. The expression profile was studied and the results indicated that the tobacco AO gene was diversely expressed in different tobacco tissues, including leaves, stem, roots and flowers. Our experiment laid the grounds for further research on this tobacco gene.

  16. Genetic differentiation of the mitochondrial cytochrome oxidase C subunit I gene in genus Paramecium (Protista, Ciliophora.

    Directory of Open Access Journals (Sweden)

    Yan Zhao

    Full Text Available BACKGROUND: The mitochondrial cytochrome c oxidase subunit I (COI gene is being used increasingly for evaluating inter- and intra-specific genetic diversity of ciliated protists. However, very few studies focus on assessing genetic divergence of the COI gene within individuals and how its presence might affect species identification and population structure analyses. METHODOLOGY/PRINCIPAL FINDINGS: We evaluated the genetic variation of the COI gene in five Paramecium species for a total of 147 clones derived from 21 individuals and 7 populations. We identified a total of 90 haplotypes with several individuals carrying more than one haplotype. Parsimony network and phylogenetic tree analyses revealed that intra-individual diversity had no effect in species identification and only a minor effect on population structure. CONCLUSIONS: Our results suggest that the COI gene is a suitable marker for resolving inter- and intra-specific relationships of Paramecium spp.

  17. Cloning and characterization of an up-regulated GA 20-oxidase gene in hybrid maize

    Institute of Scientific and Technical Information of China (English)

    Jinkun Du; Yingyin Yao; Zhongfu Ni; Qixin Sun

    2009-01-01

    Previous studies revealed that GA content and metabolism are positively correlated with a faster shoot growth rate of hybrid, and recently, genes participating in both GA biosynthesis and GA response pathways were also found to be differentially expressed between wheat hybrid and its parental inbreds. In this study, an up-regulated GA 20-oxidase gene in a maize hybrid, designated ZmGA20, was cloned. ZmGA20 contains an open reading frame (ORF) encoding 391 amino acid residues. BLASTX searches in GenBank revealed that the ZmGA20 is homologous to the sequences of GA20ox proteins from different species, and analysis also indicated that ZmGA20 had typical features of GA 20-oxidase proteins, including a "LPWKET" sequence. Semi-quantitative RT-PCR analysis showed that ZmGA20 was expressed in different tissues and/or organs. The expression level of ZmGA20 in the hybrid was higher than that in two parents (in roots, leaves, stems and embryo, and ears). The abundance of ZmGA20 transcript was equal to that of the highly expressed parents, which provided molecular evidence for the observed GA content heterosis in maize hybrids.

  18. Cloning and characterization of the gene for L-amino acid oxidase in hybrid tilapia.

    Science.gov (United States)

    Shen, Yubang; Fu, Gui Hong; Liu, Feng; Yue, Gen Hua

    2015-12-01

    Tilapia is the common name for a group of cichlid fishes. Identification of DNA markers significantly associated with important traits in candidate genes may speed up genetic improvement. L-Amino acid oxidase (LAO) plays a crucial role in the innate immune defences of animals. Previously, whether LAO variants were associated with economic traits had not been studied in fish. We characterized the cDNA sequence of the LAO gene of hybrid tilapia (Oreochromis spp.). Its ORF was 1536 bp, encoding a flavoenzyme of 511 amino acids. This gene consisted of seven exons and six introns. Its expression was detected in the intestine, blood, kidney, skin, liver. It was highly expressed in the intestine. After a challenge with a bacterial pathogen, Streptococcus agalactiae, its expression was up-regulated significantly in the liver, intestine and spleen (P tilapia. The investigation of relationship between polymorphism of LAO gene and disease resistance and growth in tilapia showed that one SNP was associated significantly with body length. Further experiments on whether SNPs in the LAO gene are associated with growth in tilapia and other populations could be useful in understanding more functions of the LAO gene.

  19. Mutations affecting the expression of the MOX gene encoding peroxisomal methanol oxidase in Hansenula polymorpha.

    Science.gov (United States)

    Vallini, V; Berardi, E; Strabbioli, R

    2000-11-01

    In this study, aimed at identifying genetic factors acting positively upon the MOX gene, we report the isolation and characterisation of several methanol utilisation-defective (Mut-) mutants of Hansenula polymorpha. These fall into 12 complementation groups, eight of which show significant reductions in alcohol (methanol) oxidase activity in methanol. Three of these groups, identifying the MUT3, MUT5 and MUT10 loci, exhibit extremely low levels of MOX promoter activity, not only in methanol medium, but also during growth in glycerol or methylamine. We suggest that these loci play a significant role in the derepression of the MOX gene expression. One of these genes (MUT10) also seems to be involved in the utilisation of carbon sources other than methanol, and it is apparent that the same gene plays some role in the biogenesis or in the enlargement of the peroxisome. Three other genes (MUT7, MUT8 and MUT9) appear to be involved in peroxisome biogenesis, whereas most other mutants harbour lesions that leave the peroxisome biogenesis and proliferation unaffected.

  20. The polyphenol oxidase gene family in land plants: Lineage-specific duplication and expansion

    Directory of Open Access Journals (Sweden)

    Tran Lan T

    2012-08-01

    Full Text Available Abstract Background Plant polyphenol oxidases (PPOs are enzymes that typically use molecular oxygen to oxidize ortho-diphenols to ortho-quinones. These commonly cause browning reactions following tissue damage, and may be important in plant defense. Some PPOs function as hydroxylases or in cross-linking reactions, but in most plants their physiological roles are not known. To better understand the importance of PPOs in the plant kingdom, we surveyed PPO gene families in 25 sequenced genomes from chlorophytes, bryophytes, lycophytes, and flowering plants. The PPO genes were then analyzed in silico for gene structure, phylogenetic relationships, and targeting signals. Results Many previously uncharacterized PPO genes were uncovered. The moss, Physcomitrella patens, contained 13 PPO genes and Selaginella moellendorffii (spike moss and Glycine max (soybean each had 11 genes. Populus trichocarpa (poplar contained a highly diversified gene family with 11 PPO genes, but several flowering plants had only a single PPO gene. By contrast, no PPO-like sequences were identified in several chlorophyte (green algae genomes or Arabidopsis (A. lyrata and A. thaliana. We found that many PPOs contained one or two introns often near the 3’ terminus. Furthermore, N-terminal amino acid sequence analysis using ChloroP and TargetP 1.1 predicted that several putative PPOs are synthesized via the secretory pathway, a unique finding as most PPOs are predicted to be chloroplast proteins. Phylogenetic reconstruction of these sequences revealed that large PPO gene repertoires in some species are mostly a consequence of independent bursts of gene duplication, while the lineage leading to Arabidopsis must have lost all PPO genes. Conclusion Our survey identified PPOs in gene families of varying sizes in all land plants except in the genus Arabidopsis. While we found variation in intron numbers and positions, overall PPO gene structure is congruent with the phylogenetic

  1. Gene-Gene-Environment Interactions of Serotonin Transporter, Monoamine Oxidase A and Childhood Maltreatment Predict Aggressive Behavior in Chinese Adolescents

    Science.gov (United States)

    Zhang, Yun; Ming, Qing-sen; Yi, Jin-yao; Wang, Xiang; Chai, Qiao-lian; Yao, Shu-qiao

    2017-01-01

    Gene-environment interactions that moderate aggressive behavior have been identified independently in the serotonin transporter (5-HTT) gene and monoamine oxidase A gene (MAOA). The aim of the present study was to investigate epistasis interactions between MAOA-variable number tandem repeat (VNTR), 5-HTTlinked polymorphism (LPR) and child abuse and the effects of these on aggressive tendencies in a group of otherwise healthy adolescents. A group of 546 Chinese male adolescents completed the Child Trauma Questionnaire and Youth self-report of the Child Behavior Checklist. Buccal cells were collected for DNA analysis. The effects of childhood abuse, MAOA-VNTR, 5-HTTLPR genotypes and their interactive gene-gene-environmental effects on aggressive behavior were analyzed using a linear regression model. The effect of child maltreatment was significant, and a three-way interaction among MAOA-VNTR, 5-HTTLPR and sexual abuse (SA) relating to aggressive behaviors was identified. Chinese male adolescents with high expression of the MAOA-VNTR allele and 5-HTTLPR “SS” genotype exhibited the highest aggression tendencies with an increase in SA during childhood. The findings reported support aggression being a complex behavior involving the synergistic effects of gene-gene-environment interactions. PMID:28203149

  2. Expression of ACC Oxidase Gene from Sugarcane Induced by Hormones and Environmental Force

    Institute of Scientific and Technical Information of China (English)

    WANG Ai-qin; YANG Li-tao; WANG Zi-zhang; WEI Yu-tuo; HE Long-fei; LI Yang-rui

    2005-01-01

    In the present study, a full-length cDNA encoding 1-aminocyclopropane-1-carboxylic acid oxidase gene has been cloned from sugarcane (named GZ-ACO). Two primers were designed for coding the ORF in the full-length cDNA of GZ-ACO gene from sugarcane. PCR amplification was performed with sugarcane DNA template, and a fragment of 1 104 bp (GZ34)was obtained. GZ34 was labeled with [α-32p] dCTP as the probe and used for hybridization after cloning and sequencing.Southern blotting analysis indicated that there were at least three other sequences, which weakly hybridized with the GZ34. Northern analysis showed that GZ34 was strongly induced by treatment with IAA, BA, ethephon, LiC1 and cold stress, respectively. As a contrast, the mRNA for ACO gene was at lower levels for both the light-grown and dark-grown plants without additional treatment. There were two transcripts in the dark-grown plants and three transcripts in the treatments with IAA, BA and cold stress, but there was only one transcript in ethephon treatment. It showed that GZ-ACO might be a gene connected with ethylene formation and take part in response to the induction of plant hormone and environmental stress.

  3. Analysis of the cytochrome c oxidase subunit II (COX2) gene in giant panda, Ailuropoda melanoleuca.

    Science.gov (United States)

    Ling, S S; Zhu, Y; Lan, D; Li, D S; Pang, H Z; Wang, Y; Li, D Y; Wei, R P; Zhang, H M; Wang, C D; Hu, Y D

    2017-01-23

    The giant panda, Ailuropoda melanoleuca (Ursidae), has a unique bamboo-based diet; however, this low-energy intake has been sufficient to maintain the metabolic processes of this species since the fourth ice age. As mitochondria are the main sites for energy metabolism in animals, the protein-coding genes involved in mitochondrial respiratory chains, particularly cytochrome c oxidase subunit II (COX2), which is the rate-limiting enzyme in electron transfer, could play an important role in giant panda metabolism. Therefore, the present study aimed to isolate, sequence, and analyze the COX2 DNA from individuals kept at the Giant Panda Protection and Research Center, China, and compare these sequences with those of the other Ursidae family members. Multiple sequence alignment showed that the COX2 gene had three point mutations that defined three haplotypes, with 60% of the sequences corresponding to haplotype I. The neutrality tests revealed that the COX2 gene was conserved throughout evolution, and the maximum likelihood phylogenetic analysis, using homologous sequences from other Ursidae species, showed clustering of the COX2 sequences of giant pandas, suggesting that this gene evolved differently in them.

  4. Isolation and Characterization of Cucumber ACC Oxidase Gene and Its Upstream

    Institute of Scientific and Technical Information of China (English)

    CHEN Yin-hua; OUYANG Bo; LI Han-xia; ZHANG Jun-hong; YE Zhi-biao

    2005-01-01

    Ethylene has been implicated as a sex-determining hormone in cucumber. Its exogenous application increases femaleness,and gynoecious genotypes were reported to produce more ethylene. 1-aminocyclopropane-1-carboxylate (ACC) oxidase (ACO) is the key enzyme in ethylene biosynthesis. In this study, a 1 200 base pair (bp) candidate fragment was amplified from the cucumber genome with degenerated primers derived from the ACO amino acid consensus sequence among different plant species. The coding region and its upstream (1 155 bp) were obtained by vector-mediated inverse PCR. The novel gene was analyzed by bioinformatics tools. Four exons and three introns were identified in the coding sequence.The spliced length of mRNA was 933 nucleotides (nts) and it encoded 311 amino acids. Phylogenic analysis result of the new gene (CsACO4, GenBank accession number AY450356) was in accordance with the evolution relationship of genetics among various plant species. Northern blotting showed that the gene expressed among female flowers of gynoecious and monoecious genotypes, it could not express in other organs. This implied that the gene might be correlated with the female behavior positively. Further work is on the way to demonstrate the complexity of the relationship between the endogenous ethylene and the sex determination.

  5. Collection of mitochondrial cytochrome oxidase I gene sequences from Rhipicephalus ticks from various geographic locations around the world

    Science.gov (United States)

    Determining the origin of the cattle tick, Rhipicephalus microplus, will be helpful to the effort to find biological control agents. Molecular phylogenetics can assist in this determination. Thus, we sequenced and assembled partial gene sequences from the mitochondrial cytochrome oxidase I coding r...

  6. The role of coproporphyrinogen III oxidase and ferrochelatase genes in heme biosynthesis and regulation in Aspergillus niger

    NARCIS (Netherlands)

    Franken, A.C.W.; Werner, E.R.; Haas, H.; Lokman, B.C.; Hondel, C.A.M.J.J. van den; Ram, A.F.J.; Weert, S. de; Punt, P.J.

    2013-01-01

    Heme is a suggested limiting factor in peroxidase production by Aspergillus spp., which are well-known suitable hosts for heterologous protein production. In this study, the role of genes coding for coproporphyrinogen III oxidase (hemF) and ferrochelatase (hemH) was analyzed by means of deletion and

  7. Isolation and transcript analysis of gibberellin 20-oxidase genes in pea and bean in relation to fruit development.

    Science.gov (United States)

    García-Martínez, J L; López-Diaz, I; Sánchez-Beltrán, M J; Phillips, A L; Ward, D A; Gaskin, P; Hedden, P

    1997-04-01

    PCR was used with degenerate primers based on conserved amino acid sequences in gibberellin (GA) 20-oxidases to isolate cDNA clones for these enzymes from young seeds of pea (Pisum sativum) and developing embryos of French bean (Phaseolus vulgaris). One GA 20-oxidase cDNA (Ps27-12) was obtained from pea and three (Pv 15-11, Pv73-1 and Pv85-26) from bean. Their identities were confirmed by demonstrating that fusion proteins expressed in Escherichia coli exhibited GA 20-oxidase activity, converting [14C]GA12 to [14C]GA9. The intermediates in this three-step reaction, GA15 and GA24, were also identified as products. The expression proteins from three of the clones (Ps27-12, Pv15-11 and Pv73-1) were also shown to convert GA53 to GA20, as effectively as they did GA12. On the basis of transcript levels measured by northern blot analysis, the pea GA 20-oxidase gene is most highly expressed in young leaves, fully expanded internodes, very young seeds (until 4 days after anthesis) and expanding pods (from 3 days after anthesis at least until day 6). Expression in pods from 3-day-old unpollinated ovaries is higher than in those from pollinated ovaries. Treatment of unpollinated ovaries with GA3 to induce parthenocarpic fruit-set severely reduced the amount of GA 20-oxidase mRNA, whereas treatment with 2,4-D, although inducing fruit-set, did not reduce the levels of these transcripts. Plant decapitation above an unpollinated ovary resulted in very high levels of GA 20-oxidase mRNA in the pod. The three GA 20-oxidase genes from French bean showed very different patterns of expression: Pv 15-1 was expressed in the roots, young leaves, and developing seeds, but most highly in immature cotyledons, while Pv73-1 has a similar expression pattern to Ps27-12, with transcripts found only in young seeds and young leaves, where it was particularly abundant. Transcripts corresponding to Pv85-26 were detected in developing seeds, and just traces in the young leaves. Southern blot analysis

  8. Global Transcriptomic Analysis of Targeted Silencing of Two Paralogous ACC Oxidase Genes in Banana

    Science.gov (United States)

    Xia, Yan; Kuan, Chi; Chiu, Chien-Hsiang; Chen, Xiao-Jing; Do, Yi-Yin; Huang, Pung-Ling

    2016-01-01

    Among 18 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase homologous genes existing in the banana genome there are two genes, Mh-ACO1 and Mh-ACO2, that participate in banana fruit ripening. To better understand the physiological functions of Mh-ACO1 and Mh-ACO2, two hairpin-type siRNA expression vectors targeting both the Mh-ACO1 and Mh-ACO2 were constructed and incorporated into the banana genome by Agrobacterium-mediated transformation. The generation of Mh-ACO1 and Mh-ACO2 RNAi transgenic banana plants was confirmed by Southern blot analysis. To gain insights into the functional diversity and complexity between Mh-ACO1 and Mh-ACO2, transcriptome sequencing of banana fruits using the Illumina next-generation sequencer was performed. A total of 32,093,976 reads, assembled into 88,031 unigenes for 123,617 transcripts were obtained. Significantly enriched Gene Oncology (GO) terms and the number of differentially expressed genes (DEGs) with GO annotation were ‘catalytic activity’ (1327, 56.4%), ‘heme binding’ (65, 2.76%), ‘tetrapyrrole binding’ (66, 2.81%), and ‘oxidoreductase activity’ (287, 12.21%). Real-time RT-PCR was further performed with mRNAs from both peel and pulp of banana fruits in Mh-ACO1 and Mh-ACO2 RNAi transgenic plants. The results showed that expression levels of genes related to ethylene signaling in ripening banana fruits were strongly influenced by the expression of genes associated with ethylene biosynthesis. PMID:27681726

  9. Life without putrescine: disruption of the gene-encoding polyamine oxidase in Ustilago maydis odc mutants.

    Science.gov (United States)

    Valdés-Santiago, Laura; Guzmán-de-Peña, Doralinda; Ruiz-Herrera, José

    2010-11-01

    In previous communications the essential role of spermidine in Ustilago maydis was demonstrated by means of the disruption of the genes encoding ornithine decarboxylase (ODC) and spermidine synthase (SPE). However, the assignation of specific roles to each polyamine in different cellular functions was not possible because the spermidine added to satisfy the auxotrophic requirement of odc/spe double mutants is partly back converted into putrescine. In this study, we have approached this problem through the disruption of the gene-encoding polyamine oxidase (PAO), required for the conversion of spermidine into putrescine, and the construction of odc/pao double mutants that were unable to synthesize putrescine by either ornithine decarboxylation or retroconversion from spermidine. Phenotypic analysis of the mutants provided evidence that putrescine is only an intermediary in spermidine biosynthesis, and has no direct role in cell growth, dimorphic transition, or any other vital function of U. maydis. Nevertheless, our results show that putrescine may play a role in the protection of U. maydis against salt and osmotic stress, and possibly virulence. Evidence was also obtained that the retroconversion of spermidine into putrescine is not essential for U. maydis growth but may be important for its survival under natural conditions.

  10. Monoamine oxidase A gene DNA hypomethylation - a risk factor for panic disorder?

    Science.gov (United States)

    Domschke, Katharina; Tidow, Nicola; Kuithan, Henriette; Schwarte, Kathrin; Klauke, Benedikt; Ambrée, Oliver; Reif, Andreas; Schmidt, Hartmut; Arolt, Volker; Kersting, Anette; Zwanzger, Peter; Deckert, Jürgen

    2012-10-01

    The monoamine oxidase A (MAOA) gene has been suggested as a prime candidate in the pathogenesis of panic disorder. In the present study, DNA methylation patterns in the MAOA regulatory and exon 1/intron 1 region were investigated for association with panic disorder with particular attention to possible effects of gender and environmental factors. Sixty-five patients with panic disorder (44 females, 21 males) and 65 healthy controls were analysed for DNA methylation status at 42 MAOA CpG sites via direct sequencing of sodium bisulfate treated DNA extracted from blood cells. The occurrence of recent positive and negative life events was ascertained. Male subjects showed no or only very minor methylation with some evidence for relative hypomethylation at one CpG site in intron 1 in patients compared to controls. Female patients exhibited significantly lower methylation than healthy controls at 10 MAOA CpG sites in the promoter as well as in exon/intron 1, with significance surviving correction for multiple testing at four CpG sites (p≤0.001). Furthermore, in female subjects the occurrence of negative life events was associated with relatively decreased methylation, while positive life events were associated with increased methylation. The present pilot data suggest a potential role of MAOA gene hypomethylation in the pathogenesis of panic disorder particularly in female patients, possibly mediating a detrimental influence of negative life events. Future studies are warranted to replicate the present finding in independent samples, preferably in a longitudinal design.

  11. Molecular evolution of the cytochrome c oxidase subunit 5A gene in primates

    Directory of Open Access Journals (Sweden)

    Wildman Derek E

    2008-01-01

    Full Text Available Abstract Background Many electron transport chain (ETC genes show accelerated rates of nonsynonymous nucleotide substitutions in anthropoid primate lineages, yet in non-anthropoid lineages the ETC proteins are typically highly conserved. Here, we test the hypothesis that COX5A, the ETC gene that encodes cytochrome c oxidase subunit 5A, shows a pattern of anthropoid-specific adaptive evolution, and investigate the distribution of this protein in catarrhine brains. Results In a dataset comprising 29 vertebrate taxa, including representatives from all major groups of primates, there is nearly 100% conservation of the COX5A amino acid sequence among extant, non-anthropoid placental mammals. The most recent common ancestor of these species lived about 100 million years (MY ago. In contrast, anthropoid primates show markedly elevated rates of nonsynonymous evolution. In particular, branch site tests identify five positively selected codons in anthropoids, and ancestral reconstructions infer that substitutions in these codons occurred predominantly on stem lineages (anthropoid, ape and New World monkey and on the human terminal branch. Examination of catarrhine brain samples by immunohistochemistry characterizes for the first time COX5A protein distribution in the primate neocortex, and suggests that the protein is most abundant in the mitochondria of large-size projection neurons. Real time quantitative PCR supports previous microarray results showing COX5A is expressed in cerebral cortical tissue at a higher level in human than in chimpanzee or gorilla. Conclusion Taken together, these results suggest that both protein structural and gene regulatory changes contributed to COX5A evolution during humankind's ancestry. Furthermore, these findings are consistent with the hypothesis that adaptations in ETC genes contributed to the emergence of the energetically expensive anthropoid neocortex.

  12. Sudden infant death syndrome (SIDS) and polymorphisms in Monoamine oxidase A gene (MAOA): a revisit.

    Science.gov (United States)

    Groß, Maximilian; Bajanowski, Thomas; Vennemann, Mechtild; Poetsch, Micaela

    2014-01-01

    Literature describes multiple possible links between genetic variations in the neuroadrenergic system and the occurrence of sudden infant death syndrome. The X-chromosomal Monoamine oxidase A (MAOA) is one of the genes with regulatory activity in the noradrenergic and serotonergic neuronal systems and a polymorphism of the promoter which affects the activity of this gene has been proclaimed to contribute significantly to the prevalence of sudden infant death syndrome (SIDS) in three studies from 2009, 2012 and 2013. However, these studies described different significant correlations regarding gender or age of children. Since several studies, suggesting associations between genetic variations and SIDS, were disproved by follow-up analysis, this study was conducted to take a closer look at the MAOA gene and its polymorphisms. The functional MAOA promoter length polymorphism was investigated in 261 SIDS cases and 93 control subjects. Moreover, the allele distribution of 12 coding and non-coding single nucleotide polymorphisms (SNPs) of the MAOA gene was examined in 285 SIDS cases and 93 controls by a minisequencing technique. In contrast to prior studies with fewer individuals, no significant correlations between the occurrence of SIDS and the frequency of allele variants of the promoter polymorphism could be demonstrated, even including the results from the abovementioned previous studies. Regarding the SNPs, three statistically significant associations were observed which had not been described before. This study clearly disproves interactions between MAOA promoter polymorphisms and SIDS, even if variations in single nucleotide polymorphisms of MAOA should be subjected to further analysis to clarify their impact on SIDS.

  13. ZFN-mediated gene targeting of the Arabidopsis protoporphyrinogen oxidase gene through Agrobacterium-mediated floral dip transformation.

    Science.gov (United States)

    de Pater, Sylvia; Pinas, Johan E; Hooykaas, Paul J J; van der Zaal, Bert J

    2013-05-01

    Previously, we showed that ZFN-mediated induction of double-strand breaks (DSBs) at the intended recombination site enhanced the frequency of gene targeting (GT) at an artificial target locus using Agrobacterium-mediated floral dip transformation. Here, we designed zinc finger nucleases (ZFNs) for induction of DSBs in the natural protoporphyrinogen oxidase (PPO) gene, which can be conveniently utilized for GT experiments. Wild-type Arabidopsis plants and plants expressing the ZFNs were transformed via floral dip transformation with a repair T-DNA with an incomplete PPO gene, missing the 5' coding region but containing two mutations rendering the enzyme insensitive to the herbicide butafenacil as well as an extra KpnI site for molecular analysis of GT events. Selection on butafenacil yielded 2 GT events for the wild type with a frequency of 0.8 × 10⁻³ per transformation event and 8 GT events for the ZFNs expressing plant line with a frequency of 3.1 × 10⁻³ per transformation event. Molecular analysis using PCR and Southern blot analysis showed that 9 of the GT events were so-called true GT events, repaired via homologous recombination (HR) at the 5' and the 3' end of the gene. One plant line contained a PPO gene repaired only at the 5' end via HR. Most plant lines contained extra randomly integrated T-DNA copies. Two plant lines did not contain extra T-DNAs, and the repaired PPO genes in these lines were transmitted to the next generation in a Mendelian fashion.

  14. Arsenite exposure accelerates aging process regulated by the transcription factor DAF-16/FOXO in Caenorhabditis elegans.

    Science.gov (United States)

    Yu, Chan-Wei; How, Chun Ming; Liao, Vivian Hsiu-Chuan

    2016-05-01

    Arsenic is a known human carcinogen and high levels of arsenic contamination in food, soils, water, and air are of toxicology concerns. Nowadays, arsenic is still a contaminant of emerging interest, yet the effects of arsenic on aging process have received little attention. In this study, we investigated the effects and the underlying mechanisms of chronic arsenite exposure on the aging process in Caenorhabditis elegans. The results showed that prolonged arsenite exposure caused significantly decreased lifespan compared to non-exposed ones. In addition, arsenite exposure (100 μM) caused significant changes of age-dependent biomarkers, including a decrease of defecation frequency, accumulations of intestinal lipofuscin and lipid peroxidation in an age-dependent manner in C. elegans. Further evidence revealed that intracellular reactive oxygen species (ROS) level was significantly increased in an age-dependent manner upon 100 μM arsenite exposure. Moreover, the mRNA levels of transcriptional makers of aging (hsp-16.1, hsp-16.49, and hsp-70) were increased in aged worms under arsenite exposure (100 μM). Finally, we showed that daf-16 mutant worms were more sensitive to arsenite exposure (100 μM) on lifespan and failed to induce the expression of its target gene sod-3 in aged daf-16 mutant under arsenite exposure (100 μM). Our study demonstrated that chronic arsenite exposure resulted in accelerated aging process in C. elegans. The overproduction of intracellular ROS and the transcription factor DAF-16/FOXO play roles in mediating the accelerated aging process by arsenite exposure in C. elegans. This study implicates a potential ecotoxicological and health risk of arsenic in the environment.

  15. Direct and indirect effects of RNA interference against pyridoxal kinase and pyridoxine 5'-phosphate oxidase genes in Bombyx mori.

    Science.gov (United States)

    Huang, ShuoHao; Yao, LiLi; Zhang, JianYun; Huang, LongQuan

    2016-08-01

    Vitamin B6 comprises six interconvertible pyridine compounds (vitamers), among which pyridoxal 5'-phosphate is a coenzyme involved in a high diversity of biochemical reactions. Humans and animals obtain B6 vitamers from diet, and synthesize pyridoxal 5'-phosphate by pyridoxal kinase and pyridoxine 5'-phosphate oxidase. Currently, little is known on how pyridoxal 5'-phosphate biosynthesis is regulated, and pyridoxal 5'-phosphate is supplied to meet their requirement in terms of cofactor. Bombyx mori is a large silk-secreting insect, in which protein metabolism is most active, and the vitamin B6 demand is high. In this study, we successfully down-regulated the gene expression of pyridoxal kinase and pyridoxine 5'-phosphate oxidase by body cavity injection of synthesized double-stranded small interfering RNA to 5th instar larvae of Bombyx mori, and analyzed the gene transcription levels of pyridoxal 5'-phosphate dependent enzymes, phosphoserine aminotransferase and glutamic-oxaloacetic transaminase. Results show that the gene expression of pyridoxal kinase and pyridoxine 5'-phosphate oxidase has a greater impact on the gene transcription of enzymes using pyridoxal 5'-phosphate as a cofactor in Bombyx mori. Our study suggests that pyridoxal 5'-phosphate biosynthesis and dynamic balance may be regulated by genetic networks.

  16. The ccoNOQP gene cluster codes for a cb-type cytochrome oxidase that functions in aerobic respiration of Rhodobacter capsulatus.

    Science.gov (United States)

    Thöny-Meyer, L; Beck, C; Preisig, O; Hennecke, H

    1994-11-01

    The genes for a new type of a haem-copper cytochrome oxidase were cloned from Rhodobacter capsulatus strain 37b4, using the Bradyrhizobium japonicum fixNOQP gene region as a hybridizing probe. Four genes, probably organized in an operon (ccoNOQP), were identified; their products share extensive amino acid sequence similarity with the FixN, O, Q and P proteins that have recently been shown to be the subunits of a cb-type oxidase. CcoN is a b-type cytochrome, CcoO and CcoP are membrane-bound mono- and dihaem c-type cytochromes and CcoQ is a small membrane protein of unknown function. Genes for a similar oxidase are also present in other non-rhizobial bacterial species such as Azotobacter vinelandii, Agrobacterium tumefaciens and Pseudomonas aeruginosa, as revealed by polymerase chain reaction analysis. A ccoN mutant was constructed whose phenotype, in combination with the structural information on the gene products, provides evidence that the CcoNOQP oxidase is a cytochrome c oxidase of the cb type, which supports aerobic respiration in R. capsulatus and which is probably identical to the cbb3-type oxidase that was recently purified from a different strain of the same species. Mutant analysis also showed that this oxidase has no influence on photosynthetic growth and nitrogen-fixation activity.

  17. [Prolonging the vase life of carnation "Mabel" through integrating repeated ACC oxidase genes into its genome].

    Science.gov (United States)

    Yu, Yi-Xun; Bao, Man-Zhu

    2004-10-01

    Carnation (Dianthus caryophyllus L.) is one of the most important cut flowers. The cultivar "Mabel" of carnation was transformed with direct repeat gene of ACC oxidase, the key enzyme in ethylene synthesis, driven by the CaMV35S promoter mediated by Agrobacterium tumefacien. Hygromycin phosphotransferase (HPT) gene was used as selection marker. Leaf explants were pre-cultured on shoot-inducing medium for 2 d, then immersed in Agrobacterium suspension for 8-12 min. Co-cultivation was carried out on the medium (MS+BA 1.0 mg/L+NAA 0.3 mg/L +Acetosyringone 100 micromol/L, pH 5.8-6.0) for 3 d. After that transformants were obtained by transferring explants to selection medium supplemented with 5 mg/L hygromycin (Hyg) and 400 mg/L cefotaxime (Cef). Southern blotting detection showed that a foreign gene was integrated into the carnation genome and 3 transgenic lines (T257, T299 and T273 line) obtained. Addition of acetosyringone and the time of co-culture were the main factors that influenced transformation frequency. After being transplanted to soil, transgenic plants were grew normally in greenhouse. Ethylene production of cut flower of transgenic T257 line was 95% lower than that of the control, and that of T299 line was reduced by 90% than that of the control, while that of transgenic T273 line has no of significantly different from control. Vase life of transgenic T257 line was 5 d longer than that of the control line at 25 degrees C.

  18. PHYLOGENY OF ANGIOSTRONGYLUS CANTONENSIS IN THAILAND BASED ON CYTOCHROME C OXIDASE SUBUNIT I GENE SEQUENCE.

    Science.gov (United States)

    Apichat, Vitta; Narongrit, Srisongcram; Jittranuch, Thiproaj; Anucha, Wongma; Wilaiwan, Polsut; Chamaiporn, Fukruksa; Thatcha, Yimthin; Bandid, Mangkit; Aunchalee, Thanwisai; Paron, Dekumyoy

    2016-05-01

    Angiostrongylus cantonensis is an emerging infectious agent causing eosinophilic meningitis or meningoencephalitis in humans with clinical manifestation of severe headache. Molecular genetic studies on classification and phylogeny of A. cantonensis in Thailand are limited. This study surveyed A. cantonensis larvae prevalence in natural intermediate hosts across Thailand and analyzed their phylogenetic relationships. A total of 14,032 freshwater and land snails were collected from 19 provinces of Thailand. None of Filopaludina sp, Pomacea sp, and Cyclophorus sp were infected with Angiostrongylus larvae, whereas Achatina fulica, Cryptozona siamensis, and Megaustenia siamensis collected from Kalasin, Kamphaeng Phet, Phetchabun, Phitsanulok, and Tak Provinces were infected, with C. siamensis being the common intermediate host. Based on morphology, larvae isolated from 11 samples of these naturally infected snails preliminarily were identified as A. cantonensis. Comparison of partial nucleotide sequences of cytochrome c oxidase subunit I gene revealed that four sequences are identical to A. cantonensis haplotype ac4 from Bangkok and the other seven to that of A. cantonensis isolate AC Thai, indicating two independent lineages of A. cantonensis in Thailand.

  19. Mutations in the SURF1 gene associated with Leigh syndrome and cytochrome C oxidase deficiency.

    Science.gov (United States)

    Péquignot, M O; Dey, R; Zeviani, M; Tiranti, V; Godinot, C; Poyau, A; Sue, C; Di Mauro, S; Abitbol, M; Marsac, C

    2001-05-01

    Cytochrome c oxidase (COX) deficiency is one of the major causes of Leigh Syndrome (LS), a fatal encephalopathy of infancy or childhood, characterized by symmetrical lesions in the basal ganglia and brainstem. Mutations in the nuclear genes encoding COX subunits have not been found in patients with LS and COX deficiency, but mutations have been identified in SURF1. SURF1 encodes a factor involved in COX biogenesis. To date, 30 different mutations have been reported in 40 unrelated patients. We aim to provide an overview of all known mutations in SURF1, and to propose a common nomenclature. Twelve of the mutations were insertion/deletion mutations in exons 1, 4, 6, 8, and 9; 10 were missense/nonsense mutations in exons 2, 4, 5, 7, and 8; and eight were detected at splicing sites in introns 3 to 7. The most frequent mutation was 312_321del 311_312insAT which was found in 12 patients out of 40. Twenty mutations have been described only once. We also list all polymorphisms discovered to date.

  20. Molecular evolution at the cytochrome oxidase subunit 2 gene among divergent populations of the intertidal copepod, Tigriopus californicus.

    Science.gov (United States)

    Rawson, Paul D; Burton, Ronald S

    2006-06-01

    The cytochrome c oxidase subunit 2 gene (COII) encodes a highly conserved protein that is directly responsible for the initial transfer of electrons from cytochrome c to cytochrome c oxidase (COX) crucial to the production of ATP during cellular respiration. Despite its integral role in electron transport, we have observed extensive intraspecific nucleotide and amino acid variation among 26 full-length COII sequences sampled from seven populations of the marine copepod, Tigriopus californicus. Although intrapopulation divergence was virtually nonexistent, interpopulation divergence at the COII locus was nearly 20% at the nucleotide level, including 38 nonsynonymous substitutions. Given the high degree of interaction between the cytochrome c oxidase subunit 2 protein (COX2) and the nuclear-encoded subunits of COX and cytochrome c (CYC), we hypothesized that some codons in the COII gene are likely to be under positive selection in order to compensate for amino acid substitutions in other subunits. Estimates of the ratio of nonsynonymous to synonymous substitution (omega), obtained using a series of maximum likelihood models of codon substitution, indicated that the majority of codons in T. californicus COII are under strong purifying selection (omega < 1), while approximately 4% of the sites in this gene appear to evolve under relaxed selective constraint (omega = 1). A branch-site maximum likelihood model identified three sites that may have experienced positive selection within the central California sequence clade in our COII phylogeny; these results are consistent with previous studies showing functional and fitness consequences among interpopulation hybrids between central and northern California populations.

  1. Altered Hepatic Transport by Fetal Arsenite Exposure in Diet-Induced Fatty Liver Disease.

    Science.gov (United States)

    Ditzel, Eric J; Li, Hui; Foy, Caroline E; Perrera, Alec B; Parker, Patricia; Renquist, Benjamin J; Cherrington, Nathan J; Camenisch, Todd D

    2016-07-01

    Non-alcoholic fatty liver disease can result in changes to drug metabolism and disposition potentiating adverse drug reactions. Furthermore, arsenite exposure during development compounds the severity of diet-induced fatty liver disease. This study examines the effects of arsenite potentiated diet-induced fatty liver disease on hepatic transport in male mice. Changes were detected for Mrp2/3/4 hepatic transporter gene expression as well as for Oatp1a4/2b1/1b2. Plasma concentrations of Mrp and Oatp substrates were increased in arsenic exposure groups compared with diet-only controls. In addition, murine embryonic hepatocytes and adult primary hepatocytes show significantly altered transporter expression after exposure to arsenite alone: a previously unreported phenomenon. These data indicate that developmental exposure to arsenite leads to changes in hepatic transport which could increase the risk for ADRs during fatty liver disease.

  2. Increased Incidence of Mitochondrial Cytochrome C Oxidase 1 Gene Mutations in Patients with Primary Ovarian Insufficiency.

    Directory of Open Access Journals (Sweden)

    Xiumei Zhen

    Full Text Available Primary ovarian insufficiency (POI, also known as premature ovarian failure (POF, is defined as more than six months of cessation of menses before the age of 40 years, with two serum follicle stimulating hormone (FSH levels (at least 1 month apart falling in the menopause range. The cause of POI remains undetermined in the majority of cases, although some studies have reported increased levels of reactive oxygen species (ROS in idiopathic POF. The role of mitochondrial DNA in the pathogenesis of POI has not been studied extensively. This aim of this study was to uncover underlying mitochondrial genetic defects in patients with POI. The entire region of the mitochondrial genome was amplified in subjects with idiopathic POI (n=63 and age-matched healthy female controls (n=63 using nine pair sets of primers, followed by screening of the mitochondrial genome using an Illumina MiSeq. We identified a total of 96 non-synonymous mitochondrial variations in POI patients and 93 non-synonymous variations in control subjects. Of these, 21 (9 in POI and 12 in control non-synonymous variations had not been reported previously. Eight mitochondrial cytochrome coxidase 1 (MT-CO1 missense variants were identified in POI patients, whereas only four missense mutations were observed in controls. A high incidence of MT-CO1 missense variants were identified in POI patients compared with controls, and the difference between the groups was statistically significant (13/63 vs. 5/63, p=0.042. Our results show that patients with primary ovarian insufficiency exhibit an increased incidence of mitochondrial cytochrome c oxidase 1 gene mutations, suggesting that MT-CO1 gene mutation may be causal in POI.

  3. [Association between the canine monoamine oxidase B (MAOB) gene polymorphisms and behavior of puppies in open-field test].

    Science.gov (United States)

    Li, Xiao-Hui; Xu, Han-Kun; Mao, Da-Gan; Ma, Da-Jun; Chen, Peng; Yang, Li-Guo

    2006-11-01

    Excitability, activity and exploration behavior of puppies in a novel open-field were tested in a total of 204 two-month-old German shepherd dog, labrador retriever or English springer spaniel puppies. The polymorphisms of monoamine oxidase B gene (MAOB) were detected by PCR-RFLP. Statistics analysis indicated that genotype and allele frequencies of the polymorphisms were significantly different among three breeds (P open-field test. The results showed that MAOB gene polymorphisms had a significant effect on walking time, squares crossed, lying time, the times of standing up against walls(P open-field test and TT genotype has favorable effects in these behavior traits.

  4. The role of the monoamine oxidase A gene in moderating the response to adversity and associated antisocial behavior: a review

    Directory of Open Access Journals (Sweden)

    Buades-Rotger M

    2014-07-01

    Full Text Available Macià Buades-Rotger,1,2 David Gallardo-Pujol1,3 1Department of Personality, Faculty of Psychology, University of Barcelona, Barcelona, Spain; 2Department of Neurology, University of Lübeck, Lübeck, Germany; 3Institute for Brain, Cognition and Behavior (IR3C, University of Barcelona, Barcelona, Spain Abstract: Hereditary factors are increasingly attracting the interest of behavioral scientists and practitioners. Our aim in the present article is to introduce some state-of-the-art topics in behavioral genetics, as well as selected findings in the field, in order to illustrate how genetic makeup can modulate the impact of environmental factors. We focus on the most-studied polymorphism to date for antisocial responses to adversity: the monoamine oxidase A gene. Advances, caveats, and promises of current research are reviewed. We also discuss implications for the use of genetic information in applied settings. Keywords: behavioral genetics, antisocial behaviors, monoamine oxidase A

  5. Expressional studies of the aldehyde oxidase (AOX1) gene during myogenic differentiation in C2C12 cells

    Energy Technology Data Exchange (ETDEWEB)

    Kamli, Majid Rasool; Kim, Jihoe; Pokharel, Smritee; Jan, Arif Tasleem [School of Biotechnology, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of); Lee, Eun Ju [School of Biotechnology, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of); Bovine Genome Resources Bank, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of); Choi, Inho, E-mail: inhochoi@ynu.ac.kr [School of Biotechnology, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of); Bovine Genome Resources Bank, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of)

    2014-08-08

    Highlights: • AOX1 contributes to the formation of myotube. • Silencing of AOX1 reduces myotube formation. • AOX1 regulates MyoG gene expression. • AOX1 contributes to myogenesis via H{sub 2}O{sub 2}. - Abstract: Aldehyde oxidases (AOXs), which catalyze the hydroxylation of heterocycles and oxidation of a wide variety of aldehydic compounds, have been present throughout evolution from bacteria to humans. While humans have only a single functional aldehyde oxidase (AOX1) gene, rodents are endowed with four AOXs; AOX1 and three aldehyde oxidase homologs (AOH1, AOH2 and AOH3). In continuation of our previous study conducted to identify genes differentially expressed during myogenesis using a microarray approach, we investigated AOX1 with respect to its role in myogenesis to conceptualize how it is regulated in C2C12 cells. The results obtained were validated by silencing of the AOX1 gene. Analysis of their fusion index revealed that formation of myotubes showed a marked reduction of up to 40% in AOX1{sub kd} cells. Expression of myogenin (MYOG), one of the marker genes used to study myogenesis, was also found to be reduced in AOX1{sub kd} cells. AOX1 is an enzyme of pharmacological and toxicological importance that metabolizes numerous xenobiotics to their respective carboxylic acids. Hydrogen peroxide (H{sub 2}O{sub 2}) produced as a by-product in this reaction is considered to be involved as a part of the signaling mechanism during differentiation. An observed reduction in the level of H{sub 2}O{sub 2} among AOX1{sub kd} cells confirmed production of H{sub 2}O{sub 2} in the reaction catalyzed by AOX1. Taken together, these findings suggest that AOX1 acts as a contributor to the process of myogenesis by influencing the level of H{sub 2}O{sub 2}.

  6. Correlation between single nucleotide polymorphisms of NADPH oxidase p22phox gene and ischemic stroke in Shanghai Han population

    Directory of Open Access Journals (Sweden)

    Wei XU

    2015-09-01

    Full Text Available Objective This paper aims to investigate the distribution of genotypes and alleles of nicotinamide adenine dinucleotide phosphate (NADPH oxidase p22phox -930A/G, 242C/T and -675A/T, so as to evaluate the association between three single-nucleotide polymorphisms (SNPs and risk of atherosclerotic ischemic stroke in permanent resident population of Han nationality living in Shanghai area. Methods The genotypes and allele frequencies of NADPH oxidase p22phox subunit -930A/G, 242C/T and -675A/T were detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP analysis in 205 patients with ischemic stroke and 136 healthy controls. Results In patients with ischemic stroke, the results of PCR-RFLP in variant genetic loci were different. For -930A/G, one band appeared at 268 bp of genotype AA; 2 bands appeared at 197 and 71 bp of genotype GG; 3 bands appeared at 268, 197 and 71 bp of genotype AG. For 242C/T, one band appeared at 348 bp of genotype CC; 2 bands appeared at 188 and 160 bp of genotype TT; 3 bands appeared at 348, 188 and 160 bp of genotype CT. For -675A/T, 2 bands appeared at 158 and 54 bp of genotype TT; 3 bands appeared at 212, 158 and 54 bp of genotype AT. The genotypes and allele frequency of all three SNPs of NADPH oxidase p22phox gene had no significant difference between ischemic stroke patients and healthy controls (P > 0.05. Conclusions The genetic polymorphism of NADPH oxidase p22phox gene -930A/G, 242C/T and -675A/T might have no association with ischemic stroke. DOI: 10.3969/j.issn.1672-6731.2015.09.011

  7. Sorption of Arsenite onto Mackinawite Coated Sand

    Science.gov (United States)

    Gallegos, T. J.; Hayes, K. F.; Abriola, L. M.

    2004-05-01

    Arsenic contamination of groundwater is a widespread problem affecting aquifers in the United States as well as abroad. Recent strengthening of the US EPA MCL for arsenic has prompted the need for technology capable of removing both arsenite and arsenate from solution. Arsenite, the more toxic form of arsenic, is more difficult to remove from anoxic zones in the subsurface. Studies by others have demonstrated the affinity of some types of iron sulfides for arsenite, such as troilite, pyrite, amorphous iron sulfide and mackinawite. However, these studies have not provided a comprehensive investigation of the macroscopic behavior of arsenite in the presence of crystalline mackinawite in a form that can be readily applied to real-world treatment technologies. This study examines the behavior of arsenite in the presence of mackinawite coated sand. PH edge results demonstrate that arsenite sorption onto mackinawite coated sand increases with increasing pH, reaching maximum removal at pH 10. Arsenite removal, albeit slight, occurring below pH 5 is independent of pH indicative of a different removal mechanism. Isotherm studies show that at low concentrations, removal is Langmuirian in nature. Arsenite sorption abruptly converts to linear behavior at high concentrations, possibly attributed to the saturation of the monolayer. Ionic strength effects were assessed by comparing pH edge data developed for three different concentrations of NaCl background electrolyte solution. Increases in ionic strength enhance the removal of arsenite from solution, suggesting possible inner-sphere surface complexation removal mechanisms. Information gathered in this study can be used to further develop surface complexation models to describe and predict reactivity of arsenite in the presence of mackinawite coated sands in anoxic regions. Mackinawite coated sands investigated here may provide a feasible reactive medium for implementation in above-ground sorption reactors or subsurface

  8. NUCLEOTIDE-SEQUENCE OF THE LAST EXON OF THE GENE FOR HUMAN CYTOCHROME-C-OXIDASE SUBUNIT-VIB AND ITS FLANKING REGIONS

    NARCIS (Netherlands)

    TAANMAN, JW; SCHRAGE, C; BOKMA, E; REUVEKAMP, P; AGSTERIBBE, E; DEVRIES, H

    1991-01-01

    A human genomic clone encompassing the last exon of the gene for cytochrome c oxidase subunit VIb and a human genomic clone containing the most distal end of this gene were characterized. The last exon of the gene codes for the 17 C-terminal amino acid residues of the subunit and the 3' noncoding re

  9. Arsenite-induced autophagy is associated with proteotoxicity in human lymphoblastoid cells

    Energy Technology Data Exchange (ETDEWEB)

    Bolt, Alicia M.; Zhao, Fei; Pacheco, Samantha; Klimecki, Walter T., E-mail: klimecki@pharmacy.arizona.edu

    2012-10-15

    Epidemiological studies of arsenic-exposed populations have provided evidence that arsenic exposure in humans is associated with immunosuppression. Previously, we have reported that arsenite-induced toxicity is associated with the induction of autophagy in human lymphoblastoid cell lines (LCL). Autophagy is a cellular process that functions in the degradation of damaged cellular components, including protein aggregates formed by misfolded or damaged proteins. Accumulation of misfolded or damaged proteins in the endoplasmic reticulum (ER) lumen causes ER stress and activates the unfolded protein response (UPR). In an effort to investigate the mechanism of autophagy induction by arsenite in the LCL model, we examined the potential contribution of ER stress and activation of the UPR. LCL exposed to sodium arsenite for 8-days induced expression of UPR-activated genes, including CHOP and GRP78, at the RNA and the protein level. Evidence for activation of the three arms of the UPR was observed. The arsenite-induced activation of the UPR was associated with an accumulation of protein aggregates containing p62 and LC3, proteins with established roles in the sequestration and autophagic clearance of protein aggregates. Taken together, these data provide evidence that arsenite-induced autophagy is associated with the generation of ER stress, activation of the UPR, and formation of protein aggregates that may be targeted to the lysosome for degradation. -- Highlights: ► Arsenite induces endoplasmic reticulum stress and the unfolded protein response. ► Arsenite induces the formation of protein aggregates that contain p62 and LC3-II. ► Time-course data suggests that arsenite-induced autophagy precedes ER stress.

  10. Spermine oxidase maintains basal skeletal muscle gene expression and fiber size and is strongly repressed by conditions that cause skeletal muscle atrophy.

    Science.gov (United States)

    Bongers, Kale S; Fox, Daniel K; Kunkel, Steven D; Stebounova, Larissa V; Murry, Daryl J; Pufall, Miles A; Ebert, Scott M; Dyle, Michael C; Bullard, Steven A; Dierdorff, Jason M; Adams, Christopher M

    2015-01-15

    Skeletal muscle atrophy is a common and debilitating condition that remains poorly understood at the molecular level. To better understand the mechanisms of muscle atrophy, we used mouse models to search for a skeletal muscle protein that helps to maintain muscle mass and is specifically lost during muscle atrophy. We discovered that diverse causes of muscle atrophy (limb immobilization, fasting, muscle denervation, and aging) strongly reduced expression of the enzyme spermine oxidase. Importantly, a reduction in spermine oxidase was sufficient to induce muscle fiber atrophy. Conversely, forced expression of spermine oxidase increased muscle fiber size in multiple models of muscle atrophy (immobilization, fasting, and denervation). Interestingly, the reduction of spermine oxidase during muscle atrophy was mediated by p21, a protein that is highly induced during muscle atrophy and actively promotes muscle atrophy. In addition, we found that spermine oxidase decreased skeletal muscle mRNAs that promote muscle atrophy (e.g., myogenin) and increased mRNAs that help to maintain muscle mass (e.g., mitofusin-2). Thus, in healthy skeletal muscle, a relatively low level of p21 permits expression of spermine oxidase, which helps to maintain basal muscle gene expression and fiber size; conversely, during conditions that cause muscle atrophy, p21 expression rises, leading to reduced spermine oxidase expression, disruption of basal muscle gene expression, and muscle fiber atrophy. Collectively, these results identify spermine oxidase as an important positive regulator of muscle gene expression and fiber size, and elucidate p21-mediated repression of spermine oxidase as a key step in the pathogenesis of skeletal muscle atrophy.

  11. Alternative Splicing and Differential Expression of Two Transcripts of Nicotine Adenine Dinucleotide Phosphate Oxidase B Gene from Zea mays

    Institute of Scientific and Technical Information of China (English)

    Fan Lin; Yun Zhang; Ming-Yi Jiang

    2009-01-01

    With the exception of rice, little is known about the existence of respiratory burst oxidase homolog (rboh) gene in cereals. The present study reports the cloning and analysis of a novel rboh gene, termed ZmrbohB, from maize (Zea mays L.). The full-length cDNA of ZmrbohB encodes a 942 amino acid protein containing all of the respiratory burst oxidase homolog catalytically critical motifs.Altemative splicing of ZmrbohB has generated two transcript isoforms, ZmrbohB-α and -β. Spliced transcript ZmrbohB-β retains an unspliced intron 11 that carries a premature termination codon and probably leads to nonsense-mediated mRNA decay. Expression analysis showed that two splice isoforms were differentially expressed in various tissues and at different developmental stages, and the major product was ZmrbohB-α. The transcripts of ZmrbohB-α accumulated markedly when the maize seedlings were subjected to various abiotic stimuli, such as wounding, cold (4℃), heat (40℃), UV and salinity stress. In addition, several abiotic stimuli also affected the alternative splicing pattern of ZmrbohB except wounding. These results provide new insight into roles in the expression regulation of plant rboh genes and suggest that ZmrbohB gene may play a role in response to environmental stresses.

  12. Tet1 oxidase regulates neuronal gene transcription, active DNA hydroxymethylation, object location memory, and threat recognition memory

    Directory of Open Access Journals (Sweden)

    Dinesh Kumar

    2015-10-01

    Full Text Available A dynamic equilibrium between DNA methylation and demethylation of neuronal activity-regulated genes is crucial for memory processes. However, the mechanisms underlying this equilibrium remain elusive. Tet1 oxidase has been shown to play a key role in the active DNA demethylation in the central nervous system. In this study, we used Tet1 gene knockout (Tet1KO mice to examine the involvement of Tet1 in memory consolidation and storage in the adult brain. We found that Tet1 ablation leads to altered expression of numerous neuronal activity-regulated genes, compensatory upregulation of active demethylation pathway genes, and upregulation of various epigenetic modifiers. Moreover, Tet1KO mice showed an enhancement in the consolidation and storage of threat recognition (cued and contextual fear conditioning and object location memories. We conclude that Tet1 plays a critical role in regulating neuronal transcription and in maintaining the epigenetic state of the brain associated with memory consolidation and storage.

  13. From the Cover: Arsenite Uncouples Mitochondrial Respiration and Induces a Warburg-like Effect in Caenorhabditis elegans.

    Science.gov (United States)

    Luz, Anthony L; Godebo, Tewodros R; Bhatt, Dhaval P; Ilkayeva, Olga R; Maurer, Laura L; Hirschey, Matthew D; Meyer, Joel N

    2016-08-01

    Millions of people worldwide are chronically exposed to arsenic through contaminated drinking water. Despite decades of research studying the carcinogenic potential of arsenic, the mechanisms by which arsenic causes cancer and other diseases remain poorly understood. Mitochondria appear to be an important target of arsenic toxicity. The trivalent arsenical, arsenite, can induce mitochondrial reactive oxygen species production, inhibit enzymes involved in energy metabolism, and induce aerobic glycolysis in vitro, suggesting that metabolic dysfunction may be important in arsenic-induced disease. Here, using the model organism Caenorhabditis elegans and a novel metabolic inhibition assay, we report an in vivo induction of aerobic glycolysis following arsenite exposure. Furthermore, arsenite exposure induced severe mitochondrial dysfunction, including altered pyruvate metabolism; reduced steady-state ATP levels, ATP-linked respiration and spare respiratory capacity; and increased proton leak. We also found evidence that induction of autophagy is an important protective response to arsenite exposure. Because these results demonstrate that mitochondria are an important in vivo target of arsenite toxicity, we hypothesized that deficiencies in mitochondrial electron transport chain genes, which cause mitochondrial disease in humans, would sensitize nematodes to arsenite. In agreement with this, nematodes deficient in electron transport chain complexes I, II, and III, but not ATP synthase, were sensitive to arsenite exposure, thus identifying a novel class of gene-environment interactions that warrant further investigation in the human populace.

  14. Over-expression of polyphenol oxidase gene in strawberry fruit delays the fungus infection process

    Science.gov (United States)

    Polyphenols are secondary metabolites widely present in plants and beneficial to human health. In this study, the changes of polyphenol contents during strawberry fruit development as well as changes of polyphenol oxidase (PPO) was analyzed. The polyphenol content showed declining trend during fruit...

  15. Structural analysis of tissues affected by cytochrome C oxidase deficiency due to mutations in the SCO2 gene.

    Science.gov (United States)

    Vesela, Katerina; Hulkova, Helena; Hansikova, Hana; Zeman, Jiri; Elleder, Milan

    2008-01-01

    Structural and histochemical studies carried out in a series of seven cases (from five families) with isolated cytochrome c oxidase (COX) deficiency caused by mutations in the SCO2 gene (1, 2) disclosed changes concentrated in the nervous system, skeletal muscle and myocardium. In five patients homozygous for the E140K mutation, the phenotype was predominantly neuromuscular and the average life span ranged between 9 and 15 months. In two cases, the course was more rapid (death at 7 and 11 weeks of life) and featured marked cardiac hypertrophy (3- and 4-fold increase in heart weight). This predominantly cardiomyopathic phenotype was associated with compound heterozygosity (E140K with another nonsense mutation) in the SCO2 gene. Polioencephalopathy with neurodegeneration and neuronal drop out was present in all cases with evidence that retinal neurons might be seriously affected too. Involvement of spinal motoneurons together with cytochrome c oxidase deficiency in muscle represents a "double hit" for the skeletal muscle. The mitochondrial population was not found to be significantly increased or structurally altered, with the exception of two compound heterozygotes in which the cardiac mitochondria were increased in number and size. Our report extends knowledge of the pathology of COX deficiency caused by mutations in the SCO2 gene.

  16. Dysbindin and d-amino-acid-oxidase gene polymorphisms associated with positive and negative symptoms in schizophrenia

    DEFF Research Database (Denmark)

    Wirgenes, Katrine V; Djurovic, Srdjan; Agartz, Ingrid;

    2009-01-01

    BACKGROUND: Schizophrenia is a genetically complex disorder with an unknown pathophysiology. Several genes implicated in glutamate metabolism have been associated with the disorder. Recent studies of polymorphisms in the dystrobrevin-binding protein 1 gene (DTNBP1; dysbindin) and D......-amino-acid-oxidase (DAO) gene, both involved in glutamate receptor function, reported associations with negative symptoms and with anxiety and depression, respectively, when measured with the Positive and Negative Syndrome Scale (PANSS). METHODS: In the present study, the suggested association between dysbindin and DAO...... single nucleotide polymorphisms (SNPs) and PANSS scores was analyzed in 155 Norwegian schizophrenia patients. RESULTS: There was a significant association between the dysbindin SNP rs3213207 and severity of both negative symptoms and total symptom load, as well as between the DAO SNP rs2070587 and total...

  17. ASSIGNMENT OF THE GENE CODING FOR HUMAN CYTOCHROME-C-OXIDASE SUBUNIT-VIB TO CHROMOSOME-19, BAND-Q13.1, BY FLUORESCENCE INSITU HYBRIDIZATION

    NARCIS (Netherlands)

    TAANMAN, JW; VANDERVEEN, AY; SCHRAGE, C; DEVRIES, H; BUYS, CHCM

    1991-01-01

    A cloned, 40 kb, genomic DNA fragment, containing the last exon of the gene for human cytochrome c oxidase subunit VIb and its flanking sequences, was used as a probe to localize the subunit VIb gene on human metaphase chromosomes. The probe was labelled with Bio-11-dUTP and detected by fluorescence

  18. Anaerobic oxidation of arsenite in Mono Lake water and by a facultative, arsenite-oxidizing chemoautotroph, strain MLHE-1

    Science.gov (United States)

    Oremland, R.S.; Hoeft, S.E.; Santini, J.M.; Bano, N.; Hollibaugh, R.A.; Hollibaugh, J.T.

    2002-01-01

    Arsenite [As(III)]-enriched anoxic bottom water from Mono Lake, California, produced arsenate [As(V)] during incubation with either nitrate or nitrite. No such oxidation occurred in killed controls or in live samples incubated without added nitrate or nitrite. A small amount of biological As(III) oxidation was observed in samples amended with Fe(III) chelated with nitrolotriacetic acid, although some chemical oxidation was also evident in killed controls. A pure culture, strain MLHE-1, that was capable of growth with As(III) as its electron donor and nitrate as its electron acceptor was isolated in a defined mineral salts medium. Cells were also able to grow in nitrate-mineral salts medium by using H2 or sulfide as their electron donor in lieu of As(III). Arsenite-grown cells demonstrated dark 14CO2 fixation, and PCR was used to indicate the presence of a gene encoding ribulose-1,5-biphosphate carboxylase/oxygenase. Strain MLHE-1 is a facultative chemoautotroph, able to grow with these inorganic electron donors and nitrate as its electron acceptor, but heterotrophic growth on acetate was also observed under both aerobic and anaerobic (nitrate) conditions. Phylogenetic analysis of its 16S ribosomal DNA sequence placed strain MLHE-1 within the haloalkaliphilic Ectothiorhodospira of the ??-Proteobacteria. Arsenite oxidation has never been reported for any members of this subgroup of the Proteobacteria.

  19. Elimination of manganese(II,III) oxidation in Pseudomonas putida GB-1 by a double knockout of two putative multicopper oxidase genes.

    Science.gov (United States)

    Geszvain, Kati; McCarthy, James K; Tebo, Bradley M

    2013-01-01

    Bacterial manganese(II) oxidation impacts the redox cycling of Mn, other elements, and compounds in the environment; therefore, it is important to understand the mechanisms of and enzymes responsible for Mn(II) oxidation. In several Mn(II)-oxidizing organisms, the identified Mn(II) oxidase belongs to either the multicopper oxidase (MCO) or the heme peroxidase family of proteins. However, the identity of the oxidase in Pseudomonas putida GB-1 has long remained unknown. To identify the P. putida GB-1 oxidase, we searched its genome and found several homologues of known or suspected Mn(II) oxidase-encoding genes (mnxG, mofA, moxA, and mopA). To narrow this list, we assumed that the Mn(II) oxidase gene would be conserved among Mn(II)-oxidizing pseudomonads but not in nonoxidizers and performed a genome comparison to 11 Pseudomonas species. We further assumed that the oxidase gene would be regulated by MnxR, a transcription factor required for Mn(II) oxidation. Two loci met all these criteria: PputGB1_2447, which encodes an MCO homologous to MnxG, and PputGB1_2665, which encodes an MCO with very low homology to MofA. In-frame deletions of each locus resulted in strains that retained some ability to oxidize Mn(II) or Mn(III); loss of oxidation was attained only upon deletion of both genes. These results suggest that PputGB1_2447 and PputGB1_2665 encode two MCOs that are independently capable of oxidizing both Mn(II) and Mn(III). The purpose of this redundancy is unclear; however, differences in oxidation phenotype for the single mutants suggest specialization in function for the two enzymes.

  20. Analysis of Taxonomic Relationships and Species Divergence Of Libellulidae (Odonata: Anisoptera Members Using Cytochrome Oxidase I Gene

    Directory of Open Access Journals (Sweden)

    Jisha Krishnan, E. K.,

    2016-04-01

    Full Text Available Libellulidae are commonly called ‘skimmers’ or ‘perchers’ representing the largest dragonfly family in the world. They are cosmopolitan in distribution and consist of 142 genera and 871 species. This family displays remarkable diversity in behaviour and morphology and consequently focused on studies of comparative population ecology, sexual selection, phylogeography and the evolution of mating behaviour. In the present study we deciphered the phylogenetic relationships of nine Libellulidae members by Neighbour-joining (NJ and Maximum likelihood methods using partial cytochrome oxidase I gene as the marker. The phylogenetic tree inferred the sister clade relationship of the representing libellulidae members and confirmed the evolutionary divergence in relation with branch length. The averages A+T content of all these species are 62.03 % while G+C content is 37.97 % showing strong A+T bias. The transition/ transversion ratio are found to be 0.858 for purines and 2.533 for pyramidines indicating higher mutations are exhibited by the transition of Thymine, Uracil and Cytosine. The present study thus concluded that the mitochondrial cytochrome oxidase subunit I (COI gene sequence of Libellulidae members demonstrated substantial variation; therefore it can be used for molecular taxonomy and for the phylogenetic studies.

  1. High-level expression of the Penicillium notatum glucose oxidase gene in Pichia pastoris using codon optimization.

    Science.gov (United States)

    Gao, Zhaowei; Li, Zhuofu; Zhang, Yuhong; Huang, Huoqing; Li, Mu; Zhou, Liwei; Tang, Yunming; Yao, Bin; Zhang, Wei

    2012-03-01

    The glucose oxidase (GOD) gene from Penicillium notatum was expressed in Pichia pastoris. The 1,815 bp gene, god-w, encodes 604 amino acids. Recombinant GOD-w had optimal activity at 35-40°C and pH 6.2 and was stable, from pH 3 to 7 maintaining >75% maximum activity after incubation at 50°C for 1 h. GOD-w worked as well as commercial GODs to improve bread making. To achieve high-level expression of recombinant GOD in P. pastoris, 272 nucleotides involving 228 residues were mutated, consistent with the codon bias of P. pastoris. The optimized recombinant GOD-m yielded 615 U ml(-1) (2.5 g protein l(-1)) in a 3 l fermentor--410% higher than GOD-w (148 U ml(-1)), and thus is a low-cost alternative for the bread baking industry.

  2. A novel phylogeny and morphological reconstruction of the PIN genes and first phylogeny of the ACC-oxidases (ACOs

    Directory of Open Access Journals (Sweden)

    Ronald Matthew Clouse

    2014-06-01

    Full Text Available The PIN and ACO gene families present interesting questions about the evolution of plant physiology, including testing hypotheses about the ecological drivers of their diversification and whether unrelated genes have been recruited for similar functions. The PIN-formed proteins contribute to the polar transport of auxin, a hormone which regulates plant growth and development. PIN loci are categorized into groups according to their protein length and structure, as well as subcellular localization. An interesting question with PIN genes is the nature of the ancestral form and location. ACOs are members of a superfamily of oxygenases and oxidases that catalyze the last step of ethylene synthesis, which regulates many aspects of the plant life cycle. We used publicly available PIN and ACO sequences to conduct phylogenetic analyses. Third codon positions of these genes in monocots have a high GC content, which could be historical but is more likely due to a mutational bias. Thus we developed methods to extract phylogenetic information from nucleotide sequences while avoiding this convergent feature. One method consisted in using only A-T transformations, and another used only the first and second codon positions for serine, which can only take A or T and G or C, respectively. We also conducted tree-searches for both gene families using unaligned amino acid sequences and dynamic homology. PIN genes appear to have diversified earlier than ACOs, with monocot and dicot copies more mixed in the phylogeny. However, gymnosperm PINs appear to be derived and not closely related to those from primitive plants. We find strong support for a long PIN gene ancestor with short forms subsequently evolving one or more times. ACO genes appear to have diversified mostly since the dicot-monocot split, as most genes cluster into a small number of monocot and dicot clades when the tree is rooted by genes from mosses. Gymnosperm ACOs were recovered as closely related and

  3. A novel phylogeny and morphological reconstruction of the PIN genes and first phylogeny of the ACC-oxidases (ACOs).

    Science.gov (United States)

    Clouse, Ronald M; Carraro, Nicola

    2014-01-01

    The PIN and ACO gene families present interesting questions about the evolution of plant physiology, including testing hypotheses about the ecological drivers of their diversification and whether unrelated genes have been recruited for similar functions. The PIN-formed proteins contribute to the polar transport of auxin, a hormone which regulates plant growth and development. PIN loci are categorized into groups according to their protein length and structure, as well as subcellular localization. An interesting question with PIN genes is the nature of the ancestral form and location. ACOs are members of a superfamily of oxygenases and oxidases that catalyze the last step of ethylene synthesis, which regulates many aspects of the plant life cycle. We used publicly available PIN and ACO sequences to conduct phylogenetic analyses. Third codon positions of these genes in monocots have a high GC content, which could be historical but is more likely due to a mutational bias. Thus, we developed methods to extract phylogenetic information from nucleotide sequences while avoiding this convergent feature. One method consisted in using only A-T transformations, and another used only the first and second codon positions for serine, which can only take A or T and G or C, respectively. We also conducted tree-searches for both gene families using unaligned amino acid sequences and dynamic homology. PIN genes appear to have diversified earlier than ACOs, with monocot and dicot copies more mixed in the phylogeny. However, gymnosperm PINs appear to be derived and not closely related to those from primitive plants. We find strong support for a long PIN gene ancestor with short forms subsequently evolving one or more times. ACO genes appear to have diversified mostly since the dicot-monocot split, as most genes cluster into a small number of monocot and dicot clades when the tree is rooted by genes from mosses. Gymnosperm ACOs were recovered as closely related and derived.

  4. Identification of forensically important blow fly species (Diptera: Calliphoridae) in China by mitochondrial cytochrome oxidase I gene differentiation

    Institute of Scientific and Technical Information of China (English)

    Qin-Lai Liu; Li Yang; Kun-Lu Wu; Ling-mei Lan; Jiang-Feng Wang; Yao-Qing Chen; Ji-Feng Cai; Yun-Feng Chang; Yan Gu; Ya-Dong Guo; Xing-Hua Wang; Ji-FangWeng; Ming Zhong; Xiang Wang

    2011-01-01

    Unambiguous and rapid sarcosaphagous insect species identification is an essential requirement for forensic investigations. Although some insect species are difficult to classify morphologically, they can be effectively identified using molecular methods based on similarity with abundant authenticated reference DNA sequences in local databases.However, local databases are still relatively incomplete in China because of the large land area with distinct regional conditions. In this study, 75 forensically important blow flies were collected from 23 locations in 16 Chinese provinces, and a 278-bp segment of the cytochrome oxidase subunit Ⅰ gene of all specimens was successfully sequenced. Phylogenetic analysis of the sequenced segments showed that all Calliphorid specimens were properly assigned into nine species with relatively strong supporting values, thus indicating that the 278-bp cytochrome oxidase subunit one region is suitable for identification of Calliphorid species. The clear difference between intraspecific threshold and interspecific divergence confirmed the potential of this region for Calliphorid species identification,especially for distinguishing between morphologically similar species. Intraspecific geographic variations were observed in Lucilia sericata (Meigen, 1826) and Lucilia caesar (Linnaeus, 1758).

  5. Knockdown of the Rhipicephalus microplus cytochrome c oxidase subunit III gene is associated with a failure of Anaplasma marginale transmission.

    Directory of Open Access Journals (Sweden)

    Thais D Bifano

    Full Text Available Rhipicephalus microplus is an obligate hematophagous ectoparasite of cattle and an important biological vector of Anaplasma marginale in tropical and subtropical regions. The primary determinants for A. marginale transmission are infection of the tick gut, followed by infection of salivary glands. Transmission of A. marginale to cattle occurs via infected saliva delivered during tick feeding. Interference in colonization of either the tick gut or salivary glands can affect transmission of A. marginale to naïve animals. In this study, we used the tick embryonic cell line BME26 to identify genes that are modulated in response to A. marginale infection. Suppression-subtractive hybridization libraries (SSH were constructed, and five up-regulated genes {glutathione S-transferase (GST, cytochrome c oxidase sub III (COXIII, dynein (DYN, synaptobrevin (SYN and phosphatidylinositol-3,4,5-triphosphate 3-phosphatase (PHOS} were selected as targets for functional in vivo genomic analysis. RNA interference (RNAi was used to determine the effect of tick gene knockdown on A. marginale acquisition and transmission. Although RNAi consistently knocked down all individually examined tick genes in infected tick guts and salivary glands, only the group of ticks injected with dsCOXIII failed to transmit A. marginale to naïve calves. To our knowledge, this is the first report demonstrating that RNAi of a tick gene is associated with a failure of A. marginale transmission.

  6. Analysis of the cytochrome c oxidase subunit 1 (COX1) gene reveals the unique evolution of the giant panda.

    Science.gov (United States)

    Hu, Yao-Dong; Pang, Hui-Zhong; Li, De-Sheng; Ling, Shan-Shan; Lan, Dan; Wang, Ye; Zhu, Yun; Li, Di-Yan; Wei, Rong-Ping; Zhang, He-Min; Wang, Cheng-Dong

    2016-11-05

    As the rate-limiting enzyme of the mitochondrial respiratory chain, cytochrome c oxidase (COX) plays a crucial role in biological metabolism. "Living fossil" giant panda (Ailuropoda melanoleuca) is well-known for its special bamboo diet. In an effort to explore functional variation of COX1 in the energy metabolism behind giant panda's low-energy bamboo diet, we looked at genetic variation of COX1 gene in giant panda, and tested for its selection effect. In 1545 base pairs of the gene from 15 samples, 9 positions were variable and 1 mutation leaded to an amino acid sequence change. COX1 gene produces six haplotypes, nucleotide (pi), haplotype diversity (Hd). In addition, the average number of nucleotide differences (k) is 0.001629±0.001036, 0.8083±0.0694 and 2.517, respectively. Also, dN/dS ratio is significantly below 1. These results indicated that giant panda had a low population genetic diversity, and an obvious purifying selection of the COX1 gene which reduces synthesis of ATP determines giant panda's low-energy bamboo diet. Phylogenetic trees based on the COX1 gene were constructed to demonstrate that giant panda is the sister group of other Ursidae.

  7. An Oxidoreductase AioE is Responsible for Bacterial Arsenite Oxidation and Resistance

    Science.gov (United States)

    Wang, Qian; Han, Yushan; Shi, Kaixiang; Fan, Xia; Wang, Lu; Li, Mingshun; Wang, Gejiao

    2017-01-01

    Previously, we found that arsenite (AsIII) oxidation could improve the generation of ATP/NADH to support the growth of Agrobacterium tumefaciens GW4. In this study, we found that aioE is induced by AsIII and located in the arsenic island near the AsIII oxidase genes aioBA and co-transcripted with the arsenic resistant genes arsR1-arsC1-arsC2-acr3-1. AioE belongs to TrkA family corresponding the electron transport function with the generation of NADH and H+. An aioE in-frame deletion strain showed a null AsIII oxidation and a reduced AsIII resistance, while a cytC mutant only reduced AsIII oxidation efficiency. With AsIII, aioE was directly related to the increase of NADH, while cytC was essential for ATP generation. In addition, cyclic voltammetry analysis showed that the redox potential (ORP) of AioBA and AioE were +0.297 mV vs. NHE and +0.255 mV vs. NHE, respectively. The ORP gradient is AioBA > AioE > CytC (+0.217 ~ +0.251 mV vs. NHE), which infers that electron may transfer from AioBA to CytC via AioE. The results indicate that AioE may act as a novel AsIII oxidation electron transporter associated with NADH generation. Since AsIII oxidation contributes AsIII detoxification, the essential of AioE for AsIII resistance is also reasonable. PMID:28128323

  8. Transcript Profiling Reveals the Presence of Abiotic Stress and Developmental Stage Specific Ascorbate Oxidase Genes in Plants

    Science.gov (United States)

    Batth, Rituraj; Singh, Kapil; Kumari, Sumita; Mustafiz, Ananda

    2017-01-01

    Abiotic stress and climate change is the major concern for plant growth and crop yield. Abiotic stresses lead to enhanced accumulation of reactive oxygen species (ROS) consequently resulting in cellular damage and major losses in crop yield. One of the major scavengers of ROS is ascorbate (AA) which acts as first line of defense against external oxidants. An enzyme named ascorbate oxidase (AAO) is known to oxidize AA and deleteriously affect the plant system in response to stress. Genome-wide analysis of AAO gene family has led to the identification of five, three, seven, four, and six AAO genes in Oryza sativa, Arabidopsis, Glycine max, Zea mays, and Sorghum bicolor genomes, respectively. Expression profiling of these genes was carried out in response to various abiotic stresses and during various stages of vegetative and reproductive development using publicly available microarray database. Expression analysis in Oryza sativa revealed tissue specific expression of AAO genes wherein few members were exclusively expressed in either root or shoot. These genes were found to be regulated by both developmental cues as well as diverse stress conditions. The qRT-PCR analysis in response to salinity and drought stress in rice shoots revealed OsAAO2 to be the most stress responsive gene. On the other hand, OsAAO3 and OsAAO4 genes showed enhanced expression in roots under salinity/drought stresses. This study provides lead about important stress responsive AAO genes in various crop plants, which could be used to engineer climate resilient crop plants. PMID:28261251

  9. Molecular detection of field isolates of Turkey Eimeria by polymerase chain reaction amplification of the cytochrome c oxidase I gene.

    Science.gov (United States)

    Rathinam, T; Gadde, U; Chapman, H D

    2015-07-01

    Oocysts of Eimeria spp. were isolated from litter samples obtained from 30 commercial turkey farms. Genomic DNA was extracted from clean oocysts, and polymerase chain amplification of the species-specific cytochrome c oxidase subunit I (COI) gene was performed for five species of turkey Eimeria. The species tested were Eimeria adenoeides, Eimeria meleagrimitis, Eimeria meleagridis, Eimeria dispersa, and Eimeria gallopavonis. All DNA samples were positive for E. meleagrimitis, nine were positive for E. adenoeides, two were positive for E. dispersa, and none for E. meleagridis and E. gallopavonis. E. meleagrimitis occurred as a single species in 21 (70 %) of the farms while 9 (30 %) farms had a mixed species with E. meleagrimitis and E. adenoeides and 2 (7 %) were triple positive with E. meleagrimitis, E. adenoeides, and E. dispersa. This is the first account of the field prevalence of turkey Eimeria species using molecular methods.

  10. Molecular phylogeny of silk-producing insects based on 16S ribosomal RNA and cytochrome oxidase subunit I genes

    Indian Academy of Sciences (India)

    B. Mahendran; S. K. Ghosh; S. C. Kundu

    2006-04-01

    We have examined the molecular-phylogenetic relationships between nonmulberry and mulberry silkwormspecies that belong to the families Saturniidae, Bombycidae and Lasiocampidae using 16S ribosomal RNA (16S rRNA) and cytochrome oxidase subunit I (coxI) gene sequences. Aligned nucleotide sequences of 16S rRNA and coxI from 14 silk-producing species were used for construction of phylogenetic trees by maximum likelihood and maximum parsimony methods. The tree topology on the basis of 16S rRNA supports monophyly for members of Saturniidae and Bombycidae. Weighted parsimony analysis weighted towards transversions relative to transitions (ts, tv4) for coxI resulted in more robust bootstrap support over unweighted parsimony and favours the 16S rRNA tree topology. Combined analysis reflected clear biogeographic pattern, and agrees with morphological and cytological data.

  11. Genome-wide identification and expression analysis of the polyamine oxidase gene family in sweet orange (Citrus sinensis).

    Science.gov (United States)

    Wang, Wei; Liu, Ji-Hong

    2015-01-25

    Polyamine oxidases (PAOs) are FAD-dependent enzymes associated with polyamine catabolism. In plants, increasing evidences support that PAO genes play essential roles in abiotic and biotic stresses response. In this study, six putative PAO genes (CsPAO1-CsPAO6) were unraveled in sweet orange (Citrus sinensis) using the released citrus genome sequences. A total of 203 putative cis-regulatory elements involved in hormone and stress response were predicted in 1.5-kb promoter regions at the upstream of CsPAOs. The CsPAOs can be divided into four major groups, with similar organizations with their counterparts of Arabidopsis thaliana. Transcripts of CsPAOs were detected in leaf, stem, cotyledon, and root, with the highest levels detected in the roots. The CsPAOs displayed various responses to exogenous treatments with polyamines and ABA and were differentially altered by abiotic stresses, including cold, salt, and mannitol. Overexpression of CsPAO3 in tobacco demonstrated that spermidine and spermine were decreased in the transgenic line, while putrescine was significantly enhanced, implying a potential role of this gene in polyamine back conversion. These data provide valuable knowledge for understanding the roles of the PAO genes in the future.

  12. Allelic variations in the CYBA gene of NADPH oxidase and risk of kidney complications in patients with type 1 diabetes.

    Science.gov (United States)

    Patente, Thiago A; Mohammedi, Kamel; Bellili-Muñoz, Naïma; Driss, Fathi; Sanchez, Manuel; Fumeron, Frédéric; Roussel, Ronan; Hadjadj, Samy; Corrêa-Giannella, Maria Lúcia; Marre, Michel; Velho, Gilberto

    2015-09-01

    Oxidative stress plays a pivotal role in the pathophysiology of diabetic nephropathy, and the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase system is an important source of reactive oxygen species in hyperglycemic conditions in the kidney. Plasma concentration of advanced oxidation protein products (AOPP), a marker of oxidative stress, is increased in patients with diabetic nephropathy. We investigated associations of variants in the CYBA gene, encoding the regulatory subunit p22(phox) of NADPH oxidase, with diabetic nephropathy and plasma AOPP and myeloperoxidase (MPO) concentrations in type 1 diabetic patients. Seven SNPs in the CYBA region were analyzed in 1357 Caucasian subjects with type 1 diabetes from the SURGENE (n=340), GENEDIAB (n=444), and GENESIS (n=573) cohorts. Duration of follow-up was 10, 9, and 6 years, respectively. Cox proportional hazards and logistic regression analyses were used to estimate hazard ratios (HR) or odds ratios (OR) for incidence and prevalence of diabetic nephropathy. The major G-allele of rs9932581 was associated with the incidence of renal events defined as new cases of microalbuminuria or the progression to a more severe stage of nephropathy during follow-up (HR 1.59, 95% CI 1.17-2.18, P=0.003) in SURGENE. The same allele was associated with established/advanced nephropathy (OR 1.52, 95% CI 1.22-1.92, P=0.0001) and with the incidence of end-stage renal disease (ESRD) (HR 2.01, 95% CI 1.30-3.24, P=0.001) in GENEDIAB/GENESIS pooled studies. The risk allele was also associated with higher plasma AOPP concentration in subsets of SURGENE and GENEDIAB, with higher plasma MPO concentration in a subset of GENEDIAB, and with lower estimated glomerular filtration rate (eGFR) in the three cohorts. In conclusion, a functional variant in the promoter of the CYBA gene was associated with lower eGFR and with prevalence and incidence of diabetic nephropathy and ESRD in type 1 diabetic patients. These results are consistent with

  13. Arsenite toxicity and uptake rate of rice (Oryza sativa L.) in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, Holger, E-mail: hoffmann@bgt.uni-hannover.de [Institute of Plant Nutrition, Leibniz University of Hannover, Herrenhaeuser Strasse 2, D-30419 Hannover (Germany); Schenk, Manfred K., E-mail: schenk@pflern.uni-hannover.de [Institute of Plant Nutrition, Leibniz University of Hannover, Herrenhaeuser Strasse 2, D-30419 Hannover (Germany)

    2011-10-15

    Toxicity threshold of arsenite on intact rice seedlings was determined and arsenite uptake characteristics were investigated using non-toxic concentrations of arsenite. The arsenite toxicity threshold was 2.4 {mu}M arsenite which reduced growth by 10% (EC{sub 10}). The two highest arsenite levels induced wilting of seedlings and reduced both, transpiration rate and net photosynthetic rate. Arsenic content in plant tissue increased up to 10.7 {mu}M arsenite and then declined with increasing arsenite concentration in the treatment solution. The contents of Si, P, K, and of micronutrients Cu, Fe, Mn and Zn in shoot d.m. were reduced by arsenite levels {>=} 5.3 {mu}M. In the non-toxic range, arsenite uptake rate was linearly related to arsenite concentration. High arsenite levels reduced growth without being taken up which might be due to increasing binding of arsenite to proteins at the outer side of the plasmalemma. - Highlights: > Arsenite toxicity and uptake rate were investigated with intact rice plants. > Arsenite toxicity threshold was 2.4 {mu}M arsenite. > Uptake rate was linearly related to arsenite concentration in the non-toxic range. > Arsenite concentrations above 10.6 {mu}M decreased arsenic content in plant matter. > Arsenite impaired uptake of arsenite, water and Si, P, K, Cu, Fe, Mn and Zn. - Uptake of arsenite, water, and nutrients by rice seedlings was impaired by arsenite concentrations higher than the toxicity threshold of 2.4 {mu}M.

  14. Study of a possible role of the monoamine oxidase A (MAOA) gene in paranoid schizophrenia among a Chinese population.

    Science.gov (United States)

    Sun, Yuhui; Zhang, Jiexu; Yuan, Yanbo; Yu, Xin; Shen, Yan; Xu, Qi

    2012-01-01

    Monoamine oxidase A (MAOA) is the enzyme responsible for degradation of several monoamines, such as dopamine and serotonin that are considered as being two of the most important neurotransmitters involved in the pathophysiology of schizophrenia. To study a possible role of the MAOA gene in conferring susceptibility to schizophrenia, the present study genotyped the variable number of tandem repeat (VNTR) polymorphism and 41 SNPs across this gene among 555 unrelated patients with paranoid schizophrenia and 567 unrelated healthy controls. Quantitative real-time PCR analysis was employed to quantify expression of MAOA mRNA in 73 drug-free patients. While none of these genotyped DNA markers showed allelic association with paranoid schizophrenia, haplotypic association was found for the VNTR-rs6323, VNTR-rs1137070, and VNTR-rs6323-rs1137070 haplotypes in female subjects. Nevertheless, no significant change of the expression of MAOA mRNA was detected in either female or male patients with paranoid schizophrenia. Our study suggests that the interaction between genetic variants within the MAOA gene may contribute to an increased risk of paranoid schizophrenia, but the precise mechanism needs further investigation.

  15. Estradiol plays a role in regulating the expression of lysyl oxidase family genes in mouse urogenital tissues and human Ishikawa cells.

    Science.gov (United States)

    Zong, Wen; Jiang, Yan; Zhao, Jing; Zhang, Jian; Gao, Jian-gang

    2015-10-01

    The lysyl oxidase (LOX) family encodes the copper-dependent amine oxidases that play a key role in determining the tensile strength and structural integrity of connective tissues by catalyzing the crosslinking of elastin or collagen. Estrogen may upregulate the expression of LOX and lysyl oxidase-like 1 (LOXL1) in the vagina. The objective of this study was to determine the effect of estrogen on the expression of all LOX family genes in the urogenital tissues of accelerated ovarian aging mice and human Ishikawa cells. Mice and Ishikawa cells treated with estradiol (E2) showed increased expression of LOX family genes and transforming growth factor β1 (TGF-β1). Ishikawa cells treated with TGF-β1 also showed increased expression of LOX family genes. The Ishikawa cells were then treated with either E2 plus the TGF-β receptor (TGFBR) inhibitor SB431542 or E2 alone. The expression of LOX family genes induced by E2 was reduced in the Ishikawa cells treated with TGFBR inhibitor. Our results showed that E2 increased the expression of the LOX family genes, and suggest that this induction may be mediated by the TGF-β signal pathway. E2 may play a role in regulating the expression of LOX family genes.

  16. Symbiotic Burkholderia Species Show Diverse Arrangements of nif/fix and nod Genes and Lack Typical High-Affinity Cytochrome cbb3 Oxidase Genes.

    Science.gov (United States)

    De Meyer, Sofie E; Briscoe, Leah; Martínez-Hidalgo, Pilar; Agapakis, Christina M; de-Los Santos, Paulina Estrada; Seshadri, Rekha; Reeve, Wayne; Weinstock, George; O'Hara, Graham; Howieson, John G; Hirsch, Ann M

    2016-08-01

    Genome analysis of fourteen mimosoid and four papilionoid beta-rhizobia together with fourteen reference alpha-rhizobia for both nodulation (nod) and nitrogen-fixing (nif/fix) genes has shown phylogenetic congruence between 16S rRNA/MLSA (combined 16S rRNA gene sequencing and multilocus sequence analysis) and nif/fix genes, indicating a free-living diazotrophic ancestry of the beta-rhizobia. However, deeper genomic analysis revealed a complex symbiosis acquisition history in the beta-rhizobia that clearly separates the mimosoid and papilionoid nodulating groups. Mimosoid-nodulating beta-rhizobia have nod genes tightly clustered in the nodBCIJHASU operon, whereas papilionoid-nodulating Burkholderia have nodUSDABC and nodIJ genes, although their arrangement is not canonical because the nod genes are subdivided by the insertion of nif and other genes. Furthermore, the papilionoid Burkholderia spp. contain duplications of several nod and nif genes. The Burkholderia nifHDKEN and fixABC genes are very closely related to those found in free-living diazotrophs. In contrast, nifA is highly divergent between both groups, but the papilionoid species nifA is more similar to alpha-rhizobia nifA than to other groups. Surprisingly, for all Burkholderia, the fixNOQP and fixGHIS genes required for cbb3 cytochrome oxidase production and assembly are missing. In contrast, symbiotic Cupriavidus strains have fixNOQPGHIS genes, revealing a divergence in the evolution of two distinct electron transport chains required for nitrogen fixation within the beta-rhizobia.

  17. Involvement of the NADH oxidase-encoding noxA gene in oxidative stress responses in Corynebacterium glutamicum.

    Science.gov (United States)

    Park, Jung Chul; Kim, Younhee; Lee, Heung-Shick

    2015-02-01

    Corynebacterium glutamicum ORF NCgl0328, designated noxA, encodes an NADH oxidase enzyme. The noxA gene, which was preferentially expressed in the log growth phase, was found to be under the control of the whcA, whcB, and whcE genes, which play regulatory roles in cells under oxidative stress. While noxA transcription was minimal in whcE-deleted mutant cells (ΔwhcE) during growth, its transcription was maximal even in the stationary phase in ΔwhcA cells. The transcription levels of noxA in ΔwhcB and whcB-overexpressing cells were comparable to the levels only in the log growth phase in ΔwhcA and whcA-overexpressing cells, respectively. Direct binding of purified WhcA to the promoter region of noxA was observed in vitro. The DNA-protein interaction was only possible in the presence of the reducing agent dithiothreitol. A noxA-deleted mutant strain and a strain overexpressing the noxA gene (P180-noxA) were established, and these strains were found to exhibit defective cell growth. The ΔnoxA and P180-noxA strains were sensitive to the redox-cycling oxidant menadione, suggesting a role of noxA in redox balancing. Accordingly, the purified NoxA enzyme exhibited NADH-oxidizing activity. Taken together, these data show that noxA plays a role in oxidative stress responses and also that the gene is under direct control of the WhcA protein, which was shown to be a regulatory DNA-binding protein. Furthermore, the involvement and roles of the whcA, whcB, and whcE genes in regulating the expression of noxA were demonstrated.

  18. A versatile and efficient markerless gene disruption system for Acidithiobacillus thiooxidans: application for characterizing a copper tolerance related multicopper oxidase gene.

    Science.gov (United States)

    Wen, Qing; Liu, Xiangmei; Wang, Huiyan; Lin, Jianqun

    2014-11-01

    The acidophilic bioleaching bacteria can usually survive in high concentrations of copper ions because of their special living environment. However, little is known about the copper homeostatic mechanisms of Acidithiobacillus thiooxidans, an important member of bioleaching bacteria. Here, a putative multicopper oxidase gene (cueO) was detected from the draft genome of A. thiooxidans ATCC 19377. The transcriptional level of cueO in response to 10 mM CuSO₄was upregulated 25.01 ± 2.59 folds. The response of P(cueO) to copper was also detected and might be stimulated by a putative CueR protein. Then, by using the counter-selectable marker lacZ and enhancing the expression of endonuclease I-SceI with tac promoter, a modified markerless gene disruption system was developed and the cueO gene disruption mutant (ΔcueO) of A. thiooxidans was successfully constructed with a markedly improved second homologous recombination frequency of 0.28 ± 0.048. The ΔcueO mutant was more sensitive to external copper and nearly completely lost the phenoloxidase activity; however, the activity could be restored after complementing the cueO gene. All results suggest the close relation of cueO gene to copper tolerance in A. thiooxidans. In addition, the developed efficient markerless gene knockout method can also be introduced into other Acidithiobacillus strains.

  19. The Influence of Co-Suppressing Tomato 1-Aminocyclopropane-1-Carboxylic Acid Oxidase Ⅰ on the Expression of Fruit Ripening-Related and Pathogenesis-Related Protein Genes

    Institute of Scientific and Technical Information of China (English)

    HU Zong-li; CHEN Xu-qing; CHEN Guo-ping; L(U) Li-juan; Grierson Donald

    2007-01-01

    The purpose of this study is to explore the influence of co-suppressing tomato ACC oxidase I on the expression of fruit ripening-related and pathogenesis-related protein genes, and on the biosynthesis of endogenous ethylene and storage ability of fruits. Specific fragments of several fruit ripening-related and pathogenesis-related protein genes from tomato (Lycopersicon esculentum) were cloned, such as the 1-aminocyclopropane-1-carboxylic acid oxidase 1 gene (LeACO1), 1-aminocyclopropane-1-carboxylic acid oxidase 3 gene (LeAC03), EIN3-binding F-box 1 gene (LeEBF1), pathogenesisrelated protein 1 gene (LePR1), pathogenesis-related protein 5 gene (LePR5), and pathogenesis-related protein osmotin precursor gene (LeNP24) by PCR or RT-PCR. Then these specific DNA fragments were used as probes to hybridize with the total RNAs extracted from the wild type tomato Ailsa Craig (AC++) and the LeACO1 co-suppression tomatoes (V1187 and T4B), respectively. At the same time, ethylene production measurement and storage experiment of tomato fruits were carried out. The hybridization results indicated that the expression of fruit ripening-related genes such as LeACO3 and LeEBF1, and pathogenesis-related protein genes such as LePR1, LePR5, and LeNP24, were reduced sharply, and the ethylene production in the fruits, wounded leaves decreased and the storage time of ripening fruits was prolonged, when the expression of LeACO1 gene in the transgenic tomato was suppressed. In the co-suppression tomatoes, the expression of fruit ripening-related and pathogenesis-related protein genes were restrained at different degrees, the biosynthesis of endogenous ethylene decreased and the storage ability of tomato fruits increased.

  20. Genetic characterization of Bagarius species using cytochrome c oxidase I and cytochrome b genes.

    Science.gov (United States)

    Nagarajan, Muniyandi; Raja, Manikam; Vikram, Potnuru

    2016-09-01

    In this study, we first inferred the genetic variability of two Bagarius bagarius populations collected from Ganges and Brahmaputra rivers of India using two mtDNA markers. Sequence analysis of COI gene did not show significant differences between two populations whereas cytochrome b gene showed significant differences between two populations. Followed by, genetic relationship of B. bagarius and B. yarrielli was analyzed using COI and cytochrome b gene and the results showed a higher level genetic variation between two species. The present study provides support for the suitability of COI and cytochrome b genes for the identification of B. bagarius and B. yarrielli.

  1. Identification of a gene causing human cytochrome c oxidase deficiency by integrative genomics

    DEFF Research Database (Denmark)

    Mootha, Vamsi K; Lepage, Pierre; Miller, Kathleen;

    2003-01-01

    Identifying the genes responsible for human diseases requires combining information about gene position with clues about biological function. The recent availability of whole-genome data sets of RNA and protein expression provides powerful new sources of functional insight. Here we illustrate how...

  2. Novel Homozygous Missense Mutation in SPG20 Gene Results in Troyer Syndrome Associated with Mitochondrial Cytochrome c Oxidase Deficiency.

    Science.gov (United States)

    Spiegel, Ronen; Soiferman, Devorah; Shaag, Avraham; Shalev, Stavit; Elpeleg, Orly; Saada, Ann

    2016-08-19

    Troyer syndrome is an autosomal recessive form of hereditary spastic paraplegia (HSP) caused by deleterious mutations in the SPG20 gene. Although the disease is associated with a loss of function mechanism of spartin, the protein encoded by SPG20, the precise pathogenesis is yet to be elucidated. Recent data indicated an important role for spartin in both mitochondrial maintenance and function. Here we report a child presenting with progressive spastic paraparesis, generalized muscle weakness, dysarthria, impaired growth, and severe isolated decrease in muscle cytochrome c oxidase (COX) activity. Whole exome sequencing identified the homozygous c.988A>G variant in SPG20 gene (p.Met330Val) resulting in almost complete loss of spartin in skeletal muscle. Further analyses demonstrated significant tissue specific reduction of COX 4, a nuclear encoded subunit of COX, in muscle suggesting a role for spartin in proper mitochondrial respiratory chain function mediated by COX activity. Our findings need to be verified in other Troyer syndrome patients in order to classify it as a form of HSP caused by mitochondrial dysfunction.

  3. Characterization of Fasciola hepatica genotypes from cattle and sheep in Iran using cytochrome C oxidase gene (CO1).

    Science.gov (United States)

    Moazeni, Mohammad; Sharifiyazdi, Hassan; Izadpanah, Afshin

    2012-06-01

    The present study compared the genetic variation among 19 different isolates of Fasciola hepatica from cattle and sheep in different areas of Iran using sequence data for mitochondrial DNA gene, the subunit 1 of cytochrome C oxidase gene (CO1). Four different CO1 genotypes were detected among F. hepatica isolates that showed five variable nucleotide positions (accession nos.; GQ398051, GQ398052, GQ398053, GQ398054). Nucleotide sequence variation among 19 isolates for CO1 analyzed in this study ranged from 0% to 0.98% in Iran. Among the five polymorphism sites identified in this study, only one (T to G at position 51 in 5'end of GQ175362) resulted in putative amino acid alteration of phenylalanine (TTT) to leucine (TTG) in CO1. A phylogenetic analysis of the sequence data revealed that host associations and geographic location are likely not useful markers for Fasciola genotype classification. In addition, morphological analysis showed that the ratios of body length and body width of some (n = 5) of the 19 examined F. hepatica isolates were intermediate between F. hepatica and Fasciola gigantica, representing the substantial polymorphism of the F. hepatica species and the difficulty in the accurate recognition based on morphological features. In conclusion, Iranian F. hepatica exhibited the presence of considerable genetic diversity at CO1.

  4. Apparent selection intensity for the cytochrome oxidase subunit I gene varies with mode of reproduction in echinoderms.

    Science.gov (United States)

    Foltz, David W; Hrincevich, Adam W; Rocha-Olivares, Axayácatl

    2004-10-01

    When most amino acid substitutions in protein-coding genes are slightly deleterious rather than selectively neutral, life history differences can potentially modify the effective population size or the selective regime, resulting in altered ratios of non-synonymous to synonymous substitutions among taxa. We studied substitution patterns for the mitochondrial cytochrome oxidase subunit I (COI) gene in a sea star genus (Leptasterias spp.) with an obligate brood-protecting mode of reproduction and small-scale population genetic subdivision, and compared the results to available COI sequences in nine other genera of echinoderms with pelagic larvae: three sea stars, five sea urchins and one brittle star. We predicted that this life history difference would be associated with differences in the ratio of non-synonymous (dN) to synonymous (dS) substitution rates. Leptasterias had a significantly greater dN/dS ratio (both between species and within species), a significantly smaller transition/transversion rate ratio, and a significantly lower average nucleotide diversity within species, than did the non-brooding genera. Other explanations for the results, such as altered mutation rates or selective sweeps, were not supported by the data analysis. These findings highlight the potential influence of reproductive traits and other life history factors on patterns of nucleotide substitution within and between species.

  5. Quantitative transcriptome, proteome, and sulfur metabolite profiling of the Saccharomyces cerevisiae response to arsenite.

    Science.gov (United States)

    Thorsen, Michael; Lagniel, Gilles; Kristiansson, Erik; Junot, Christophe; Nerman, Olle; Labarre, Jean; Tamás, Markus J

    2007-06-19

    Arsenic is ubiquitously present in nature, and various mechanisms have evolved enabling cells to evade toxicity and acquire tolerance. Herein, we explored how Saccharomyces cerevisiae (budding yeast) respond to trivalent arsenic (arsenite) by quantitative transcriptome, proteome, and sulfur metabolite profiling. Arsenite exposure affected transcription of genes encoding functions related to protein biosynthesis, arsenic detoxification, oxidative stress defense, redox maintenance, and proteolytic activity. Importantly, we observed that nearly all components of the sulfate assimilation and glutathione biosynthesis pathways were induced at both gene and protein levels. Kinetic metabolic profiling evidenced a significant increase in the pools of sulfur metabolites as well as elevated cellular glutathione levels. Moreover, the flux in the sulfur assimilation pathway as well as the glutathione synthesis rate strongly increased with a concomitant reduction of sulfur incorporation into proteins. By combining comparative genomics and molecular analyses, we pinpointed transcription factors that mediate the core of the transcriptional response to arsenite. Taken together, our data reveal that arsenite-exposed cells channel a large part of assimilated sulfur into glutathione biosynthesis, and we provide evidence that the transcriptional regulators Yap1p and Met4p control this response in concert.

  6. The OXA1L gene that controls cytochrome oxidase assembly maps to the 14q11.2 region of the human genome

    Energy Technology Data Exchange (ETDEWEB)

    Molina-Gomes, D.; Viegas-Pequignot, E. [INSERM, Paris (France); Bonnefoy, N.; Dujardin, G. [Universite Paris, Gif sur Yvette (France)] [and others

    1995-11-20

    Cytochrome-c oxidase, the terminal complex of the mitochondrial respiratory chain that transfers electrons from cytochrome c to oxygen, has a critical role in cellular energy metabolism. In eukaryotes, the cytochrome-c oxidase complex is composed of from 7 to 13 subunits (in mammals), and its assembly depends on several nuclear-encoded proteins. The 0XA1 gene, which was first isolated in Saccharomyces cerevisiae, encodes a protein essential for cytochrome-c oxidase assembly. The human OXA1-like (OXA1L, previously designated OXA1Hs) cDNA was isolated by functional complementation of an oxa1{sup -} mutation in yeast. The deduced sequences of the two Oxa1 and Oxa1L proteins share 33% identity. Oxygen consumption measurements and cytochrome absorption spectra show that replacement of the yeast protein with the human homolog leads to the correct assembly of cytochrome-c oxidase, suggesting that these proteins play essentially the same role in both organisms. In this report, we have used both somatic cell hybrid mapping and in situ hybridization to localize the OXA1L gene on the human genome. 7 refs., 2 figs.

  7. Association of nicotinamide adenine dinucleotide phosphate oxidase p22phox gene 549C>T polymorphism with coronary artery disease

    Institute of Scientific and Technical Information of China (English)

    LIU Tong-tao; WANG Li-li; FANG Sheng-xia; JIA Chong-qi

    2012-01-01

    Background The p22phox is a critical component of the superoxide-generating vascular nicotinamide adenine dinucleotide phosphate (NADPH) oxidase.Several polymorphisms in p22phox gene are studied for their association with cardiovascular diseases.However,no publication is available to assess the relation of 549C>T polymorphism in p22phox gene to coronary artery disease (CAD) risk.This study was to investigate the effect of the p22phox gene 549C>T polymorphism on CAD risk.Methods Hospital-based case-control study was conducted with 297 CAD patients and 343 healthy persons as the control group.Polymerase chain reaction and pyrosequencing using PSQ 96 MA Pyrosequencer (Biotage AB) were used to detect the polymorphisms.Multiple Logistic regression model was used to adjust the potential confounders and to estimate odds ratio (OR) with 95% confidence intervals (Cls).Results The observed genotype frequencies of this polymorphism obeyed the Hardy-Weinberg equilibrium in both cases (P=0.439) and controls (P=0.668).The frequency of mutant genotypes (TT+CT) in cases (41.08%) was higher than that in controls (36.73%) with an OR=-1.20 (95% CI=0.87-1.65).After the adjustment of the potential confounders,there was a significant association of the mutant genotypes with increased risk of CAD (OR=1.57,95% CI=1.01-2.46,P=0.047).Conclusions The mutant genotypes of the p22phox gene 549C>T polymorphism had a significant effect on the increased risk of CAD in this studied population.

  8. Haplotypes of the D-Amino Acid Oxidase Gene Are Significantly Associated with Schizophrenia and Its Neurocognitive Deficits.

    Directory of Open Access Journals (Sweden)

    Yu-Li Liu

    Full Text Available D-amino acid oxidase (DAO has been reported to be associated with schizophrenia. This study aimed to search for genetic variants associated with this gene. The genomic regions of all exons, highly conserved regions of introns, and promoters of this gene were sequenced. Potentially meaningful single-nucleotide polymorphisms (SNPs obtained from direct sequencing were selected for genotyping in 600 controls and 912 patients with schizophrenia and in a replicated sample consisting of 388 patients with schizophrenia. Genetic associations were examined using single-locus and haplotype association analyses. In single-locus analyses, the frequency of the C allele of a novel SNP rs55944529 located at intron 8 was found to be significantly higher in the original large patient sample (p = 0.016. This allele was associated with a higher level of DAO mRNA expression in the Epstein-Barr virus-transformed lymphocytes. The haplotype distribution of a haplotype block composed of rs11114083-rs2070586-rs2070587-rs55944529 across intron 1 and intron 8 was significantly different between the patients and controls and the haplotype frequencies of AAGC were significantly higher in patients, in both the original (corrected p < 0.0001 and replicated samples (corrected p = 0.0003. The CGTC haplotype was specifically associated with the subgroup with deficits in sustained attention and executive function and the AAGC haplotype was associated with the subgroup without such deficits. The DAO gene was a susceptibility gene for schizophrenia and the genomic region between intron 1 and intron 8 may harbor functional genetic variants, which may influence the mRNA expression of DAO and neurocognitive functions in schizophrenia.

  9. Members of rice plasma membrane intrinsic proteins subfamily are involved in arsenite permeability and tolerance in plants.

    Science.gov (United States)

    Mosa, Kareem A; Kumar, Kundan; Chhikara, Sudesh; Mcdermott, Joseph; Liu, Zijuan; Musante, Craig; White, Jason C; Dhankher, Om Parkash

    2012-12-01

    Rice accumulates high level of arsenic (As) in its edible parts and thus plays an important role in the transfer of As into the food chain. However, the mechanisms of As uptake and its detoxification in rice are not well understood. Recently, members of the Nodulin 26-like intrinsic protein (NIP) subfamily of plant aquaporins were shown to transport arsenite in rice and Arabidopsis. Here we report that members of the rice plasma membrane intrinsic protein (PIP) subfamily are also involved in As tolerance and transport. Based on the homology search with the mammalian AQP9 and yeast Fps1 arsenite transporters, we identified and cloned five rice PIP gene subfamily members. qRT-PCR analysis of PIPs in rice root and shoot tissues revealed a significant down regulation of transcripts encoding OsPIP1;2, OsPIP1;3, OsPIP2;4, OsPIP2;6, and OsPIP2;7 in response to arsenite treatment. Heterologous expression of OsPIP2;4, OsPIP2;6, and OsPIP2;7 in Xenopus laevis oocytes significantly increased the uptake of arsenite. Overexpression of OsPIP2;4, OsPIP2;6, and OsPIP2;7 in Arabidopsis yielded enhanced arsenite tolerance and higher biomass accumulation. Further, these transgenic plants showed no significant accumulation of As in shoot and root tissues in long term uptake assays. Whereas, short duration exposure to arsenite caused both active influx and efflux of As in the roots. The data suggests a bidirectional arsenite permeability of rice PIPs in plants. These rice PIPs genes will be highly useful for engineering important food and biofuel crops for enhanced crop productivity on contaminated soils without increasing the accumulation of toxic As in the biomass or edible tissues.

  10. Expression of genes belonging to the interacting TLR cascades, NADPH-oxidase and mitochondrial oxidative phosphorylation in septic patients

    Science.gov (United States)

    Nucci, Laura A.; Santos, Sidnéia S.; Brunialti, Milena K. C.; Sharma, Narendra Kumar; Machado, Flavia R.; Assunção, Murillo; de Azevedo, Luciano C. P.

    2017-01-01

    Background and objectives Sepsis is a complex disease that is characterized by activation and inhibition of different cell signaling pathways according to the disease stage. Here, we evaluated genes involved in the TLR signaling pathway, oxidative phosphorylation and oxidative metabolism, aiming to assess their interactions and resulting cell functions and pathways that are disturbed in septic patients. Materials and methods Blood samples were obtained from 16 patients with sepsis secondary to community acquired pneumonia at admission (D0), and after 7 days (D7, N = 10) of therapy. Samples were also collected from 8 healthy volunteers who were matched according to age and gender. Gene expression of 84 genes was performed by real-time polymerase chain reactions. Their expression was considered up- or down-regulated when the fold change was greater than 1.5 compared to the healthy volunteers. A p-value of ≤ 0.05 was considered significant. Results Twenty-two genes were differently expressed in D0 samples; most of them were down-regulated. When gene expression was analyzed according to the outcomes, higher number of altered genes and a higher intensity in the disturbance was observed in non-survivor than in survivor patients. The canonical pathways altered in D0 samples included interferon and iNOS signaling; the role of JAK1, JAK2 and TYK2 in interferon signaling; mitochondrial dysfunction; and superoxide radical degradation pathways. When analyzed according to outcomes, different pathways were disturbed in surviving and non-surviving patients. Mitochondrial dysfunction, oxidative phosphorylation and superoxide radical degradation pathway were among the most altered in non-surviving patients. Conclusion Our data show changes in the expression of genes belonging to the interacting TLR cascades, NADPH-oxidase and oxidative phosphorylation. Importantly, distinct patterns are clearly observed in surviving and non-surviving patients. Interferon signaling, marked by

  11. Hodgkin-Reed-Sternberg cells in classical Hodgkin lymphoma show alterations of genes encoding the NADPH oxidase complex and impaired reactive oxygen species synthesis capacity.

    Science.gov (United States)

    Giefing, Maciej; Winoto-Morbach, Supandi; Sosna, Justyna; Döring, Claudia; Klapper, Wolfram; Küppers, Ralf; Böttcher, Sebastian; Adam, Dieter; Siebert, Reiner; Schütze, Stefan

    2013-01-01

    The membrane bound NADPH oxidase involved in the synthesis of reactive oxygen species (ROS) is a multi-protein enzyme encoded by CYBA, CYBB, NCF1, NCF2 and NCF4 genes. Growing evidence suggests a role of ROS in the modulation of signaling pathways of non-phagocytic cells, including differentiation and proliferation of B-cell progenitors. Transcriptional downregulation of the CYBB gene has been previously reported in cell lines of the B-cell derived classical Hodgkin lymphoma (cHL). Thus, we explored functional consequences of CYBB downregulation on the NADPH complex. Using flow cytometry to detect and quantify superoxide anion synthesis in cHL cell lines we identified recurrent loss of superoxide anion production in all stimulated cHL cell lines in contrast to stimulated non-Hodgkin lymphoma cell lines. As CYBB loss proved to exert a deleterious effect on the NADPH oxidase complex in cHL cell lines, we analyzed the CYBB locus in Hodgkin and Reed-Sternberg (HRS) cells of primary cHL biopsies by in situ hybridisation and identified recurrent deletions of the gene in 8/18 cases. Immunohistochemical analysis to 14 of these cases revealed a complete lack of detectable CYBB protein expression in all HRS cells in all cases studied. Moreover, by microarray profiling of cHL cell lines we identified additional alterations of NADPH oxidase genes including CYBA copy number loss in 3/7 cell lines and a significant downregulation of the NCF1 transcription (p=0.006) compared to normal B-cell subsets. Besides, NCF1 protein was significantly downregulated (p<0.005) in cHL compared to other lymphoma cell lines. Together this findings show recurrent alterations of the NADPH oxidase encoding genes that result in functional inactivation of the enzyme and reduced production of superoxide anion in cHL.

  12. Enhanced drought and heat stress tolerance of tobacco plants with ectopically enhanced cytokinin oxidase/dehydrogenase gene expression.

    Science.gov (United States)

    Macková, Hana; Hronková, Marie; Dobrá, Jana; Turečková, Veronika; Novák, Ondřej; Lubovská, Zuzana; Motyka, Václav; Haisel, Daniel; Hájek, Tomáš; Prášil, Ilja Tom; Gaudinová, Alena; Štorchová, Helena; Ge, Eva; Werner, Tomáš; Schmülling, Thomas; Vanková, Radomíra

    2013-07-01

    Responses to drought, heat, and combined stress were compared in tobacco (Nicotiana tabacum L.) plants ectopically expressing the cytokinin oxidase/dehydrogenase CKX1 gene of Arabidopsis thaliana L. under the control of either the predominantly root-expressed WRKY6 promoter or the constitutive 35S promoter, and in the wild type. WRKY6:CKX1 plants exhibited high CKX activity in the roots under control conditions. Under stress, the activity of the WRKY6 promoter was down-regulated and the concomitantly reduced cytokinin degradation coincided with raised bioactive cytokinin levels during the early phase of the stress response, which might contribute to enhanced stress tolerance of this genotype. Constitutive expression of CKX1 resulted in an enlarged root system, a stunted, dwarf shoot phenotype, and a low basal level of expression of the dehydration marker gene ERD10B. The high drought tolerance of this genotype was associated with a relatively moderate drop in leaf water potential and a significant decrease in leaf osmotic potential. Basal expression of the proline biosynthetic gene P5CSA was raised. Both wild-type and WRKY6:CKX1 plants responded to heat stress by transient elevation of stomatal conductance, which correlated with an enhanced abscisic acid catabolism. 35S:CKX1 transgenic plants exhibited a small and delayed stomatal response. Nevertheless, they maintained a lower leaf temperature than the other genotypes. Heat shock applied to drought-stressed plants exaggerated the negative stress effects, probably due to the additional water loss caused by a transient stimulation of transpiration. The results indicate that modulation of cytokinin levels may positively affect plant responses to abiotic stress through a variety of physiological mechanisms.

  13. Uric acid stimulates endothelin-1 gene expression associated with NADPH oxidase in human aortic smooth muscle cells

    Institute of Scientific and Technical Information of China (English)

    Hung-hsing CHAO; Ju-chi LIU; Jia-wei LIN; Cheng-hsien CHEN; Chieh-hsi WU; Tzu-hurng CHENG

    2008-01-01

    Aim: Recent experimental and human studies have shown that hyperuricemia is associated with hypertension and cardiovascular diseases. Elevated levels of endotheliu-1 (ET-1) has been regarded as one of the most powerful indepen-dent predictors of cardiovascular diseases. For investigating whether uric acidinduced vascular diseases are related to ET-1, the uric acid-induced ET-1 expression in human aortic smooth muscle cells (HASMC) was examined. Methods: Cultured HASMC treated with uric acid, cell proliferation and ET-1 expression were examined. Antioxidant pretreatments on uric acid-induced extracellular signal-regulated kinases (ERK) phosphorylation were carried out to elucidate the redox-sensitive pathway in proliferation and ET-1 gene expression. Results: Uric acid was found to increase HASMC proliferation, ET-1 expression and reactive oxygen species production. The ability of both N-acetylcysteine and apocynin (1-[4-hydroxy-3-methoxyphenyl]ethanone, a NADPH oxidase inhibitor) to inhibit uric acid-induced ET-1 secretion and cell proliferation suggested the involvement of intracellular redox pathways. Furthermore, apocynin, and p47phox small interfering RNA knockdown inhibited ET-1 secretion and cell proliferation induced by uric acid. Inhibition of ERK by U0126 (1,4-diamino-2,3-dicyano-1,4-bis[2-aminophenylthio]butadiene) significantly suppressed uric acid-induced ET-I expression, implicating this pathway in the response to uric acid. In addition, uric acid increased the transcription factor activator protein-1 (AP-1) medi-ated reporter activity, as well as the ERK phosphorylation. Mutational analysis of the ET-1 gene promoter showed that the AP-1 binding site was an important cis-element in uric acid-induced ET-1 gene expression. Conclusion: This is the first observation of ET-1 regulation by uric acid in HASMC, which implicates the important role of uric acid in the vascular changes associated with hypertension and vascular diseases.

  14. Molecular characterization of Echinococcus granulosus from Peru by sequencing of the mitochondrial cytochrome C oxidase subunit 1 gene.

    Science.gov (United States)

    Sánchez, Elizabeth; Cáceres, Omar; Náquira, César; Garcia, David; Patiño, Gladys; Silvia, Herrera; Volotão, Aline C; Fernandes, Octavio

    2010-09-01

    Echinococcus granulosus, the etiologic agent of cystic echinococcosis (CE) in humans and other animal species, is distributed worldwide. Ten intra-specific variants, or genotypes (G1-G10), have been defined based on genetic diversity. To determine the genotypes present in endemic areas of Peru, samples were collected from cattle (44), sheep (41) and humans (14) from Junín, Puno Huancavelica, Cusco, Arequipa and Ayacucho. DNA was extracted from protoscolex and/or germinal layers derived from 99 E. granulosus isolates and used as templates to amplify the mitochondrial cytochrome C oxidase subunit 1 gene. The resulting polymerase chain reaction products were sequenced and further examined by sequence analysis. All isolates, independent of the host, exhibited the G1 genotype. Phylogenetic analysis showed that three isolates from Ayacucho shared the same cluster with microvariant G1(4). The G1 genotype is considered the most widespread and infectious form of E. granulosus worldwide and our results confirm that the same patterns apply to this country. Therefore, these findings should be taken into consideration in developing prevention strategies and control programs for CE in Peru.

  15. Molecular characterization of Echinococcus granulosusfrom Peru by sequencing of the mitochondrial cytochrome C oxidase subunit 1 gene

    Directory of Open Access Journals (Sweden)

    Elizabeth Sánchez

    2010-09-01

    Full Text Available Echinococcus granulosus, the etiologic agent of cystic echinococcosis (CE in humans and other animal species, is distributed worldwide. Ten intra-specific variants, or genotypes (G1-G10, have been defined based on genetic diversity. To determine the genotypes present in endemic areas of Peru, samples were collected from cattle (44, sheep (41 and humans (14 from Junín, Puno Huancavelica, Cusco, Arequipa and Ayacucho. DNA was extracted from protoscolex and/or germinal layers derived from 99 E. granulosus isolates and used as templates to amplify the mitochondrial cytochrome C oxidase subunit 1 gene. The resulting polymerase chain reaction products were sequenced and further examined by sequence analysis. All isolates, independent of the host, exhibited the G1 genotype. Phylogenetic analysis showed that three isolates from Ayacucho shared the same cluster with microvariant G1(4. The G1 genotype is considered the most widespread and infectious form of E. granulosusworldwide and our results confirm that the same patterns apply to this country. Therefore, these findings should be taken into consideration in developing prevention strategies and control programs for CE in Peru.

  16. D-amino acid oxidase gene therapy sensitizes glioma cells to the antiglycolytic effect of 3-bromopyruvate.

    Science.gov (United States)

    El Sayed, S M; Abou El-Magd, R M; Shishido, Y; Chung, S P; Sakai, T; Watanabe, H; Kagami, S; Fukui, K

    2012-01-01

    Glioma tumors are refractory to conventional treatment. Glioblastoma multiforme is the most aggressive type of primary brain tumors in humans. In this study, we introduce oxidative stress-energy depletion (OSED) therapy as a new suggested treatment for glioblastoma. OSED utilizes D-amino acid oxidase (DAO), which is a promising therapeutic protein that induces oxidative stress and apoptosis through generating hydrogen peroxide (H2O2). OSED combines DAO with 3-bromopyruvate (3BP), a hexokinase II (HK II) inhibitor that interferes with Warburg effect, a metabolic alteration of most tumor cells that is characterized by enhanced aerobic glycolysis. Our data revealed that 3BP induced depletion of energetic capabilities of glioma cells. 3BP induced H2O2 production as a novel mechanism of its action. C6 glioma transfected with DAO and treated with D-serine together with 3BP-sensitized glioma cells to 3BP and decreased markedly proliferation, clonogenic power and viability in a three-dimensional tumor model with lesser effect on normal astrocytes. DAO gene therapy using atelocollagen as an in vivo transfection agent proved effective in a glioma tumor model in Sprague-Dawley (SD) rats, especially after combination with 3BP. OSED treatment was safe and tolerable in SD rats. OSED therapy may be a promising therapeutic modality for glioma.

  17. Combination of polymorphic variants in serotonin transporter and monoamine oxidase-A genes may influence the risk for early-onset alcoholism.

    Science.gov (United States)

    Bordukalo-Niksic, Tatjana; Stefulj, Jasminka; Matosic, Ana; Mokrovic, Gordana; Cicin-Sain, Lipa

    2012-12-30

    The combinatory effect of polymorphisms in serotonin transporter and monoamine oxidase-A genes on the aetiopathogenesis of alcoholism was investigated in a sample of 714 individuals. Increased frequency of subjects having three 'suspected' genotypes (5-HTTLPR-LL, STin2-1010 and MAO-A 3-repeat allele) was found among type-2 alcoholic patients (P=0.0189). Results highlight serotonergic/genetic contribution to early-onset alcoholism.

  18. Hypoxia-Response Element (HRE)–Directed Transcriptional Regulation of the Rat Lysyl Oxidase Gene in Response to Cobalt and Cadmium

    OpenAIRE

    Gao, Song; Zhou, Jing; Zhao, Yinzhi; Toselli, Paul; Li, Wande

    2012-01-01

    Lysyl oxidase (LO) catalyzes crosslink of collagen, elastin, and histone H1, stabilizing the extracellular matrix and cell nucleus. This enzyme displays dual functions for tumorigenesis, i.e., as a tumor suppressor inactivating the ras oncogene and as a tumor promoter enhancing malignant cell metastasis. To elucidate LO transcriptional regulation, we have cloned the 804 base pair region upstream of the translation start site (ATG) of the rat LO gene with the maximal promoter activity. Compute...

  19. Alternative Oxidase Gene Family in Hypericum perforatum L.: Characterization and Expression at the Post-germinative Phase.

    Science.gov (United States)

    Velada, Isabel; Cardoso, Hélia G; Ragonezi, Carla; Nogales, Amaia; Ferreira, Alexandre; Valadas, Vera; Arnholdt-Schmitt, Birgit

    2016-01-01

    Alternative oxidase (AOX) protein is located in the inner mitochondrial membrane and is encoded in the nuclear genome being involved in plant response upon a diversity of environmental stresses and also in normal plant growth and development. Here we report the characterization of the AOX gene family of Hypericum perforatum L. Two AOX genes were identified, both with a structure of four exons (HpAOX1, acc. KU674355 and HpAOX2, acc. KU674356). High variability was found at the N-terminal region of the protein coincident with the high variability identified at the mitochondrial transit peptide. In silico analysis of regulatory elements located at intronic regions identified putative sequences coding for miRNA precursors and trace elements of a transposon. Simple sequence repeats were also identified. Additionally, the mRNA levels for the HpAOX1 and HpAOX2, along with the ones for the HpGAPA (glyceraldehyde-3-phosphate dehydrogenase A subunit) and the HpCAT1 (catalase 1), were evaluated during the post-germinative development. Gene expression analysis was performed by RT-qPCR with accurate data normalization, pointing out HpHYP1 (chamba phenolic oxidative coupling protein 1) and HpH2A (histone 2A) as the most suitable reference genes (RGs) according to GeNorm algorithm. The HpAOX2 transcript demonstrated larger stability during the process with a slight down-regulation in its expression. Contrarily, HpAOX1 and HpGAPA (the corresponding protein is homolog to the chloroplast isoform involved in the photosynthetic carbon assimilation in other plant species) transcripts showed a marked increase, with a similar expression pattern between them, during the post-germinative development. On the other hand, the HpCAT1 (the corresponding protein is homolog to the major H2O2-scavenging enzyme in other plant species) transcripts showed an opposite behavior with a down-regulation during the process. In summary, our findings, although preliminary, highlight the importance to

  20. Alternative Oxidase Gene Family in Hypericum perforatum L.: Characterization and Expression at the Post-germinative Phase

    Science.gov (United States)

    Velada, Isabel; Cardoso, Hélia G.; Ragonezi, Carla; Nogales, Amaia; Ferreira, Alexandre; Valadas, Vera; Arnholdt-Schmitt, Birgit

    2016-01-01

    Alternative oxidase (AOX) protein is located in the inner mitochondrial membrane and is encoded in the nuclear genome being involved in plant response upon a diversity of environmental stresses and also in normal plant growth and development. Here we report the characterization of the AOX gene family of Hypericum perforatum L. Two AOX genes were identified, both with a structure of four exons (HpAOX1, acc. KU674355 and HpAOX2, acc. KU674356). High variability was found at the N-terminal region of the protein coincident with the high variability identified at the mitochondrial transit peptide. In silico analysis of regulatory elements located at intronic regions identified putative sequences coding for miRNA precursors and trace elements of a transposon. Simple sequence repeats were also identified. Additionally, the mRNA levels for the HpAOX1 and HpAOX2, along with the ones for the HpGAPA (glyceraldehyde-3-phosphate dehydrogenase A subunit) and the HpCAT1 (catalase 1), were evaluated during the post-germinative development. Gene expression analysis was performed by RT-qPCR with accurate data normalization, pointing out HpHYP1 (chamba phenolic oxidative coupling protein 1) and HpH2A (histone 2A) as the most suitable reference genes (RGs) according to GeNorm algorithm. The HpAOX2 transcript demonstrated larger stability during the process with a slight down-regulation in its expression. Contrarily, HpAOX1 and HpGAPA (the corresponding protein is homolog to the chloroplast isoform involved in the photosynthetic carbon assimilation in other plant species) transcripts showed a marked increase, with a similar expression pattern between them, during the post-germinative development. On the other hand, the HpCAT1 (the corresponding protein is homolog to the major H2O2-scavenging enzyme in other plant species) transcripts showed an opposite behavior with a down-regulation during the process. In summary, our findings, although preliminary, highlight the importance to

  1. Coptotermes gestroi (Isoptera: Rhinotermitidae) in Brazil: possible origins inferred by mitochondrial cytochrome oxidase II gene sequences.

    Science.gov (United States)

    Martins, C; Fontes, L R; Bueno, O C; Martins, V G

    2010-09-01

    The Asian subterranean termite, Coptotermes gestroi, originally from northeast India through Burma, Thailand, Malaysia, and the Indonesian archipelago, is a major termite pest introduced in several countries around the world, including Brazil. We sequenced the mitochondrial COII gene from individuals representing 23 populations. Phylogenetic analysis of COII gene sequences from this and other studies resulted in two main groups: (1) populations of Cleveland (USA) and four populations of Malaysia and (2) populations of Brazil, four populations of Malaysia, and one population from each of Thailand, Puerto Rico, and Key West (USA). Three new localities are reported here, considerably enlarging the distribution of C. gestroi in Brazil: Campo Grande (state of Mato Grosso do Sul), Itajaí (state of Santa Catarina), and Porto Alegre (state of Rio Grande do Sul).

  2. Alternative oxidase gene family in Hypericum perforatum L.: characterization and expression at the post-germinative phase

    Directory of Open Access Journals (Sweden)

    Isabel Velada

    2016-08-01

    Full Text Available Alternative oxidase (AOX protein is located in the inner mitochondrial membrane and is encoded in the nuclear genome being involved in plant response upon diversity of environmental stresses and also in normal plant growth and development. Here we report the characterization of the AOX gene family of Hypericum perforatum L. Two AOX genes were identified, both with a structure of four exons (HpAOX1, acc. KU674355 and HpAOX2, acc. KU674356. High variability was found at the N-terminal region of the protein coincident with the high variability identified at the mitochondrial transit peptide. In silico analysis of regulatory elements located at intronic regions identified putative sequences coding for miRNA precursors and trace elements of a transposon. Simple sequence repeats were also identified. Additionally, the mRNA levels for the HpAOX1 and HpAOX2, along with the ones for the HpGAPA and the HpCAT1, were evaluated during the post-germinative development. The gene expression analysis was performed by RT-qPCR with accurate data normalization, pointing out HpHYP1 and HpH2A as the most suitable RGs according to GeNorm algorithm. The HpAOX2 transcript demonstrated larger stability during the process with a slight down-regulation in its expression. Contrarily, HpAOX1 and HpGAPA (the corresponding protein is homolog to the chloroplast isoform involved in the photosynthetic carbon assimilation in other species transcripts showed a marked increase, with a similar expression pattern between them, during the post-germinative development. On the other hand, the HpCAT1 (the corresponding protein is homolog to the major H2O2-scavenging enzyme in other species transcripts showed an opposite behavior with a down-regulation during the process. In summary, our findings, although preliminary, highlight the importance to investigate in more detail the participation of AOX genes during the post-germinative development in Hypericum, in order to explore their

  3. Expression of alternative oxidase in tomato

    Energy Technology Data Exchange (ETDEWEB)

    Kakefuda, M.; McIntosh, L. (Michigan State Univ., East Lansing (USA))

    1990-05-01

    Tomato fruit ripening is characterized by an increase in ethylene biosynthesis, a burst in respiration (i.e. the climacteric), fruit softening and pigmentation. As whole tomatoes ripened from mature green to red, there was an increase in the alternative oxidase capacity. Aging pink tomato slices for 24 and 48 hrs also showed an increase of alternative oxidase and cytochrome oxidase capacities. Monoclonal antibodies prepared to the Sauromatum guttatum alternative oxidase were used to follow the appearance of alternative oxidase in tomato fruits. There is a corresponding increase in a 36kDa protein with an increase in alternative oxidase capacity. Effects of ethylene and norbornadiene on alternative oxidase capacity were also studied. We are using an alternative oxidase cDNA clone from potato to study the expression of mRNA in ripening and wounded tomatoes to determine if the gene is transcriptionally regulated.

  4. CYP99A3: Functional identification of a diterpene oxidase from the momilactone biosynthetic gene cluster in rice

    Science.gov (United States)

    Wang, Qiang; Hillwig, Matthew L.; Peters, Reuben J.

    2013-01-01

    SUMMARY Rice (Oryza sativa) produces momilactone diterpenoids as both phytoalexins and allelochemicals. Strikingly, the rice genome contains a biosynthetic gene cluster for momilactone production, located on rice chromosome 4, which contains two cytochromes P450 mono-oxygenases, CYP99A2 and CYP99A3, with undefined roles; although it has been previously shown that RNAi double knock-down of this pair of closely related CYP reduced momilactone accumulation. Here we attempted biochemical characterization of CYP99A2 and CYP99A3, which ultimately was achieved by complete gene recoding, enabling functional recombinant expression in bacteria. With these synthetic gene constructs it was possible to demonstrate that, while CYP99A2 does not exhibit significant activity with diterpene substrates, CYP99A3 catalyzes consecutive oxidations of the C19 methyl group of the momilactone precursor syn-pimara-7,15-diene to form, sequentially, syn-pimaradien-19-ol, syn-pimaradien-19-al and syn-pimaradien-19-oic acid. These are presumably intermediates in momilactone biosynthesis, as a C19 carboxylic acid moiety is required for formation of the core 19,6-γ-lactone ring structure. We further were able to detect syn-pimaradien-19-oic acid in rice plants, which indicates physiological relevance for the observed activity of CYP99A3. In addition, we found that CYP99A3 also oxidized syn-stemod-13(17)-ene at C19 to produce, sequentially, syn-stemoden-19-ol, syn-stemoden-19-al and syn-stemoden-19-oic acid, albeit with lower catalytic efficiency than with syn-pimaradiene. Although the CYP99A3 syn-stemodene derived products were not detected in planta, these results nevertheless provide a hint at the currently unknown metabolic fate of this diterpene in rice. Regardless of any wider role, our results strongly indicate that CYP99A3 acts as a multifunctional diterpene oxidase in momilactone biosynthesis. PMID:21175892

  5. Functional expression of the Acanthamoeba castellanii alternative oxidase in Escherichia coli; regulation of the activity and evidence for Acaox gene function.

    Science.gov (United States)

    Antos-Krzeminska, Nina; Jarmuszkiewicz, Wieslawa

    2014-06-01

    To evidence Acanthamoeba castellanii alternative oxidase (AcAOX) gene product function, we studied alterations in the levels of mRNA and protein and AcAOX activity during growth in amoeba batch culture. Moreover, heterologous expression of AcAOX in AOX-deficient Escherichia coli confirmed by the protein immunodetection and functional studies was performed. Despite the presence of native bo and bd quinol oxidases in E. coli membrane, from which the latter is known to be cyanide-resistant, functional expression of AcAOX in E. coli conferred cyanide-resistant benzohydroxamate-sensitive respiration on the bacteria. Moreover, AcAOX activity in transformed bacteria was stimulated by GMP and inhibited by ATP, indicating that AcAOX is regulated by mutual exclusion of purine nucleotides, which was previously demonstrated in the mitochondria of A. castellanii.

  6. Heterologous expression of the glucose oxidase gene in Trichoderma atroviride leads enhanced ability to attack phytopathogenic fungi and induction of plant systemic disease resistance

    Institute of Scientific and Technical Information of China (English)

    Robert L Mach; Brunner Kurt; Matteo Lorito; Susanne Zeilinger; Rosalia Ciliento; Sheridan Woo

    2004-01-01

    @@ A transgenic strain of Trichoderma atroviride that expresses the Aspergillus niger glucose oxidase gene goxA under a homologous pathogen-inducible promoter (nag1) has been constructed, with the aim of increasing the ability of this biocontrol agent (BCA) to attack phytopathogenic fungi and enhance plant systemic disease resistance. The sporulation and growth rate of the transgenic progenies were similar to the wild-type strain Pl. goxA expression occurred immediately after contact with the plant pathogen,and the glucose oxidase formed was secreted extracellularly. The transformed strain SJ3 4, containing 12-14 copies of the transgene, produced significantly less N-acetyl-glucosaminidase and endochitinase then wild type. However, the ability of its culture filtrate to inhibit the germination of Botrytis cinerea spores was increased by about 3-fold. In comparison to P1, the transgenic strain more quickly overgrew and lysed in vitro the pathogens Rhizoctonia solani and Pythium ultimum.

  7. Severity of ulcerative colitis is associated with a polymorphism at diamine oxidase gene but not at histamine N-methyltransferase gene

    Institute of Scientific and Technical Information of China (English)

    Elena García-Martín; Juan L Mendoza; Carmen Martínez; Carlos Taxonera; Elena Urcelay; José M Ladero; Emilio G de la Concha; Manuel Díaz-Rubio; José AG Agúndez

    2006-01-01

    AIM: To analyse the role of two common polymorphisms in genes coding for histamine metabolising enzymes as it relates to the risk to develop ulcerative colitis (UC) and the clinical course of these patients.METHODS: A cohort of 229 unrelated patients with UC recruited from a single centre and 261 healthy volunteers were analysed for the presence of Thr105Ile and His645Asp amino acid substitutions at histamine N-methyltransferase (HNMT) and diamine oxidase (ABP1) enzymes, respectively, by amplification-restriction procedures. All patients were phenotyped and followed up for at least 2 years (mean time 11 years).RESULTS: There were no significant differences in the distribution of ABP1 alleles between ulcerative colitis patients and healthy individuals [OR (95% CI) for variant alleles= 1.22 (0.91-1.61)]. However, mutated ABP1 alleles were present with higher frequency among the 58 patients that required immunosuppresive drugs [OR (95 % CI) for carriers of mutated alleles 2.41 (1.21-4.83;P=0.006)], with a significant gene-dose effect (P= 0.0038). In agreement with the predominant role of ABP1 versus HNMT on local histamine metabolism in human bowel, the frequencies for carriers ofHNMT genotypes or mutated alleles were similar among patients,regardless clinical evolution, and control individuals.CONCLUSION: The His645Asp polymorphism of the histamine metabolising enzyme ABP1 is related to severity of ulcerative colitis.

  8. Association between monoamine oxidase A gene promoter 30 bp repeat polymorphism and tardive dyskinesia in Chinese schizophrenics

    Institute of Scientific and Technical Information of China (English)

    Changhe Fan; Lihua Li; Yan Fu; Hehuang Deng; Xiangjiao Liao; Youcai Zhou

    2006-01-01

    BACKGROUND: The pathophysiology of tardive dyskinesia (TD) is not yet fully understood. With the hypothesis of altered dopaminergic neurotransmission, altered activities of dopamine degrading enzymes such as monoamine oxidase A (MAOA) and their coding genes are supposed to be related to the pathophysiology of TD.OBJECTIVE: To investigate possible association between 30 bp variable number tandem repeat (VNTR) polymorphism in the promoter of MAOA gene and susceptibility, severity of neuroleptic induced TD in Chinese Han people in Guandong Province.DESIGN: Non-randomization-synchronization controlled study. SETTING: Guangdong Mental Health Institute, Guangdong Provincial People's Hospital; Guangzhou Psychiatric Hospital; Affiliated Psychiatric Hospital of Guangzhou Municipal Bureau of Civil Administration. PARTICIPANTS: A total of 179 subjects were enrolled in the study. All subjects were sporadic and genetically unrelated Chinese schizophrenic patients who were hospitalizing in Guangzhou Psychiatric Hospital or Affiliated Psychiatric Hospital of Guangzhou Municipal Bureau of Civil Administration during January to April 2005. The diagnosis of schizophrenia was made according to the criteria of Diagnostic and Statistic Manual of Mental Disorder-the third edition-revised (DSM-Ⅲ-R). Among all patients, 88 were diagnosed as with TD and 91 without TD according to the research diagnostic criteria described by Schooler-Kane. Informed consent was obtained from all subjects or their relatives.METHODS: ① TD severity was assessed with the AIMS which was a 5-degree rating scale from 0 to 4 (corresponding to none, minimal, mild, moderate and severe, respectively). The study was approved by the Ethics Committees of the two hospitals and informed consent was obtained from all subjects or their relatives. ② The polymerase chain reaction (PCR) and polyacrylamide gel electrophoresis (PAGE) techniques were used to detect MAOA gene 30 bp VNTR polymorphism in schizophrenic patients

  9. RNAi Plasmid Construction of PttGA 20-oxidase Gene%PttGA20-氧化酶基因dsRNA抑止载体的构建

    Institute of Scientific and Technical Information of China (English)

    周冰彬; 陈晓阳

    2008-01-01

    [Objective] Genetic Engineering technology was used to regulate the expression of PttGA20-oxidase gene thus restrained plant height growth and internode elongation for cultivating dwarfed plant. [Method] Based on the RNAi principle, the gene specific sequences of PttGA20-oxidase in the antisense and sense orientations interrupted by a gene sequence from GUS were cloned into a binary vector pBI121. The selection marker gene npt Ⅱ was replaced with bar gene to RNAi plasmid. [Result] After undergone different endonuclease restrictions, the constructed constraint vector released different segments whose sizes were similar to that of target segment, which demonstrated that the RNAi plasmid of PttGA20-oxidase gene was successfully constructed. [Conclusion] The experiment provided a new way for culturing dwarfed plant.

  10. Human retina-specific amine oxidase: genomic structure of the gene (AOC2), alternatively spliced variant, and mRNA expression in retina.

    Science.gov (United States)

    Imamura, Y; Noda, S; Mashima, Y; Kudoh, J; Oguchi, Y; Shimizu, N

    1998-07-15

    Previously, we reported the isolation of cDNA for human retina-specific amine oxidase (RAO) and the expression of RAO exclusively in retina. Bacterial artificial chromosome clones containing the human RAO gene (AOC2) were mapped to human chromosome 17q21 (Imamura et al., 1997, Genomics 40: 277-283). Here, we report the complete genomic structure of the RAO gene, including 5' flanking sequence, and mRNA expression in retina. The human RAO gene spans 6 kb and is composed of four exons corresponding to the amino acid sequence 1-530, 530-598, 598-641, and 642-729 separated by three introns of 3000, 310, and 351 bp. Screening of a human retina cDNA library revealed the existence of an alternatively spliced cDNA variant with an additional 81 bp at the end of exon 2. The sizes of exons and the locations of exon/intron boundaries in the human RAO gene showed remarkable similarity to those of the human kidney diamine oxidase gene (AOC1). In situ hybridization revealed that mRNA coding for RAO is expressed preferentially in the ganglion cell layer of the mouse retina. We designed four sets of PCR primers to amplify four exons, which will be valuable for analyzing mutations in patients with ocular diseases affecting the retinal ganglion cell layer.

  11. RNA interference of 1-aminocyclopropane-1-carboxylic acid oxidase (ACO1 and ACO2) genes expression prolongs the shelf life of Eksotika (Carica papaya L.) papaya fruit.

    Science.gov (United States)

    Sekeli, Rogayah; Abdullah, Janna Ong; Namasivayam, Parameswari; Muda, Pauziah; Abu Bakar, Umi Kalsom; Yeong, Wee Chien; Pillai, Vilasini

    2014-06-19

    The purpose of this study was to evaluate the effectiveness of using RNA interference in down regulating the expression of 1-aminocyclopropane-1-carboxylic acid oxidase gene in Eksotika papaya. One-month old embryogenic calli were separately transformed with Agrobacterium strain LBA 4404 harbouring the three different RNAi pOpOff2 constructs bearing the 1-aminocyclopropane-1-carboxylic acid oxidase gene. A total of 176 putative transformed lines were produced from 15,000 calli transformed, selected, then regenerated on medium supplemented with kanamycin. Integration and expression of the targeted gene in putatively transformed lines were verified by PCR and real-time RT-PCR. Confined field evaluation of a total of 31 putative transgenic lines planted showed a knockdown expression of the targeted ACO1 and ACO2 genes in 13 lines, which required more than 8 days to achieve the full yellow colour (Index 6). Fruits harvested from lines pRNAiACO2 L2-9 and pRNAiACO1 L2 exhibited about 20 and 14 days extended post-harvest shelf life to reach Index 6, respectively. The total soluble solids contents of the fruits ranged from 11 to 14° Brix, a range similar to fruits from non-transformed, wild type seed-derived plants.

  12. RNA Interference of 1-Aminocyclopropane-1-carboxylic Acid Oxidase (ACO1 and ACO2 Genes Expression Prolongs the Shelf Life of Eksotika (Carica papaya L. Papaya Fruit

    Directory of Open Access Journals (Sweden)

    Rogayah Sekeli

    2014-06-01

    Full Text Available The purpose of this study was to evaluate the effectiveness of using RNA interference in down regulating the expression of 1-aminocyclopropane-1-carboxylic acid oxidase gene in Eksotika papaya. One-month old embryogenic calli were separately transformed with Agrobacterium strain LBA 4404 harbouring the three different RNAi pOpOff2 constructs bearing the 1-aminocyclopropane-1-carboxylic acid oxidase gene. A total of 176 putative transformed lines were produced from 15,000 calli transformed, selected, then regenerated on medium supplemented with kanamycin. Integration and expression of the targeted gene in putatively transformed lines were verified by PCR and real-time RT-PCR. Confined field evaluation of a total of 31 putative transgenic lines planted showed a knockdown expression of the targeted ACO1 and ACO2 genes in 13 lines, which required more than 8 days to achieve the full yellow colour (Index 6. Fruits harvested from lines pRNAiACO2 L2-9 and pRNAiACO1 L2 exhibited about 20 and 14 days extended post-harvest shelf life to reach Index 6, respectively. The total soluble solids contents of the fruits ranged from 11 to 14° Brix, a range similar to fruits from non-transformed, wild type seed-derived plants.

  13. Genomic evidence reveals the extreme diversity and wide distribution of the arsenic-related genes in Burkholderiales.

    Science.gov (United States)

    Li, Xiangyang; Zhang, Linshuang; Wang, Gejiao

    2014-01-01

    So far, numerous genes have been found to associate with various strategies to resist and transform the toxic metalloid arsenic (here, we denote these genes as "arsenic-related genes"). However, our knowledge of the distribution, redundancies and organization of these genes in bacteria is still limited. In this study, we analyzed the 188 Burkholderiales genomes and found that 95% genomes harbored arsenic-related genes, with an average of 6.6 genes per genome. The results indicated: a) compared to a low frequency of distribution for aio (arsenite oxidase) (12 strains), arr (arsenate respiratory reductase) (1 strain) and arsM (arsenite methytransferase)-like genes (4 strains), the ars (arsenic resistance system)-like genes were identified in 174 strains including 1,051 genes; b) 2/3 ars-like genes were clustered as ars operon and displayed a high diversity of gene organizations (68 forms) which may suggest the rapid movement and evolution for ars-like genes in bacterial genomes; c) the arsenite efflux system was dominant with ACR3 form rather than ArsB in Burkholderiales; d) only a few numbers of arsM and arrAB are found indicating neither As III biomethylation nor AsV respiration is the primary mechanism in Burkholderiales members; (e) the aio-like gene is mostly flanked with ars-like genes and phosphate transport system, implying the close functional relatedness between arsenic and phosphorus metabolisms. On average, the number of arsenic-related genes per genome of strains isolated from arsenic-rich environments is more than four times higher than the strains from other environments. Compared with human, plant and animal pathogens, the environmental strains possess a larger average number of arsenic-related genes, which indicates that habitat is likely a key driver for bacterial arsenic resistance.

  14. Genomic evidence reveals the extreme diversity and wide distribution of the arsenic-related genes in Burkholderiales.

    Directory of Open Access Journals (Sweden)

    Xiangyang Li

    Full Text Available So far, numerous genes have been found to associate with various strategies to resist and transform the toxic metalloid arsenic (here, we denote these genes as "arsenic-related genes". However, our knowledge of the distribution, redundancies and organization of these genes in bacteria is still limited. In this study, we analyzed the 188 Burkholderiales genomes and found that 95% genomes harbored arsenic-related genes, with an average of 6.6 genes per genome. The results indicated: a compared to a low frequency of distribution for aio (arsenite oxidase (12 strains, arr (arsenate respiratory reductase (1 strain and arsM (arsenite methytransferase-like genes (4 strains, the ars (arsenic resistance system-like genes were identified in 174 strains including 1,051 genes; b 2/3 ars-like genes were clustered as ars operon and displayed a high diversity of gene organizations (68 forms which may suggest the rapid movement and evolution for ars-like genes in bacterial genomes; c the arsenite efflux system was dominant with ACR3 form rather than ArsB in Burkholderiales; d only a few numbers of arsM and arrAB are found indicating neither As III biomethylation nor AsV respiration is the primary mechanism in Burkholderiales members; (e the aio-like gene is mostly flanked with ars-like genes and phosphate transport system, implying the close functional relatedness between arsenic and phosphorus metabolisms. On average, the number of arsenic-related genes per genome of strains isolated from arsenic-rich environments is more than four times higher than the strains from other environments. Compared with human, plant and animal pathogens, the environmental strains possess a larger average number of arsenic-related genes, which indicates that habitat is likely a key driver for bacterial arsenic resistance.

  15. IDENTIFICATION OF 3 HUMAN PSEUDOGENES FOR SUBUNIT-VIB OF CYTOCHROME-C-OXIDASE - A MOLECULAR RECORD OF GENE EVOLUTION

    NARCIS (Netherlands)

    TAANMAN, JW; SCHRAGE, C; REUVEKAMP, P; BIJL, J; HARTOG, M; DEVRIES, H; AGSTERIBBE, E

    1991-01-01

    Three pseudogenes for the nuclear-encoded subunit VIb of cytochrome c oxidase (COX) were isolated by screening a human genomic library with cloned human cDNA coding for COX subunit VIb. The nucleotide sequences of the pseudogenes, designated PSI-COX6b-1, PSI-COX6b-2 and PSI-COX6b-3, were determined.

  16. Phenolic profiles and polyphenol oxidase (PPO) gene expression of red clover (Trifolium pratense) selected for decreased postharvest browning

    Science.gov (United States)

    Red clover (Trifolium pratense L.) is a legume forage abundant in phenolic compounds. It tends to brown when cut for hay, due to oxidation of phenolic compounds catalyzed by polyphenol oxidase (PPO), and subsequent binding to proteins. Selecting for a greener hay may provide information about the re...

  17. The terminal oxidases of Paracoccus denitrificans

    OpenAIRE

    de Gier, Jan-Willem L.; Lübben, Mathias; Reijnders, Willem N.M.; Tipker, Corinne A.; Slotboom, Dirk-Jan; Van Spanning, Rob J. M.; Stouthamer, Adriaan H.; van der Oost, John

    1994-01-01

    Three distinct types of terminal oxidases participate in the aerobic respiratory pathways of Paracoccus denitrificans. Two alternative genes encoding subunit I of the aa3-type cytochrome c oxidase have been isolated before, namely ctaDI and ctaDII. Each of these genes can be expressed separately to complement a double mutant (ΔctaDI, ΔctaDII), indicating that they are isoforms of subunit I of the aa3-type oxidase. The genomic locus of a quinol oxidase has been isolated: cyoABC. This protohaem...

  18. Relationship between reduced nicotinamide adenine dinucleotide phosphate oxidase subunit p22phox gene polymorphism and obstructive sleep apnea-hypopnea syndrome in the Chinese Han population

    Institute of Scientific and Technical Information of China (English)

    LIU Hui-guo; LIU Kui; ZHOU Yan-ning; XU Yong-jian

    2009-01-01

    Background Increased production of reactive oxygen species (ROS) is thought to play a major role in the pathogenesis of obstructive sleep apnea-hypopnea syndrome (OSAHS). The reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex is an important source of ROS. The p22phox subunit is polymorphic with a C242T variant that changes histidine-72 for a tyrosine in the potential heme binding site. This study aimed to investigate the relationship between NADPH oxidase subunit p22phox gene polymorphism and OSAHS. Methods The genotypes of p22phox polymorphism were determined by polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP) assay in 176 unrelated subjects of the Han population in southern region of China (including 107 OSAHS subjects and 69 non-OSAHS subjects), while the plasma concentration of superoxide dismutase (SOD) was detected in the two groups, and p22phox mRNA expression in peripheral blood mononuclear cell (PBMC) was determined with reverse transcription polymerase chain reaction (RT-PCR).Results The phagocyte NADPH oxidase subunit p22phox mRNA expression was significantly increased in the OSAHS group than that in the non-OSAHS group (P<0.01). Compared with the non-OSAHS control group ((85.31±9.23) U/ml), the levels of SOD were lower in patients with OSAHS ((59.65±11.61) U/ml (P<0.01). There were significant differences in genotypes distribution in p22phox polymorphism between the two groups (P=0.02). Compared with the non-OSAHS control group, the OSAHS group had a significantly higher T allele frequency in p22phox polymorphism (P=0.03). There were independent effects of p22phox polymorphism on body mass index (BMI), neck circumference (NC), waist-to-hip ratio (WHR) in the OSAHS group, and the carriers of the T allele of p22phox polymorphism had greater NC, WHR, systolic blood pressure (SBP), diastolic blood pressure (DBP) and apnea-hypopnea index (AHI) (P <0.05), but the carriers of the T allele had lower SOD

  19. Novel Point Mutations and A8027G Polymorphism in Mitochondrial-DNA-Encoded Cytochrome c Oxidase II Gene in Mexican Patients with Probable Alzheimer Disease.

    Science.gov (United States)

    Loera-Castañeda, Verónica; Sandoval-Ramírez, Lucila; Pacheco Moisés, Fermín Paul; Macías-Islas, Miguel Ángel; Alatorre Jiménez, Moisés Alejandro; González-Renovato, Erika Daniela; Cortés-Enríquez, Fernando; Célis de la Rosa, Alfredo; Velázquez-Brizuela, Irma E; Ortiz, Genaro Gabriel

    2014-01-01

    Mitochondrial dysfunction has been thought to contribute to Alzheimer disease (AD) pathogenesis through the accumulation of mitochondrial DNA mutations and net production of reactive oxygen species (ROS). Mitochondrial cytochrome c-oxidase plays a key role in the regulation of aerobic production of energy and is composed of 13 subunits. The 3 largest subunits (I, II, and III) forming the catalytic core are encoded by mitochondrial DNA. The aim of this work was to look for mutations in mitochondrial cytochrome c-oxidase gene II (MTCO II) in blood samples from probable AD Mexican patients. MTCO II gene was sequenced in 33 patients with diagnosis of probable AD. Four patients (12%) harbored the A8027G polymorphism and three of them were early onset (EO) AD cases with familial history of the disease. In addition, other four patients with EOAD had only one of the following point mutations: A8003C, T8082C, C8201T, or G7603A. Neither of the point mutations found in this work has been described previously for AD patients, and the A8027G polymorphism has been described previously; however, it hasn't been related to AD. We will need further investigation to demonstrate the role of the point mutations of mitochondrial DNA in the pathogenesis of AD.

  20. Novel Point Mutations and A8027G Polymorphism in Mitochondrial-DNA-Encoded Cytochrome c Oxidase II Gene in Mexican Patients with Probable Alzheimer Disease

    Science.gov (United States)

    Loera-Castañeda, Verónica; Sandoval-Ramírez, Lucila; Pacheco Moisés, Fermín Paul; Macías-Islas, Miguel Ángel; Alatorre Jiménez, Moisés Alejandro; González-Renovato, Erika Daniela; Cortés-Enríquez, Fernando; Célis de la Rosa, Alfredo; Velázquez-Brizuela, Irma E.

    2014-01-01

    Mitochondrial dysfunction has been thought to contribute to Alzheimer disease (AD) pathogenesis through the accumulation of mitochondrial DNA mutations and net production of reactive oxygen species (ROS). Mitochondrial cytochrome c-oxidase plays a key role in the regulation of aerobic production of energy and is composed of 13 subunits. The 3 largest subunits (I, II, and III) forming the catalytic core are encoded by mitochondrial DNA. The aim of this work was to look for mutations in mitochondrial cytochrome c-oxidase gene II (MTCO II) in blood samples from probable AD Mexican patients. MTCO II gene was sequenced in 33 patients with diagnosis of probable AD. Four patients (12%) harbored the A8027G polymorphism and three of them were early onset (EO) AD cases with familial history of the disease. In addition, other four patients with EOAD had only one of the following point mutations: A8003C, T8082C, C8201T, or G7603A. Neither of the point mutations found in this work has been described previously for AD patients, and the A8027G polymorphism has been described previously; however, it hasn't been related to AD. We will need further investigation to demonstrate the role of the point mutations of mitochondrial DNA in the pathogenesis of AD. PMID:24701363

  1. Novel Point Mutations and A8027G Polymorphism in Mitochondrial-DNA-Encoded Cytochrome c Oxidase II Gene in Mexican Patients with Probable Alzheimer Disease

    Directory of Open Access Journals (Sweden)

    Verónica Loera-Castañeda

    2014-01-01

    Full Text Available Mitochondrial dysfunction has been thought to contribute to Alzheimer disease (AD pathogenesis through the accumulation of mitochondrial DNA mutations and net production of reactive oxygen species (ROS. Mitochondrial cytochrome c-oxidase plays a key role in the regulation of aerobic production of energy and is composed of 13 subunits. The 3 largest subunits (I, II, and III forming the catalytic core are encoded by mitochondrial DNA. The aim of this work was to look for mutations in mitochondrial cytochrome c-oxidase gene II (MTCO II in blood samples from probable AD Mexican patients. MTCO II gene was sequenced in 33 patients with diagnosis of probable AD. Four patients (12% harbored the A8027G polymorphism and three of them were early onset (EO AD cases with familial history of the disease. In addition, other four patients with EOAD had only one of the following point mutations: A8003C, T8082C, C8201T, or G7603A. Neither of the point mutations found in this work has been described previously for AD patients, and the A8027G polymorphism has been described previously; however, it hasn’t been related to AD. We will need further investigation to demonstrate the role of the point mutations of mitochondrial DNA in the pathogenesis of AD.

  2. Overexpression of a maize sulfite oxidase gene in tobacco enhances tolerance to sulfite stress via sulfite oxidation and CAT-mediated H2O2 scavenging.

    Directory of Open Access Journals (Sweden)

    Zongliang Xia

    Full Text Available Sulfite oxidase (SO plays an important role in sulfite metabolism. To date, the molecular mechanisms of sulfite metabolism in plants are largely unknown. Previously, a full-length cDNA of the putative sulfite oxidase gene from maize (ZmSO was cloned, and its response to SO(2/sulfite stress at the transcriptional level was characterized. In this study, the recombinant ZmSO protein was purified from E. coli. It exhibited sulfite-dependent activity and had strong affinity for the substrate sulfite. Over-expression (OE of ZmSO in tobacco plants enhanced their tolerance to sulfite stress. The plants showed much less damage, less sulfite accumulation, but greater amounts of sulfate. This suggests that tolerance of transgenic plants to sulfite was enhanced by increasing SO expression levels. Interestingly, H(2O(2 accumulation levels by histochemical detection and quantitative determination in the OE plants were much less than those in the wild-type upon sulfite stress. Furthermore, reductions of catalase levels detected in the OE lines were considerably less than in the wild-type plants. This indicates that SO may play an important role in protecting CAT from inhibition by excess sulfite. Collectively, these data demonstrate that transgenic tobacco plants over-expressing ZmSO enhance tolerance to excess sulfite through sulfite oxidation and catalase-mediated hydrogen peroxide scavenging. This is the first SO gene from monocots to be functionally characterized.

  3. Effects of arsenic on modification of promyelocytic leukemia (PML): PML responds to low levels of arsenite

    Energy Technology Data Exchange (ETDEWEB)

    Hirano, Seishiro, E-mail: seishiro@nies.go.jp [Research Center for Environmental Risk, National Institute for Environmental Studies (Japan); Graduate School of Pharmaceutical Sciences, Chiba University (Japan); Watanabe, Takayuki [Graduate School of Pharmaceutical Sciences, Chiba University (Japan); Kobayashi, Yayoi [Graduate School of Pharmaceutical Sciences, Chiba University (Japan); Center for Environmental Health Sciences, National Institute for Environmental Studies (Japan)

    2013-12-15

    Inorganic arsenite (iAs{sup 3+}) is a two-edged sword. iAs{sup 3+} is a well-known human carcinogen; nevertheless, it has been used as a therapeutic drug for acute promyelocytic leukemia (APL), which is caused by a fusion protein comprising retinoic acid receptor-α and promyelocytic leukemia (PML). PML, a nuclear transcription factor, has a RING finger domain with densely positioned cysteine residues. To examine PML-modulated cellular responses to iAs{sup 3+}, CHO-K1 and HEK293 cells were each used to establish cell lines that expressed ectopic human PML. Overexpression of PML increased susceptibility to iAs{sup 3+} in CHO-K1 cells, but not in HEK293 cells. Exposure of PML-transfected cells to iAs{sup 3+} caused PML to change from a soluble form to less soluble forms, and this modification of PML was observable even with just 0.1 μM iAs{sup 3+} (7.5 ppb). Western blot and immunofluorescent microscopic analyses revealed that the biochemical changes of PML were caused at least in part by conjugation with small ubiquitin-like modifier proteins (SUMOylation). A luciferase reporter gene was used to investigate whether modification of PML was caused by oxidative stress or activation of antioxidant response element (ARE) in CHO-K1 cells. Modification of PML protein occurred faster than activation of the ARE in response to iAs{sup 3+}, suggesting that PML was not modified as a consequence of oxidative stress-induced ARE activation. - Highlights: • PML was found in nuclear microspecles in response to arsenite. • Arsenite triggers SUMOylation of PML. • Arsenite modifies PML at as low as 0.1 μM. • Modification of PML is not caused by ARE activation.

  4. The molecular pathway of low concentration of sodium arsenite in inducing differentiation of liver cancer stem cells by down-regulating promyelocytic leukemia protein expression

    Directory of Open Access Journals (Sweden)

    Shi-long JIN

    2016-01-01

    Full Text Available Objective  To study the molecular pathway of low concentration of sodium arsenite in inducing differentiation of liver cancer stem cells. Methods  Western blotting analysis, immunofluorescence assay and quantitative PCR were used to examine the gene and protein expression of promyelocytic leukemia (PML, Oct4 and Sox2 in HCC tissue and cell lines, and the molecule pathway of low concentration of sodium arsenite inducing differentiation of liver cancer stem cells was confirmed by comparing the changes in the gene and protein expression of PML,Oct4 and Sox2 in HCC cells and biological function of LCSCs after the treatment with low concentration of sodium arsenite. Results  0.5μg/ml of sodium arsenite was shown to alter the biological characteristics of LCSCs in HuH7 and primary HCC cells, including the ability to form tumor spheres, resistance to pirarubicin (P<0.01, and the capability of forming tumors after allogeneic transplantation (P<0.05. Both HCC cells and tissues expressed the gene and protein of PML,Oct4 and Sox2, and 0.5μg/ml of sodium arsenite not only downregulated the gene and protein expression of Oct4 (P<0.05 and Sox2 in HCC cells (P<0.05, but also downregulated the protein expression of PML (P<0.05. In contrast, sodium arsenite did not inhibit the gene expression of PML in Hep3B, HepG2, SMCC-7721, HuH7 and primary HCC cells. Furthermore, through down-regulated PML protein expression with arsenite, the biological characteristics of HuH7 and primary HCC cells containing LCSCs was simultaneously altered, and the expression of stem gene Oct4 and Sox2 was downregulated (P<0.05, while HCC cells proliferation was inhibited as well. Conclusions  Both HCC tissues and cells can express the PML gene and PML protein. Low concentrations of sodium arsenite would directly bind to PML protein in HCC cells, resulting in degradation of the PML protein, followed by collapse of PML-NBs, inhibition of transcription of the proliferation

  5. [Integration of different T-DNA structures of ACC oxidase gene into carnation genome extended cut flower vase-life differently].

    Science.gov (United States)

    Yu, Yi-Xun; Bao, Man-Zhu

    2004-09-01

    The cultivar 'Master' of carnation (Dianthus caryophyllus L.) was transformed with four T-DNA structures containing sense, antisense, sense direct repeat and antisense direct repeat gene of ACC oxidase mediated by Agrobacterium tumefaciens. Southern blotting detection showed that foreign gene was integrated into the carnation genome and 14 transgenic lines were obtained. The transgenic plants were transplanted to soil and grew normally in greenhouse. Of the 12 transgenic lines screened, the cut flower vase life of 8 transgenic lines is up to 11 days and the longest one is 12.8 days while the vase life of the control is 5.8 days under 25 degrees C. The vase life of 2 lines out of 3 with single sense ACO gene is same as that of the control, while the vase life of 3 lines out of 4 with single antisense ACO gene is prolonged. The vase life of cut flowers of 5 lines with direct repeat ACO genes is all prolonged by about 6 days, while the vase life of 3 out of 7 lines with single ACO gene is same as that of the control. During the senescence of cut flowers, the ethylene production of the most of the transgenic lines decreased significantly, and the production of ethylene is not detectable in lines T456, T556 and T575. The results of the research demonstrate that antisense foreign gene inhibits expression of endogenesis gene more significantly than sense one. Both sense direct repeat and antisense direct repeat foreign genes can suppress endogenous gene expression more significantly comparing to single foreign genes. The transgenic lines obtained from this research are useful to minimize carnation cut flower transportation and storage expenses.

  6. Ion Chromatographic Estimation of Arsenite and Arsenate at Trace Level

    Directory of Open Access Journals (Sweden)

    Chetan Chavan

    2011-01-01

    Full Text Available Present method shows simple and specific determination of traces of inorganic arsenic in water. This method enables simultaneous determination of arsenite by electrochemical detection and arsenate by suppressed conductivity detection. The applicability of this method was illustrated by determining the inorganic arsenite and arsenate content from bore-well water and river water samples without any special pretreatment. The present method for direct determination of arsenite and arsenate shows good sensitivity, selectivity, precision and accuracy. Detection limits determined using this procedure was found to be 2.0 μg/L for arsenite and 30.0 μg/L for Arsenate. The simplicity, ease of use, low detection limit and low running cost of this method makes it appealing for increasing capability of testing in the lab.

  7. Industrial experiment of copper electrolyte purification by copper arsenite

    Institute of Scientific and Technical Information of China (English)

    ZHENG Ya-jie; XIAO Fa-xin; WANG Yong; LI Chun-hua; XU Wei; JIAN Hong-sheng; MA Yut-ian

    2008-01-01

    Copper electrolyte was purified by copper arsenite that was prepared with As2O3. And electrolysis experiments of purified electrolyte were carried out at 235 and 305 A/m2, respectively. The results show that the yield of copper arsenite is up to 98.64% when the molar ratio of Cu to As is 1.5 in the preparation of copper arsenite. The removal rates of Sb and Bi reach 74.11% and 65.60% respectively after copper arsenite is added in electrolyte. The concentrations of As, Sb and Bi in electrolyte nearly remain constant during electrolysis of 13 d. The appearances of cathode copper obtained at 235 and 305 A/m2 are slippery and even, and the qualification rate is 100% according to the Chinese standard of high-pure cathode copper(GB/T467-97).

  8. Status and Advances of Researches on GA 20-oxidases

    Institute of Scientific and Technical Information of China (English)

    Li Wei; Chen Xiaoyang; Li Hui; Guo Hai

    2003-01-01

    GA 20-oxidase, the most important limiting enzyme, can catalyze a series of oxidization of GA biosynthesis pathwayfrom GA12 to GA9 and from GA53 to GA20 in the higher plants. This paper reviews the studies on the characters of GA 20-oxidase,the gene and the protein of GA 20-oxidase and the regulation of GA 20-oxidase gene expression in recent years. At the same time,the prospects for the gene transformation of GA 20-oxidase in agriculture, forestry and horticulture are also discussed.

  9. Molecular cloning and sequence analysis of a PVGOX gene encoding glucose oxidase in Penicillium viticola F1 strain and it's expression quantitation.

    Science.gov (United States)

    Khan, Ibrar; Qayyum, Sadia; Ahmed, Shehzad; Niaz, Zeeshan; Fatima, Nighat; Chi, Zhen-Ming

    2016-11-05

    The PVGOX gene (accession number: KT452630) was isolated from genomic DNA of the marine fungi Penicillium viticola F1 by Genome Walking and their expression analysis was done by Fluorescent RT-PCR. An open reading frame of 1806bp encoding a 601 amino acid protein (isoelectric point: 5.01) with a calculated molecular weight of 65,535.4 was characterized. The deduced protein showed 75%, 71%, 69% and 64% identity to those deduced from the glucose oxidase (GOX) genes from different fungal strains including; Talaromyces variabilis, Beauveria bassiana, Aspergillus terreus, and Aspergillus niger, respectively. The promoter of the gene (intronless) had two TATA boxes around the base pair number -88 and -94 and as well as a CAAT box at -100. However, the terminator of the PVGOX gene does not contain any polyadenylation site (AATAAA). The protein deduced from the PVGOX gene had a signal peptide containing 17 amino acids, three cysteine residues and six potential N-linked glycosylation sites, among them, -N-K-T-Y- at 41 amino acid, -N-R-S-L- at 113 amino acid, -N-G-T-I- at 192 amino acid, -N-T-T-A at 215 amino acid, -N-F-T-E at 373 amino acid and -N-V-T-A- at 408 amino acid were the most possible N-glycosylation sites. Furthermore, the relative transcription level of the PVGOX gene was also stimulated in the presence of 4% (w/v) of calcium carbonate and 0.5 % (v/v) of CSL in the production medium compared with that of the PVGOX gene when the fungal strain F1 was grown in the absence of calcium carbonate and CSL in the production medium, suggesting that under the optimal conditions, the expression of the PVGOX gene responsible for gluconic acid biosynthesis was enhanced, leading to increased gluconic acid production. Therefore, the highly glycosylated oxidase enzyme produced by P. viticola F1 strain might be a good producer in the fermentation process for the industrial level production of gluconic acid.

  10. Photoinduced Oxidation of Arsenite to Arsenate on Ferrihydrite

    Energy Technology Data Exchange (ETDEWEB)

    N Bhandari; R Reeder; D Strongin

    2011-12-31

    The photochemistry of an aqueous suspension of the iron oxyhydroxide, ferrihydrite, in the presence of arsenite has been investigated using attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), X-ray absorption near edge structure (XANES), and solution phase analysis. Both ATR-FTIR and XANES show that the exposure of ferrihydrite to arsenite in the dark leads to no change in the As oxidation state, but the exposure of this arsenite-bearing surface, which is in contact with pH 5 water, to light leads to the conversion of the majority of the adsorbed arsenite to the As(V) bearing species, arsenate. Analysis of the solution phase shows that ferrous iron is released into solution during the oxidation of arsenite. The photochemical reaction, however, shows the characteristics of a self-terminating reaction in that there is a significant suppression of this redox chemistry before 10% of the total iron making up the ferrihydrite partitions into solution as ferrous iron. The self-terminating behavior exhibited by this photochemical arsenite/ferrihydrite system is likely due to the passivation of the ferrihydrite surface by the strongly bound arsenate product.

  11. C242T polymorphism of the NADPH oxidase p22PHOX gene and its association with endothelial dysfunction in asymptomatic individuals with essential systemic hypertension.

    Science.gov (United States)

    Rafiq, Adnan; Aslam, Khursheed; Malik, Rouf; Afroze, Dil

    2014-05-01

    Vascular oxidative stress is an important factor in hypertension-associated vascular damage and is mediated by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation. The C242T polymorphism at the p22PHOX gene affects binding of p22PHOX to heme, leading to variants of NADPH oxidase that produce different levels of reactive oxygen species (ROS). Specific variations in ROS are associated with an altered risk of developing cardiovascular disease. In the present study, 140 permanent Kashmiri-resident individuals were recruited (75 with essential systemic hypertension and 65 normotensive controls). Endothelial function was assessed non-invasively using high-resolution ultrasonography of the brachial artery. Endothelium-dependent vasoreactivity was expressed in terms of flow-mediated dilation. The TT genotype was identified in 2% of hypertensive and 7% of normotensive individuals. Frequency of the T-allele was not observed as significantly different between hypertensive and normotensive individuals (P=0.24; OR=0.4; 95% CI, 0.07-2.2). Blood pressure or the prevalence of hypertension did not vary between C242T p22PHOX genotypes or in the presence or absence of the T-allele.

  12. The sense and antisense expression of gibberellin 20-oxidase gene (rga5) in rice and its effects on GA1 level and agronomic traits

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A gibberellin 20-oxidase gene rga5 was isolated by PCR from genomic DNA of rice (Oryza sativa ssp indica) cultivars 'Aizizhan' and 'Nante'. Compared with the reported OsGA20ox, the rga5 was partial-frame-shifted with 11 different amino acids. Then the rga5 with CaMV 35S promotor and NOS terminator was inserted into the polylinker site of pCambia1301 to construct sense and antisense gene expressing vectors pSrga5 and pArga5. The transgenic plants were obtained by biolistic bombardment with pSrga5 or pArga5. The transgenic rice plants showed that the over- expression and antisense-expression of rga5 have remarkable effects on the biological characters of rice. The sense transgenic plants showed heightening with longer spike, more seed-bearing and unaffected flowering, whereas antisense transgenic plants showed dwarfing, early-flowering with slender stem, dark leaf color, shorter leaf and shorter spike. The PCR amplification and Southern blot hybridization showed that the rga5 has been integrated into the transgenic rice genome and the transcription of rga5 was identified by Northern blot hybridization. In the sense transgenic plants the GA1 content increased of about 50%, however, the antisense transgenic rice decreased of 90% approximately compared with control plant 'Zhonghua 8'. These results demonstrated that the rga5 is a functional gene encoding gibberellin 20-oxidase in rice. Over-expressing rga5 significantly increases the endogenous GA1 level and plant height of rice, whereas the expression of antisense rga5 decreases the GA1 level and plant height of rice dramatically.

  13. Additive effect of polymorphisms in the β2 -adrenoceptor and NADPH oxidase p22 phox genes contributes to the loss of estimated glomerular filtration rate in Chinese.

    Science.gov (United States)

    Wang, Tao; Zhang, Yan; Ma, JingTao; Feng, Zhen; Niu, Kai; Liu, Bing

    2014-09-01

    Because increased oxidative stress may mediate the detrimental actions of enhanced sympathetic nervous activity on renal function and vice versa, we investigated the effect of the polymorphic Arg16Gly in the β2 -adrenoceptor (ADRB2) gene, Trp64Arg in the β3 -adrenoceptor (ADRB3) gene and C242T in the NADPH oxidase p22phox (CYBA) gene on estimated glomerular filtration rate (eGFR) in a Chinese population. Initially recruited from different outpatient services of HeBei General Hospital in northern China, 668 individuals were finally included in the study, with complete demographic information. Laboratory tests were performed and estimated glomerular filtration rate (eGFR) was derived from the Modification of Diet in Renal Disease (MDRD) equation for the Chinese population. Plasma noradrenaline levels and genotype were determined by HPLC and the TaqMan method, respectively. Only across the Arg16Gly polymorphism did eGFR show significant difference: it was lower in individuals with the Gly16Gly variation, who also had the highest plasma noradrenaline levels. This polymorphism remained a significant determinant of eGFR after multivariate analysis. Of importance, the multifactor dimensionality reduction method further detected a significant synergism between the Arg16Gly and C242T polymorphisms in reducing eGFR. These observations clarify the effects of the studied polymorphisms on eGFR and exemplify gene-gene interactions influencing renal function.

  14. Sodium arsenite-induced inhibition of cell proliferation is related to inhibition of IL-2 mRNA expression in mouse activated T cells

    Energy Technology Data Exchange (ETDEWEB)

    Conde, Patricia; Acosta-Saavedra, Leonor C.; Calderon-Aranda, Emma S. [Centro de Investigacion y de Estudios Avanzados, CINVESTAV, Seccion Toxicologia, P.O. Box 14-740, Mexico, D.F. (Mexico); Goytia-Acevedo, Raquel C. [Universidad Juarez del Estado de Durango, Facultad de Medicina, Gomez Palacio, Durango (Mexico)

    2007-04-15

    A proposed mechanism for the As-induced inhibition of cell proliferation is the inhibition of IL-2 secretion. However, the effects of arsenite on IL-2 mRNA expression or on the ERK pathway in activated-T cells have not yet been described. We examined the effect of arsenite on IL-2 mRNA expression, cell activation and proliferation in PHA-stimulated murine lymphocytes. Arsenite (1 and 10 {mu}M) decreased IL-2 mRNA expression, IL-2 secretion and cell proliferation. Arsenite (10 {mu}M) strongly inhibited ERK-phosphorylation. However, the partial inhibition (50%) of IL-2 mRNA produced by 1 {mu}M, consistent with the effects on IL-2 secretion and cell proliferation, could not be explained by the inhibition of ERK-phosphorylation, which was not affected at this concentration. The inhibition of IL-2 mRNA expression caused by 1 {mu}M could be associated to effects on pathways located downstream or parallel to ERK. Arsenite also decreased early activation (surface CD69{sup +} expression) in both CD4{sup +} and CD8{sup +}, and decreased total CD8{sup +} count without significantly affecting CD4{sup +}, supporting that the cellular immune response mediated by cytotoxic T cells is an arsenic target. Thus, our results suggest that arsenite decreases IL-2 mRNA levels and T-cell activation and proliferation. However, further studies on the effects of arsenite on IL-2 gene transcription and IL-2 mRNA stability are needed. (orig.)

  15. Daucus carota L.--an old model for cell reprogramming gains new importance through a novel expansion pattern of alternative oxidase (AOX) genes.

    Science.gov (United States)

    Costa, J H; Cardoso, H G; Campos, M D; Zavattieri, A; Frederico, A M; Fernandes de Melo, D; Arnholdt-Schmitt, B

    2009-08-01

    The paper highlights Daucus carota L. as an ideal model to complement plant stress research on Arabidopsis thaliana L. Recently, alternative oxidase (AOX) is discussed as functional marker candidate for cell reprogramming upon stress. Carrot is the most studied species for cell reprogramming and our current research reveals that it is the only one that has expanded both AOX sub-family genes. We point to recently published, but not discussed results on conserved differences in the vicinity of the most active functional site of AOX1 and AOX2, which indicate the importance of studying AOX sequence polymorphism, structure and functionality. Thus, stress-inducible experimental systems of D. carota are especially appropriate to bring research on stress tolerance a significant step forward.

  16. Population structure of the Monocelis lineata (Proseriata, Monocelididae species complex assessed by phylogenetic analysis of the mitochondrial Cytochrome c Oxidase subunit I (COI gene

    Directory of Open Access Journals (Sweden)

    Daria Sanna

    2009-01-01

    Full Text Available Monocelis lineata consists of a complex of sibling species, widespread in the Mediterranean and Atlantic Ocean. Previous genetic analysis placed in evidence at least four sibling species. Nevertheless, this research was not conclusive enough to fully resolve the complex or to infer the phylogeny/phylogeography of the group. We designed specific primers aiming at obtaining partial sequences of the mtDNA gene Cytochrome c Oxidase subunit I (COI of M. lineata, and have identified 25 different haplotypes in 32 analyzed individuals. The dendrogram generated by Neighbor-Joining analysis confirmed the differentiation between Atlantic and Mediterranean siblings, as well as the occurrence of at least two Mediterranean sibling species. Thus validated, the method here presented appears as a valuable tool in population genetics and biodiversity surveys on the Monocelis lineata complex.

  17. The Characteristics of Cytochrome C Oxidase Gene Subunit I in Wild Silkmoth Cricula trifenestrata Helfer and Its Evaluation for Species Marker

    Directory of Open Access Journals (Sweden)

    Suriana

    2012-08-01

    Full Text Available The study was conducted to assess the characteristics of partial gene of cytochrome C oxidase subunit I (COI of wild silkmoth Cricula trifenestrata, and to detect the diagnostic sites from these gene for evaluation as species marker. A total of fifteen larvae of C. tifenestrata were collected from Bogor, Purwakarta, and Bantul Regencies. Genomic DNA was extracted from silk gland of individual larvae, then amplified by PCR method and sequenced. DNA sequencing was done to characterize their nucleotide and amino acid contents. The results showed that 595 nucleotides at the 5 ‘end of COI gene of C. tifenestrata was conserved at the species level, but varies at the family level. Nucleotide dominated by thymine and adenine bases (± 70%. There were 25 diagnostic sites for C. tifenestrata, and four diagnostic sites for genus level. One hundred eigthty nine (189 amino acids were alignment, and only one percent of the genes was varied among species. The 107th amino acid (valine and 138th (threonine were diagnostics amino acid for C. tifenestrata. Based on nucleotides and amino acids sequences, the phylogeny showed that C. tifenestrata lied on the same nodes with Antheraea, so the Saturniidae family is monophyletic.

  18. Cloning and Expression of an Alternative Oxidase Gene from Lycopersicon esculentum%番茄交替氧化酶基因的克隆和表达

    Institute of Scientific and Technical Information of China (English)

    宋从凤; Broth wayne; 王金生; 胡晋生

    2004-01-01

    A full-length cDNA gene (LeAoxlau) was isolated from a cDNA library made from ripening fruit probing with alternative oxidase (AOX) gene fragments, obtained by degenerate primer PCR. Sequence analysis showed that LeAoxlau was 1 418 bp long and contained a 1 077-bp open reading frame encoding a about 40 kD precursor protein which is processed to a mature protein of 32 kD. Southern blot analysis suggested LeAoxlau is present as a single copy in the genome of tomato. RT-PCR analysis indicated LeAoxlau was expressed in roots, stems, leaves and cotyledons of tomato plants. A recombinant construct containing the open reading frame sequence of the LeAoxlau was transformed into Escherichia coli to express the alternative oxidase precursor protein.%利用简并PCR扩增产物做探针筛选番茄cDNA基因文库获得一个全长交替氧化酶cDNA基因LeAoxlau.经序列分析得出,该基因全长1 418bp,编码区序列长1 077 bp,编码约40 kD的前体蛋白.该蛋白在转运到线粒体时被加工成32kD的成熟蛋白.Southern印迹杂交分析结果显示该基因以单拷贝形式存在于番茄的基因组中RT-PCR显示,该基因在在番茄植株的根、茎、叶和子叶中表达.重组表达实验表明该基因能在大肠杆菌中表达.

  19. Stress-induced co-expression of two alternative oxidase (VuAox1 and 2b) genes in Vigna unguiculata.

    Science.gov (United States)

    Costa, José Hélio; Mota, Erika Freitas; Cambursano, Mariana Virginia; Lauxmann, Martin Alexander; de Oliveira, Luciana Maia Nogueira; Silva Lima, Maria da Guia; Orellano, Elena Graciela; Fernandes de Melo, Dirce

    2010-05-01

    Cowpea (Vigna unguiculata) alternative oxidase is encoded by a small multigene family (Aox1, 2a and 2b) that is orthologous to the soybean Aox family. Like most of the identified Aox genes in plants, VuAox1 and VuAox2 consist of 4 exons interrupted by 3 introns. Alignment of the orthologous Aox genes revealed high identity of exons and intron variability, which is more prevalent in Aox1. In order to determine Aox gene expression in V. unguiculata, a steady-state analysis of transcripts involved in seed development (flowers, pods and dry seeds) and germination (soaked seeds) was performed and systemic co-expression of VuAox1 and VuAox2b was observed during germination. The analysis of Aox transcripts in leaves from seedlings under different stress conditions (cold, PEG, salicylate and H2O2 revealed stress-induced co-expression of both VuAox genes. Transcripts of VuAox2a and 2b were detected in all control seedlings, which was not the case for VuAox1 mRNA. Estimation of the primary transcript lengths of V. unguiculata and soybean Aox genes showed an intron length reduction for VuAox1 and 2b, suggesting that the two genes have converged in transcribed sequence length. Indeed, a bioinformatics analysis of VuAox1 and 2b promoters revealed a conserved region related to a cis-element that is responsive to oxidative stress. Taken together, the data provide evidence for co-expression of Aox1 and Aox2b in response to stress and also during the early phase of seed germination. The dual nature of VuAox2b expression (constitutive and induced) suggests that the constitutive Aox2b gene of V. unguiculata has acquired inducible regulatory elements.

  20. Mitochondrial encephalomyopathy with cytochrome c oxidase deficiency caused by a novel mutation in the MTCO1 gene.

    Science.gov (United States)

    Debray, François-Guillaume; Seneca, Sara; Gonce, Michel; Vancampenhaut, Kim; Bianchi, Elettra; Boemer, François; Weekers, Laurent; Smet, Joél; Van Coster, Rudy

    2014-07-01

    Cytochrome c oxidase (COX) deficiency is one of the most common respiratory chain deficiencies. A woman was presented at the age of 18y with acute loss of consciousness, non-convulsive status epilepticus, slow neurological deterioration, transient cortical blindness, exercise intolerance, muscle weakness, hearing loss, cataract and cognitive decline. Muscle biopsy revealed ragged-red fibers, COX negative fibers and a significant decreased activity of complex IV in a homogenate. Using next generation massive parallel sequencing of the mtDNA, a novel heteroplasmic mutation was identified in MTCO1, m.7402delC, causing frameshift and a premature termination codon. Single fiber PCR showed co-segregation of high mutant load in COX negative fibers. Mutation in mitochondrially encoded complex IV subunits should be considered in mitochondrial encephalomyopathies and COX negative fibers after the common mtDNA mutations have been excluded.

  1. Genetic Differences of Mitten Crabs Based on RFLP Analysis on Mitochondrial Cytochrome Oxidase Subunit I (COI) Gene

    Institute of Scientific and Technical Information of China (English)

    HU Pengfei; WANG Qian; DAI Wei; WANG Xiaomei

    2008-01-01

    The genetic differences of 15 mitten crab populations from 6 river systems in mainland China and 1 population from Russia were studied based on RFLP analysis of mitochondrial cytochrome oxidase subunit I (COI).The results showed that Tas I-RFLP pattern could be used as a genetic marker to distinguish Eriocheir hepuensis from Eriocheir sinensis, Eriocheirjaponica and Eriocheir leptognathus;genetic distances among 13 populations ofEriocheir sinensis range from 0 to 0.015, indicating that they were different geographic strains;the subspecies status ofEriocheir sinensis and Eriocheir hepuensis (population from Nanliujiang) were considered owning to their genetic distances of 0.02-0.044,indicating that genetic divergence between them was low; Eriocheir leptognathus (population from Nanpaihe, Tianjin) was the most distant taxon with genetic distances value of 0.147-0.195,which could be defined as genetic distances between species in genus Eriocheir.

  2. Sodium arsenite alters cell cycle and MTHFR, MT1/2, and c-Myc protein levels in MCF-7 cells.

    Science.gov (United States)

    Ruiz-Ramos, Ruben; López-Carrillo, Lizbeth; Albores, Arnulfo; Hernández-Ramírez, Raúl U; Cebrian, Mariano E

    2009-12-15

    There is limited available information on the effects of arsenic on enzymes participating in the folate cycle. Therefore, our aim was to evaluate the effects of sodium arsenite on the protein levels of methylenetetrahydrofolate reductase (MTHFR) and dihydrofolate reductase (DHFR) and its further relationship with the expression MT1/2 and c-myc in MCF-7 cells. Arsenite treatment (0-10 microM) for 4 h decreased MTHFR levels in a concentration-dependent fashion without significant effects on DHFR. The effects on MTHFR were observed at arsenite concentrations not significantly affecting cell viability. We also observed an increase in S-phase recruitment at all concentrations probed. Lower concentrations ( or =5 microM) or longer treatment periods induced apoptosis. Arsenite also induced dose-dependent increases in MT1/2 and c-Myc protein levels. The levels of MTHFR were inversely correlated to MT1/2 and c-Myc overexpression and increased S-phase recruitment. Our findings indicate that breast epithelial cells are responsive to arsenite and suggest that exposure may pose a risk for breast cancer. The reductions in MTHFR protein levels contribute to understand the mechanisms underlying the induction of genes influencing growth regulation, such as c-myc and MT1/2. However, further research is needed to ascertain if the effects here reported following short-time and high-dose exposure are relevant for human populations chronically exposed to low arsenic concentrations.

  3. Gene engineered construction of urate oxidase highly-expressing Lactococcus lactis%高产尿酸氧化酶乳酸工程菌的构建

    Institute of Scientific and Technical Information of China (English)

    张彦新; 曾雪芳; 刘芳; 蒋云生

    2015-01-01

    目的 将尿酸氧化酶基因克隆到乳酸乳球菌(Llactis)NZ9000中,使之能启动nisA放大系统增加尿酸氧化酶活性,构建一株高效分解尿酸的基因工程菌.方法 根据GenBank上已知的产朊假丝酵母菌尿酸氧化酶基因序列(Uricase,E12709)设计引物,PCR扩增尿酸氧化酶基因片段,将其克隆入质粒PNZ8048、PMG36e,构建重组质粒PNZ8048-U、PMG36e-U,重组质粒电转化L.lactis NZ9000构建基因工程菌L.lactis NZ9000-PNZ8048-U、L.lactis NZ9000-PMG36e-U,经十二烷基硫酸钠-聚丙烯酰氨凝胶电泳(SDS-PAGE)鉴定重组菌体裂解液中的尿酸氧化酶,测定尿酸氧化酶的活性和在高尿酸患者血清中降解尿酸的能力.结果 构建的重组质粒PNZ8048-U、PMG36e-U经酶切和测序显示,尿酸氧化酶基因片段长度为0.9 kb,基因片段序列与GenBank上尿酸氧化酶基因序列完全一致.构建重组基因工二程菌L.lactis NZ9000-PNZ8048-U、L.lactis NZ9000-PMG36e-U,均表达相对分子质量约为34 000的重组蛋白,与从尿酸氧化酶基因序列推测的303个氨基酸的理论分子量相符.体外测定菌酶液活性,L.lactis NZ9000-PNZ8048-U组酶活性为(1.92±0.14)u/ml,产朊假丝酵母菌组酶活性为(0.55±0.05)u/ml,L.lactis NZ9000-PMG36e-U组酶活性为(0.29±0.06) u/ml.高尿酸血症患者血清培养结果显示加入生理盐水的对照组尿酸值(620.0±58.7) μmol/L,L.lactis NZ9000-PNZ8048-U组(321.0±46.2) μmol/L,L.lactis NZ9000-PMG36e-U组(568.0±47.3)μmol/L,产朊假丝酵母菌组(406.0±42.4)μmol/L,其他3组与对照组比较,差异均有统计学意义(均P<0.05).结论 成功构建基因工程菌L.lactis NZ9000-PNZ8048-U,重组菌酶活性较基因来源菌产朊假丝酵母菌高,并可高效分解高尿酸患者血清中的尿酸.%Objective To construct a bacterial strain with genectically-engineered high-efficiency in uric acid degradation,through cloning the urate oxidase gene into Lactococcus lactis NZ9000 so that it can

  4. Real time expression of ACC oxidase and PR-protein genes mediated by Methylobacterium spp. in tomato plants challenged with Xanthomonas campestris pv. vesicatoria.

    Science.gov (United States)

    Yim, W J; Kim, K Y; Lee, Y W; Sundaram, S P; Lee, Y; Sa, T M

    2014-07-15

    Biotic stress like pathogenic infection increases ethylene biosynthesis in plants and ethylene inhibitors are known to alleviate the severity of plant disease incidence. This study aimed to reduce the bacterial spot disease incidence in tomato plants caused by Xanthomonas campestris pv. vesicatoria (XCV) by modulating stress ethylene with 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity of Methylobacterium strains. Under greenhouse condition, Methylobacterium strains inoculated and pathogen challenged tomato plants had low ethylene emission compared to pathogen infected ones. ACC accumulation and ACC oxidase (ACO) activity with ACO related gene expression increased in XCV infected tomato plants over Methylobacterium strains inoculated plants. Among the Methylobacterium spp., CBMB12 resulted lowest ACO related gene expression (1.46 Normalized Fold Expression), whereas CBMB20 had high gene expression (3.42 Normalized Fold Expression) in pathogen challenged tomato. But a significant increase in ACO gene expression (7.09 Normalized Fold Expression) was observed in the bacterial pathogen infected plants. In contrast, Methylobacterium strains enhanced β-1,3-glucanase and phenylalanine ammonia-lyase (PAL) enzyme activities in pathogen challenged tomato plants. The respective increase in β-1,3-glucanase related gene expressions due to CBMB12, CBMB15, and CBMB20 strains were 66.3, 25.5 and 10.4% higher over pathogen infected plants. Similarly, PAL gene expression was high with 0.67 and 0.30 Normalized Fold Expression, in pathogen challenged tomato plants inoculated with CBMB12 and CBMB15 strains. The results suggest that ethylene is a crucial factor in bacterial spot disease incidence and that methylobacteria with ACC deaminase activity can reduce the disease severity with ultimate pathogenesis-related protein increase in tomato.

  5. Synthetic liver X receptor agonist T0901317 inhibits semicarbazide-sensitive amine oxidase gene expression and activity in apolipoprotein E knockout mice

    Institute of Scientific and Technical Information of China (English)

    Xiaoyan Dai; Xiang Ou; Xinrui Hao; Dongli Cao; Yaling Tang; Yanwei Hu; Xiaoxu Li; Chaoke Tang

    2008-01-01

    Semicarbazide-sensitive amine oxidase(SSAO)catalyzes oxidative deamination of primary aromatic and aliphatic amines.Increased SSAO activity has been found in atherosclerosis and diabetes mellitus.We hypothesize that the anti-atherogenic effect of liver X receptors(LXRs)might be related to the inhibition of SSAD gene expression and its activity.In this study,we investigated the effect of LXR agonist T0901317 on SSAO gene expression and its activity in apolipoprotein E knockout(apoE-/-)mice.Male apoE-/-mice(8 weeks old) were randomly divided into four groups:basal control group;vehicle group;prevention group;and treatment group.SSAO gene expression was analyzed by real-time quantitative polymerase chain reaction and its activity was determined.The activity of superoxide dismutase and content of malondialdehy de in the aorta and liver were also determined.In T0901317-treated mice,SSAO gene expression was significantly decreased in the aorta,liver,small intestine,and brain.SSAO activities in serum and in these tissues were also inhibited.The amount of superoxide dismutase in the aorta and liver of the prevention group and treatment group was significantly higher compared with the vehicle group(P<0.05).Malondialdehyde in the tissues of these two groups was significantly lower compared with the vehicle group(P<0.05).Our results showed that T0901317 inhibits SSAO gene expression and its activity in atherogenic apoE-/-mice.The atheroprotective effect of LXR agonist T0901317 is related to the inhibition of SSAO gene expression and its activity.

  6. Arsenite Oxidation and Arsenite Resistance by Bacillus sp. PNKP-S2

    Directory of Open Access Journals (Sweden)

    Pranee Pattanapipitpaisal

    2015-01-01

    Full Text Available Arsenic causes human health problems after accumulate in the body for 10-15 years and arsenite [As(III] is generally regarded as being more mobile and toxic than other oxidation states. In this study, two-hundred and three bacterial strains were isolated from groundwater and soil samples collecting in Ubon Ratchathani Province, Thailand. All strains were screened for arsenic tolerant efficiency at 1-10 mM of sodium arsenite. Eighteen selected strains which had the highest resistance to 10 mM of As(III were further studied for their As(III-oxidizing activity and growth in enrichment and growth medium (EG medium supplemented with 0.58 mM of As(III. It was found that strain PNKP-S2 was able to grow in the medium with As(III as a sole energy source and had 89.11% As(III removal within 48 h. The PCR-based 16S rDNA sequencing analysis revealed that the strain PNKP-S2 was closed relative to Bacillus sp. This is the first report on Bacillus sp. chemolithoautotrophic As(III-oxidizer and this strain could be a potential candidate for application in arsenic remediation of contaminated water.

  7. Partial protoporphyrinogen oxidase (PPOX gene deletions, due to different Alu-mediated mechanisms, identified by MLPA analysis in patients with variegate porphyria

    Directory of Open Access Journals (Sweden)

    Barbaro Michela

    2013-01-01

    Full Text Available Abstract Variegate porphyria (VP is an autosomal dominantly inherited hepatic porphyria. The genetic defect in the PPOX gene leads to a partial defect of protoporphyrinogen oxidase, the penultimate enzyme of heme biosynthesis. Affected individuals can develop cutaneous symptoms in sun-exposed areas of the skin and/or neuropsychiatric acute attacks. The identification of the genetic defect in VP families is of crucial importance to detect the carrier status which allows counseling to prevent potentially life threatening neurovisceral attacks, usually triggered by factors such as certain drugs, alcohol or fasting. In a total of 31 Swedish VP families sequence analysis had identified a genetic defect in 26. In the remaining five families an extended genetic investigation was necessary. After the development of a synthetic probe set, MLPA analysis to screen for single exon deletions/duplications was performed. We describe here, for the first time, two partial deletions within the PPOX gene detected by MLPA analysis. One deletion affects exon 5 and 6 (c.339-197_616+320del1099 and has been identified in four families, most probably after a founder effect. The other extends from exon 5 to exon 9 (c.339-350_987+229del2609 and was found in one family. We show that both deletions are mediated by Alu repeats. Our findings emphasize the usefulness of MLPA analysis as a complement to PPOX gene sequencing analysis for comprehensive genetic diagnostics in patients with VP.

  8. Phylogenetic relationships within Taenia taeniaeformis variants and other taeniid cestodes inferred from the nucleotide sequence of the cytochrome c oxidase subunit I gene.

    Science.gov (United States)

    Okamoto, M; Bessho, Y; Kamiya, M; Kurosawa, T; Horii, T

    1995-01-01

    Nucleotide sequence variations in a region of the mitochondrial cytochrome c oxidase subunit I (COI) gene (391 bp) were examined within seven species of the genus Taenia and two species of the genus Echinococcus, including ten isolates of T. taeniaeformis and six isolates of E. multilocularis. More than a 12% rate of nucleotide differences between taeniid species was found, allowing the species to be distinguished. In E. multilocularis, no sequence variation was observed among isolates, regardless of the host (gray red-backed vole, tundra vole, pig, Norway rat) or area (Japan, Alaska) from which each metacestode had been isolated. In contrast, six distinct sequences were detected among the ten T. taeniaeformis isolates examined. The level of nucleotide variation in the COI gene within T. taeniaeformis isolates except for one isolate from the gray red-backed vole (TtACR), which has been proposed as a distinct strain or a different species, was about 0.3%-4.1%, whereas the COI gene sequence for TtACR differed from those of the other isolates, with levels being 9.0%-9.5%. Phylogenetic trees were then inferred from these sequence data using two different algorithms.

  9. Neuron-specific specificity protein 4 bigenomically regulates the transcription of all mitochondria- and nucleus-encoded cytochrome c oxidase subunit genes in neurons.

    Science.gov (United States)

    Johar, Kaid; Priya, Anusha; Dhar, Shilpa; Liu, Qiuli; Wong-Riley, Margaret T T

    2013-11-01

    Neurons are highly dependent on oxidative metabolism for their energy supply, and cytochrome c oxidase (COX) is a key energy-generating enzyme in the mitochondria. A unique feature of COX is that it is one of only four proteins in mammalian cells that are bigenomically regulated. Of its thirteen subunits, three are encoded in the mitochondrial genome and ten are nuclear-encoded on nine different chromosomes. The mechanism of regulating this multisubunit, bigenomic enzyme poses a distinct challenge. In recent years, we found that nuclear respiratory factors 1 and 2 (NRF-1 and NRF-2) mediate such bigenomic coordination. The latest candidate is the specificity factor (Sp) family of proteins. In N2a cells, we found that Sp1 regulates all 13 COX subunits. However, we discovered recently that in primary neurons, it is Sp4 and not Sp1 that regulates some of the key glutamatergic receptor subunit genes. The question naturally arises as to the role of Sp4 in regulating COX in primary neurons. The present study utilized multiple approaches, including chromatin immunoprecipitation, promoter mutational analysis, knockdown and over-expression of Sp4, as well as functional assays to document that Sp4 indeed functionally regulate all 13 subunits of COX as well as mitochondrial transcription factors A and B. The present study discovered that among the specificity family of transcription factors, it is the less known neuron-specific Sp4 that regulates the expression of all 13 subunits of mitochondrial cytochrome c oxidase (COX) enzyme in primary neurons. Sp4 also regulates the three mitochondrial transcription factors (TFAM, TFB1M, and TFB2M) and a COX assembly protein SURF-1 in primary neurons.

  10. Hypoxia-response element (HRE)-directed transcriptional regulation of the rat lysyl oxidase gene in response to cobalt and cadmium.

    Science.gov (United States)

    Gao, Song; Zhou, Jing; Zhao, Yinzhi; Toselli, Paul; Li, Wande

    2013-04-01

    Lysyl oxidase (LO) catalyzes crosslink of collagen, elastin, and histone H1, stabilizing the extracellular matrix and cell nucleus. This enzyme displays dual functions for tumorigenesis, i.e., as a tumor suppressor inactivating the ras oncogene and as a tumor promoter enhancing malignant cell metastasis. To elucidate LO transcriptional regulation, we have cloned the 804 base pair region upstream of the translation start site (ATG) of the rat LO gene with the maximal promoter activity. Computer analysis indicated that at least four hypoxia-response element (HRE) consensuses (5'-ACGTG-3') exist in the cloned LO promoter. Treatment of rat lung fibroblasts (RFL6) with CoCl2 (Co, 10-100 μM), a chemical hypoxia reagent, enhanced LO mRNA expression and promoter activities. Overexpression of LO was associated with upregulation of hypoxia-inducible factor (HIF)-1α at mRNA levels in cobalt (Co)-treated cells. Thus, LO is a hypoxia-responsive gene. Dominant negative-HIF-1α inhibited LO promoter activities stimulated by Co. Electrophoretic mobility shift, oligonucleotide competition, and in vitro translated HIF-1α binding assays indicated that only one HRE mapped at -387/-383 relative to ATG was functionally active among four consensuses. Site-directed mutation of this HRE significantly diminished the Co-induced and LO promoter-directed expression of the reporter gene. Cadmium (Cd), an inducer of reactive oxygen species, inhibited HIF-1α mRNA expression and HIF-1α binding to the LO gene in Co-treated cells as revealed by RT-PCR and ChIP assays, respectively. Thus, modulation of the HRE activity by Co and Cd plays a critical role in LO gene transactivation.

  11. Arsenite exposure compromises early embryonic development in the Golden hamster.

    Science.gov (United States)

    Unis, Dave; Osborne, Cassandra; Diawara, Moussa M

    2009-11-01

    The toxicity of arsenite to 8-cell stage hamster embryos was evaluated. Females were superovulated and mated; embryos were collected and grown for 72 h in culture medium containing vehicle control, 25, 50, 250, 500, or 750 nM arsenite. Morphological observations were taken at 0 and 24h increments. A TUNEL assay was used for determining DNA damage. Survival was expressed by the ability to undergo zona escape. The control group had 78% survival and no evidence of deformities. Embryos in the 25, 50 and 250 nM groups had survival rates of 63%, 55% and 27%, respectively. Arsenite exposure caused total embryo lethality, major deformities, complete failure to undergo zona lysis, and significantly higher number of cells with fragmented DNA in embryos at the 500 and 750 nM concentrations. The study underscores the sensitivity of preimplantation stage embryos to the presence of even relatively small amounts of arsenic in luminal fluid.

  12. Cloning and expression of zebrafish genes encoding the heme synthesis enzymes uroporphyrinogen III synthase (UROS) and protoporphyrinogen oxidase (PPO).

    Science.gov (United States)

    Hanaoka, Ryuki; Dawid, Igor B; Kawahara, Atsuo

    2007-02-01

    Heme is synthesized from glycine and succinyl CoA by eight heme synthesis enzymes. Although genetic defects in any of these enzymes are known to cause severe human blood diseases, their developmental expression in mammals is unknown. In this paper, we report two zebrafish heme synthesis enzymes, uroporphyrinogen III synthase (UROS) and protoporphyrinogen oxidase (PPO) that are well conserved in comparison to their human counterparts. Both UROS and PPO formed pairs of bilateral stripes in the lateral plate mesoderm at the 15-somite stage. At 24 h post-fertilization (hpf), UROS and PPO were predominantly expressed in the intermediate cell mass (ICM) that is the major site of primitive hematopoiesis. The expression of UROS and PPO was drastically suppressed in the bloodless mutants cloche and vlad tepes/gata 1 from 15-somite to 24hpf stages, indicating that both cloche and vlad tepes/gata 1 are required for the induction and maintenance of UROS and PPO expression in the ICM.

  13. Characterization of the polyphenol oxidase gene family reveals a novel microRNA involved in posttranscriptional regulation of PPOs in Salvia miltiorrhiza

    Science.gov (United States)

    Li, Caili; Li, Dongqiao; Li, Jiang; Shao, Fenjuan; Lu, Shanfa

    2017-01-01

    Salvia miltiorrhiza is a well-known material of traditional Chinese medicine. Understanding the regulatory mechanisms of phenolic acid biosynthesis and metabolism are important for S. miltiorrhiza quality improvement. We report here that S. miltiorrhiza contains 19 polyphenol oxidases (PPOs), forming the largest PPO gene family in plant species to our knowledge. Analysis of gene structures and sequence features revealed the conservation and divergence of SmPPOs. SmPPOs were differentially expressed in plant tissues and eight of them were predominantly expressed in phloem and xylem, indicating that some SmPPOs are functionally redundant, whereas the others are associated with different physiological processes. Expression patterns of eighteen SmPPOs were significantly altered under MeJA treatment, and twelve were yeast extract and Ag+-responsive, suggesting the majority of SmPPOs are stress-responsive. Analysis of high-throughput small RNA sequences and degradome data showed that miR1444-mediated regulation of PPOs existing in P. trichocarpa is absent from S. miltiorrhiza. Instead, a subset of SmPPOs was posttranscriptionally regulated by a novel miRNA, termed Smi-miR12112. It indicates the specificity and significance of miRNA-mediated regulation of PPOs. The results shed light on the regulation of SmPPO expression and suggest the complexity of SmPPO-associated phenolic acid biosynthesis and metabolism. PMID:28304398

  14. Inhibition of development of experimental abdominal aortic aneurysm by c-jun N-terminal protein kinase inhibitor combined with lysyl oxidase gene modified smooth muscle progenitor cells.

    Science.gov (United States)

    Chen, Feng; Zhang, ZhenDong; Zhu, XianHua

    2015-11-05

    Chronic inflammation, imbalance between the extracellular matrix synthesis and degradation, and loss of vascular smooth muscle cells (SMCs) contribute to the development of abdominal aortic aneurysm (AAA). The purpose of this study was to investigate the effect of the therapy with periaortic incubation of c-Jun N-terminal protein kinase inhibitor SP600125 infused from an osmotic pump and subadventitial injection of lysyl oxidase (LOX) gene modified autologous smooth muscle progenitor cells (SPCs) on treatment of AAA in a rabbit model. Obvious dilation of the abdominal aorta in the control group was caused by periaortic incubation of calcium chloride and elastase. But the progression of aortic dilation was significantly decreased after the treatment with SP600125 and LOX gene modified SPCs compared to the treatment with phosphate-buffered saline. This therapy could inhibit matrix metalloproteinases expression, enhance elastin synthesis, improve preservation of elastic laminar integrity, benefit SPCs survival and restore SMCs population. It seemed that this method might provide a novel therapeutic strategy to treat AAA.

  15. A mutation in the FAM36A gene, the human ortholog of COX20, impairs cytochrome c oxidase assembly and is associated with ataxia and muscle hypotonia.

    Science.gov (United States)

    Szklarczyk, Radek; Wanschers, Bas F J; Nijtmans, Leo G; Rodenburg, Richard J; Zschocke, Johannes; Dikow, Nicola; van den Brand, Mariël A M; Hendriks-Franssen, Marthe G M; Gilissen, Christian; Veltman, Joris A; Nooteboom, Marco; Koopman, Werner J H; Willems, Peter H G M; Smeitink, Jan A M; Huynen, Martijn A; van den Heuvel, Lambertus P

    2013-02-15

    The mitochondrial respiratory chain complex IV (cytochrome c oxidase) is a multi-subunit enzyme that transfers electrons from cytochrome c to molecular oxygen, yielding water. Its biogenesis requires concerted expression of mitochondria- and nuclear-encoded subunits and assembly factors. In this report, we describe a homozygous missense mutation in FAM36A from a patient who displays ataxia and muscle hypotonia. The FAM36A gene is a remote, putative ortholog of the fungal complex IV assembly factor COX20. Messenger RNA (mRNA) and protein co-expression analyses support the involvement of FAM36A in complex IV function in mammals. The c.154A>C mutation in the FAM36A gene, a mutation that is absent in sequenced exomes, leads to a reduced activity and lower levels of complex IV and its protein subunits. The FAM36A protein is nearly absent in patient's fibroblasts. Cells affected by the mutation accumulate subassemblies of complex IV that contain COX1 but are almost devoid of COX2 protein. We observe co-purification of FAM36A and COX2 proteins, supporting that the FAM36A defect hampers the early step of complex IV assembly at the incorporation of the COX2 subunit. Lentiviral complementation of patient's fibroblasts with wild-type FAM36A increases the complex IV activity as well as the amount of holocomplex IV and of individual subunits. These results establish the function of the human gene FAM36A/COX20 in complex IV assembly and support a causal role of the gene in complex IV deficiency.

  16. The effects of child maltreatment on early signs of antisocial behavior: genetic moderation by tryptophan hydroxylase, serotonin transporter, and monoamine oxidase A genes.

    Science.gov (United States)

    Cicchetti, Dante; Rogosch, Fred A; Thibodeau, Eric L

    2012-08-01

    Gene-environment interaction effects in predicting antisocial behavior in late childhood were investigated among maltreated and nonmaltreated low-income children (N = 627, M age = 11.27). Variants in three genes were examined: tryptophan hydroxylase 1 (TPH1), serotonin transporter linked polymorphic region (5-HTTLPR), and monoamine oxidase A (MAOA) upstream variable number tandem repeat. In addition to child maltreatment status, we considered the impact of maltreatment subtypes, developmental timing of maltreatment, and chronicity. Indicators of antisocial behavior were obtained from self-, peer, and adult counselor reports. In a series of analyses of covariance, child maltreatment and its parameters demonstrated strong main effects on early antisocial behavior as assessed by all report forms. Genetic effects operated primarily in the context of gene-environment interactions, moderating the impact of child maltreatment on outcomes. Across the three genes, among nonmaltreated children no differences in antisocial behavior were found based on genetic variation. In contrast, among maltreated children specific polymorphisms of TPH1, 5-HTTLPR, and MAOA were each related to heightened self-report of antisocial behavior; the interaction of 5-HTTLPR and developmental timing of maltreatment also indicated more severe antisocial outcomes for children with early onset and recurrent maltreatment based on genotype. TPH1 and 5-HTTLPR interacted with maltreatment subtype to predict peer reports of antisocial behavior; genetic variation contributed to larger differences in antisocial behavior among abused children. The TPH1 and 5-HTTLPR polymorphisms also moderated the effects of maltreatment subtype on adult reports of antisocial behavior; again, the genetic effects were strongest for children who were abused. In addition, TPH1 moderated the effect of developmental timing of maltreatment and chronicity on adult reports of antisocial behavior. The findings elucidate how genetic

  17. Agrobacterium-mediated transformation of Eucalyptus globulus using explants with shoot apex with introduction of bacterial choline oxidase gene to enhance salt tolerance.

    Science.gov (United States)

    Matsunaga, Etsuko; Nanto, Kazuya; Oishi, Masatoshi; Ebinuma, Hiroyasu; Morishita, Yoshihiko; Sakurai, Nozomu; Suzuki, Hideyuki; Shibata, Daisuke; Shimada, Teruhisa

    2012-01-01

    Eucalyptus globulus is one of the most economically important plantation hardwoods for paper making. However, its low transformation frequency has prevented genetic engineering of this species with useful genes. We found the hypocotyl section with a shoot apex has the highest regeneration ability among another hypocotyl sections, and have developed an efficient Agrobacterium-mediated transformation method using these materials. We then introduced a salt tolerance gene, namely a bacterial choline oxidase gene (codA) with a GUS reporter gene, into E. globulus. The highest frequency of transgenic shoot regeneration from hypocotyls with shoot apex was 7.4% and the average frequency in four experiments was 4.0%, 12-fold higher than that from hypocotyls without shoot apex. Using about 10,000 explants, over 250 regenerated buds were confirmed as transformants by GUS analysis. Southern blot analysis of 100 elongated shoots confirmed successful generation of stable transformants. Accumulation of glycinebetaine was investigated in 44 selected transgenic lines, which showed 1- to 12-fold higher glycinebetaine levels than non-transgenic controls. Rooting of 16 transgenic lines was successful using a photoautotrophic method under enrichment with 1,000 ppm CO(2). The transgenic whole plantlets were transplanted into potting soil and grown normally in a growth room. They showed salt tolerance to 300 mM NaCl. The points of our system are using explants with shoot apex as materials, inhibiting the elongation of the apex on the selection medium, and regenerating transgenic buds from the side opposite to the apex. This approach may also solve transformation problems in other important plants.

  18. Mitochondrial DNA diversity in the acanthocephalan Prosthenorchis elegans in Colombia based on cytochrome c oxidase I (COI gene sequence

    Directory of Open Access Journals (Sweden)

    Ana Carolina Falla

    2015-12-01

    Full Text Available Prosthenorchis elegans is a member of the Phylum Acanthocephala and is an important parasite affecting New World Primates in the wild in South America and in captivity around the world. It is of significant management concern due to its pathogenicity and mode of transmission through intermediate hosts. Current diagnosis of P. elegans is based on the detection of eggs by coprological examination. However, this technique lacks both specificity and sensitivity, since eggs of most members of the genus are morphologically indistinguishable and shed intermittently, making differential diagnosis difficult, and coprological examinations are often negative in animals severely infected at death. We examined sequence variation in 633 bp of mitochondrial DNA (mtDNA cytochrome c oxidase I (COI sequence in 37 isolates of P. elegans from New World monkeys (Saguinus leucopus and Cebus albifrons in Colombia held in rescue centers and from the wild. Intraspecific divergence ranged from 0.0 to 1.6% and was comparable with corresponding values within other species of acanthocephalans. Furthermore, comparisons of patterns of sequence divergence within the Acanthocephala suggest that Prosthenorchis represents a separate genus within the Oligacanthorhynchida. Six distinct haplotypes were identified within P. elegans which grouped into one of two well-supported mtDNA haplogroups. No association between haplogroup/haplotype, holding facility and species was found. This information will help pave the way to the development of molecular-based diagnostic tools for the detection of P. elegans as well as furthering research into the life cycle, intermediate hosts and epidemiological aspects of the species.

  19. Mitochondrial DNA diversity in the acanthocephalan Prosthenorchis elegans in Colombia based on cytochrome c oxidase I (COI) gene sequence.

    Science.gov (United States)

    Falla, Ana Carolina; Brieva, Claudia; Bloor, Paul

    2015-12-01

    Prosthenorchis elegans is a member of the Phylum Acanthocephala and is an important parasite affecting New World Primates in the wild in South America and in captivity around the world. It is of significant management concern due to its pathogenicity and mode of transmission through intermediate hosts. Current diagnosis of P. elegans is based on the detection of eggs by coprological examination. However, this technique lacks both specificity and sensitivity, since eggs of most members of the genus are morphologically indistinguishable and shed intermittently, making differential diagnosis difficult, and coprological examinations are often negative in animals severely infected at death. We examined sequence variation in 633 bp of mitochondrial DNA (mtDNA) cytochrome c oxidase I (COI) sequence in 37 isolates of P. elegans from New World monkeys (Saguinus leucopus and Cebus albifrons) in Colombia held in rescue centers and from the wild. Intraspecific divergence ranged from 0.0 to 1.6% and was comparable with corresponding values within other species of acanthocephalans. Furthermore, comparisons of patterns of sequence divergence within the Acanthocephala suggest that Prosthenorchis represents a separate genus within the Oligacanthorhynchida. Six distinct haplotypes were identified within P. elegans which grouped into one of two well-supported mtDNA haplogroups. No association between haplogroup/haplotype, holding facility and species was found. This information will help pave the way to the development of molecular-based diagnostic tools for the detection of P. elegans as well as furthering research into the life cycle, intermediate hosts and epidemiological aspects of the species.

  20. Arsenite induced oxidative damage in mouse liver is associated with increased cytokeratin 18 expression

    Energy Technology Data Exchange (ETDEWEB)

    Gonsebatt, M.E. [UNAM, Ciudad Universitaria, Dept. Medicina Genomica y Toxicologia Ambiental, Instituto de Investigaciones Biomedicas, Mexico (Mexico); Razo, L.M. del; Sanchez-Pena, L.C. [Seccion de Toxicologia, CINVESTAV, Mexico (Mexico); Cerbon, M.A. [Facultad de Quimica, UNAM, Departamento de Biologia, Mexico (Mexico); Zuniga, O.; Ramirez, P. [Facultad de Estudios Superiores Cuautitlan, UNAM, Laboratorio de Toxicologia Celular, Coordinacion General de Estudios de Posgrado e Investigacion, Cuautitlan Izcalli, Estado de Mexico (Mexico)

    2007-09-15

    Cytokeratins (CK) constitute a family of cytoskeletal intermediate filament proteins that are typically expressed in epithelial cells. An abnormal structure and function are effects that are clearly related to liver diseases as non-alcoholic steatohepatitis, cirrhosis and hepatocellular carcinoma. We have previously observed that sodium arsenite (SA) induced the synthesis of CK18 protein and promotes a dose-related disruption of cytoplasmic CK18 filaments in a human hepatic cell line. Both abnormal gene expression and disturbance of structural organization are toxic effects that are likely to cause liver disease by interfering with normal hepatocyte function. To investigate if a disruption in the CK18 expression pattern is associated with arsenite liver damage, we investigated CK18 mRNA and protein levels in liver slices treated with low levels of SA. Organotypic cultures were incubated with 0.01, 1 and 10 {mu}M of SA in the absence and presence of N-acetyl cysteine (NAC). Cell viability and inorganic arsenic metabolism were determined. Increased expression of CK18 was observed after exposure to SA. The addition of NAC impeded the oxidative effects of SA exposure, decreasing the production of thiobarbituric acid-reactive substances and significantly diminishing the up regulation of CK18 mRNA and protein. Liver arsenic levels correlated with increased levels of mRNA. Mice treated with intragastric single doses of 2.5 and 5 mg/kg of SA showed an increased expression of CK18. Results suggest that CK18 expression may be a sensible early biomarker of oxidative stress and damage induced by arsenite in vitro and in vivo. Then, during SA exposure, altered CK expression may compromise liver function. (orig.)

  1. The role of the rice aquaporin Lsi1 in arsenite efflux from roots.

    Science.gov (United States)

    Zhao, Fang-Jie; Ago, Yukiko; Mitani, Namiki; Li, Ren-Ying; Su, Yu-Hong; Yamaji, Naoki; McGrath, Steve P; Ma, Jian Feng

    2010-04-01

    *When supplied with arsenate (As(V)), plant roots extrude a substantial amount of arsenite (As(III)) to the external medium through as yet unidentified pathways. The rice (Oryza sativa) silicon transporter Lsi1 (OsNIP2;1, an aquaporin channel) is the major entry route of arsenite into rice roots. Whether Lsi1 also mediates arsenite efflux was investigated. *Expression of Lsi1 in Xenopus laevis oocytes enhanced arsenite efflux, indicating that Lsi1 facilitates arsenite transport bidirectionally. *Arsenite was the predominant arsenic species in arsenate-exposed rice plants. During 24-h exposure to 5 mum arsenate, rice roots extruded arsenite to the external medium rapidly, accounting for 60-90% of the arsenate uptake. A rice mutant defective in Lsi1 (lsi1) extruded significantly less arsenite than the wild-type rice and, as a result, accumulated more arsenite in the roots. By contrast, Lsi2 mutation had little effect on arsenite efflux to the external medium. *We conclude that Lsi1 plays a role in arsenite efflux in rice roots exposed to arsenate. However, this pathway accounts for only 15-20% of the total efflux, suggesting the existence of other efflux transporters.

  2. A Penicillium expansum glucose oxidase-encoding gene, GOX2, is essential for gluconic acid production and acidification during colonization of deciduous fruit.

    Science.gov (United States)

    Barad, Shiri; Horowitz, Sigal Brown; Moscovitz, Oren; Lichter, Amnon; Sherman, Amir; Prusky, Dov

    2012-06-01

    Penicillium expansum, the causal agent of blue mold rot, causes severe postharvest maceration of fruit through secretion of total, d-gluconic acid (GLA). Two P. expansum glucose oxidase (GOX)-encoding genes, GOX1 and GOX2, were analyzed. GOX activity and GLA accumulation were strongly related to GOX2 expression, which increased with pH to a maximum at pH 7.0, whereas GOX1 was expressed at pH 4.0, where no GOX activity or extracellular GLA were detected. This differential expression was also observed at the leading edge of the decaying tissue, where GOX2 expression was dominant. The roles of the GOX genes in pathogenicity were further studied through i) development of P. expansum goxRNAi mutants exhibiting differential downregulation of GOX2, ii) heterologous expression of the P. expansum GOX2 gene in the nondeciduous fruit-pathogen P. chrysogenum, and iii) modulation of GLA production by FeSO(4) chelation. Interestingly, in P. expansum, pH and GLA production elicited opposite effects on germination and biomass accumulation: 26% of spores germinated at pH 7.0 when GOX activity and GLA were highest whereas, in P. chrysogenum at the same pH, when GLA did not accumulate, 72% of spores germinated. Moreover, heterologous expression of P. expansum GOX2 in P. chrysogenum resulted in enhanced GLA production and reduced germination, suggesting negative regulation of spore germination and GLA production. These results demonstrate that pH modulation, mediated by GLA accumulation, is an important factor in generating the initial signal or signals for fungal development leading to host-tissue colonization by P. expansum.

  3. Inhibition of mitotic-specific histone phophorylation by sodium arsenite

    Energy Technology Data Exchange (ETDEWEB)

    Cobo, J.M. [Universidad de Alcala de Henares, Madrid (Spain); Valdez, J.G.; Gurley, L.R. [Los Alamos National Lab., NM (United States)

    1994-10-01

    Synchronized cultures of Chinese hamster cells (line CHO) were used to measure the effects of 10{mu}M sodium arsenite on histone phosphorylation. This treatment caused cell proliferation to be temporarily arrested, after which the cells spontaneously resumed cell proliferation in a radiomimetric manner. Immediately following treatment, it was found that sodium arsenite affected only mitotic-specific HI and H3 phosphorylations. Neither interphase, nor mitotic, H2A and H4 phosphorylations were affected, nor was interphase HI Phosphorylation affected. The phosphorylation of HI was inhibited only in mitosis, reducing HI phosphorylation to 38.1% of control levels, which was the level of interphase HI phosphorylation. The phosphorylation of both H3 variants was inhibited in mitosis, the less hydrophobic H3 to 19% and the more hydrophobic H3 to 24% of control levels. These results suggest that sodium arsenite may inhibite cell proliferation by interfering with the cyclin B/p34{sup cdc2} histone kinase activity which is thought to play a key role in regulating the cell cycle. It has been proposed by our laboratory that HI and H3 phosphorylations play a role in restructuring interphase chromatin into metaphase chromosomes. Interference of this process by sodium arsenite may lead to structurally damaged chromosomes resulting in the increased cancer risks known to be produced by arsenic exposure from the environment.

  4. Sorption and desorption of arsenate and arsenite on calcite

    DEFF Research Database (Denmark)

    Sø, Helle Ugilt; Postma, Diederik Jan; Jakobsen, Rasmus

    2008-01-01

    The adsorption and desorption of arsenate (As(V)) and arsenite (As(111)) oil calcite was investigated in a series of batch experiments in calcite-equilibrated solutions. The solutions covered a broad range of pH, alkalinity, calcium concentration and ionic strength. The initial arsenic...

  5. Expression of the genes dual oxidase 2, lipocalin 2 and regenerating islet-derived 1 alpha in Crohn's disease

    DEFF Research Database (Denmark)

    Csillag, C.; Nielsen, O.H.; Vainer, Ben

    2007-01-01

    OBJECTIVE: A global gene expression profile of non-inflamed colonic mucosal cells from patients with Crohn's disease (CD) and of colonic mucosal cells from controls was performed. MATERIAL AND METHODS: Tissue specimens from macroscopically non-inflamed descending colon were obtained colonoscopica......OBJECTIVE: A global gene expression profile of non-inflamed colonic mucosal cells from patients with Crohn's disease (CD) and of colonic mucosal cells from controls was performed. MATERIAL AND METHODS: Tissue specimens from macroscopically non-inflamed descending colon were obtained...

  6. Association of a Monoamine Oxidase-A Gene Promoter Polymorphism with ADHD and Anxiety in Boys with Autism Spectrum Disorder

    Science.gov (United States)

    Roohi, Jasmin; DeVincent, Carla J.; Hatchwell, Eli; Gadow, Kenneth D.

    2009-01-01

    The aim of the present study was to examine the association between a variable number tandem repeat (VNTR) functional polymorphism in the promoter region of the MAO-A gene and severity of ADHD and anxiety in boys with ASD. Parents and teachers completed a DSM-IV-referenced rating scale for 5- to 14-year-old boys with ASD (n = 43). Planned…

  7. D-amino acid oxidase activator gene (DAOA) variation affects cerebrospinal fluid homovanillic acid concentrations in healthy Caucasians

    DEFF Research Database (Denmark)

    Andreou, Dimitrios; Saetre, Peter; Werge, Thomas;

    2012-01-01

    3918342 and rs1421292, were significantly associated with CSF HVA concentrations. Rs3918342 was found to be nominally associated with CSF 5-HIAA concentrations. None of the polymorphisms were significantly associated with MHPG concentrations. Our results indicate that DAOA gene variation affects dopamine...

  8. Genetic structure of the snakehead murrel, Channa striata (channidae) based on the cytochrome c oxidase subunit I gene: Influence of historical and geomorphological factors.

    Science.gov (United States)

    Jamsari, Amirul Firdaus Jamaluddin; Jamaluddin, Jamsari Amirul Firdaus; Pau, Tan Min; Siti-Azizah, Mohd Nor

    2011-01-01

    Nucleotide sequences of a partial cytochrome c oxidase subunit I gene were used to assess the manner in which historical processes and geomorphological effects may have influenced genetic structuring and phylogeographic patterns in Channa striata. Assaying was based on individuals from twelve populations in four river systems, which were separated into two regions, the eastern and western, of the biodiversely rich state of Perak in central Peninsular Malaysia. In 238 specimens, a total of 368-bp sequences with ten polymorphic sites and eleven unique haplotypes were detected. Data on all the twelve populations revealed incomplete divergence due to past historical coalescence and the short period of separation. Nevertheless, SAMOVA and F(ST) revealed geographical structuring existed to a certain extent in both regions. For the eastern region, the data also showed that the upstream populations were genetically significantly different compared to the mid- and downstream ones. It is inferred that physical barriers and historical processes played a dominant role in structuring the genetic dispersal of the species. A further inference is that the Grik, Tanjung Rambutan and Sungkai are potential candidates for conservation and aquaculture programmes since they contained most of the total diversity in this area.

  9. Genetic structure of the snakehead murrel, Channa striata (channidae based on the cytochrome c oxidase subunit I gene: influence of historical and geomorphological factors

    Directory of Open Access Journals (Sweden)

    Jamsari Amirul Firdaus Jamaluddin

    2011-01-01

    Full Text Available Nucleotide sequences of a partial cytochrome c oxidase subunit I gene were used to assess the manner in which historical processes and geomorphological effects may have influenced genetic structuring and phylogeographic patterns in Channa striata. Assaying was based on individuals from twelve populations in four river systems, which were separated into two regions, the eastern and western, of the biodiversely rich state of Perak in central Peninsular Malaysia. In 238 specimens, a total of 368-bp sequences with ten polymorphic sites and eleven unique haplotypes were detected. Data on all the twelve populations revealed incomplete divergence due to past historical coalescence and the short period of separation. Nevertheless, SAMOVA and F ST revealed geographical structuring existed to a certain extent in both regions. For the eastern region, the data also showed that the upstream populations were genetically significantly different compared to the mid- and downstream ones. It is inferred that physical barriers and historical processes played a dominant role in structuring the genetic dispersal of the species. A further inference is that the Grik, Tanjung Rambutan and Sungkai are potential candidates for conservation and aquaculture programmes since they contained most of the total diversity in this area.

  10. A role for NADPH oxidase in antigen presentation

    Directory of Open Access Journals (Sweden)

    Gail J Gardiner

    2013-09-01

    Full Text Available The nicotinamide adenine dinucleotide phosphate (NADPH oxidase expressed in phagocytes is a multi-subunit enzyme complex that generates superoxide (O2.-. This radical is an important precursor of hydrogen peroxide (H2O2 and other reactive oxygen species (ROS needed for microbicidal activity during innate immune responses. Inherited defects in NADPH oxidase give rise to chronic granulomatous disease (CGD, a primary immunodeficiency characterized by recurrent infections and granulomatous inflammation. Interestingly, CGD, CGD carrier status, and oxidase gene polymorphisms have all been associated with autoinflammatory and autoimmune disorders, suggesting a potential role for NADPH oxidase in regulating adaptive immune responses. Here, NADPH oxidase function in antigen processing and presentation is reviewed. NADPH oxidase influences dendritic cell (DC crosspresentation by major histocompatibility complex class I molecules (MHC-I through regulation of the phagosomal microenvironment, while in B lymphocytes, NADPH oxidase alters epitope selection by major histocompatibility complex class II molecules (MHC-II.

  11. A novel frameshift mutation of the mtDNA COIII gene leads to impaired assembly of cytochrome c oxidase in a patient affected by Leigh-like syndrome.

    Science.gov (United States)

    Tiranti, V; Corona, P; Greco, M; Taanman, J W; Carrara, F; Lamantea, E; Nijtmans, L; Uziel, G; Zeviani, M

    2000-11-01

    We report on a novel frameshift mutation in the mtDNA gene encoding cytochrome c oxidase (COX) subunit III. The proband is an 11-year-old girl with a negative family history and an apparently healthy younger brother. Since 4 years of age, she has developed a progressive spastic paraparesis associated with ophthalmoparesis and moderate mental retardation. The presence of severe lactic acidosis and Leigh-like lesions of putamina prompted us to perform muscle and skin biopsies. In both, a profound, isolated defect of COX was found by histochemical and biochemical assays. Sequence analysis of muscle mtDNA resulted in the identification of a virtually homoplasmic frameshift mutation in the COIII gene, due to the insertion of an extra C at nucleotide position 9537 of mtDNA. Although the 9537C(ins) does not impair transcription of COIII, no full-length COX III protein was detected in mtDNA translation assays in vivo. Western blot analysis of two-dimensional blue-native electrophoresis showed a reduction of specific crossreacting material and the accumulation of early-assembly intermediates of COX, whereas the fully assembled complex was absent. One of these intermediates had an electrophoretic mobility different from those seen in controls, suggesting the presence of a qualitative abnormality of COX assembly. Immunostaining with specific antibodies failed to detect the presence of several smaller subunits in the complex lacking COX III, in spite of the demonstration that these subunits were present in the crude mitochondrial fraction of patient's cultured fibroblasts. Taken together, the data indicate a role for COX III in the incorporation and maintenance of smaller COX subunits within the complex.

  12. The Diamine Oxidase Gene Is Associated with Hypersensitivity Response to Non-Steroidal Anti-Inflammatory Drugs

    Science.gov (United States)

    Agúndez, José A. G.; Ayuso, Pedro; Cornejo-García, José A.; Blanca, Miguel; Torres, María J.; Doña, Inmaculada; Salas, María; Blanca-López, Natalia; Canto, Gabriela; Rondon, Carmen; Campo, Paloma; Laguna, José J.; Fernández, Javier; Martínez, Carmen; García-Martín, Elena

    2012-01-01

    Non-steroidal anti-inflammatory drugs (NSAIDs) are the drugs most frequently involved in hypersensitivity drug reactions. Histamine is released in the allergic response to NSAIDs and is responsible for some of the clinical symptoms. The aim of this study is to analyze clinical association of functional polymorphisms in the genes coding for enzymes involved in histamine homeostasis with hypersensitivity response to NSAIDs. We studied a cohort of 442 unrelated Caucasian patients with hypersensitivity to NSAIDs. Patients who experienced three or more episodes with two or more different NSAIDs were included. If this requirement was not met diagnosis was established by challenge. A total of 414 healthy unrelated controls ethnically matched with patients and from the same geographic area were recruited. Analyses of the SNPs rs17740607, rs2073440, rs1801105, rs2052129, rs10156191, rs1049742 and rs1049793 in the HDC, HNMT and DAO genes were carried out by means of TaqMan assays. The detrimental DAO 16 Met allele (rs10156191), which causes decreased metabolic capacity, is overrepresented among patients with crossed-hypersensitivity to NSAIDs with an OR  = 1.7 (95% CI  = 1.3–2.1; Pc  = 0.0003) with a gene-dose effect (P = 0.0001). The association was replicated in two populations from different geographic areas (Pc  = 0.008 and Pc  = 0.004, respectively). Conclusions and implications The DAO polymorphism rs10156191 which causes impaired metabolism of circulating histamine is associated with the clinical response in crossed-hypersensitivity to NSAIDs and could be used as a biomarker of response. PMID:23152756

  13. Sex-specific associations of variants in regulatory regions of NADPH oxidase-2 (CYBB) and glutathione peroxidase 4 (GPX4) genes with kidney disease in type 1 diabetes.

    Science.gov (United States)

    Monteiro, M B; Patente, T A; Mohammedi, K; Queiroz, M S; Azevedo, M J; Canani, L H; Parisi, M C; Marre, M; Velho, G; Corrêa-Giannella, M L

    2013-10-01

    Oxidative stress is involved in the pathophysiology of diabetic nephropathy. The superoxide-generating nicotinamide adenine dinucleotide phosphate-oxidase 2 (NOX2, encoded by the CYBB gene) and the antioxidant enzyme glutathione peroxidase 4 (GPX4) play opposing roles in the balance of cellular redox status. In the present study, we investigated associations of single nucleotide polymorphisms (SNPs) in the regulatory regions of CYBB and GPX4 with kidney disease in patients with type 1 diabetes. Two functional SNPs, rs6610650 (CYBB promoter region, chromosome X) and rs713041 (GPX4 3'untranslated region, chromosome 19), were genotyped in 451 patients with type 1 diabetes from a Brazilian cohort (diabetic nephropathy: 44.6%) and in 945 French/Belgian patients with type 1 diabetes from Genesis and GENEDIAB cohorts (diabetic nephropathy: 62.3%). The minor A-allele of CYBB rs6610650 was associated with lower estimated glomerular filtration rate (eGFR) in Brazilian women, and with the prevalence of established/advanced nephropathy in French/Belgian women (odds ratio 1.75, 95% CI 1.11-2.78, p = 0.016). The minor T-allele of GPX4 rs713041 was inversely associated with the prevalence of established/advanced nephropathy in Brazilian men (odds ratio 0.30, 95% CI 0.13-0.68, p = 0.004), and associated with higher eGFR in French/Belgian men. In conclusion, these heterogeneous results suggest that neither CYBB nor GPX4 are major genetic determinants of diabetic nephropathy, but nevertheless, they could modulate in a gender-specific manner the risk for renal disease in patients with type 1 diabetes.

  14. Developmental mechanisms of arsenite toxicity in zebrafish (Danio rerio) embryos

    Energy Technology Data Exchange (ETDEWEB)

    Li Dan [Department of Genetics, National Research Institute for Family Planning, Beijing (China); Graduate School of Peking Union Medical College, Beijing (China); Lu Cailing [Department of Genetics, National Research Institute for Family Planning, Beijing (China); Wang Ju; Hu Wei; Cao Zongfu; Sun Daguang [Department of Genetics, National Research Institute for Family Planning, Beijing (China); Graduate School of Peking Union Medical College, Beijing (China); Xia Hongfei [Department of Genetics, National Research Institute for Family Planning, Beijing (China); Ma Xu [Department of Genetics, National Research Institute for Family Planning, Beijing (China) and Graduate School of Peking Union Medical College, Beijing (China) and Department of Reproductive Genetics, WHO Collaborative Center for Research in Human Reproduction, Beijing (China)], E-mail: genetic@263.net.cn

    2009-02-19

    Arsenic usually accumulates in soil, water and airborne particles, from which it is taken up by various organisms. Exposure to arsenic through food and drinking water is a major public health problem affecting some countries. At present there are limited laboratory data on the effects of arsenic exposure on early embryonic development and the mechanisms behind its toxicity. In this study, we used zebrafish as a model system to investigate the effects of arsenite on early development. Zebrafish embryos were exposed to a range of sodium arsenite concentrations (0-10.0 mM) between 4 and 120 h post-fertilization (hpf). Survival and early development of the embryos were not obviously influenced by arsenite concentrations below 0.5 mM. However, embryos exposed to higher concentrations (0.5-10.0 mM) displayed reduced survival and abnormal development including delayed hatching, retarded growth and changed morphology. Alterations in neural development included weak tactile responses to light (2.0-5.0 mM, 30 hpf), malformation of the spinal cord and disordered motor axon projections (2.0 mM, 48 hpf). Abnormal cardiac function was observed as bradycardia (0.5-2.0 mM, 60 hpf) and altered ventricular shape (2.0 mM, 48 hpf). Furthermore, altered cell proliferation (2.0 mM, 24 hpf) and apoptosis status (2.0 mM, 24 and 48 hpf), as well as abnormal genomic DNA methylation patterning (2.0 mM, 24 and 48 hpf) were detected in the arsenite-treated embryos. All of these indicate a possible relationship between arsenic exposure and developmental failure in early embryogenesis. Our studies suggest that the negative effects of arsenic on vertebrate embryogenesis are substantial.

  15. Phylogenetic position of Linguatula arctica and Linguatula serrata (Pentastomida) as inferred from the nuclear 18S rRNA gene and the mitochondrial cytochrome c oxidase subunit I gene.

    Science.gov (United States)

    Gjerde, Bjørn

    2013-10-01

    Genomic DNA was isolated from a Linguatula serrata female expelled from a dog imported to Norway from Romania and from four Linguatula arctica females collected from semi-domesticated reindeer from northern Norway and subjected to PCR amplification of the complete nuclear 18S rRNA gene and a 1,045-bp portion of the mitochondrial cytochrome c oxidase subunit I gene (cox1). The two species differed at two of 1,830 nucleotide positions (99.9% identity) of the complete 18S rRNA gene sequences and at 102 of 1,045 nucleotide positions (90.2% identity) of the partial cox1 sequences. The four isolates of L. arctica showed no genetic variation in either gene. The new cox1 primers may facilitate the diagnosis of various developmental stages of L. arctica and L. serrata in their hosts. In separate phylogenetic analyses using the maximum likelihood method on sequence data from either gene, L. arctica and L. serrata clustered with members of the order Cephalobaenida rather than with members of the order Porocephalida, in which the genus Linguatula is currently placed based on morphological characters. The phylogenetic relationship of L. arctica, L. serrata and other pentastomids to other metazoan groups could not be clearly resolved, but the pentastomids did not seem to have a sister relationship to crustaceans of the subclass Branchiura as found in other studies. A more extensive taxon sampling, including molecular characterisation of more pentastomid taxa across different genera, seems to be necessary in order to estimate the true relationship of the Pentastomida to other metazoan groups.

  16. Dual functions of transcription factors, transforming growth factor-beta-inducible early gene (TIEG)2 and Sp3, are mediated by CACCC element and Sp1 sites of human monoamine oxidase (MAO) B gene.

    Science.gov (United States)

    Ou, Xiao-Ming; Chen, Kevin; Shih, Jean C

    2004-05-14

    Monoamine oxidases (MAO) A and B catalyze the oxidative deamination of many biogenic and dietary amines. Abnormal expression of MAO has been implicated in several psychiatric and neurodegenerative disorders. Human MAO B core promoter (-246 to -99 region) consists of CACCC element flanked by two clusters of overlapping Sp1 sites. Here, we show that cotransfection with transforming growth factor (TGF)-beta-inducible early gene (TIEG)2 increased MAO B gene expression at promoter, mRNA, protein, and catalytic activity levels in both SH-SY5Y and HepG2 cells. Mutation of the CACCC element increased the MAO B promoter activity, and cotransfection with TIEG2 further increased the promoter activity, suggesting that CACCC was a repressor element. This increase was reduced when the proximal Sp1 overlapping sites was mutated. Similar interactions were found with Sp3. These results showed that TIEG2 and Sp3 were repressors at the CACCC element but were activators at proximal Sp1 overlapping sites of MAO B. Gel-shift and chromatin immunoprecipitation assays showed that TIEG2 and Sp3 bound directly to CACCC element and the proximal Sp1 sites in both synthetic oligonucleotides and natural MAO B core promoter. TIEG2 had a higher affinity to Sp1 sites than CACCC element, whereas Sp3 had an equal affinity to both elements. Thus, TIEG2 was an activator, but Sp3 had no effect on MAO B gene expression. This study provides new insights into MAO B gene expression and illustrates the complexity of gene regulation.

  17. Involvement of HIF-2α-mediated inflammation in arsenite-induced transformation of human bronchial epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yuan; Zhao, Yue; Xu, Wenchao; Luo, Fei; Wang, Bairu; Li, Yuan; Pang, Ying; Liu, Qizhan, E-mail: drqzliu@hotmail.com

    2013-10-15

    Arsenic is a well established human carcinogen that causes diseases of the lung. Some studies have suggested a link between inflammation and lung cancer; however, it is unknown if arsenite-induced inflammation causally contributes to arsenite-caused malignant transformation of cells. In this study, we investigated the molecular mechanisms underlying inflammation during neoplastic transformation induced in human bronchial epithelial (HBE) cells by chronic exposure to arsenite. The results showed that, on acute or chronic exposure to arsenite, HBE cells over-expressed the pro-inflammatory cytokines, interleukin-6 (IL-6), interleukin-8 (IL-8), and interleukin-1β (IL-1β). The data also indicated that HIF-2α was involved in arsenite-induced inflammation. Moreover, IL-6 and IL-8 were essential for the malignant progression of arsenite-transformed HBE cells. Thus, these experiments show that HIF-2α mediates arsenite-induced inflammation and that such inflammation is involved in arsenite-induced malignant transformation of HBE cells. The results provide a link between the inflammatory response and the acquisition of a malignant transformed phenotype by cells chronically exposed to arsenite and thus establish a previously unknown mechanism for arsenite-induced carcinogenesis. - Highlights: • Arsenite induces inflammation. • Arsenite-induced the increases of IL-6 and IL-8 via HIF-2α. • Inflammation is involved in arsenite-induced carcinogenesis.

  18. Reduction of arsenite-enhanced ultraviolet radiation-induced DNA damage by supplemental zinc

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, Karen L.; King, Brenee S.; Sandoval, Monica M.; Liu, Ke Jian; Hudson, Laurie G., E-mail: lhudson@salud.unm.edu

    2013-06-01

    Arsenic is a recognized human carcinogen and there is evidence that arsenic augments the carcinogenicity of DNA damaging agents such as ultraviolet radiation (UVR) thereby acting as a co-carcinogen. Inhibition of DNA repair is one proposed mechanism to account for the co-carcinogenic actions of arsenic. We and others find that arsenite interferes with the function of certain zinc finger DNA repair proteins. Furthermore, we reported that zinc reverses the effects of arsenite in cultured cells and a DNA repair target protein, poly (ADP-ribose) polymerase-1. In order to determine whether zinc ameliorates the effects of arsenite on UVR-induced DNA damage in human keratinocytes and in an in vivo model, normal human epidermal keratinocytes and SKH-1 hairless mice were exposed to arsenite, zinc or both before solar-simulated (ss) UVR exposure. Poly (ADP-ribose) polymerase activity, DNA damage and mutation frequencies at the Hprt locus were measured in each treatment group in normal human keratinocytes. DNA damage was assessed in vivo by immunohistochemical staining of skin sections isolated from SKH-1 hairless mice. Cell-based findings demonstrate that ssUVR-induced DNA damage and mutagenesis are enhanced by arsenite, and supplemental zinc partially reverses the arsenite effect. In vivo studies confirm that zinc supplementation decreases arsenite-enhanced DNA damage in response to ssUVR exposure. From these data we can conclude that zinc offsets the impact of arsenic on ssUVR-stimulated DNA damage in cells and in vivo suggesting that zinc supplementation may provide a strategy to improve DNA repair capacity in arsenic exposed human populations. - Highlights: • Low levels of arsenite enhance UV-induced DNA damage in human keratinocytes. • UV-initiated HPRT mutation frequency is enhanced by arsenite. • Zinc supplementation offsets DNA damage and mutation frequency enhanced by arsenite. • Zinc-dependent reduction of arsenite enhanced DNA damage is confirmed in vivo.

  19. STEADY-STATE TRANSCRIPT LEVELS OF CYTOCHROME-C-OXIDASE GENES DURING HUMAN MYOGENESIS INDICATE SUBUNIT SWITCHING OF SUBUNIT VIA AND COEXPRESSION OF SUBUNIT VIIA ISOFORMS

    NARCIS (Netherlands)

    TAANMAN, JW; HERZBERG, NH; DEVRIES, H; BOLHUIS, PA; VANDENBOGERT, C

    1992-01-01

    Steady-state levels of the mitochondrial rRNAs, of mRNAs for mitochondrially and nuclear-encoded subunits of cytochrome c oxidase and for the beta-subunit of ATP synthase were assessed by Northern blot hybridizations during the in vitro differentiation of human myoblasts. Transcript levels of the so

  20. Complexation of arsenite with phytochelatins reduces arsenite efflux and translocation from roots to shoots in Arabidopsis.

    Science.gov (United States)

    Liu, Wen-Ju; Wood, B Alan; Raab, Andrea; McGrath, Steve P; Zhao, Fang-Jie; Feldmann, Jörg

    2010-04-01

    Complexation of arsenite [As(III)] with phytochelatins (PCs) is an important mechanism employed by plants to detoxify As; how this complexation affects As mobility was little known. We used high-resolution inductively coupled plasma-mass spectrometry and accurate mass electrospray ionization-mass spectrometry coupled to HPLC to identify and quantify As(III)-thiol complexes and free thiol compounds in Arabidopsis (Arabidopsis thaliana) exposed to arsenate [As(V)]. As(V) was efficiently reduced to As(III) in roots. In wild-type roots, 69% of As was complexed as As(III)-PC4, As(III)-PC3, and As(III)-(PC2)2. Both the glutathione (GSH)-deficient mutant cad2-1 and the PC-deficient mutant cad1-3 were approximately 20 times more sensitive to As(V) than the wild type. In cad1-3 roots, only 8% of As was complexed with GSH as As(III)-(GS)3 and no As(III)-PCs were detected, while in cad2-1 roots, As(III)-PCs accounted for only 25% of the total As. The two mutants had a greater As mobility, with a significantly higher accumulation of As(III) in shoots and 4.5 to 12 times higher shoot-to-root As concentration ratio than the wild type. Roots also effluxed a substantial proportion of the As(V) taken up as As(III) to the external medium, and this efflux was larger in the two mutants. Furthermore, when wild-type plants were exposed to l-buthionine sulfoximine or deprived of sulfur, both As(III) efflux and root-to-shoot translocation were enhanced. The results indicate that complexation of As(III) with PCs in Arabidopsis roots decreases its mobility for both efflux to the external medium and for root-to-shoot translocation. Enhancing PC synthesis in roots may be an effective strategy to reduce As translocation to the edible organs of food crops.

  1. Arsenic methylation by an arsenite S-adenosylmethionine methyltransferase from Spirulina platensis.

    Science.gov (United States)

    Guo, Yuqing; Xue, Ximei; Yan, Yu; Zhu, Yongguan; Yang, Guidi; Ye, Jun

    2016-11-01

    Arsenic-contaminated water is a serious hazard for human health. Plankton plays a critical role in the fate and toxicity of arsenic in water by accumulation and biotransformation. Spirulina platensis (S. platensis), a typical plankton, is often used as a supplement or feed for pharmacy and aquiculture, and may introduce arsenic into the food chain, resulting in a risk to human health. However, there are few studies about how S. platensis biotransforms arsenic. In this study, we investigated arsenic biotransformation by S. platensis. When exposed to arsenite (As(III)), S. platensis accumulated arsenic up to 4.1mg/kg dry weight. After exposure to As(III), arsenate (As(V)) was the predominant species making up 64% to 86% of the total arsenic. Monomethylarsenate (MMA(V)) and dimethylarsenate (DMA(V)) were also detected. An arsenite S-adenosylmethionine methyltransferase from S. platensis (SpArsM) was identified and characterized. SpArsM showed low identity with other reported ArsM enzymes. The Escherichia coli AW3110 bearing SparsM gene resulted in As(III) methylation and conferring resistance to As(III). The in vitro assay showed that SpArsM exhibited As(III) methylation activity. DMA(V) and a small amount of MMA(V) were detected in the reaction system within 0.5hr. A truncated SpArsM derivative lacking the last 34 residues still had the ability to methylate As(III). The three single mutants of SpArsM (C59S, C186S, and C238S) abolished the capability of As(III) methylation, suggesting the three cysteine residues are involved in catalysis. We propose that SpArsM is responsible for As methylation and detoxification of As(III) and may contribute to As biogeochemistry.

  2. Effect of sodium arsenite on the gene and protein expression of p53, mdm2 and Kras in islet cells%亚砷酸钠对胰岛细胞中 p53、mdm2和Kras基因及蛋白表达的影响

    Institute of Scientific and Technical Information of China (English)

    姚晓峰; 孙睿; 姜丽平; 耿成燕; 仲来福; 郑白璐; 杨光; 刘爽; 孙鲜策

    2014-01-01

    Objective To investigate the effect of sodium arsenite on p53, mdm2 and Kras expressions in islet βcells (INS-1) of rat.Methods The levels of wild type p53 (Tp53), mdm2 and Kras in sodium arsenite-treated rat islet βcells were detected by real-time PCR.The expression of mutant p53 and mdm2 protein were detected by western blot. Results After treatment with sodium arsenite, the level of Tp53 decreased, but those of mdm2、Kras increased.The protein expressions of mutant p53 and mdm2 increased.Conclusion Sodium arsenite could induce the transformation of Tp53 to mutant p53, and increase the level of mdm2 and Kras in INS-1 cells.%目的:探讨砷对大鼠胰岛β细胞(INS-1)p53、mdm2和Kras基因和蛋白表达的影响。方法荧光实时定量PCR法检测亚砷酸钠对大鼠胰岛β细胞中野生型p53(Tp53)、mdm2和Kras基因表达的影响,Western blot检测亚砷酸钠对大鼠胰岛β细胞突变型p53和mdm2蛋白表达的影响。结果亚砷酸钠作用于INS-1细胞后,Tp53基因水平降低,mdm2、Kras基因水平升高;突变型p53和mdm2蛋白表达增加。结论亚砷酸钠可使INS-1细胞中抑癌基因Tp53向突变型p53转变,癌基因mdm2和Kras的水平升高。

  3. Autecology of an arsenite chemolithotroph: sulfide constraints on function and distribution in a geothermal spring.

    Science.gov (United States)

    D'Imperio, Seth; Lehr, Corinne R; Breary, Michele; McDermott, Timothy R

    2007-11-01

    Previous studies in an acid-sulfate-chloride spring in Yellowstone National Park found that microbial arsenite [As(III)] oxidation is absent in regions of the spring outflow channel where H(2)S exceeds approximately 5 microM and served as a backdrop for continued efforts in the present study. Ex situ assays with microbial mat samples demonstrated immediate As(III) oxidation activity when H(2)S was absent or at low concentrations, suggesting the presence of As(III) oxidase enzymes that could be reactivated if H(2)S is removed. Cultivation experiments initiated with mat samples taken from along the H(2)S gradient in the outflow channel resulted in the isolation of an As(III)-oxidizing chemolithotroph from the low-H(2)S region of the gradient. The isolate was phylogenetically related to Acidicaldus and was characterized in vitro for spring-relevant properties, which were then compared to its distribution pattern in the spring as determined by denaturing gradient gel electrophoresis and quantitative PCR. While neither temperature nor oxygen requirements appeared to be related to the occurrence of this organism within the outflow channel, H(2)S concentration appeared to be an important constraint. This was verified by in vitro pure-culture modeling and kinetic experiments, which suggested that H(2)S inhibition of As(III) oxidation is uncompetitive in nature. In summary, the studies reported herein illustrate that H(2)S is a potent inhibitor of As(III) oxidation and will influence the niche opportunities and population distribution of As(III) chemolithotrophs.

  4. Mitochondrial cytochrome c oxidase deficiency.

    Science.gov (United States)

    Rak, Malgorzata; Bénit, Paule; Chrétien, Dominique; Bouchereau, Juliette; Schiff, Manuel; El-Khoury, Riyad; Tzagoloff, Alexander; Rustin, Pierre

    2016-03-01

    As with other mitochondrial respiratory chain components, marked clinical and genetic heterogeneity is observed in patients with a cytochrome c oxidase deficiency. This constitutes a considerable diagnostic challenge and raises a number of puzzling questions. So far, pathological mutations have been reported in more than 30 genes, in both mitochondrial and nuclear DNA, affecting either structural subunits of the enzyme or proteins involved in its biogenesis. In this review, we discuss the possible causes of the discrepancy between the spectacular advances made in the identification of the molecular bases of cytochrome oxidase deficiency and the lack of any efficient treatment in diseases resulting from such deficiencies. This brings back many unsolved questions related to the frequent delay of clinical manifestation, variable course and severity, and tissue-involvement often associated with these diseases. In this context, we stress the importance of studying different models of these diseases, but also discuss the limitations encountered in most available disease models. In the future, with the possible exception of replacement therapy using genes, cells or organs, a better understanding of underlying mechanism(s) of these mitochondrial diseases is presumably required to develop efficient therapy.

  5. Characterization of polyphenol oxidase from plants

    Institute of Scientific and Technical Information of China (English)

    LEI Dongfeng; FENG Yi; JIANG Dazong

    2004-01-01

    Polyphenol oxidase (PPO) which can mediate browning reaction is a bifunctional copper-containing enzyme encoded by plant nucleolus gene. It usually leads to excessive browning reaction which reduces the coercial profits of fruits and vegetables. In this paper, PPO genes and enzymes in plants are characterized systematically, and the latest progress is reviewed. Some clonings of PPOs genes are reported; the specific temporal and spatial expression pattern of PPOs genes is described; the model of the structure of the precursor form of catechol oxidase is introduced; the possible functions of PPOs in defending against pathogen, wounding, surrounding stress and other inducing factors are demonstrated; the induction and activation of latent PPOs in some plants is elucidated; the scheme of browning inhibition by L-cysteine is clarified; the mechanism of suicide inhibition of latent PPO and kinetic synergism are established. Furthermore, the area for future study is also discussed.

  6. Aqueous and ethanolic leaf extracts of Ocimum basilicum (sweet basil) protect against sodium arsenite-induced hepatotoxicity in Wistar rats.

    Science.gov (United States)

    Gbadegesin, M A; Odunola, O A

    2010-11-25

    We evaluated the effects of aqueous and ethanolic leaf extracts of Ocimum basilicum (sweet basil) on sodium arsenite-induced hepatotoxicity in Wistar rats. We observed that treatment of the animals with the extracts before or just after sodium arsenite administration significantly (p basilicum before the administration of sodium arsenite resulted in the attenuation of the sodium arsenite-induced aspartate and alanine aminotransferase activities: ALT (from 282.6% to 167.7% and 157.8%), AST (from 325.1% to 173.5% and 164.2%) for the group administered sodium arsenite alone, the aqueous extracts plus sodium arsenite, and ethanolic extracts plus sodium arsenite respectively, expressed as percentage of the negative control. These findings support the presence of hepatoprotective activity in the O.basilicum extracts.

  7. Effect of arsenite-oxidizing bacterium B. laterosporus on arsenite toxicity and arsenic translocation in rice seedlings.

    Science.gov (United States)

    Yang, Gui-Di; Xie, Wan-Ying; Zhu, Xi; Huang, Yi; Yang, Xiao-Jun; Qiu, Zong-Qing; Lv, Zhen-Mao; Wang, Wen-Na; Lin, Wen-Xiong

    2015-10-01

    Arsenite [As (III)] oxidation can be accelerated by bacterial catalysis, but the effects of the accelerated oxidation on arsenic toxicity and translocation in rice plants are poorly understood. Herein we investigated how an arsenite-oxidizing bacterium, namely Brevibacillus laterosporus, influences As (III) toxicity and translocation in rice plants. Rice seedlings of four cultivars, namely Guangyou Ming 118 (GM), Teyou Hang II (TH), Shanyou 63 (SY) and Minghui 63 (MH), inoculated with or without the bacterium were grown hydroponically with As (III) to investigate its effects on arsenic toxicity and translocation in the plants. Percentages of As (III) oxidation in the solutions with the bacterium (100%) were all significantly higher than those without (30-72%). The addition of the bacterium significantly decreased As (III) concentrations in SY root, GM root and shoot, while increased the As (III) concentrations in the shoot of SY, MH and TH and in the root of MH. Furthermore, the As (III) concentrations in the root and shoot of SY were both the lowest among the treatments with the bacterium. On the other hand, its addition significantly alleviated the As (III) toxicity on four rice cultivars. Among the treatments amended with B. laterosporus, the bacterium showed the best remediation on SY seedlings, with respect to the subdued As (III) toxicity and decreased As (III) concentration in its roots. These results indicated that As (III) oxidation accelerated by B. laterosporus could be an effective method to alleviate As (III) toxicity on rice seedlings.

  8. Arsenite Sorption by Drinking-Water Treatment Residuals: Redox Effects

    Science.gov (United States)

    Makris, K. C.; Sarkar, D.; Datta, R.

    2005-05-01

    Arsenic (As) is a major human carcinogen and could pose a serious human health risk at concentrations as low as 50 ppb in drinking water. Elevated As concentrations in soils currently used for residential purposes (located on former agricultural lands amended with arsenical pesticides) have increased the possibility of human contact with soil-As. Studies have shown that As bioavailability in the environment is primarily a function of its chemical speciation, which depends upon the redox potential. Arsenic toxicity and carcinogenicity to living organisms is primarily due to exposure to the reduced species of As - arsenite, i.e., As(III), rather than the oxidized species - arsenate, i.e., As(V); the mobility of As(III) is much higher than As(V). One of the most promising methods to decrease the mobility of arsenite in the soil-water system is promoting its retention onto amorphous Fe/Al hydroxides. Drinking-Water Treatment Residuals (WTRs) are an inexpensive source of such Fe/Al hydroxides, which can be land-applied following the USEPA-regulated biosolids application rules. The WTRs are byproducts of drinking-water purification processes and generally contain sediment, organic carbon, and Al/Fe hydroxides. The hydroxides are typically amorphous and have tremendous affinity for oxyanions (e.g., arsenate). Preliminary work showed that WTRs are characterized by large internal surface area and porosity that partly explains their high affinity for As(V). The current study examines the potential of two WTRs (Fe-based and Al-based) to adsorb arsenite from solution. We hypothesize that As(III) adsorption onto the Fe-based WTR (whose stability is highly redox-sensitive) would be vastly different from the adsorption of As(III) onto the redox-insensitive Al-based WTR. Our main objective is to characterize As(III) sorption by both Fe- and Al-based WTRs by changing critical factors, such as the solid:solution ratio, contact time, and initial As(III) load. Results from this study

  9. Molecular characterization of Fasciola hepatica and phylogenetic analysis based on mitochondrial (nicotiamide adenine dinucleotide dehydrogenase subunit I and cytochrome oxidase subunit I) genes from the North-East of Iran

    Science.gov (United States)

    Reaghi, Saber; Haghighi, Ali; Harandi, Majid Fasihi; Spotin, Adel; Arzamani, Kourosh; Rouhani, Soheila

    2016-01-01

    Aim: Fascioliasis is one of the most zoonotic diseases with global extension. As the epidemiological distribution of Fasciola may lead to various genetic patterns of the parasite, the aim of this study is to identify Fasciola hepatica based on spermatogenesis, and phylogenetic analysis using mitochondrial (nicotiamide adenine dinucleotide dehydrogenase subunit I [ND1] and cytochrome oxidase subunit I) gene marker. Materials and Methods: In this study, 90 F. hepatica collected from 30 cattle at slaughterhouse located in three different geographical locations in the North-East of Iran were evaluated based on spermatogenetic ability and internal transcribed spacer 1 gene restriction fragment length polymorphism pattern. Genetic diversity and phylogenetic relationship using mtDNA gene marker for the isolates from the North-East of Iran, and other countries were then analyzed. Results: Partial sequences of mtDNA showed eight haplotypes in both genes. The phylogenic analysis using neighbor joining as well as maximum likelihood methods showed similar topologies of trees. Pairwise fixation index between different F. hepatica populations calculated from the nucleotide data set of ND1 gene are statistically significant and show the genetic difference. Conclusion: F. hepatica found in this region of Iran has different genetic structures through the other Fasciola populations in the world. PMID:27733809

  10. Purification and characterization of a novel caffeine oxidase from Alcaligenes species.

    Science.gov (United States)

    Mohapatra, B R; Harris, N; Nordin, R; Mazumder, A

    2006-09-18

    Alcaligenes species CF8 isolated from surface water of a lake produced a novel serine type metallo-caffeine oxidase. The optimal medium for caffeine oxidase production by this strain was (w/v) NaNO(3), 0.4%; KH(2)PO(4), 0.15%; Na(2)HPO(4), 0.05%; FeCl(3).6H(2)O, 0.0005%; CaCl(2).2H(2)O, 0.001%; MgSO(4).7H(2)O, 0.02%; glucose, 0.2%; caffeine, 0.05%, pH 7.5. The enzyme was purified to 63-fold by using ammonium sulfate precipitation, dialysis, ion exchange (diethylaminoethyl-cellulose) and gel filtration (Sephadex G-100) chromatographic techniques. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that the purified caffeine oxidase was monomeric with a molecular mass of 65 kDa. The purified caffeine oxidase with a half-life of 20 min at 50 degrees C had maximal activity at pH 7.5 and 35 degrees C. The purified caffeine oxidase had strict substrate specificity towards caffeine (K(m) 8.94 microM and V(max) 47.62 U mg protein(-1)) and was not able to oxidize xanthine and hypoxanthine. The enzyme activity was not inhibited by para-chloromercuribenzoic acid, iodoacetamide, n-methylmaleimide, salicylic acid and sodium arsenite indicating the enzyme did not belong to xanthine oxidase family. The enzyme was not affected by Ca(+2), Mg(+2) and Na(+), but was completely inhibited by Co(+2), Cu(+2) and Mn(+2) at 1mM level. The novel caffeine oxidase isolated here from Alcaligenes species CF8 may be useful in biotechnological processes including waste treatment and biosensor development.

  11. Metalloid tolerance based on phytochelatins is not functionally equivalent to the arsenite transporter Acr3p.

    Science.gov (United States)

    Wysocki, Robert; Clemens, Stephan; Augustyniak, Daria; Golik, Pawel; Maciaszczyk, Ewa; Tamás, Markus J; Dziadkowiec, Dorota

    2003-05-01

    Active transport of metalloids by Acr3p and Ycf1p in Saccharomyces cerevisiae and chelation by phytochelatins in Schizosaccharomyces pombe, nematodes, and plants represent distinct strategies of metalloid detoxification. In this report, we present results of functional comparison of both resistance mechanisms. The S. pombe and wheat phytochelatin synthase (PCS) genes, when expressed in S. cerevisiae, mediate only modest resistance to arsenite and thus cannot functionally compensate for Acr3p. On the other hand, we show for the first time that phytochelatins also contribute to antimony tolerance as PCS fully complement antimonite sensitivity of ycf1Delta mutant. Remarkably, heterologous expression of PCS sensitizes S. cerevisiae to arsenate, while ACR3 confers much higher arsenic resistance in pcsDelta than in wild-type S. pombe. The analysis of PCS and ACR3 homologues distribution in various organisms and our experimental data suggest that separation of ACR3 and PCS genes may lead to the optimal tolerance status of the cell.

  12. COMPARATIVE GENOTOXIC RESPONSES TO ARSENITE IN GUINEA PIG, MOUSE, RAT AND HUMAN LYMPHOCYTES

    Science.gov (United States)

    Comparative genotoxic responses to arsenite in guinea pig, mouse, rat and human lymphocytes.Inorganic arsenic is a known human carcinogen causing skin, lung, and bladder cancer following chronic exposures. Yet, long-term laboratory animal carcinogenicity studies have ...

  13. Synergistic effect of radon and sodium arsenite on DNA damage in HBE cells.

    Science.gov (United States)

    Liu, Xing; Sun, Bin; Wang, Xiaojuan; Nie, Jihua; Chen, Zhihai; An, Yan; Tong, Jian

    2016-01-01

    Human epidemiological studies showed that radon and arsenic exposures are major risk factors for lung cancer in Yunnan tin miners. However, biological evidence for this phenomenon is absent. In this study, HBE cells were exposed to different concentrations of sodium arsenite, different radon exposure times, or a combination of these two factors. The results showed a synergistic effect of radon and sodium arsenite in cell cytotoxicity as determined by cell viability. Elevated intracellular ROS levels and increased DNA damage indexed by comet assay and γ-H2AX were detected. Moreover, DNA HR repair in terms of Rad51 declined when the cells were exposed to both radon and sodium arsenite. The synergistic effect of radon and sodium arsenite in HBE cells may be attributed to the enhanced DSBs and inhibited HR pathway upon co-exposure.

  14. Selenite modulates the level of phenolics and nutrient element to alleviate the toxicity of arsenite in rice (Oryza sativa L.).

    Science.gov (United States)

    Chauhan, Reshu; Awasthi, Surabhi; Tripathi, Preeti; Mishra, Seema; Dwivedi, Sanjay; Niranjan, Abhishek; Mallick, Shekhar; Tripathi, Pratibha; Pande, Veena; Tripathi, Rudra Deo

    2017-04-01

    Arsenic (As) contamination of paddy rice is a serious threat all over the world particularly in South East Asia. Selenium (Se) plays important role in protection of plants against various abiotic stresses including heavy metals. Moreover, arsenite (AsIII) and selenite (SeIV) can be biologically antagonistic due to similar electronic configuration and sharing the common transporter for their uptake in plant. In the present study, the response of oxidative stress, phenolic compounds and nutrient elements was analyzed to investigate Se mediated As tolerance in rice seedlings during AsIII and SeIV exposure in hydroponics. Selenite (25µM) significantly decreased As accumulation in plant than As (25µM) alone treated plants. Level of oxidative stress related parameters viz., reactive oxygen species (ROS), lipid peroxidation, electrical conductivity, nitric oxide and pro-oxidant enzyme (NADPH oxidase), were in the order of As>As+Se>control>Se. Selenium ameliorated As phytotoxicity by increased level of phenolic compounds particularly gallic acid, protocatechuic acid, ferulic acid and rutin and thiol metabolism related enzymes viz., serine acetyl transferase (SAT) and cysteine synthase (CS). Selenium supplementation enhanced the uptake of nutrient elements viz., Fe, Mn, Co, Cu, Zn, Mo, and improved plant growth. The results concluded that Se addition in As contaminated environment might be an important strategy to reduce As uptake and associated phytotoxicity in rice plant by modulation of phenolic compounds and increased uptake of nutrient elements.

  15. Identification of Bovine, Pig and Duck Meat Species in Mixtures and in Meat Products on the Basis of the mtDNA Cytochrome Oxidase Subunit I (COI Gene Sequence

    Directory of Open Access Journals (Sweden)

    Spychaj Anita

    2016-03-01

    Full Text Available The aim of this study was to develop a method using PCR and self-designed primers on the basis of the mtDNA cytochrome oxidase subunit I (COI gene sequence to enable direct identification of the meat of three species of animals, i.e. bovines, pigs and ducks, in the single type sample, in meat mixtures and meat products. The mixtures comprised up to six meat species including apart from beef, pork and duck also chicken, turkey and goose meat. The obtained results indicate the possibility of qualitative identification of the aforementioned meat species in all types of investigated food products. The maximum length of PCR products did not exceed 300 bp, which was supposed to favour the amplification of DNA from meat products which are usually thermally processed and/or exposed to high pressure. PCR primers hybridised selectively with bovine, pig and duck DNA, showing total species specificity.

  16. Silymarin protects plasma membrane and acrosome integrity in sperm treated with sodium arsenite

    Directory of Open Access Journals (Sweden)

    Farzaneh Eskandari

    2016-01-01

    Full Text Available Background: Exposure to arsenic is associated with impairment of male reproductive function by inducing oxidative stress. Silymarin with an antioxidant property scavenges free radicals. Objective: The aim of this study was to investigate if silymarin can prevent the adverse effects of sodium arsenite on ram sperm plasma membrane and acrosome integrity. Materials and Methods: Ram epidydimal spermatozoa were divided into five groups: spermatozoa at 0 hr, spermatozoa at 180 min (control, spermatozoa treated with silymarin (20 μM + sodium arsenite (10 μM for 180 min, spermatozoa treated with sodium arsenite (10 μM for 180 min and spermatozoa treated with silymarin (20 μM for 180 min. Double staining of Hoechst and propidium iodide was performed to evaluate sperm plasma membrane integrity, whereas comassie brilliant blue staining was used to assess acrosome integrity. Results: Plasma membrane (p< 0.001 and acrosome integrity (p< 0.05 of the spermatozoa were significantly reduced in sodium arsenite group compared to the control. In silymarin + sodium arsenite group, silymarin was able to significantly (p< 0.001 ameliorate the adverse effects of sodium arsenite on these sperm parameters compared to sodium arsenite group. The incubation of sperm for 180 min (control group showed a significant (p< 0.001 decrease in acrosome integrity compared to the spermatozoa at 0 hour. The application of silymarin alone for 180 min could also significantly (p< 0.05 increase sperm acrosome integrity compared to the control. Conclusion: Silymarin as a potent antioxidant could compensate the adverse effects of sodium arsenite on the ram sperm plasma membrane and acrosome integrity.

  17. Identification of DNA-binding proteins that interact with the 5'-flanking region of the human D-amino acid oxidase gene by pull-down assay coupled with two-dimensional gel electrophoresis and mass spectrometry.

    Science.gov (United States)

    Tran, Diem Hong; Shishido, Yuji; Chung, Seong Pil; Trinh, Huong Thi Thanh; Yorita, Kazuko; Sakai, Takashi; Fukui, Kiyoshi

    2015-12-10

    D-Amino acid oxidase (DAO) is a flavoenzyme that metabolizes D-amino acids and is expected to be a promising therapeutic target of schizophrenia and glioblastoma. The study of DNA-binding proteins has yielded much information in the regulation of transcription and other biological processes. However, proteins interacting with DAO gene have not been elucidated. Our assessment of human DAO promoter activity using luciferase reporter system indicated the 5'-flanking region of this gene (-4289 bp from transcription initiation site) has a regulatory sequence for gene expression, which is regulated by multi-protein complexes interacting with this region. By using pull-down assay coupled with two-dimensional gel electrophoresis and mass spectrometry, we identified six proteins binding to the 5'-flanking region of the human DAO gene (zinc finger C2HC domain-containing protein 1A; histidine-tRNA ligase, cytoplasmic; molybdenum cofactor biosynthesis protein; 60S ribosomal protein L37; calponin-1; calmodulin binding protein and heterogeneous nuclear ribonucleoprotein A2/B1). These preliminary results will contribute to the advance in the understanding of the potential factors associated with the regulatory mechanism of DAO expression.

  18. Monoamine Oxidase A (MAOA) and Catechol-O-Methyltransferase (COMT) Gene Polymorphisms Interact with Maternal Parenting in Association with Adolescent Reactive Aggression but not Proactive Aggression: Evidence of Differential Susceptibility.

    Science.gov (United States)

    Zhang, Wenxin; Cao, Cong; Wang, Meiping; Ji, Linqin; Cao, Yanmiao

    2016-04-01

    To date, whether and how gene-environment (G × E) interactions operate differently across distinct subtypes of aggression remains untested. More recently, in contrast with the diathesis-stress hypothesis, an alternative hypothesis of differential susceptibility proposes that individuals could be differentially susceptible to environments depending on their genotypes in a "for better and for worse" manner. The current study examined interactions between monoamine oxidase A (MAOA) T941G and catechol-O-methyltransferase (COMT) Val158Met polymorphisms with maternal parenting on two types of aggression: reactive and proactive. Moreover, whether these potential G × E interactions would be consistent with the diathesis-stress versus the differential susceptibility hypothesis was tested. Within the sample of 1399 Chinese Han adolescents (47.2 % girls, M age = 12.32 years, SD = 0.50), MAOA and COMT genes both interacted with positive parenting in their associations with reactive but not proactive aggression. Adolescents with T alleles/TT homozygotes of MAOA gene or Met alleles of COMT gene exhibited more reactive aggression when exposed to low positive parenting, but less reactive aggression when exposed to high positive parenting. These findings provide the first evidence for distinct G × E interaction effects on reactive versus proactive aggression and lend further support for the differential susceptibility hypothesis.

  19. Transporters of arsenite in rice and their role in arsenic accumulation in rice grain.

    Science.gov (United States)

    Ma, Jian Feng; Yamaji, Naoki; Mitani, Namiki; Xu, Xiao-Yan; Su, Yu-Hong; McGrath, Steve P; Zhao, Fang-Jie

    2008-07-22

    Arsenic poisoning affects millions of people worldwide. Human arsenic intake from rice consumption can be substantial because rice is particularly efficient in assimilating arsenic from paddy soils, although the mechanism has not been elucidated. Here we report that two different types of transporters mediate transport of arsenite, the predominant form of arsenic in paddy soil, from the external medium to the xylem. Transporters belonging to the NIP subfamily of aquaporins in rice are permeable to arsenite but not to arsenate. Mutation in OsNIP2;1 (Lsi1, a silicon influx transporter) significantly decreases arsenite uptake. Furthermore, in the rice mutants defective in the silicon efflux transporter Lsi2, arsenite transport to the xylem and accumulation in shoots and grain decreased greatly. Mutation in Lsi2 had a much greater impact on arsenic accumulation in shoots and grain in field-grown rice than Lsi1. Arsenite transport in rice roots therefore shares the same highly efficient pathway as silicon, which explains why rice is efficient in arsenic accumulation. Our results provide insight into the uptake mechanism of arsenite in rice and strategies for reducing arsenic accumulation in grain for enhanced food safety.

  20. [Molecular phylogeny and the time of divergence of minges (Chironomidae, Nematocera, Diptera) inferred from a partial nucleotide sequence of the cytochrome oxidase I gene (COI)].

    Science.gov (United States)

    Demin, A G; Polukonova, N V; Miuge, N S

    2011-10-01

    This is the first study to infer the phylogenetic structure of minges of the subfamily Chironominae from the amino acid sequence of cytochrome oxidase I (COI). The subdivision of Chironominae into two tribes, Chironomini and Tanytarsini, has been confirmed. The segregation of the genera Pseudochironomus and Riethia into a separate tribe has not been confirmed. Stenochironomus gibbus forms a branch considerably deviating from the subfamily Chironominae. The genus Micropsectra is formed by a large polyphyletic cluster that also includes the genera Virgotanytharsus, Reotanytharsus, Kenopsectra, and Parapsectra. Tanytarsus is the basal genus of the tribe Tanytarsini. The times of divergence of the main taxa of Chironominae have been estimated. The calculated time of divergence of the genus Chironomus disproves the assumption that it is phylogenetically old.

  1. 家蚕磷酸吡哆醇氧化酶基因的表达谱分析%Expression profiling of pyridoxine 5’-phosphate oxidase gene in Bombyx mori

    Institute of Scientific and Technical Information of China (English)

    葛俊楠; 张剑韵; 黄龙全

    2011-01-01

    [Aim] The expression profile of gene encoding pyridoxine phosphate oxidase (PNPO) , which is a key enzyme related to VB6 metabolism, was analyzed in different developmental stages and tissues of the 5th instar larvae of Bombyx mori. [ Methods ] The recombinant plasmid pET-22b ( + ) -PNPO was transformed to Escherichia coli Rosetta for induction, expression and purification of PNPO, and then the polyclonal antibody was prepared. The expression profile of PNPO gene was analyzed by Real-time PCR and Western blot, respectively. [ Results ] The highest translation level of PNPO gene was found in the 5th instar larvae. The transcription level in tissues of 5th instar larvae was in sequence of testis > head > tnidgut > Malpighian tubules > ovary > cuticle > fat body > silk glands. However, the highest translation level was found in testis, and then was in head, midgut, and malpighian tubules, respectively. [ Conclusion ] The expression profile PNPO gene in B. Mori has been defined by this study.%目的 了解家蚕Bombyx mori维生素B6关键代谢酶磷酸吡哆醇氧化酶(pyridoxine-5'-phosphate oxidase,PNPO)基因在家蚕不同发育阶段及5龄幼虫不同组织中的表达差异.方法 将家蚕PNPO基因的重组表达质粒pET-22b(+)-PNPO转化入大肠杆菌Escherichia coli Rosetta中诱导表达,纯化蛋白制备多克隆抗体.分别采用荧光定量PCR和Western blot方法对家蚕PNPO基因进行了转录水平和翻译水平的表达分析.结果 在家蚕发育水平上,5龄幼虫的PNPO翻译量为最高.PNPO基因在5龄幼虫各组织中的转录水平由高到低依次为精巢、头、中肠、马氏管、卵巢、表皮、脂肪体、丝腺;翻译量也以精巢为最高,其次是头、中肠和马氏管.结论 明确了PNPO在家蚕各发育阶段及5龄幼虫各组织中的表达情况.

  2. 亚砷酸钠对HaCaT细胞中DNMT1、HDAC1基因mRNA转录及蛋白表达的影响%Effects of Sodium Arsenite on Transcription and Expression of DNA Methyltransferase 1 (DNMT1) and Histone Deacetylase 1 (HDAC1) Gene in HaCaT Cells

    Institute of Scientific and Technical Information of China (English)

    潘雪莉; 张爱华

    2011-01-01

    Objective To observe the influences of different doses of sodium .arsenite on mRNA transcription and protein expression of DNA methyltransferase 1 (DNMTl) and histone deacetylase 1 (HDA Cl) gene in HaCaT cells. Methods HaCaT cells were treated with NaAsO2 at the doses of 0, 3.13, 6.25, 12.5,25 μmol/L, every other day, 24 h one time, for three times.The mRNA transcription of DNMT1 and HDA Cl was detected by real-time quantitative PCR, the protein expression of DNMT1 and HDAC1 was detected by Western blot. Human epidermal squamous carcinoma cell line A431 cells were set as the positive control group. Results Among the groups of HaCaT cells treated by 0, 3.13, 6.25, 12.5 and 25μmol/L NaAsO2, the level of DNMT1 mRNA transcription were 0.650 90±0.174 05, 0.930 53±0.145 56, 0.752 93±0.244 62, 0.558 1l ±0.051 02 and 0.370 17±0.08 84, the differences were significant (F=6.539, P<0.05); the level of HDAC1 mRNA transcription were 2.02180±0.179 57,1.496 98±0.107 55, 1.303 24±0.152 08, 1.037 75±0.204 88 and 0.816 74±0.153 12, the differences were significant(F=17.914,P<0.05). The level of DNMT1 protein expression were 0.000 87±0.000 10, 0.026 04±0.002 63, 0.283 19±0.072 62, 0.842 61±0.082 39 and 1.579 87±0.200 83, the differences were significant(F=27.799, P<0.05); the level of HDACl protein expression were 0.034 65±0.012 03, 0.273 65±0.012 02, 0.634 90±0.239 76, 0.775 03±0.126 51 and 1.126 16±0.167 52, the differences were significant(F=9.820, P<0.05). Conclusion DNMT1 and HDACl protein high expression is the important molecular event of arsenic-induced skin lesion, which may provide the possibility for using its inhibitors to explore the arsenic poisoning prevention and treatment.%目的 了解不同剂量的亚砷酸钠(NaAsO2)对人皮肤角质形成细胞(HaCaT细胞)中DNA甲基转移酶1(DNMT1)、组蛋白去乙酰化酶1(HDAC1)基因mRNA转录和蛋白表达的影响.方法 分别以0、3.13、6.25、12.5和25μmol/L NaAsO2溶液

  3. The defensive effect of benfotiamine in sodium arsenite-induced experimental vascular endothelial dysfunction.

    Science.gov (United States)

    Verma, Sanjali; Reddy, Krishna; Balakumar, Pitchai

    2010-10-01

    The present study has been designed to investigate the effect of benfotiamine, a thiamine derivative, in sodium arsenite-induced vascular endothelial dysfunction (VED) in rats. Sodium arsenite (1.5 mg(-1) kg(-1) day(-1) i.p., 2 weeks) was administered in rats to produce VED. The development of VED was assessed by employing isolated aortic ring preparation and estimating the serum and aortic concentrations of nitrite/nitrate. Further, the integrity of vascular endothelium in thoracic aorta was assessed by scanning electron microscopy. Moreover, the oxidative stress was assessed by estimating serum thiobarbituric acid reactive substances (TBARS) and aortic superoxide anion generation. The administration of sodium arsenite markedly produced VED by attenuating acetylcholine-induced endothelium-dependent relaxation, decreasing serum and aortic concentrations of nitrite/nitrate, and impairing the integrity of vascular endothelium. Further, sodium arsenite produced oxidative stress by increasing serum TBARS and aortic superoxide generation. The treatment with benfotiamine (25, 50, and 100 mg(-1) kg(-1) day(-1) p.o.) or atorvastatin (30 mg(-1) kg(-1) day(-1) p.o., a standard agent) prevented sodium arsenite-induced VED and oxidative stress. However, the beneficial effects of benfotiamine in preventing the sodium arsenite-induced VED were attenuated by co-administration with N-omega-nitro-L: -arginine methyl ester (L: -NAME) (25 mg(-1) kg(-1) day(-1), i.p.), an inhibitor of NOS. Thus, it may be concluded that benfotiamine reduces oxidative stress and activates endothelial nitric oxide synthase to enhance the generation and bioavailability of NO and subsequently improves the integrity of vascular endothelium to prevent sodium arsenite-induced experimental VED.

  4. Physico chemical studies on the composition of complex arsenites of metals Part IV: conductometric and potentiometric studies on the composition of cadmium arsenite

    Directory of Open Access Journals (Sweden)

    M. S. Bhadraver

    1962-07-01

    Full Text Available The formation and precipitation of cadmium arsenite has been studied by conductometric and potentiometric titrations between cadmium nitrate and sodium arsenite (meta at different concentrations with either of the substances used as the reagent in titration. In the case of direct titrations (cadmium nitrate added to sodium arsenite in the conductivity cell, one distinct break in the curves is observed corresponding to the formation of the Cd (AsO/sub 2//sub 2/ where the molecular ratio is 2:1. The direct and reverse potentiometric titrations curves give one maxima in dE/dV at point corresponding to the formation of the complex Cd (AsO/sub/2/sub/2 where the molecular ratio of reactants Cd:AsO/sub/2 is 1:2. The composition has been arrived at by comparing the calculated values with observed values by conductometric and potentiometric titrations. The composition of cadmium arsenite arrived at both by conductometry and potentiometry is best representative as Cd(AsO/sub/2/sub/2

  5. Lysyl Oxidase Gene G473A Polymorphism and Cigarette Smoking in Association with a High Risk of Lung and Colorectal Cancers in a North Chinese Population

    Directory of Open Access Journals (Sweden)

    Guoli Wang

    2016-06-01

    Full Text Available The relationship among the lysyl oxidase (LOX G473A single nucleotide polymorphism (SNP, cigarette smoking and lung, colorectal, colon and rectum cancer susceptibility was studied in 200 cases of lung cancer, 335 cases of colorectal cancer including 130 cases of colon cancer and 205 cases of rectum cancer, and 335 healthy people in Tangshan, China. Peripheral blood DNA samples were collected, DNA sequencing and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP performed, followed by multivariate logistic regression analysis. In comparison to LOX473GG genotype carriers, individuals with LOX473AA exhibited a higher susceptibility to lung, colon-rectum, colon, and rectum cancers with OR values amounting to 3.84-, 2.74-, 2.75-, and 2.74-fold of the control, respectively. In the LOX 473AA-positive population, females were more susceptible than males to carcinogenesis with OR values (female vs. male: 5.25 vs. 3.23, 2.29 vs. 1.51, 2.27 vs. 1.45, and 2.25 vs. 1.53, respectively, for lung, colon-rectum combined, colon, and rectum cancers. LOX G473A polymorphism apparently elevated human sensitivity to cigarette smoking carcinogens for eliciting cancers in the lung and colon only. Thus, LOX G473A polymorphism positively correlates with carcinogenesis and it may be used as an ideal intrinsic biomarker for prediction or diagnosis of carcinogenesis in humans.

  6. Improved detection of malaria cases in island settings of Vanuatu and Kenya by PCR that targets the Plasmodium mitochondrial cytochrome c oxidase III (cox3) gene.

    Science.gov (United States)

    Isozumi, Rie; Fukui, Mayumi; Kaneko, Akira; Chan, Chim W; Kawamoto, Fumihiko; Kimura, Masatsugu

    2015-06-01

    Detection of sub-microscopic parasitemia is crucial for all malaria elimination programs. PCR-based methods have proven to be sensitive, but two rounds of amplification (nested PCR) are often needed to detect the presence of Plasmodium DNA. To simplify the detection process, we designed a nested PCR method whereby only the primary PCR is required for the detection of the four major human Plasmodium species. Primers designed for the detection of the fifth species, Plasmodium knowlesi, were not included in this study due to the absence of appropriate field samples. Compared to the standard 18S rDNA PCR method, our cytochrome c oxidase III (cox3) method detected 10-50% more cases while maintaining high sensitivities (1.00) for all four Plasmodium species in our samples from Vanuatu (n=77) and Kenya (n=76). Improvement in detection efficiency was more substantial for samples with sub-microscopic parasitemia (54%) than those with observable parasitemia (10-16%). Our method will contribute to improved malaria surveillance in low endemicity settings.

  7. Adaptation of a methanogenic consortium to arsenite inhibition.

    Science.gov (United States)

    Rodriguez-Freire, Lucia; Moore, Sarah E; Sierra-Alvarez, Reyes; Field, James A

    2015-12-01

    Arsenic (As) is a ubiquitous metalloid known for its adverse effects to human health. Microorganisms are also impacted by As toxicity, including methanogenic archaea, which can affect the performance of process in which biological activity is required (i.e. stabilization of activated sludge in wastewater treatment plants). The novel ability of a mixed methanogenic granular sludge consortium to adapt to the inhibitory effect of arsenic (As) was investigated by exposing the culture to approximately 0.92 mM of As(III) for 160 d in an arsenate (As(V)) reducing bioreactor using ethanol as the electron donor. The results of shaken batch bioassays indicated that the original, unexposed sludge was severely inhibited by arsenite (As(III)) as evidenced by the low 50% inhibition concentrations (IC50) determined, i.e., 19 and 90 μM for acetoclastic- and hydrogenotrophic methanogenesis, respectively. The tolerance of the acetoclastic and hydrogenotrophic methanogens in the sludge to As(III) increased 47-fold (IC50 = 910 μM) and 12-fold (IC50= 1100 μM), respectively, upon long-term exposure to As. In conclusion, the methanogenic community in the granular sludge demonstrated a considerable ability to adapt to the severe inhibitory effects of As after a prolonged exposure period.

  8. A bacterial view of the periodic table: genes and proteins for toxic inorganic ions.

    Science.gov (United States)

    Silver, Simon; Phung, Le T

    2005-12-01

    Essentially all bacteria have genes for toxic metal ion resistances and these include those for Ag+, AsO2-, AsO4(3-), Cd2+ Co2+, CrO4(2-), Cu2+, Hg2+, Ni2+, Pb2+, TeO3(2-), Tl+ and Zn2+. The largest group of resistance systems functions by energy-dependent efflux of toxic ions. Fewer involve enzymatic transformations (oxidation, reduction, methylation, and demethylation) or metal-binding proteins (for example, metallothionein SmtA, chaperone CopZ and periplasmic silver binding protein SilE). Some of the efflux resistance systems are ATPases and others are chemiosmotic ion/proton exchangers. For example, Cd2+-efflux pumps of bacteria are either inner membrane P-type ATPases or three polypeptide RND chemiosmotic complexes consisting of an inner membrane pump, a periplasmic-bridging protein and an outer membrane channel. In addition to the best studied three-polypeptide chemiosmotic system, Czc (Cd2+, Zn2+, and Co2), others are known that efflux Ag+, Cu+, Ni2+, and Zn2+. Resistance to inorganic mercury, Hg2+ (and to organomercurials, such as CH3Hg+ and phenylmercury) involve a series of metal-binding and membrane transport proteins as well as the enzymes mercuric reductase and organomercurial lyase, which overall convert more toxic to less toxic forms. Arsenic resistance and metabolizing systems occur in three patterns, the widely-found ars operon that is present in most bacterial genomes and many plasmids, the more recently recognized arr genes for the periplasmic arsenate reductase that functions in anaerobic respiration as a terminal electron acceptor, and the aso genes for the periplasmic arsenite oxidase that functions as an initial electron donor in aerobic resistance to arsenite.

  9. Label-free signal-on aptasensor for sensitive electrochemical detection of arsenite.

    Science.gov (United States)

    Cui, Lin; Wu, Jie; Ju, Huangxian

    2016-05-15

    A signal-on aptasensor was fabricated for highly sensitive and selective electrochemical detection of arsenite with a label-free Ars-3 aptamer self-assembled on a screen-printed carbon electrode (SPCE) via Au-S bond. The Ars-3 aptamer could adsorb cationic polydiallyldimethylammonium (PDDA) via electrostatic interaction to repel other cationic species. In the presence of arsenite, the change of Ars-3 conformation due to the formation of Ars-3/arsenite complex led to less adsorption of PDDA, and the complex could adsorb more positively charged [Ru(NH3)6](3+) as an electrochemically active indicator on the aptasensor surface, which produced a sensitive "turn-on" response. The target-induced structure switching could be used for sensitive detection of arsenite with a linear range from 0.2 nM to 100 nM and a detection limit down to 0.15 nM. Benefiting from Ars-3 aptamer, the proposed system exhibited excellent specificity against other heavy metal ions. The SPCE-based aptasensor exhibited the advantages of low cost and simple fabrication, providing potential application of arsenite detection in environment.

  10. A Comparative Study on Rat Intestinal Epithelial Cells and Resident Gut Bacteria (ii) Effect of Arsenite

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In order to use facultative gut bacteria as an alternate to animals for the initial gastrointestinal toxicity screening of heavy metals, a comparative study on rat intestinal epithelial cells and resident gut bacteria was undertaken.Methods in vitro growth rate of four gut bacteria, dehydrogenase (DHA) and esterase (EA) activity test, intestinal epithelial and bacterial cell membrane enzymes and in situ effect of arsenite were analysed. Results Growth profile of mixed resident population of gut bacteria and pure isolates of Escherichia coli, Pseudomonas sp., Lactobacillus sp., and Staphylococcus sp.revealed an arsenite (2-20 ppm) concentration-dependent inhibition. The viability pattern of epithelial cells also showed similar changes. DHA and EA tests revealed significant inhibition (40%-72%) with arsenite exposure of 5 and 10 ppm in isolated gut bacteria and epithelial cells. Decrease in membrane alkaline phosphatase and Ca2+-Mg2+-ATPase activities was in the range of 33%-55% in four bacteria at the arsenite exposure of 10 ppm, whereas it was 60%-65% in intestinal epithelial villus cells. in situ incubation of arsenite using intestinal loops also showed more or less similar changes in membrane enzymes of resident gut bacterial population and epithelial cells. Conclusion The results indicate that facultative gut bacteria can be used as suitable in vitro model for the preliminary screening of arsenical gastrointestinal cytotoxic effects.

  11. An aquaporin PvTIP4;1 from Pteris vittata may mediate arsenite uptake.

    Science.gov (United States)

    He, Zhenyan; Yan, Huili; Chen, Yanshan; Shen, Hongling; Xu, Wenxiu; Zhang, Haiyan; Shi, Lei; Zhu, Yong-Guan; Ma, Mi

    2016-01-01

    The fern Pteris vittata is an arsenic hyperaccumulator. The genes involved in arsenite (As(III)) transport are not yet clear. Here, we describe the isolation and characterization of a new P. vittata aquaporin gene, PvTIP4;1, which may mediate As(III) uptake. PvTIP4;1 was identified from yeast functional complement cDNA library of P. vittata. Arsenic toxicity and accumulating activities of PvTIP4;1 were analyzed in Saccharomyces cerevisiae and Arabidopsis. Subcellular localization of PvTIP4;1-GFP fusion protein in P. vittata protoplast and callus was conducted. The tissue expression of PvTIP4;1 was investigated by quantitative real-time PCR. Site-directed mutagenesis of the PvTIP4;1 aromatic/arginine (Ar/R) domain was studied. Heterologous expression in yeast demonstrates that PvTIP4;1 was able to facilitate As(III) diffusion. Transgenic Arabidopsis showed that PvTIP4;1 increases arsenic accumulation and induces arsenic sensitivity. Images and FM4-64 staining suggest that PvTIP4;1 localizes to the plasma membrane in P. vittata cells. A tissue location study shows that PvTIP4;1 transcripts are mainly expressed in roots. Site-directed mutation in yeast further proved that the cysteine at the LE1 position of PvTIP4;1 Ar/R domain is a functional site. PvTIP4;1 is a new represented tonoplast intrinsic protein (TIP) aquaporin from P. vittata and the function and location results imply that PvTIP4;1 may be involved in As(III) uptake.

  12. 西瓜交替氧化酶AOX2基因的克隆与分析%Cloning and analysis of the alternative oxidase-2(AOX2) gene in watermelon

    Institute of Scientific and Technical Information of China (English)

    李严曼; 朱磊; 杨景华; 张明方

    2011-01-01

    In order to study the possible functions of the alternative oxidase gene family in watermelon plants,high-quality RNA was extracted from cold-tolerant watermelon(Citrullus lanatus) germplasm IVSM No.9 and then cDNA was obtained through reverse transcription kit.A cDNA fragment of alternative oxidase was amplified using degenerate oligonucleotide primers designed on the basis of the conserved domain of alternative oxidase genes in other plants.According to the cDNA fragment sequence,the 5' and 3' end fragment sequences were obtained using RACE technology respectively.The full length cDNA of ClAOX2 was obtained by DNAMAN5.22 from the above three sequences.The cDNA fragment exhibited high homology to the alternative oxidase-2(AOX2) of other species and could be referred to as ClAOX2.Then the full lengths of cDNA and DNA were obtained by PCR according to the known cDNA sequence.The full-length cDNA of ClAOX2 was 1 263 bp in size with a 1050 bp open reading frame(ORF).The full-length DNA was 1 983 bp which has consisted of four exons interrupted by three introns.The accession number of ClAOX2 in GenBank database is ADD84880.Real-time PCR showed that the ClAOX2 gene expressed in root,stem,leaf,flower,and fruit of watermelon seedling and significantly higher in the fruit.These results demonstrated that ClAOX2 may play a role during fruit development.%为了研究西瓜交替氧化酶基因家族在西瓜植株中可能发挥的功能,以西瓜(Citrullus lanatus)耐冷种质IVSM9为材料,根据植物不同物种交替氧化酶基因核苷酸保守区序列设计兼并引物,得到西瓜交替氧化酶(alterna-tive oxidase)AOX基因的中间片段。在已知序列的基础上,分别设计5’和3’末端扩增的特异引物,采用cDNA末端快速扩增(RACE)的方法得到西瓜交替氧化酶基因的5’端和3’端序列,用DNAMAN5.22软件对3个序列进行拼接和分析,获得全长序列。得到的基因片段同其

  13. 巴西橡胶树乙醇酸氧化酶HbGOX1基因的鉴定与表达分析%Identification and Expression of Glycolate Oxidase HbGOX1 Gene from Hevea brasiliensis

    Institute of Scientific and Technical Information of China (English)

    程汉; 陈相黄华孙

    2016-01-01

    Photorespiratory pathway is an important metabolic pathway in plant,which consumes the products of photo-synthesis and reduces crop final yield. Glycolate oxidase is the key regulatory enzyme of this pathway, while the study in rubber tree is absence. In this study, the cDNA sequence of HbGOX1 gene was identified and characterized, and the peptide sequence was analyzed bioinformatically. The expression pattern of HbGOX1 gene was further explored under cold stress. The results showed that this gene was negatively regulated by cold stress. This study provided some fundenmental information for the roles of photorespiration in rubber biosynthesis in Hevea brasiliensis.%光呼吸途径是植物中重要的反应途径,它通过消耗光合作用产物影响作物的产量。乙醇酸氧化酶是该途径的关键调控酶,在橡胶树中尚未见研究报道。本研究分离和鉴定橡胶树HbGOX1基因的全长cDNA序列,对其编码的蛋白质进行生物信息学分析,并通过qPCR技术进一步研究HbGOX1基因在低温胁迫下的表达情况。结果发现,该基因受低温胁迫负调控。此结果为进一步揭示橡胶树光呼吸途径在橡胶合成中的作用奠定了基础。

  14. In vitro effect of sodium arsenite on Echinococcus granulosus protoscoleces.

    Science.gov (United States)

    Xing, Guoqiang; Wang, Bo; Lei, Ying; Liu, Chunli; Wang, Zhuo; Shi, Hongjuan; Yang, Rentan; Qin, Wenjuan; Jiang, Yufeng; Lv, Hailong

    2016-06-01

    Cystic echinococcosis (CE) caused by the metacestodes of Echinococcus granulosus is an important cosmopolitan zoonosis. Surgery is the main treatment option for CE. Meanwhile, chemotherapy is used as an significant adjunct to surgery. However, the benzimidazole carbamate group and the existing scolicidal agents may not be as effective as hoped. In this study, we aimed to explore the in vitro effect of sodium arsenite (NaAsO2) on Echinococcus granulosus protoscoleces, the causative agents of CE. Protoscoleces of E. granulosus were incubated in vitro with 4, 8, 12, 16, and 20μM NaAsO2. Viability and changes in morphology were investigated by 0.1% eosin staining. The ultrastructural alterations were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Additionally, caspase-3 activity was measured by colorimetric assay. Obvious protoscolicidal effect was seen with NaAsO2 at concentrations of 16μM and 20μM. Protoscolex mortality was 83.24% (16μM) and 100% (20μM) after 6 days post-incubation. SEM showed that the primary site of drug damage was the tegument of the protoscoleces. TEM analysis demonstrated that the internal tissues were severely affected and revealed an increase in the number of lipid droplets and vacuoles after treatment with 16μM NaAsO2. Meanwhile, the caspase-3 activity significantly increased in protoscoleces after 24h of NaAsO2 incubation compared to the untreated controls. Our study demonstrated the clear in vitro scolicidal effect of NaAsO2 against E. granulosus protoscoleces. However, the in vivo efficacy, specific mechanism, and any possible side effects of NaAsO2 remain to be investigated.

  15. [Effectiveness of arsenite adsorption by ferric and alum water treatment residuals with different grain sizes].

    Science.gov (United States)

    Lin, Lu; Xu, Jia-Rui; Wu, Hao; Wang, Chang-Hui; Pei, Yuan-Sheng

    2013-07-01

    Effectiveness of arsenite adsorption by ferric and alum water treatment residuals (FARs) with different grain sizes was studied. The results indicated that the content of active Fe and Al, the specific surface area and pore volume in FARs with different grain sizes were in the range of 523.72-1 861.72 mmol x kg(-1), 28.15-265.59 m2 x g(-1) and 0.03-0.09 cm3 x g(-1), respectively. The contents of organic matter, fulvic acid, humic acid and humin were in the range of 46.97-91.58 mg x kg(-1), 0.02-32.27 mg x kg(-1), 22.27-34.09 mg x kg(-1) and 10.76-34.22 mg x kg(-1), respectively. Results of SEM and XRD analysis further demonstrated that FARs with different grain sizes were amorphousness. Batch experiments suggested that both the pseudo-first-order and pseudo-second-order equations could well describe the kinetics adsorption processes of arsenite by FARs. Moreover, the contents of arsenite absorbed by FARs increased with the increase of arsenite concentrations. The theoretical saturated adsorption capacities calculated from Langmuir isotherm model were in the range of 6.72-21.79 mg x g(-1). Interestingly, pH showed little effect on the arsenite adsorption capability of FARs. The capability of FARs had a close relationship with their physicochemical properties. Correlation analysis showed that the active Fe and Al contents and pore volume had major effects on the arsenite adsorption capability of FARs.

  16. Effect of rosiglitazone in sodium arsenite-induced experimental vascular endothelial dysfunction.

    Science.gov (United States)

    Kaur, Tajpreet; Goel, Rajesh Kumar; Balakumar, Pitchai

    2010-04-01

    The present study has been designed to investigate the effect of rosiglitazone, a peroxisome proliferator activated receptor gamma agonist in sodium arsenite-induced vascular endothelial dysfunction (VED) in rats. The rats were administered sodium arsenite (1.5 mg/kg/day, i.p., 2 weeks) to induce VED. The development of VED was assessed by employing isolated aortic ring preparation and estimating serum nitrite/nitrate concentration. Further, the integrity of the aortic endothelium was assessed histologically using haematoxylin-eosin staining. Moreover, the oxidative stress was assessed by estimating serum thiobarbituric acid reactive substances, aortic reactive oxygen species and reduced form of glutathione. The administration of sodium arsenite produced VED by impairing acetylcholine-induced endothelium dependent relaxation, diminishing the integrity of vascular endothelium and decreasing the serum nitrite/nitrate concentration. In addition, sodium arsenite was noted to produce oxidative stress as it increased serum thiobarbituric acid reactive substances and aortic reactive oxygen species and consequently decreased glutathione. Treatment with rosiglitazone (3 mg/kg/day, p.o., 2 weeks and 5 mg/kg/day, p.o., 2 weeks) significantly prevented sodium arsenite-induced VED by enhancing acetylcholine-induced endothelium dependent relaxation, improving the integrity of vascular endothelium, increasing the nitrite/nitrate concentration and decreasing the oxidative stress. However, the vascular protective effect of rosiglitazone was markedly abolished by co-administration of nitric oxide synthase inhibitor, N-Omega-Nitro-L-Arginine Methyl Ester (L-NAME) (25 mg/kg/day, i.p., 2 weeks). Thus, it may be concluded that rosiglitazone reduces oxidative stress, activates eNOS and enhances the generation of nitric oxide to prevent sodium arsenite-induced VED in rats.

  17. Arsenite treatment induces oxidative stress, upregulates antioxidant system, and causes phytochelatin synthesis in rice seedlings.

    Science.gov (United States)

    Mishra, Shruti; Jha, A B; Dubey, R S

    2011-07-01

    The effects of arsenite treatment on generation of reactive oxygen species, induction of oxidative stress, response of antioxidative system, and synthesis of phytochelatins were investigated in two indica rice (Oryza sativa L.) cvs. Malviya-36 and Pant-12 grown in sand cultures for a period of 5-20 days. Arsenite (As(2)O(3); 25 and 50 μM) treatment resulted in increased formation of superoxide anion (O (2) (.-) ), elevated levels of H(2)O(2) and thiobarbituric acid reactive substances, showing enhanced lipid peroxidation. An enhanced level of ascorbate (AA) and glutathione (GSH) was observed irrespective of the variation in the level of dehydroascorbate (DHA) and oxidized glutathione (GSSG) which in turn influenced redox ratios AA/DHA and GSH/GSSG. With progressive arsenite treatment, synthesis of total acid soluble thiols and phytochelatins (PC) increased in the seedlings. Among antioxidative enzymes, the activities of superoxide dismutase (EC 1.15.1.1), catalase (EC 1.11.1.6), total ascorbate peroxidase (APX, EC 1.11.1.11), chloroplastic ascorbate peroxidase, guaiacol peroxidase (EC 1.11.1.7), monodehydroascorbate reductase (EC 1.6.5.4), and glutathione reductase (EC 1.6.4.2) increased in arsenite treated seedlings, while dehyroascorbate reductase (EC 1.8.5.1) activity declined initially during 5-10 days and increased thereafter. Results suggest that arsenite treatment causes oxidative stress in rice seedlings, increases the levels of many enzymatic and non-enzymatic antioxidants, and induces synthesis of thiols and PCs, which may serve as important components in mitigating arsenite-induced oxidative damage.

  18. Role of amine oxidase expression to maintain putrescine homeostasis in Rhodococcus opacus.

    Science.gov (United States)

    Foster, Alexander; Barnes, Nicole; Speight, Robert; Morris, Peter C; Keane, Mark A

    2013-04-10

    While applications of amine oxidases are increasing, few have been characterised and our understanding of their biological role and strategies for bacteria exploitation are limited. By altering the nitrogen source (NH4Cl, putrescine and cadaverine (diamines) and butylamine (monoamine)) and concentration, we have identified a constitutive flavin dependent oxidase (EC 1.4.3.10) within Rhodococcus opacus. The activity of this oxidase can be increased by over two orders of magnitude in the presence of aliphatic diamines. In addition, the expression of a copper dependent diamine oxidase (EC 1.4.3.22) was observed at diamine concentrations>1mM or when cells were grown with butylamine, which acts to inhibit the flavin oxidase. A Michaelis-Menten kinetic treatment of the flavin oxidase delivered a Michaelis constant (KM)=190μM and maximum rate (kcat)=21.8s(-1) for the oxidative deamination of putrescine with a lower KM (=60μM) and comparable kcat (=18.2s(-1)) for the copper oxidase. MALDI-TOF and genomic analyses have indicated a metabolic clustering of functionally related genes. From a consideration of amine oxidase specificity and sequence homology, we propose a putrescine degradation pathway within Rhodococcus that utilises oxidases in tandem with subsequent dehydrogenase and transaminase enzymes. The implications of PUT homeostasis through the action of the two oxidases are discussed with respect to stressors, evolution and application in microbe-assisted phytoremediation or bio-augmentation.

  19. 以线粒体COⅠ基因探讨萧氏松茎象的分类地位%Phylogenetic Relationship of Hylobitelus xiaoi inferred from Cytochrome C Oxidasegene

    Institute of Scientific and Technical Information of China (English)

    栾丰刚; 丁俊杰; 何龙喜; 王建国

    2013-01-01

    用蛋白酶K消化法提取萧氏松茎象总DNA,并对细胞色素C氧化酶亚基Ⅰ(cytochrome c oxidasegene,COⅠ)序列分析发现,CO Ⅰ序列4种核苷酸量平均为A=30.2%,C=17.3%,G=15.4%,T=37.0%.将所获得的5个不同地区萧氏松茎象个体CO Ⅰ序列排序后,比较形成了一个含1 209个位点的矩阵,其中1 174个不变位点,35个变异位点,所占比例为2.89%,序列的A+T含量较高.遗传距离、核酸和氨基酸变异及系统发育树分析表明:萧氏松茎象与树皮象属亲缘关系最近,且分子水平上萧氏松茎象与树皮象属之间较之树皮象属内种间无明显差异,对目前的分类地位提出质疑.

  20. Transcriptional coupling of synaptic transmission and energy metabolism: role of nuclear respiratory factor 1 in co-regulating neuronal nitric oxide synthase and cytochrome c oxidase genes in neurons.

    Science.gov (United States)

    Dhar, Shilpa S; Liang, Huan Ling; Wong-Riley, Margaret T T

    2009-10-01

    Neuronal activity is highly dependent on energy metabolism; yet, the two processes have traditionally been regarded as independently regulated at the transcriptional level. Recently, we found that the same transcription factor, nuclear respiratory factor 1 (NRF-1) co-regulates an important energy-generating enzyme, cytochrome c oxidase, as well as critical subunits of glutamatergic receptors. The present study tests our hypothesis that the co-regulation extends to the next level of glutamatergic synapses, namely, neuronal nitric oxide synthase, which generates nitric oxide as a downstream signaling molecule. Using in silico analysis, electrophoretic mobility shift assay, chromatin immunoprecipitation, promoter mutations, and NRF-1 silencing, we documented that NRF-1 functionally bound to Nos1, but not Nos2 (inducible) and Nos3 (endothelial) gene promoters. Both COX and Nos1 transcripts were up-regulated by depolarizing KCl treatment and down-regulated by TTX-mediated impulse blockade in neurons. However, NRF-1 silencing blocked the up-regulation of both Nos1 and COX induced by KCl depolarization, and over-expression of NRF-1 rescued both Nos1 and COX transcripts down-regulated by TTX. These findings are consistent with our hypothesis that synaptic neuronal transmission and energy metabolism are tightly coupled at the molecular level.

  1. Overexpression of a GmCnx1 gene enhanced activity of nitrate reductase and aldehyde oxidase, and boosted mosaic virus resistance in soybean.

    Directory of Open Access Journals (Sweden)

    Zheng Zhou

    Full Text Available Molybdenum cofactor (Moco is required for the activities of Moco-dependant enzymes. Cofactor for nitrate reductase and xanthine dehydrogenase (Cnx1 is known to be involved in the biosynthesis of Moco in plants. In this work, a soybean (Glycine max L. Cnx1 gene (GmCnx1 was transferred into soybean using Agrobacterium tumefaciens-mediated transformation method. Twenty seven positive transgenic soybean plants were identified by coating leaves with phosphinothricin, bar protein quick dip stick and PCR analysis. Moreover, Southern blot analysis was carried out to confirm the insertion of GmCnx1 gene. Furthermore, expression of GmCnx1 gene in leaf and root of all transgenic lines increased 1.04-2.12 and 1.55-3.89 folds, respectively, as compared to wild type with GmCnx1 gene and in line 10 , 22 showing the highest expression. The activities of Moco-related enzymes viz nitrate reductase (NR and aldehydeoxidase (AO of T1 generation plants revealed that the best line among the GmCnx1 transgenic plants accumulated 4.25 μg g(-1 h(-1 and 30 pmol L(-1, respectively (approximately 2.6-fold and 3.9-fold higher than non-transgenic control plants.In addition, overexpression ofGmCnx1boosted the resistance to various strains of soybean mosaic virus (SMV. DAS-ELISA analysis further revealed that infection rate of GmCnx1 transgenic plants were generally lower than those of non-transgenic plants among two different virus strains tested. Taken together, this study showed that overexpression of a GmCnx1 gene enhanced NR and AO activities and SMV resistance, suggesting its important role in soybean genetic improvement.

  2. Life in an arsenic-containing gold mine: genome and physiology of the autotrophic arsenite-oxidizing bacterium rhizobium sp. NT-26.

    Science.gov (United States)

    Andres, Jérémy; Arsène-Ploetze, Florence; Barbe, Valérie; Brochier-Armanet, Céline; Cleiss-Arnold, Jessica; Coppée, Jean-Yves; Dillies, Marie-Agnès; Geist, Lucie; Joublin, Aurélie; Koechler, Sandrine; Lassalle, Florent; Marchal, Marie; Médigue, Claudine; Muller, Daniel; Nesme, Xavier; Plewniak, Frédéric; Proux, Caroline; Ramírez-Bahena, Martha Helena; Schenowitz, Chantal; Sismeiro, Odile; Vallenet, David; Santini, Joanne M; Bertin, Philippe N

    2013-01-01

    Arsenic is widespread in the environment and its presence is a result of natural or anthropogenic activities. Microbes have developed different mechanisms to deal with toxic compounds such as arsenic and this is to resist or metabolize the compound. Here, we present the first reference set of genomic, transcriptomic and proteomic data of an Alphaproteobacterium isolated from an arsenic-containing goldmine: Rhizobium sp. NT-26. Although phylogenetically related to the plant-associated bacteria, this organism has lost the major colonizing capabilities needed for symbiosis with legumes. In contrast, the genome of Rhizobium sp. NT-26 comprises a megaplasmid containing the various genes, which enable it to metabolize arsenite. Remarkably, although the genes required for arsenite oxidation and flagellar motility/biofilm formation are carried by the megaplasmid and the chromosome, respectively, a coordinate regulation of these two mechanisms was observed. Taken together, these processes illustrate the impact environmental pressure can have on the evolution of bacterial genomes, improving the fitness of bacterial strains by the acquisition of novel functions.

  3. 四川宜宾产桃花水母的线粒体CO I序列片段分析%Sequence analyses of mitochondrial cytochrome c oxidase subunitⅠgene fragment of freshwater jellyfish from Yibin, Sichuan

    Institute of Scientific and Technical Information of China (English)

    蔡延森; 刘芹; 王译伟; 马明义; 税青林

    2014-01-01

    目的:针对桃花水母形态分类中存在的一些混乱和矛盾,引入分子生物学方法阐明其分类难题。方法:采用PCR和DNA测序技术,对四川宜宾产桃花水母标本的线粒体细胞色素C氧化酶亚基Ⅰ基因(mitochondrial cytochrome c oxidase subunitⅠ,COⅠ)片段进行了扩增与测序,并与GenBank中已有的淡水水母目COⅠ基因序列进行比对分析,利用MEGA 5计算它们的遗传距离,构建NJ树。结果:该桃花水母标本与索氏桃花水母Craspedacusta sowerbii的COI基因相似度极高,同源性在99%以上,遗传距离为0.003,在进化树中与索氏桃花水母聚为同一支。结论:该标本属于索氏桃花水母。%objective:Molecular biological method was introduced to clarify the difficult classification problem of freshwater jellyfish (Craspedacusta sowerbii). Methods:The mitochondrial cytochrome c oxidase subunit I (COI) gene of freshwater jellyfish (from Yibin, Sichuan) was amplified by polymerase chain reaction (PCR) and then sequenced. Aligning with other Limnomedusae species retrieved from GenBank, genetic distance among species was calculated by using the Kimura-2-parameter (K2P) method in MEGA 5. Neighbor-Joining (NJ) tree based on K2P distances was created to provide a graphic representation of the divergence patterns for among-and within-species. Results:The result showed that COI sequence of freshwater jellyfish was highly similar to those of C. sowerbii (similarity 99%). The genetic distance between the sample and C. sowerbii was 0.003. The NJ tree showed 100%degree of confidence cluster of our sample and C. sowerbii from Germany. Conclusion:Our sample is C. sowerbii.

  4. 苹果内根-贝壳杉烯氧化酶基因的克隆及序列分析%Cloning and sequence analysis of ent-Kaurene Oxidase Gene in apple( Malus×domestica )

    Institute of Scientific and Technical Information of China (English)

    田伟; 田义轲; 王彩虹; 宋伟; 李节法; 殷豪

    2011-01-01

    内根-贝壳杉烯氧化酶(KO)是赤霉素合成代谢的关键酶.以苹果(Malus×domestica Borkh.)品种富士(Fuji)为供试材料,应用同源克隆和RACE方法从其茎尖中克隆到KO的cDNA全长序列,命名为MdKO,GenBank登录号:AY563549,其长度为1 859 bp.MdKO的开放性阅读框(ORF)编码514个氨基酸残基,推断其相对分子量为58.9 ku,等电点为7.63.氨基酸同源性分析表明,MdKO与已报道的其他植物的KO氨基酸序列具有较高的相似性;氨基酸聚类分析表明,苹果和梨首先聚类,其次是葡萄;序列结构分析表明MdKO属于细胞色素超家族P450系,具有细胞色素P450的血红素结构域FXXGXRXCXG和跨膜结构域;亚细胞定位分析发现MdKO可能位于内质网膜上.%Ent-Kaurene oxidase(KO)is a critical enzyme in the pathway of gibberellins biosynthesis. In this research, ent-kaurene oxidase gene in apple, designated as MdKO(GenBank accession number:AY563549), was isolated from the apical tissue of Fuji apple stem. The full cDNA was 1 859 bp in length with an open reading frame(ORF)of 1 545 bp encoding a protein of 514 amino acids. The protein molecular weight and isoelectric point were predicted to be 58.9 ku and 7.63, respectively. Amino acids homology analysis indicated a high similarity with its counterparts in other species. Amino acids cluster analysis showed that KO from pear was clustered together with MdKO firstly, and followed by that from grape. Sequence analysis exhibited that MdKO belonged to cytochrome P450 superfamily and contained cysteine heme-iron ligand signature (FXXGXRXCXG)and transmembrane region. Moreover, MdKO was located in endoplasmic reticulum membrane.

  5. Arsenite tolerance is related to proportional thiolic metabolite synthesis in rice (Oryza sativa L.).

    Science.gov (United States)

    Dave, Richa; Singh, Pradyumna Kumar; Tripathi, Preeti; Shri, Manju; Dixit, Garima; Dwivedi, Sanjay; Chakrabarty, Debasis; Trivedi, Prabodh Kumar; Sharma, Yogesh Kumar; Dhankher, Om Prakash; Corpas, Francisco Javier; Barroso, Juan B; Tripathi, Rudra Deo

    2013-02-01

    Thiol metabolism is the primary detoxification strategy by which rice plants tolerate arsenic (As) stress. In light of this, it is important to understand the importance of harmonised thiol metabolism with As accumulation and tolerance in rice plant. For this aim, tolerant (T) and sensitive (S) genotypes were screened from 303 rice (Oryza sativa) genotypes on exposure to 10 and 25 μM arsenite (As(III)) in hydroponic culture. On further As accumulation estimation, contrasting (13-fold difference) T (IC-340072) and S (IC-115730) genotypes were selected. This difference was further evaluated using biochemical and molecular approaches to understand involvement of thiolic metabolism vis-a-vis As accumulation in these two genotypes. Various phytochelatin (PC) species (PC(2), PC(3) and PC(4)) were detected in both the genotypes with a dominance of PC(3). However, PC concentrations were greater in the S genotype, and it was noticed that the total PC (PC(2) + PC(3 )+ PC(4))-to-As(III) molar ratio (PC-SH:As(III)) was greater in T (2.35 and 1.36 in shoots and roots, respectively) than in the S genotype (0.90 and 0.15 in shoots and roots, respectively). Expression analysis of several metal(loid) stress-related genes showed significant upregulation of glutaredoxin, sulphate transporter, and ascorbate peroxidase in the S genotype. Furthermore, enzyme activity of phytochelatin synthase and cysteine synthase was greater on As accumulation in the S compared with the T genotype. It was concluded that the T genotype synthesizes adequate thiols to detoxify metalloid load, whereas the S genotype synthesizes greater but inadequate levels of thiols to tolerate an exceedingly greater load of metalloids, as evidenced by thiol-to-metalloid molar ratios, and therefore shows a phytotoxicity response.

  6. Identification of Single Nucleotide Polymorphism (SNP in Mono Amine Oxidase A (MAO-A Gene as a genetic marker for aggressiveness in sheep

    Directory of Open Access Journals (Sweden)

    Eko Handiwirawan

    2012-12-01

    Full Text Available In the population, there are aggressive sheep in a small number which requires special management those specific animal house and routine management. The purpose of this study was to identify the variation of DNA marker SNP (single nucleotide polymorphism as a genetic marker for the aggressive trait in several of sheep breed. The identification of point mutations in exon 8 of MAO-A gene associated with aggressive behavior in sheep may be further useful to become of DNA markers for the aggressive trait in sheep. Five of sheep breed were used, i.e.: Barbados Black belly Cross sheep (BC, Composite Garut (KG, Local Garut (LG, Composite Sumatra (KS and St. Cross Croix (SC. Duration of ten behavior traits, blood serotonin concentrations and DNA sequence of exon 8 of MAO-A gene from the sheep aggressive and nonaggressive were observed. PROC GLM of SAS Ver. 9.0 program was used to analyze variable behavior and blood serotonin concentrations. DNA polymorphism in exon 8 of MAO-A gene was analyzed using the MEGA software Ver. 4.0. The results show that the percentage of the aggressive rams of each breed was less than 10 percent; except for the KS sheep is higher (23%. Based on the duration of behavior, aggressive sheep group was not significantly different with non aggressive sheep group, except duration of care giving and drinking behavior. It is known that concentration of blood serotonin in aggressive and non aggressive rams was not significantly different. The aggressive trait in sheep has a mechanism or a different cause like that occurs in mice and humans. In this study, aggressive behavior in sheep was not associated with a mutation in exon 8 of MAO-A gene.

  7. Lysyl oxidase in colorectal cancer.

    Science.gov (United States)

    Cox, Thomas R; Erler, Janine T

    2013-11-15

    Colorectal cancer is the third most prevalent form of cancer worldwide and fourth-leading cause of cancer-related mortality, leading to ~600,000 deaths annually, predominantly affecting the developed world. Lysyl oxidase is a secreted, extracellular matrix-modifying enzyme previously suggested to act as a tumor suppressor in colorectal cancer. However, emerging evidence has rapidly implicated lysyl oxidase in promoting metastasis of solid tumors and in particular colorectal cancer at multiple stages, affecting tumor cell proliferation, invasion, and angiogenesis. This emerging research has stimulated significant interest in lysyl oxidase as a strong candidate for developing and deploying inhibitors as functional efficacious cancer therapeutics. In this review, we discuss the rapidly expanding body of knowledge concerning lysyl oxidase in solid tumor progression, highlighting recent advancements in the field of colorectal cancer.

  8. Sodium arsenite mediated immuno-disruption through alteration of transcription profile of cytokines in chicken splenocytes under in vitro system.

    Science.gov (United States)

    Das, Subhashree; Pan, Diganta; Bera, Asit Kumar; Rana, Tanmoy; Bhattacharya, Debasis; Bandyapadyay, Subhasis; De, Sumanta; Sreevatsava, V; Bhattacharya, Somnath; Das, Subrata Kumar; Bandyopadhayay, Sandip

    2011-01-01

    Arsenic is a ubiquitously found metalloid that commonly contaminates drinking water and agricultural food. To understand the ecotoxicological effects of arsenic in environment, it is essential to ameliorate the deleterious effects on human and animal health, particularly on the immune response. We investigated the effects of inorganic arsenic (iAs) on the immune response of chicken splenocytes. Both 1 and 10 mM concentrations of sodium arsenite treatment significantly reduced (Ptreatment also revealed time dependent differences. Relative quantification of expression of IFNγ and IL2 revealed that both genes were significantly down regulated (P<0.001) at both concentrations at each time point. iNOS gene was rapidly down regulated in splenocytes at 24 h at the high doses of As treated splenocyte, a gradual decreasing trend at low doses. Down regulation of IL-2 gene expression in response to As was further evidenced by a significant reduction (P<0.001) in the release of IL-2 into the splenocyte culture medium. We suggest that arsenic, a potent immunotoxic agent, modulates non-specific immune responses and alters the expression of cytokines in a dose and time dependent manner.

  9. Sodium arsenite induces chromosome endoreduplication and inhibits protein phosphatase activity in human fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Rong-Nan Huang; I-Ching Ho; Ling-Hui Yih [Institute of Biomedical Sciences, Taiwan (China)] [and others

    1995-08-01

    Arsenic, strongly associated with increased risks of human cancers, is a potent clastogen in a variety of mammalian cell systems. The effect of sodium arsenite (a trivalent arsenic compound) on chromatid separation was studied in human skin fibroblasts (HFW). Human fibroblasts were arrested in S phase by the aid of serum starvation and aphidicolin blocking and then these cells were allowed to synchronously progress into G2 phase. Treatment of the G2-enriched HFW cells with sodium arsenite (0-200 {mu}M) resulted in arrest of cells in the G2 phase, interference with mitotic division, inhibition of spindle assembly, and induction of chromosome endoreduplication in their second mitosis. Sodium arsenite treatment also inhibited the activities of serine/threonine protein phosphatases and enhanced phosphorylation levels of a small heat shock protein (HSP27). These results suggest that sodium arsenite may mimic okadaic acid to induce chromosome endoreduplication through its inhibitory effect on protein phosphatase activity. 61 refs., 6 figs., 2 tabs.

  10. Cytokinin oxidase or dehydrogenase? Mechanism of cytokinin degradation in cereals

    DEFF Research Database (Denmark)

    Galuszka, P.; Frebort, I.; Sebela, M.

    2001-01-01

    wheat enzyme is a monomer 60 kDa, its N-terminal amino-acid sequence shows similarity to hypothetical cytokinin oxidase genes from Arabidopsis thaliana, but not to the enzyme from maize. N-6-isopentenyl-2-(2-hydroxyethylamino)-9-methyladenine is the best substrate from all the cytokinins tested...

  11. Adsorption and oxidation of arsenite by iron minerals in the presence of microorganisms

    Science.gov (United States)

    Perelomov, Leonid; Corsini, Anna; Andreoni, Vincenza

    2010-05-01

    It is known the two most commonly occurring forms of As in the environment are anionic arsenate [AsO43-, As(V)] and arsenite [AsO33-, As(III)]. Arsenite has been found to be the more mobile and toxic species in soil environments (Tamaki and Frankenberger, 1992). Arsenic speciation and toxicity are functions of pH, redox potential, the presence and type of adsorbing surfaces, and microbial populations. Biotransformation of arsenic species (reduction or oxidation) is mainly enzymatic process, while biosorption is metabolism independent process that governed by physico-chemical interactions on the cell surface. Special ternary bio-mineral systems, consisting of iron minerals (synthetic goethite, and magnetite, which was prepared by oxidation from special commercial product - nano-iron), special strains of arsenite-oxidizing microorganisms (Ancylobacter dichlorometanicus) and arsenite solution, were constructed and processes of arsenic compounds adsorption and oxidation were studied. As control experiments without microorganisms or without minerals were carried out. For determination of arsenic species, adsorbed on the surface of the minerals, desorption experiments were carried out also. Desorption ability of several chemicals, used for arsenic extraction from soils, was tested. Magnetite and goethite, with very small size of particles, have high chemical affinity to arsenite at wide range of pH values, but at pH above 9 adsorption of arsenite decreased in comparison with pH below of the isoelectric points of the minerals. We carried out experiments at initial pH 7,2. Experiments on kinetics of adsorption showed that equilibrium time for adsorption is 2 hours. In the ternary bio-mineral systems consisting of fresh-prepared magnetite,the effect of arsenite-oxidizing microorganisms on the oxidation process was negligible in all cases, because magnetite demonstrated very high oxidation ability in comparison with bacteria. During 4 hours all arsenite, adsorbed on the

  12. Structural and functional analysis of aa3-type and cbb3-type cytochrome c oxidases of Paracoccus denitrificans reveals significant differences in proton-pump design

    OpenAIRE

    de Gier, Jan-Willem L.; Schepper, Mike; Reijnders, Willem N.M.; Dyck, Stef J. van; Slotboom, Dirk Jan; Warne, Antony; Saraste, Matti; Krab, Klaas; Finel, Moshe; Stouthamer, Adriaan H.; Van Spanning, Rob J. M.; van der Oost, John

    1996-01-01

    In Paracoccus denitrificans the aa3-type cytochrome c oxidase and the bb3-type quinol oxidase have previously been characterized in detail, both biochemically and genetically. Here we report on the isolation of a genomic locus that harbours the gene cluster ccoNOQP, and demonstrate that it encodes an alternative cbb3-type cytochrome c oxidase. This oxidase has previously been shown to be specifically induced at low oxygen tensions, suggesting that its expression is controlled by an oxygen-sen...

  13. Multiple origins of the phenol reaction negative phenotype in foxtail millet, Setaria italica (L.) P. Beauv., were caused by independent loss-of-function mutations of the polyphenol oxidase (Si7PPO) gene during domestication.

    Science.gov (United States)

    Inoue, Takahiko; Yuo, Takahisa; Ohta, Takeshi; Hitomi, Eriko; Ichitani, Katsuyuki; Kawase, Makoto; Taketa, Shin; Fukunaga, Kenji

    2015-08-01

    Foxtail millet shows variation in positive phenol color reaction (Phr) and negative Phr in grains, but predominant accessions of this crop are negative reaction type, and the molecular genetic basis of the Phr reaction remains unresolved. In this article, we isolated polyphenol oxidase (PPO) gene responsible for Phr using genome sequence information and investigated molecular genetic basis of negative Phr and crop evolution of foxtail millet. First of all, we searched for PPO gene homologs in a foxtail millet genome database using a rice PPO gene as a query and successfully found three copies of the PPO gene. One of the PPO gene homologs on chromosome 7 showed the highest similarity with PPO genes expressed in hulls (grains) of other cereal species including rice, wheat, and barley and was designated as Si7PPO. Phr phenotypes and Si7PPO genotypes completely co-segregated in a segregating population. We also analyzed the genetic variation conferring negative Phr reaction. Of 480 accessions of the landraces investigated, 87 (18.1 %) showed positive Phr and 393 (81.9 %) showed negative Phr. In the 393 Phr negative accessions, three types of loss-of-function Si7PPO gene were predominant and independently found in various locations. One of them has an SNP in exon 1 resulting in a premature stop codon and was designated as stop codon type, another has an insertion of a transposon (Si7PPO-TE1) in intron 2 and was designated as TE1-insertion type, and the other has a 6-bp duplication in exon 3 resulting in the duplication of 2 amino acids and was designated as 6-bp duplication type. As a rare variant of the stop codon type, one accession additionally has an insertion of a transposon, Si7PPO-TE2, in intron 2 and was designated as "stop codon +TE2 insertion type". The geographical distribution of accessions with positive Phr and those with three major types of negative Phr was also investigated. Accessions with positive Phr were found in subtropical and tropical regions at

  14. Absorption of Arsenite on Several Iron (Hydro-)Oxides and Impact from Pre-processing Methods

    Institute of Scientific and Technical Information of China (English)

    YE Ying; JI Shanshan; WU Daidai; LI Jun; ZHANG Weirui

    2006-01-01

    The absorption reactions of arsenite on Fe (hydro-)oxides are studied. The three absorbent types are Fe(OH)3 gel and two Fe (hydro-)oxides, in which the Fe(OH)3 gel was dried in a microwave oven under vacuum at 80℃. It is found that pH changes from 9.71 to 10.36 in 6 minutes after the Fe (OH)3 gel was mixed with NaAsO2 solution, as the arsenite replaces the OH- in goethite and Fe(OH)3.At the 40th minute after the start of the reaction, pH decreases, which is most probably because that the monodentate surface complex of absorbed arsenite has changed into mononuclear-bidentate complex and released proton. The decline in pH values indicates not the end of the absorption but a change in the reaction type. Temperature and dissolved gas has little effect on these two types of reactions. The total absorption of arsenite increases after the absorbent is irradiated with ultrasound, which also lead to difficulty in separating the solids from solution. The absorption capacity for arsenite of Fe(OH)3 gel dried in a microwave oven under vacuum is 53.18% and 17.22% respectively better than that of Fe (OH)3 gel and gel dried at 80℃. The possible reasons are that the water molecules in the gel vibrates with high frequency under the effect of microwave irradiation, thereby producing higher porosity and improved surface activity.

  15. 枇杷胚性培养物ACC氧化酶基因的克隆及序列分析%Cloning and Sequence Analysis of ACC Oxidase Gene from Eriobotrya japonica Embryonic Cultures

    Institute of Scientific and Technical Information of China (English)

    音建华; 赖钟雄; 林玉玲; 李惠华; 李丽秀

    2012-01-01

    Homologous cloning method was used to clone the 1-aminocyclopropane-l -carboxylic acid oxidase (ACO)gene, EjACO-1, Eriobotrya japonica embryonic cultures. The gene, GenBank accession number GQ377219, was of 1 160 bp, encoding 322 amino acids, and highly homologous to other rosaceous plants origins (Malus x domestica, Prunus persica, Pyrus pyrifolia and so on), and was distant from that of monocotyledons (Oryza sativa, Dendrobium and so on) . Moreover, gACO, which encoding EjACO-1 mRNA, was obtained from the genomic DNA. The length of gACO was 1 517 bp, and the accession number was GU180353 in GenBank. The gACO gene contained 3 introns consistent with the GT-AG dogma for eukaryotic introns, with lengths 114,240 and 194 bp, respectively. The cloning of EjACO provides a foundation for further study of ethylene function in Eriobotrya japonica.%以枇杷胚性培养物(Eriobotrya j(a)ponica emnbryonic cultures)为材料,采用同源克隆方法,从其mRNA中分离得到ACC氧化酶(ACO)基因EjA CO-1,在GenBank中登录号为GQ377219.结果表明:EjA CO-1大小为1 160bp,编码322个氨基酸.枇杷EjACO-1与苹果、桃和梨等蔷薇科植物同源性较高,而与水稻、石斛兰等单子叶植物距离较远.此外,从枇杷基因组DNA中分离了转录为EjACO-1 mRNA的基因gACO,大小为1 517 bp,在GenBank中的登录号为GU233743.生物信息学分析显示,gACO基因中含有3个内含子,大小分别为114、240、194 bp,均符合真核生物内含子通用的GT-AG法则.EjACO基因的克隆为以后研究乙烯在枇杷中的功能奠定基础.

  16. Molecular identification of sibling species of Sclerodermus (Hymenoptera: Bethylidae that parasitize buprestid and cerambycid beetles by using partial sequences of mitochondrial DNA cytochrome oxidase subunit 1 and 28S ribosomal RNA gene.

    Directory of Open Access Journals (Sweden)

    Yuan Jiang

    Full Text Available The species belonging to Sclerodermus (Hymenoptera: Bethylidae are currently the most important insect natural enemies of wood borer pests, mainly buprestid and cerambycid beetles, in China. However, some sibling species of this genus are very difficult to distinguish because of their similar morphological features. To address this issue, we conducted phylogenetic and genetic analyses of cytochrome oxidase subunit I (COI and 28S RNA gene sequences from eight species of Sclerodermus reared from different wood borer pests. The eight sibling species were as follows: S. guani Xiao et Wu, S. sichuanensis Xiao, S. pupariae Yang et Yao, and Sclerodermus spp. (Nos. 1-5. A 594-bp fragment of COI and 750-bp fragment of 28S were subsequently sequenced. For COI, the G-C content was found to be low in all the species, averaging to about 30.0%. Sequence divergences (Kimura-2-parameter distances between congeneric species averaged to 4.5%, and intraspecific divergences averaged to about 0.09%. Further, the maximum sequence divergences between congeneric species and Sclerodermus sp. (No. 5 averaged to about 16.5%. All 136 samples analyzed were included in six reciprocally monophyletic clades in the COI neighbor-joining (NJ tree. The NJ tree inferred from the 28S rRNA sequence yielded almost identical results, but the samples from S. guani, S. sichuanensis, S. pupariae, and Sclerodermus spp. (Nos. 1-4 clustered together and only Sclerodermus sp. (No. 5 clustered separately. Our findings indicate that the standard barcode region of COI can be efficiently used to distinguish morphologically similar Sclerodermus species. Further, we speculate that Sclerodermus sp. (No. 5 might be a new species of Sclerodermus.

  17. Expression of the Aspergillus niger Glucose Oxidase Gene in Pichia pastoris SMD1168%黑曲霉葡萄糖氧化酶在毕赤酵母SMD1168中的表达

    Institute of Scientific and Technical Information of China (English)

    郭元芳; 孙高英; 郝建荣; 彭炳银; 毕文祥; 鲍晓明

    2013-01-01

    目的:在毕赤酵母SMD1168中用3-磷酸甘油醛脱氢酶基因启动子(glyceraldehyde-3-phosphate dehygrogenase gene promoter,pGAP)表达黑曲霉葡萄糖氧化酶(glucose oxidase,GOD).方法:将黑曲霉accc30161的GOD基因插入具有pGAP的pGAPZαA质粒中,构建黑曲霉GOD毕赤酵母表达载体,并用菌落PCR、重组质粒琼脂糖凝胶电泳、限制性酶切分析及测序等方法对其进行验证.然后用重组质粒电转化毕赤酵母SMD1168,并用PCR扩增分析观察转化效果,用SDS-PAGE及酶活检测观察重组酵母黑曲霉GOD的表达和活性.结果:用黑曲霉accc30161的GOD基因成功构建了GOD表达载体pGAPZαA-GOD.转化后,pGAPZαA-GOD相关DNA片段已整合进重组毕赤酵母SMD1168-GOD基因组中.SMD1168-GOD可高表达具有活性的GOD,在30℃、pH 6的条件下,其培养液上清GOD酶活可达107.18 u/mL.结论:重组蛋白缺陷性毕赤酵母SMD1168-GOD可以利用pGAP高效表达黑曲霉GOD.

  18. Effect of curcumin on kidney histopathological changes, lipid peroxidation and total antioxidant capacity of serum in sodium arsenite-treated mice.

    Science.gov (United States)

    Momeni, Hamid Reza; Eskandari, Najmeh

    2017-02-01

    Sodium arsenite is an environmental pollutant with the ability to generate free radicals and curcumin acts as a potent antioxidant. This study investigates the effect of curcumin on kidney histopathology, lipid peroxidation and antioxidant capacity of serum in the mice treated with sodium arsenite. Adult male mice were divided into four groups: control, sodium arsenite, curcumin and curcumin+sodium arsenite. The treatments were delivered for 5 weeks. After the treatment period, blood samples were collected and the concentrations of malondialdehyde (MDA) and total antioxidant capacity of serum were determined. Left kidney was dissected, weighed and used for histopathological and histomorphometrical studies. Sodium arsenite-treated mice showed a significant decrease in the diameter of glomerulus and proximal tubule, glomerular area, total antioxidant capacity of serum as well as a significant increase in serum concentration of MDA compared to the control group. However, no significant difference was found in kidney weight, area and diameter of Bowman's capsule as well as the diameter of distal tubule in mice treated with sodium arsenite compared to the control. In curcumin+sodium arsenite group, curcumin significantly reversed the adverse effects of sodium arsenite on the diameter of glomerulus and proximal tubule, glomerular area, total antioxidant capacity of serum and serum concentration of MDA compared to the sodium arsenite group. The application of curcumin alone significantly increased the total antioxidant capacity of serum compared to the control. Curcumin compensated the adverse effects of sodium arsenite on kidney tissue, lipid peroxidation and total antioxidant capacity of serum.

  19. Cultivable diversity of thermophilic arsenite/ferrous-oxidizing microorganisms in hot springs of Taiwan

    Science.gov (United States)

    Lu, G.; Lin, Y.; Chang, Y.; Wang, P.; Lin, L.

    2009-12-01

    Elevated levels of arsenic in groundwater and surface water bodies have posed a stringent threat to the deterioration of the water quality for drinking and agriculture purposes around the world. In particular, arsenic liberated from volcanic and sedimentary rocks at high temperatures would be immobilized through adsorption on iron oxide and/or crystallization of iron-bearing minerals downstream at low temperatures. Understanding how microbially-catalytic reactions are involved in the changes of the redox state of arsenic and iron along a flow path would provide important constraints on the arsenic mobility in natural occurrences. The aims of this study were to isolate and characterize thermophilic arsenite- and iron-oxidizing microbes that would facilitate to establish the linkages between microbial distribution and in situ Fe/As cycling processes. Four source waters (LH05, LH08, SYK and MT) from acid-sulfate springs (pH 2-3, 60-97oC) located in the Tatun volcanic area of northern Taiwan were collected and inoculated into media targeting on autotrophic ferrous iron (FC3), arsenite (AC3 ,ACC3, AC7, ACC7), arsenite-resistant hydrogen (AH23), arsenite-resistant hydrogen-sulfur (AH2S3), and arsenite-resistant sulfur oxidations(AS3), and heterotrophic arsenite oxidation(AH3, AH7) at pH 3, and 7 at temperatures of 50, 70 and 80oC. Samples from the Kuantzuling mud springs (KTL) in southwestern Taiwan known with elevated arsenic levels (0.4 ppm) were also collected, inoculated into the heterotrophic medium and incubated at 50, 60, 70 and 80oC. Isolates obtained from KTL were subject to test on the AH7 and ACC7. Two positive enrichments for iron oxidation at 50oC and 70oC were confirmed by the steadily decrease of ferrous iron and increase of precipitates over 4 transfers for samples from the SYK spring. Diverse morphological types of microbes were enriched in all types of arsenite-bearing media at 50oC except for AH23. At 70oC, positive enrichments were found in media

  20. Effects of cultivation conditions on the uptake of arsenite and arsenic chemical species accumulated by Pteris vittata in hydroponics.

    Science.gov (United States)

    Hatayama, Masayoshi; Sato, Takahiko; Shinoda, Kozo; Inoue, Chihiro

    2011-03-01

    The physiological responses of the arsenic-hyperaccumulator, Pteris vittata, such as arsenic uptake and chemical transformation in the fern, have been investigated. However, a few questions remain regarding arsenic treatment in hydroponics. Incubation conditions such as aeration, arsenic concentration, and incubation period might affect those responses of P. vittata in hydroponics. Arsenite uptake was low under anaerobic conditions, as previously reported. However, in an arsenite uptake experiment, phosphorous (P) starvation-dependent uptake of arsenate was observed under aerobic conditions. Time course-dependent analysis of arsenite oxidation showed that arsenite was gradually oxidized to arsenate during incubation. Arsenite oxidation was not observed in any of the control conditions, such as exposure to a nutrient solution or to culture medium only, or with the use of dried root; arsenite oxidation was only observed when live root was used. This result suggests that sufficient aeration allows the rhizosphere system to oxidize arsenite and enables the fern to efficiently take up arsenite as arsenate. X-ray absorption near edge structure (XANES) analyses showed that long-duration exposure to arsenic using a hydroponic system led to the accumulation of arsenate as the dominant species in the root tips, but not in the whole roots, partly because up-regulation of arsenate uptake by P starvation of the fern was caused and retained by long-time incubation. Analysis of concentration-dependent arsenate uptake by P. vittata showed that the uptake switched from a high-affinity transport system to a low-affinity system at high arsenate concentrations, which partially explains the increased arsenate abundance in the whole root.

  1. The novel role of fenofibrate in preventing nicotine- and sodium arsenite-induced vascular endothelial dysfunction in the rat.

    Science.gov (United States)

    Kaur, Jagdeep; Reddy, Krishna; Balakumar, Pitchai

    2010-09-01

    The present study investigated the effect of fenofibrate, an agonist of PPAR-alpha, in nicotine- and sodium arsenite-induced vascular endothelial dysfunction (VED) in rats. Nicotine (2 mg/kg/day, i.p., 4 weeks) and sodium arsenite (1.5 mg/kg/day, i.p., 2 weeks) were administered to produce VED in rats. The scanning electron microscopy study in thoracic aorta revealed that administration of nicotine or sodium arsenite impaired the integrity of vascular endothelium. Further, administration of nicotine or sodium arsenite significantly decreased serum and aortic concentrations of nitrite/nitrate and subsequently reduced acetylcholine-induced endothelium-dependent relaxation. Moreover, nicotine or sodium arsenite produced oxidative stress by increasing serum thiobarbituric acid reactive substances (TBARS) and aortic superoxide generation. However, treatment with fenofibrate (30 mg/kg/day, p.o.) or atorvastatin (30 mg/kg/day p.o., a standard agent) significantly prevented nicotine- and sodium arsenite-induced VED and oxidative stress by improving the integrity of vascular endothelium, increasing the concentrations of serum and aortic nitrite/nitrate, enhancing the acetylcholine-induced endothelium-dependent relaxation and decreasing serum TBARS and aortic superoxide anion generation. Conversely, co-administration of L-NAME (25 mg/kg/day, i.p.), an inhibitor of nitric oxide synthase, markedly attenuated these vascular protective effects of fenofibrate. The administration of nicotine or sodium arsenite altered the lipid profile by increasing serum cholesterol and triglycerides and consequently decreasing high-density lipoprotein levels, which were significantly prevented by treatment with fenofibrate or atorvastatin. It may be concluded that fenofibrate improves the integrity and function of vascular endothelium, and the vascular protecting potential of fenofibrate in preventing the development of nicotine- and sodium arsenite-induced VED may be attributed to its

  2. Involvement of NADH Oxidase in Biofilm Formation in Streptococcus sanguinis.

    Directory of Open Access Journals (Sweden)

    Xiuchun Ge

    Full Text Available Biofilms play important roles in microbial communities and are related to infectious diseases. Here, we report direct evidence that a bacterial nox gene encoding NADH oxidase is involved in biofilm formation. A dramatic reduction in biofilm formation was observed in a Streptococcus sanguinis nox mutant under anaerobic conditions without any decrease in growth. The membrane fluidity of the mutant bacterial cells was found to be decreased and the fatty acid composition altered, with increased palmitic acid and decreased stearic acid and vaccenic acid. Extracellular DNA of the mutant was reduced in abundance and bacterial competence was suppressed. Gene expression analysis in the mutant identified two genes with altered expression, gtfP and Idh, which were found to be related to biofilm formation through examination of their deletion mutants. NADH oxidase-related metabolic pathways were analyzed, further clarifying the function of this enzyme in biofilm formation.

  3. The Arsenite Oxidation Potential of Native Microbial Communities from Arsenic-Rich Freshwaters.

    Science.gov (United States)

    Fazi, Stefano; Crognale, Simona; Casentini, Barbara; Amalfitano, Stefano; Lotti, Francesca; Rossetti, Simona

    2016-07-01

    Microorganisms play an important role in speciation and mobility of arsenic in the environment, by mediating redox transformations of both inorganic and organic species. Since arsenite [As(III)] is more toxic than arsenate [As(V)] to the biota, the microbial driven processes of As(V) reduction and As(III) oxidation may play a prominent role in mediating the environmental impact of arsenic contamination. However, little is known about the ecology and dynamics of As(III)-oxidizing populations within native microbial communities exposed to natural high levels of As. In this study, two techniques for single cell quantification (i.e., flow cytometry, CARD-FISH) were used to analyze the structure of aquatic microbial communities across a gradient of arsenic (As) contamination in different freshwater environments (i.e., groundwaters, surface and thermal waters). Moreover, we followed the structural evolution of these communities and their capacity to oxidize arsenite, when experimentally exposed to high As(III) concentrations in experimental microcosms. Betaproteobacteria and Deltaproteobacteria were the main groups retrieved in groundwaters and surface waters, while Beta and Gammaproteobacteria dominated the bacteria community in thermal waters. At the end of microcosm incubations, the communities were able to oxidize up to 95 % of arsenite, with an increase of Alphaproteobacteria in most of the experimental conditions. Finally, heterotrophic As(III)-oxidizing strains (one Alphaproteobacteria and two Gammaproteobacteria) were isolated from As rich waters. Our findings underlined that native microbial communities from different arsenic-contaminated freshwaters can efficiently perform arsenite oxidation, thus contributing to reduce the overall As toxicity to the aquatic biota.

  4. Effect of arsenite on urea production by long-term cultures of adult rat hepatocytes.

    Science.gov (United States)

    Sierra-Santoyo, A; Hernández, A; López, M L; Mendoza-Figueroa, T

    1996-01-01

    Urea cycle is a hepatic metabolic pathway involving five enzymes and several intermediary metabolites and can be altered by different chemicals. To investigate the effect of arsenic, an ubiquitous hepatotoxic agent, on urea production we exposed long-term cultures of adult rat hepatocytes, which produce urea, to 1.33 and 6.67 microM arsenite for 2 weeks. In cultures exposed to 6.67 microM, urea production decreased 60-70% and cellular arginase activity decreased 30, 70 and 85% after 4, 7 and 14 days of exposure, respectively. The arginase activity released to the medium increased significantly after 4, 7 and 14 days, with a maximum value after 7 days of exposure that was 27-fold higher than that of the untreated controls. The total arginase activity also decreased 35, 52 and 82% after 4, 7 and 14 days of exposure and protein content decreased 57 and 65% after 7 and 14 days of exposure, respectively. Exposure to 6.67 microM arsenite also produced accumulation of intracytoplasmic lipid droplets, vacuolizations and enlargement of the intercellular spaces. On the other hand, exposure of hepatocytes to 1.33 microM arsenite caused an initial decrease of 20% in urea production, did not change cellular, released and total arginase activity and cellular protein content and produced accumulation of intracytoplasmic lipid droplets. These results show that long-term exposure of cultured rat hepatocytes to 6.67 microM arsenite decreases urea production, cellular and total arginase activity and protein content and increases the release of arginase into the culture medium. These alterations could be useful markers of hepatotoxicity in in vitro assays.

  5. Arsenite-oxidizing and arsenate-reducing bacteria associated with arsenic-rich groundwater in Taiwan

    Science.gov (United States)

    Liao, Vivian Hsiu-Chuan; Chu, Yu-Ju; Su, Yu-Chen; Hsiao, Sung-Yun; Wei, Chia-Cheng; Liu, Chen-Wuing; Liao, Chung-Min; Shen, Wei-Chiang; Chang, Fi-John

    2011-04-01

    Drinking highly arsenic-contaminated groundwater is a likely cause of blackfoot disease in Taiwan, but microorganisms that potentially control arsenic mobility in the subsurface remain unstudied. The objective of this study was to investigate the relevant arsenite-oxidizing and arsenate-reducing microbial community that exists in highly arsenic-contaminated groundwater in Taiwan. We cultured and identified arsenic-transforming bacteria, analyzed arsenic resistance and transformation, and determined the presence of genetic markers for arsenic transformation. In total, 11 arsenic-transforming bacterial strains with different colony morphologies and varying arsenic transformation abilities were isolated, including 10 facultative anaerobic arsenate-reducing bacteria and one strictly aerobic arsenite-oxidizing bacterium. All of the isolates exhibited high levels of arsenic resistance with minimum inhibitory concentrations of arsenic ranging from 2 to 200 mM. Strain AR-11 was able to rapidly oxidize arsenite to arsenate at concentrations relevant to environmental groundwater samples without the addition of any electron donors or acceptors. We provide evidence that arsenic-reduction activity may be conferred by the ars operon(s) that were not amplified by the designed primers currently in use. The 16S rRNA sequence analysis grouped the isolates into the following genera: Pseudomonas, Bacillus, Psychrobacter, Vibrio, Citrobacter, Enterobacter, and Bosea. Among these genera, we present the first report of the genus Psychrobacter being involved in arsenic reduction. Our results further support the hypothesis that bacteria capable of either oxidizing arsenite or reducing arsenate coexist and are ubiquitous in arsenic-contaminated groundwater.

  6. Lysyl oxidase in colorectal cancer

    DEFF Research Database (Denmark)

    Cox, Thomas R; Erler, Janine T

    2013-01-01

    Colorectal cancer is the third most prevalent form of cancer worldwide and fourth-leading cause of cancer-related mortality, leading to ~600,000 deaths annually, predominantly affecting the developed world. Lysyl oxidase is a secreted, extracellular matrix-modifying enzyme previously suggested...

  7. Flavoprotein oxidases : classification and applications

    NARCIS (Netherlands)

    Dijkman, Willem P.; de Gonzalo, Gonzalo; Mattevi, Andrea; Fraaije, Marco W.

    2013-01-01

    This review provides an overview of oxidases that utilise a flavin cofactor for catalysis. This class of oxidative flavoenzymes has shown to harbour a large number of biotechnologically interesting enzymes. Applications range from their use as biocatalysts for the synthesis of pharmaceutical compoun

  8. Genetically Engineering Bacillus subtilis with a Heat-Resistant Arsenite Methyltransferase for Bioremediation of Arsenic-Contaminated Organic Waste.

    Science.gov (United States)

    Huang, Ke; Chen, Chuan; Shen, Qirong; Rosen, Barry P; Zhao, Fang-Jie

    2015-10-01

    Organic manures may contain high levels of arsenic (As) due to the use of As-containing growth-promoting substances in animal feed. To develop a bioremediation strategy to remove As from organic waste, Bacillus subtilis 168, a bacterial strain which can grow at high temperature but is unable to methylate and volatilize As, was genetically engineered to express the arsenite S-adenosylmethionine methyltransferase gene (CmarsM) from the thermophilic alga Cyanidioschyzon merolae. The genetically engineered B. subtilis 168 converted most of the inorganic As in the medium into dimethylarsenate and trimethylarsine oxide within 48 h and volatized substantial amounts of dimethylarsine and trimethylarsine. The rate of As methylation and volatilization increased with temperature from 37 to 50°C. When inoculated into an As-contaminated organic manure composted at 50°C, the modified strain significantly enhanced As volatilization. This study provides a proof of concept of using genetically engineered microorganisms for bioremediation of As-contaminated organic waste during composting.

  9. Protective effect of Juglans nigra on sodium arsenite-induced toxicity in rats

    Directory of Open Access Journals (Sweden)

    Solomon E Owumi

    2013-01-01

    Full Text Available Background: Consumption of arsenic contaminated water has been implicated in metalloid-induced carcinogenesis. Dietary intake of certain plant products with chemoprotective properties may protect against the onset of diseases and promote maintenance of health. Objectives: We investigated the outcome of black walnut Juglans nigra (JN consumption on sodium arsenite (SA-induced toxicity in rats. Materials and Methods: Wister albino rats were treated as follows: Control, SA only (positive control (2.5 mg/kg body weight, JN only (100 mg/kg weight, and JN+SA coadministered. After 5 weeks animals were sacrificed whole blood, femur, liver and testis harvested were assessed for hepatic transaminases and clastogenicity. Histology of the liver, sperm morphology and quality were also assessed. Data were analyzed (ANOVA and expressed as means ±SD. Results: SA treatment elevated hepatic transaminases level in serum (P < 0.05, induced histological changes in liver: fibroplasia and periportal hepatocytes infiltration by mononuclear cells. These changes were ameliorated by JN (P < 0.05 coadministration. SA induced micronuclei formation (P < 0.05. Again JN decreased (P < 0.05 micronuclei formation by 50%. Sperm count and motility decreased (P < 0.05 in all groups compared to control. Conclusion: JN showed no protection against arsenite effect on sperm quality. Hepatoprotective and anticlastogenic effects were apparent suggesting a chemopreventive potential active against arsenite genotoxicity and chromosomal instability which have implication for metalloid-induced carcinogenesis.

  10. Sodium arsenite induced biochemical perturbations in rats: ameliorating effect of curcumin.

    Science.gov (United States)

    Yousef, Mokhtar I; El-Demerdash, Fatma M; Radwan, Fatma M E

    2008-11-01

    The present study was undertaken to evaluate the therapeutic efficacy of curcumin in terms of normalization of altered biochemical parameters following sodium arsenite treatment in rats. Animals were divided into four groups. The first group was used as control. While, groups 2, 3 and 4 were orally treated with curcumin (Cur, 15 mg/kg BW), sodium arsenite (Sa, 5 mg/kg BW) and sodium arsenite plus curcumin, respectively. Results showed that the activities of transaminases and phosphatases were significantly decreased in liver due to Sa administration, whereas increased in plasma. The activity of brain and plasma acetylcholinesterase (AChE) was decreased in rats treated with Sa. Also, Sa significantly decreased plasma total protein (TP), albumin (Alb) and high density lipoprotein-cholesterol (HDL-c), while increased glucose, urea, creatinine, bilirubin, total lipid (TL), cholesterol, triglyceride (TG) and low density lipoprotein-cholesterol (LDL-c). Curcumin alone decreased the levels of glucose, urea, creatinine, TL, cholesterol, TG and LDL-c. Curcumin reduced Sa-induced transaminases, phosphatases, glucose, urea, creatinine, bilirubin, TL, cholesterol and TG. Moreover, curcumin induced Sa-reduced liver transaminases and phosphatases, plasma and brain AChE, and the levels of TP and Alb. Experimental results, therefore suggested that curcumin protects arsenic induced biochemical alterations in rats.

  11. Bioaccumulation and oxidative stress in Daphnia magna exposed to arsenite and arsenate.

    Science.gov (United States)

    Fan, Wenhong; Ren, Jinqian; Li, Xiaomin; Wei, Chaoyang; Xue, Feng; Zhang, Nan

    2015-11-01

    Arsenic pollution and its toxicity to aquatic organisms have attracted worldwide attention. The bioavailability and toxicity of arsenic are highly related to its speciation. The present study investigated the differences in bioaccumulation and oxidative stress responses in an aquatic organism, Daphnia magna, induced by 2 inorganic arsenic species (As(III) and As(V)). The bioaccumulation of arsenic, Na(+) /K(+) -adenosine triphosphatase (ATPase) activity, reactive oxygen species (ROS) content, total superoxide dismutase (SOD) activity, total antioxidative capability, and malondialdehyde content in D. magna were determined after exposure to 500 µg/L of arsenite and arsenate for 48 h. The results showed that the oxidative stress and antioxidative process in D. magna exposed to arsenite and arsenate could be divided into 3 phases, which were antioxidative response, oxidation inhibition, and antioxidative recovery. In addition, differences in bioaccumulation, Na(+) /K(+) -ATPase activity, and total SOD activity were also found in D. magna exposed to As(III) and As(V). These differences might have been the result of the high affinity of As(III) with sulfhydryl groups in enzymes and the structural similarity of As(V) to phosphate. Therefore, arsenate could be taken up by organisms through phosphate transporters, could substitute for phosphate in biochemical reactions, and could lead to a change in the bioaccumulation of arsenic and activity of enzymes. These characteristics were the possible reasons for the different toxicity mechanisms in the oxidative stress process of arsenite and arsenate.

  12. Aquaglyceroporins are involved in uptake of arsenite into murine gastrointestinal tissues.

    Science.gov (United States)

    Wang, Chun; Chen, Gang; Jiang, Junkang; Qiu, Lianglin; Hosoi, Kazuo; Yao, Chenjuan

    2009-01-01

    Aquaglyceroporins (AQGPs) are members of aquaporin (AQP) family and belong to a subgroup of this water channel family; they are transmembrane proteins that transport water as well as glycerol and other solutes of small molecules. Recent studies have also identified that AQGPs are important transporters of trivalent metalloid in some mammalian cells. However, the uptake routes of arsenite in mammals are still less defined. In this study, to understand the routes of arsenite intake in mammals, mice were treated with Hg(II), glycerol, and As(III) and uptake of As(III) into the gastrointestinal tissues was measured. The level of inorganic arsenic (iAs) in gastrointestinal tissues after As(III) stimulation was much higher than Hg(II) +As(III) or glycerol+As(III) group. RT-PCR results showed that AQGPs were extensively expressed in gastrointestinal tissues of mice. We also treated Caco-2 cells with Hg(II) and As(III); the level of iAs in a group treated with Hg(II)+As(III) decreased compared with As(III)-treated group. Our results suggested that AQGPs could be important transporters in arsenite uptake into gastrointestinal tissues of mice, but more data are need to prove if AQGPs is the only pathway involved in As transport in mammals or just one of them.

  13. Arabidopsis NIP3;1 Plays an Important Role in Arsenic Uptake and Root-to-Shoot Translocation under Arsenite Stress Conditions.

    Science.gov (United States)

    Xu, Wenzhong; Dai, Wentao; Yan, Huili; Li, Sheng; Shen, Hongling; Chen, Yanshan; Xu, Hua; Sun, Yangyang; He, Zhenyan; Ma, Mi

    2015-05-01

    In Arabidopsis, the nodulin 26-like intrinsic protein (NIP) subfamily of aquaporin proteins consists of nine members, five of which (NIP1;1, NIP1;2, NIP5;1, NIP6;1, and NIP7;1) were previously identified to be permeable to arsenite. However, the roles of NIPs in the root-to-shoot translocation of arsenite in plants remain poorly understood. In this study, using reverse genetic strategies, Arabidopsis NIP3;1 was identified to play an important role in both the arsenic uptake and root-to-shoot distribution under arsenite stress conditions. The nip3;1 loss-of-function mutants displayed obvious improvements in arsenite tolerance for aboveground growth and accumulated less arsenic in shoots than those of the wild-type plants, whereas the nip3;1 nip1;1 double mutant showed strong arsenite tolerance and improved growth of both roots and shoots under arsenite stress conditions. A promoter-β-glucuronidase analysis revealed that NIP3;1 was expressed almost exclusively in roots (with the exception of the root tips), and heterologous expression in the yeast Saccharomyces cerevisiae demonstrated that NIP3;1 was able to mediate arsenite transport. Taken together, our results suggest that NIP3;1 is involved in arsenite uptake and root-to-shoot translocation in Arabidopsis, probably as a passive and bidirectional arsenite transporter.

  14. CotA, a multicopper oxidase from Bacillus pumilus WH4, exhibits manganese-oxidase activity.

    Directory of Open Access Journals (Sweden)

    Jianmei Su

    Full Text Available Multicopper oxidases (MCOs are a family of enzymes that use copper ions as cofactors to oxidize various substrates. Previous research has demonstrated that several MCOs such as MnxG, MofA and MoxA can act as putative Mn(II oxidases. Meanwhile, the endospore coat protein CotA from Bacillus species has been confirmed as a typical MCO. To study the relationship between CotA and the Mn(II oxidation, the cotA gene from a highly active Mn(II-oxidizing strain Bacillus pumilus WH4 was cloned and overexpressed in Escherichia coli strain M15. The purified CotA contained approximately four copper atoms per molecule and showed spectroscopic properties typical of blue copper oxidases. Importantly, apart from the laccase activities, the CotA also displayed substantial Mn(II-oxidase activities both in liquid culture system and native polyacrylamide gel electrophoresis. The optimum Mn(II oxidase activity was obtained at 53°C in HEPES buffer (pH 8.0 supplemented with 0.8 mM CuCl2. Besides, the addition of o-phenanthroline and EDTA both led to a complete suppression of Mn(II-oxidizing activity. The specific activity of purified CotA towards Mn(II was 0.27 U/mg. The Km, Vmax and kcat values towards Mn(II were 14.85±1.17 mM, 3.01×10(-6±0.21 M·min(-1 and 0.32±0.02 s(-1, respectively. Moreover, the Mn(II-oxidizing activity of the recombinant E. coli strain M15-pQE-cotA was significantly increased when cultured both in Mn-containing K liquid medium and on agar plates. After 7-day liquid cultivation, M15-pQE-cotA resulted in 18.2% removal of Mn(II from the medium. Furthermore, the biogenic Mn oxides were clearly observed on the cell surfaces of M15-pQE-cotA by scanning electron microscopy. To our knowledge, this is the first report that provides the direct observation of Mn(II oxidation with the heterologously expressed protein CotA, Therefore, this novel finding not only establishes the foundation for in-depth study of Mn(II oxidation mechanisms, but also offers

  15. Peroxisomal Polyamine Oxidase and NADPH-Oxidase cross-talk for ROS homeostasis which affects respiration rate in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Efthimios A. Andronis

    2014-04-01

    Full Text Available Homeostasis of reactive oxygen species (ROS in the intracellular compartments is of critical importance as ROS have been linked with nearly all cellular processes and more importantly with diseases and aging. PAs are nitrogenous molecules with an evolutionary conserved role in the regulation of metabolic and energetic status of cells. Recent evidence also suggests that polyamines (PA are major regulators of ROS homeostasis. In Arabidopsis the backconversion of the PAs spermidine (Spd and spermine (Spm to putrescine (Put and Spd, respectively is catalyzed by two peroxisomal PA oxidases (AtPAO. However, the physiological role of this pathway remains largely elusive. Here we explore the role of peroxisomal PA backconversion and in particular that catalyzed by the highly expressed AtPAO3 in the regulation of ROS homeostasis and mitochondrial respiratory burst. Exogenous PAs exert an NADPH-oxidase dependent stimulation of oxygen consumption, with Spd exerting the strongest effect. This increase is attenuated by treatment with the NADPH-oxidase blocker diphenyleneiodonium iodide (DPI. Loss-of-function of AtPAO3 gene results to increased NADPH-oxidase-dependent production of superoxide anions (O2.-, but not H2O2, which activate the mitochondrial alternative oxidase pathway (AOX. On the contrary, overexpression of AtPAO3 results to an increased but balanced production of both H2O2 and O2.-. These results suggest that the ratio of O2.-/H2O2 regulates respiratory chain in mitochondria, with PA-dependent production of O2.- by NADPH-oxidase tilting the balance of electron transfer chain in favor of the AOX pathway. In addition, AtPAO3 seems to be an important component in the regulating module of ROS homeostasis, while a conserved role for PA backconversion and ROS across kingdoms is discussed.

  16. Syntheses, crystal structures and characterizations of new vanadium arsenites and arsenates

    Energy Technology Data Exchange (ETDEWEB)

    Liu Junhui [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100039 (China); He Zhangzhen; Kong Fang; Xu Xiang [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China); Sun Chuanfu [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100039 (China); Mao Jianggao, E-mail: mjg@fjirsm.ac.cn [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China)

    2012-08-15

    Systematic explorations in vanadium arsenites and arsenates led to the isolation four new compounds, namely, {alpha}-(V{sup IV}O){sub 3}(As{sup III}O{sub 3}){sub 2} (1), {beta}-(V{sup IV}O){sub 3}(As{sup III}O{sub 3}){sub 2} (2), (V{sup IV}O)[V{sup IV}O(H{sub 2}O)]{sub 2}(As{sup V}O{sub 4}){sub 2} (3), V{sup III}V{sup IV}O{sub 2}(As{sup V}O{sub 4}) (4). Compounds 1, 2 and 4 were synthesized by standard solid-state reactions, and compound 3 is a vanadium arsenate dihydrate synthesized through hydrothermal reactions. Compounds 1 and 2 are isomers, and they represent the first examples of ternary inorganic vanadium(IV) arsenites. Single crystal X-ray diffraction analysis indicated that the four compounds display four different structural types. Magnetic property measurements for compound 1 indicated that it exhibits ferromagnetism with the Curie temperature T{sub c}=65 K. Thermal stability and optical properties for compounds 1 and 3 were also investigated. - Graphical abstract: Hydrothermal or solid state reactions of V{sub 2}O{sub 5} (or VO{sub 2}) and As{sub 2}O{sub 3} yielded four new ternary compounds with four different types of structures, namely, {alpha}-(VO){sub 3}(AsO{sub 3}){sub 2} (1), {beta}-(VO){sub 3}(AsO{sub 3}){sub 2} (2), (VO)[VO(H{sub 2}O)]{sub 2}(AsO{sub 4}){sub 2} (3), (VO){sub 2}(AsO{sub 4}) (4). {alpha}-(VO){sub 3}(AsO{sub 3}){sub 2} (1), {beta}-(VO){sub 3}(AsO{sub 3}){sub 2} (2) represent the first examples of ternary inorganic vanadium(IV) arsenites. Highlights: Black-Right-Pointing-Pointer Hydrothermal or solid state reactions of V{sub 2}O{sub 5} (or VO{sub 2}) and As{sub 2}O{sub 3} yielded two new arsenites. Black-Right-Pointing-Pointer They represent the first examples of ternary vanadium arsenites. Black-Right-Pointing-Pointer Two new ternary vanadium arsenates were also obtained. Black-Right-Pointing-Pointer They exhibit four different structural types.

  17. Multiple amine oxidases in cucumber seedlings.

    Science.gov (United States)

    Percival, F W; Purves, W K

    1974-10-01

    Cell-free extracts of cucumber (Cucumis sativus L. cv. National Pickling) seedlings were found to have amine oxidase activity when assayed with tryptamine as a substrate. Studies of the effect of lowered pH on the extract indicated that this activity was heterogeneous, and three amine oxidases could be separated by ion exchange chromatography. The partially purified enzymes were tested for their activities with several substrates and for their sensitivities to various amine oxidase inhibitors. One of the enzymes may be a monoamine oxidase, although it is inhibited by some diamine oxidase inhibitors. The other two enzymes have properties more characteristic of the diamine oxidases. The possible relationship of the amine oxidases to indoleacetic acid biosynthesis in cucumber seedlings is discussed.

  18. Functional characterization of gibberellin oxidases from cucumber, Cucumis sativus L.

    Science.gov (United States)

    Pimenta Lange, Maria João; Liebrandt, Anja; Arnold, Linda; Chmielewska, Sara-Miriam; Felsberger, André; Freier, Eduard; Heuer, Monika; Zur, Doreen; Lange, Theo

    2013-06-01

    Cucurbits have been used widely to elucidate gibberellin (GA) biosynthesis. With the recent availability of the genome sequence for the economically important cucurbit Cucumis sativus, sequence data became available for all genes potentially involved in GA biosynthesis for this species. Sixteen cDNAs were cloned from root and shoot of 3-d to 7-d old seedlings and from mature seeds of C. sativus. Two cDNAs code for GA 7-oxidases (CsGA7ox1, and -2), five for GA 20-oxidases (CsGA20ox1, -2, -3, -4, and -5), four for GA 3-oxidases (CsGA3ox1, -2, -3, and -4), and another five for GA 2-oxidases (CsGA2ox1, -2, -3, -4, and -5). Their enzymatic activities were investigated by heterologous expression of the cDNAs in Escherichia coli and incubation of the cell lysates with (14)C-labelled, D2-labelled, or unlabelled GA-substrates. The two GA 7-oxidases converted GA12-aldehyde to GA12 efficiently. CsGA7ox1 converted GA12 to GA14, to 15α-hydroxyGA12, and further to 15α-hydroxyGA14. CsGA7ox2 converted GA12 to its 12α-hydroxylated analogue GA111. All five GA 20-oxidases converted GA12 to GA9 as a major product, and to GA25 as a minor product. The four GA 3-oxidases oxidized the C19-GA GA9 to GA4 as the only product. In addition, three of them (CsGA3ox2, -3, and -4) converted the C20-GA GA12 to GA14. The GA 2-oxidases CsGA2ox1, -2, -3, and -4 oxidized the C19-GAs GA9 and GA4 to GA34 and GA51, respectively. CsGA2ox2, -3, and -4 converted GA51 and GA34 further to respective GA-catabolites. In addition to C19-GAs, CsGA2ox4 also converted the C20-GA GA12 to GA110. In contrast, CsGA2ox5 oxidized only the C20 GA12 to GA110 as the sole product. As shown for CsGA20ox1 and CsGA3ox1, similar reactions were catalysed with 13-hydroxlyated GAs as substrates. It is likely that these enzymes are also responsible for the biosynthesis of 13-hydroxylated GAs in vivo that occur at low levels in cucumber.

  19. Sodium arsenite down-regulates the expression of X-linked inhibitor of apoptosis protein via translational and post-translational mechanisms in hepatocellular carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hong; Hao, Yuqing; Wang, Lijing; Jia, Dongwei [Gene Research Center, Shanghai Medical College, Fudan University, Shanghai 200032 (China); Ruan, Yuanyuan, E-mail: yuanyuanruan@fudan.edu.cn [Gene Research Center, Shanghai Medical College, Fudan University, Shanghai 200032 (China); Gu, Jianxin [Gene Research Center, Shanghai Medical College, Fudan University, Shanghai 200032 (China)

    2012-06-15

    Highlights: Black-Right-Pointing-Pointer Sodium arsenite down-regulates the protein expression level of XIAP in HCC. Black-Right-Pointing-Pointer Sodium arsenite inhibits the de novo XIAP synthesis and its IRES activity. Black-Right-Pointing-Pointer Sodium arsenite decreases XIAP stability and promotes its proteasomal degradation. Black-Right-Pointing-Pointer Overexpression of XIAP attenuates the pro-apoptotic effect of sodium arsenite. -- Abstract: X-linked inhibitor of apoptosis protein (XIAP) is a member of the inhibitors of apoptosis protein (IAP) family, and has been reported to exhibit elevated expression levels in hepatocellular carcinoma (HCC) and promote cell survival, metastasis and tumor recurrence. Targeting XIAP has proven effective for the inhibition of cancer cell proliferation and restoration of cancer cell chemosensitivity. Arsenic (or sodium arsenite) is a potent anti-tumor agent used to treat patients with acute promyelocytic leukemia (APL). Additionally, arsenic induces cell growth inhibition, cell cycle arrest and apoptosis in human HCC cells. In this study, we identified XIAP as a target for sodium arsenite-induced cytotoxicity in HCC. The exposure of HCC cell lines to sodium arsenite resulted in inhibition of XIAP expression in both a dose- and time-dependent manner. Sodium arsenite blocked the de novo XIAP synthesis and the activity of its internal ribosome entry site (IRES) element. Moreover, treatment with sodium arsenite decreased the protein stability of XIAP and induced its ubiquitin-proteasomal degradation. Overexpression of XIAP attenuated the pro-apoptotic effect of sodium arsenite in HCC. Taken together, our data demonstrate that sodium arsenite suppresses XIAP expression via translational and post-translational mechanisms in HCC.

  20. Oxidase-based biocatalytic processes

    DEFF Research Database (Denmark)

    Ramesh, Hemalata; Woodley, John; Krühne, Ulrich

    solvent-resistant oxygen sensors as supporting technology for oxidase-basedreactions using a glucose oxidase reaction system as an example.iiImplementation of biocatalytic oxidation at scale still requires process knowledge which includes thelimitations of the system and the knowledge about the potential......Biocatalytic processes are gaining significant focus in frontiers where they offer unique advantages(selectivity and mild operating conditions) over chemical catalysts. It is therefore not surprising that therehave been many industrial biocatalytic processes implemented.Despite past successes......, the implementation of a new biocatalytic process still presents some challenges (demands placed on the biocatalyst) in terms of the requirements to make a viable industrial process. Inorder for a biocatalytic process to be economically successful, it is necessary that certain a set of targetmetrics (product titre...

  1. Lysyl oxidase in cancer research.

    Science.gov (United States)

    Perryman, Lara; Erler, Janine T

    2014-01-01

    Metastasis is the main reason for cancer-associated deaths and therapies are desperately needed to target the progression of cancer. Lysyl oxidase (LOX) plays a pivotal role in cancer progression, including metastasis, and is therefore is an attractive therapeutic target. In this review we will breakdown the process of cancer progression and the various roles that LOX plays has in the advancement of cancer. We will highlight why LOX is an exciting therapeutic target for the future.

  2. The accumulations of HIF-1α and HIF-2α by JNK and ERK are involved in biphasic effects induced by different levels of arsenite in human bronchial epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yuan; Li, Yuan [Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing 210029, Jiangsu (China); The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 210029, Jiangsu (China); Li, Huiqiao [Qujing Center for Disease Control and Prevention, Qujing 655000, Yunnan (China); Pang, Ying; Zhao, Yue; Jiang, Rongrong; Shen, Lu [Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing 210029, Jiangsu (China); The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 210029, Jiangsu (China); Zhou, Jianwei; Wang, Xinru [The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 210029, Jiangsu (China); Liu, Qizhan, E-mail: drqzliu@hotmail.com [Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing 210029, Jiangsu (China); The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 210029, Jiangsu (China)

    2013-01-15

    The biphasic effects of arsenite, in which low levels of arsenite induce cell proliferation and high levels of arsenite induce DNA damage and apoptosis, apparently contribute to arsenite-induced carcinogenesis. However, the mechanisms underlying this phenomenon are not well understood. In this study, we investigated the effects of different levels of arsenite on cell proliferation, DNA damage and apoptosis as well as on signal transduction pathways in human bronchial epithelial (HBE) cells. Our results show that a low level of arsenite activates extracellular signal-regulated kinases (ERK), which probably mediate arsenite-inhibited degradation of ubiquitinated hypoxia-inducible factor-2α (HIF-2α) in HBE cells. ERK inhibition blocks cell proliferation induced by a low level of arsenite, in part via HIF-2α. In contrast, a high level of arsenite activates c-Jun N-terminal kinases (JNK), which provoke a response to suppress ubiquitinated HIF-1α degradation. Down-regulation of HIF-1α by inhibiting JNK, however, increases the DNA damage but decreases the apoptosis induced by a high level of arsenite. Thus, data in the present study suggest that the accumulations of HIF-1α and HIF-2α by JNK and ERK are involved in different levels of arsenite-induced biphasic effects, with low levels of arsenite inducing cell proliferation and high levels of arsenite inducing DNA damage and apoptosis in HBE cells. -- Highlights: ► Biphasic effects induced by different concentrations of arsenite. ► Different regulation of ERK or JNK signal pathway by arsenite. ► Different regulation of HIF1α or HIF 2α by arsenite.

  3. 共培养下后交叉韧带成纤维细胞中赖氨酰氧化酶的基因表达**☆%Lysyl oxidase gene expressions in the posterior cruciate ligament fibroblasts co-cultured with synovial cells

    Institute of Scientific and Technical Information of China (English)

    张艳君; 梅虎; 蒋稼欢; 谢静; 尹琳; 陈荣富; 许春明; 王春莉; 宋国立

    2013-01-01

    to improve the healing ability of injured posterior cruciate ligament, we need to find new ways for regeneration and repair of injured posterior cruciate ligament. Previous studies have demonstrated that lysyl oxidases play an important role in the tissue repair mechanism, but the effect of lysyl oxidases from injured posterior cruciate ligament on the process of wound repair remains unclear. OBJECTIVE: To investigate the expressions of lysyl oxidases in the posterior cruciate ligament fibroblasts co-cultured with synovial cel s. METHODS: The fourth passage of posterior cruciate ligament fibroblasts and synovial cel s were placed in 6-wel plates and Transwel , respectively. Two groups were designed as fol ows, posterior cruciate ligament fibroblasts group as control and co-cultured group termed as test group. At 6 hours after co-culture, total RNA was isolated and the expressions of lysyl oxidases in the posterior cruciate ligament fibroblasts were analyzed by semi-quantitative reverse-transcription PCR and quantitative real-time PCR. RESULTS AND CONCLUSION: The results revealed that co-culture contributed to up-regulations of lysyl oxidases compared with the control group, and gene levels were up to 1.1 folds in lysyl oxidase, 1.4 folds in lysyl oxidase-like 1 protein, 1.1 folds in lysyl oxidase-like 2 protein, 1.3 folds in lysyl oxidase-like 3 protein, 1.1 folds in lysyl oxidase-like 4 protein in co-cultured posterior cruciate ligament cel s (P < 0.05). The differential expression of lysyl oxidases in co-cultured posterior cruciate ligament cel s implies that cel-cel interaction and crosstalk are related with posterior cruciate ligament wound healing and have significant potential value and clinical usage for cure of injured posterior cruciate ligament.

  4. Possible vasculoprotective role of linagliptin against sodium arsenite-induced vascular endothelial dysfunction.

    Science.gov (United States)

    Jyoti, Uma; Kansal, Sunil Kumar; Kumar, Puneet; Goyal, Sandeep

    2016-02-01

    Vascular endothelial dysfunction (VED) interrupts the integrity and function of endothelial lining through enhanced markers of oxidative stress and decrease endothelial nitric oxide synthase (eNOS) expression. The main aim of the present study has been designed to investigate the possible vasculoprotective role of linagliptin against sodium arsenite-induced VED. Sodium arsenite (1.5 mg/kg, i.p., 2 weeks) abrogated the acetylcholine-induced, endothelium-dependent vasorelaxation by depicting the decrease in serum nitrite/nitrate concentration, reduced glutathione level, and simultaneously enhance the thiobarbituric acid reactive substances (TBARS) level, superoxide level, and tumor necrosis factor-alpha. These elevated markers interrupt the integrity of endothelial lining of thoracic aorta which was assessed histologically. The study elicits dose dependent effect of linagliptin (1.5 mg/kg, i.p. and 3 mg/kg, i.p.) or atorvastatin (30 mg/kg, p.o.) treatment, improved the endothelium-dependent independent relaxation, improve the integrity of endothelium lining which was assessed histologically by enhancing the serum nitrite/nitrate level, reduced glutathione level and simultaneously decreasing the TBARS level, superoxide anion level and tumor necrosis factor-alpha (TNF-α) level. L-NAME (25 mg/kg, i.p.), eNOS inhibitor, abrogated the ameliorative potential of linagliptin. However, the ameliorative potential of linagliptin has been enhanced by l-arginine (200 mg/kg, i.p.) which elicits that ameliorative potential of linagliptin was through eNOS signaling cascade and it may be concluded that linagliptin 3 mg/kg, i.p. has more significantly activated the eNOS and decreased the oxidative markers than linagliptin 1.5 mg/kg, i.p. and prevented sodium arsenite-induced VED.

  5. Low Dose and Long Term Toxicity of Sodium Arsenite Caused Caspase Dependent Apoptosis Based on Morphology and Biochemical Character

    Directory of Open Access Journals (Sweden)

    Mohammad Hussein Abnosi

    2012-01-01

    Full Text Available Objective: Although arsenite is toxic it is currently recommended for the treatment of malignancies. In this study the effects of sub-micromolar concentrations of sodium arsenite on the viability, morphology and mechanism of cell death of rat bone marrow mesenchymal stem cells (BMCs over 21 days was investigated.Materials and Methods: In this experimental study, BMCs were extracted in Dulbecco’s Modified Eagles Medium (DMEM containing 15% of fetal bovine serum (FBS and expanded till the 3rd passage. The cells were treated with 1, 10, 25, 50, 75 and 100 nM of sodium arsenite for 21 days and the viability of the cells estimated using 3-(4, 5-dimethylthiazol-2-yl-2, 5 diphenyl tetrazolium (MTT and trypan blue staining. Cells were then treated with the selected dose (25 nM of sodium arsenite to determine their colony forming ability (CFA and population doubling number (PDN. Morphology of the cells was studied using florescent dyes, and the integrity of the DNA was investigated using the comet assay and agarose gel electrophoresis. The terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL and the caspase 3 assay were then applied to understand the mechanism of cell death. Data was analyzed using one way ANOVA, Tukey test.Results: A significant reduction of viability, PDN and CFA was found following treatment of BMCs with 25 nM sodium arsenite (p<0.05. Cytoplasm shrinkage and a significant decrease in the diameter of the nuclei were also seen. Comet assay and agarose gel electrophoresis revealed DNA breakage, while positive TUNEL and activated caspase 3 confirmed the apoptosis.Conclusion: A low concentration of sodium arsenite (25 nM caused reduction of viability due to induction of apoptosis. Therefore, long term exposure to low dose of this chemical may have unwanted effects on BMCs.

  6. Arsenite Regulates Prolongation of Glycan Residues of Membrane Glycoprotein: A Pivotal Study via Wax Physisorption Kinetics and FTIR Imaging.

    Science.gov (United States)

    Lee, Chih-Hung; Hsu, Chia-Yen; Huang, Pei-Yu; Chen, Ching-Iue; Lee, Yao-Chang; Yu, Hsin-Su

    2016-03-22

    Arsenic exposure results in several human cancers, including those of the skin, lung, and bladder. As skin cancers are the most common form, epidermal keratinocytes (KC) are the main target of arsenic exposure. The mechanisms by which arsenic induces carcinogenesis remains unclear, but aberrant cell proliferation and dysregulated energy homeostasis play a significant role. Protein glycosylation is involved in many key physiological processes, including cell proliferation and differentiation. To evaluate whether arsenite exposure affected protein glycosylation, the alteration of chain length of glycan residues in arsenite treated skin cells was estimated. Herein we demonstrated that the protein glycosylation was adenosine triphosphate (ATP)-dependent and regulated by arsenite exposure by using Fourier transform infrared (FTIR) reflectance spectroscopy, synchrotron-radiation-based FTIR (SR-FTIR) microspectroscopy, and wax physisorption kinetics coupled with focal-plane-array-based FTIR (WPK-FPA-FTIR) imaging. We were able to estimate the relative length of surface protein-linked glycan residues on arsenite-treated skin cells, including primary KC and two skin cancer cell lines, HSC-1 and HaCaT cells. Differential physisorption of wax adsorbents adhered to long-chain (elongated type) and short-chain (regular type) glycan residues of glycoprotein of skin cell samples treated with various concentration of arsenite was measured. The physisorption ratio of beeswax remain/n-pentacosane remain for KC cells was increased during arsenite exposure. Interestingly, this increase was reversed after oligomycin (an ATP synthase inhibitor) pretreatment, suggesting the chain length of protein-linked glycan residues is likely ATP-dependent. This is the first study to demonstrate the elongation and termination of surface protein-linked glycan residues using WPK-FPA-FTIR imaging in eukaryotes. Herein the result may provide a scientific basis to target surface protein-linked glycan

  7. Arsenite Regulates Prolongation of Glycan Residues of Membrane Glycoprotein: A Pivotal Study via Wax Physisorption Kinetics and FTIR Imaging

    Directory of Open Access Journals (Sweden)

    Chih-Hung Lee

    2016-03-01

    Full Text Available Arsenic exposure results in several human cancers, including those of the skin, lung, and bladder. As skin cancers are the most common form, epidermal keratinocytes (KC are the main target of arsenic exposure. The mechanisms by which arsenic induces carcinogenesis remains unclear, but aberrant cell proliferation and dysregulated energy homeostasis play a significant role. Protein glycosylation is involved in many key physiological processes, including cell proliferation and differentiation. To evaluate whether arsenite exposure affected protein glycosylation, the alteration of chain length of glycan residues in arsenite treated skin cells was estimated. Herein we demonstrated that the protein glycosylation was adenosine triphosphate (ATP-dependent and regulated by arsenite exposure by using Fourier transform infrared (FTIR reflectance spectroscopy, synchrotron-radiation-based FTIR (SR-FTIR microspectroscopy, and wax physisorption kinetics coupled with focal-plane-array-based FTIR (WPK-FPA-FTIR imaging. We were able to estimate the relative length of surface protein-linked glycan residues on arsenite-treated skin cells, including primary KC and two skin cancer cell lines, HSC-1 and HaCaT cells. Differential physisorption of wax adsorbents adhered to long-chain (elongated type and short-chain (regular type glycan residues of glycoprotein of skin cell samples treated with various concentration of arsenite was measured. The physisorption ratio of beeswax remain/n-pentacosane remain for KC cells was increased during arsenite exposure. Interestingly, this increase was reversed after oligomycin (an ATP synthase inhibitor pretreatment, suggesting the chain length of protein-linked glycan residues is likely ATP-dependent. This is the first study to demonstrate the elongation and termination of surface protein-linked glycan residues using WPK-FPA-FTIR imaging in eukaryotes. Herein the result may provide a scientific basis to target surface protein

  8. Embryotoxicity of arsenite and arsenate. Distribution in pregnant mice and monkeys and effects on embryonic cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Lindgren, A.; Danielsson, R.G.; Dencker, L. (Department of Toxicology, Biomedical Center, Uppsala University, Sweden); Vahter, M. (National Institute of Environmental Medicine, Stockholm, Sweden)

    1984-01-01

    The distribution of /sup 74/As-labelled and arsenite in pregnant mice and a monkey has been studied by autoradiography and gamma counting of isolated tissues, and their in vitro toxicity to a chondrogenic system has been investigated. With both arsenic forms, given as single intravenous injections to the mother, the /sup 74/As-arsenic appeared to pass the mouse placenta relatively freely and approximately to the same extent. The retention time in material tissues including the placenta was, however, around three times longer with arsenite than with arsenate. In early gestation, high activity was registered in the embryonic neuroepithelium, which correlates well with reported CNS malformations in rodents. In late gestation, the distribution pattern was more like that in the adults. Accumulation in skin and squamous epithelia of the upper gastrointestinal tract (oral cavity, oesophagus and oesophageal region of stomach) dominated the distribution picture, especially at a long survival interval. Arsenate, but not arsenite, showed affinity for the calcified areas of the skeleton. A marmoset monkey in late gestation receiving arsenite showed a somewhat lower rate of placental transfer than the mice. Skin and liver had the highest concentrations (at 8 hrs), both in mother and foetuses. This species is known not to methylate arsenic, resulting in stronger binding and longer retention times of arsenic as compared with other species. The stronger binding in maternal tissues may possibly explain the lower rate of placental transfer. Arsenite was shown to inhibit cartilage formation in a chick limb bud mesenchymal spot culture system (ED50 approximately 5-10..mu..M) while arsenate seemed to be without effect at concentrations up to 200 ..mu..M (highest tested). Arsenate, however, showed a potential of the arsenite toxicity.

  9. Embryotoxicity of arsenite and arsenate. Distribution in pregnant mice and monkeys and effects on embryonic cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Lindgren, A.; Danielsson, R.G.; Dencker, L. (Department of Toxicology, Biomedical Center, Uppsala University, Sweden); Vahter, M. (National Institute of Environmental Medicine, Stockholm, Sweden)

    1984-01-01

    The distribution of /sup 74/As-labelled arsenate and arsenite in pregnant mice and a monkey has been studied by autoradiography and gamma counting of isolated tissues, and their in vitro toxicity to a chondrogenic system has been investigated. With both arsenic forms, given as single intravenous injections to the mother, the /sup 74/As-arsenic appeared to pass the mouse placenta relatively freely and approximately to the same extent. The retention time in material tissues including the placenta was, however, around three times longer with arsenite than with arsenate. In early gestation, high activity was registered in the embryonic neuroepithelium, which correlates well with reported CNS malformations in rodents. In late gestation, the distribution pattern was more like that in the adults. Accumulation in skin and squamous epithelia of the upper gastrointestinal tract (oral cavity, oesophagus and oesophageal region of stomach) dominated the distribution pucture, especially at a long survival interval. Arsenate, but not arsenite, showed affinity for the calcified areas of the skeleton. A marmoset monkey in late gestation receiving arsenite showed a somewhat lower rate of placental transfer than the mice. Skin and liver had the highest concentrations (at 8 hrs), both in mother and foetuses. This species is known not to methylate arsenic, resulting in stronger binding and longer retention times of arsenic as compared with other species. The stronger binding in maternal tissues may possibly explain the lower rate of placental transfer. Arsenite was shown to inhibit cartilage formation in a chick limb bud mesenchymal spot culture system (ED50 approximately 5-10..mu..M) while arsenate seemed to be without effect at concentrations up to 200 ..mu..M (highest tested). Arsenate, however, showed a potential of the arsenite toxicity.

  10. Acute Sodium Arsenite-Induced Hematological and Biochemical Changes in Wistar Rats: Protective Effects of Ethanol Extract of Ageratum conyzoides

    Science.gov (United States)

    Ola-Davies, Olufunke Eunice; Akinrinde, Akinleye Stephen

    2016-01-01

    Background: Ageratum conyzoides L. (Asteraceae) is an annual herbaceous plant used in folklore medicine for the treatment of a wide range of diseases. Objective: To investigate the protective effect of the ethanol leaf extract of A. conyzoides (EEAC) against hematological, serum biochemical and histological alterations induced by Sodium arsenite administration to Wistar rats. Materials and Methods: Twenty male Wistar rats were randomly assigned into four groups of five rats each. Group I received propylene glycol and Group II rats were given the (EEAC, 100 mg/kg b.w.) orally for 7 days. Group III were given a single oral dose of sodium arsenite (NaAsO2, 2.5 mg/kg b.w.). Animals in Group IV were pretreated with 100 mg/kg EEAC for 7 days followed by a single oral dose of sodium arsenite. Results: Arsenic exposure resulted in significant reductions (P produced significant reversal of the reduction in the erythrocytic indices (packed cell volume, red blood cell, and Hb) caused by sodium arseniteSodium arsenite-induced slight elevations in serum aspartate aminotransferase (AST), alanine transaminase (ALT), and alkaline phosphatase (ALP), correlating with the histopathological lesions observedAgeratum conyzoides produced only slight reductions in AST, ALT, and ALP compared to the sodium arsenite group, but significantly reduced the severity of histopathological lesions. Abbreviations Used: EEAC: Ethanol extract of Ageratum conyzoides; RBC: Red blood cell; WBC: White blood cell; Hb: Hemoglobin; ALT: Alanine transaminase; AST: Aspartate transaminase or Aspartate aminotransferase; ALP: Alkaline phosphatase; GGT: Gamma glutamyl transferase. PMID:27114688

  11. Discovery and characterization of a putrescine oxidase from Rhodococcus erythropolis NCIMB 11540

    NARCIS (Netherlands)

    van Hellemond, Erik W.; van Dijk, Marianne; Heuts, Dominic P. H. M.; Janssen, Dick B.; Fraaije, Marco W.

    2008-01-01

    A gene encoding a putrescine oxidase (PuORh, EC 1.4.3.10) was identified from the genome of Rhodococcus erythropolis NCIMB 11540. The gene was cloned in the pBAD vector and overexpressed at high levels in Escherichia coli. The purified enzyme was shown to be a soluble dimeric flavoprotein consisting

  12. Effects of sodium arsenite on hypermethylation, transcription and expression of O6-methylguanine-DNA methyltransferase gene in HaCaT cells%亚砷酸钠对HaCaT细胞MGMT基因甲基化和mRNA及蛋白表达水平的影响

    Institute of Scientific and Technical Information of China (English)

    潘雪莉; 张爱华

    2011-01-01

    Objective To investigate the DNA methylation feature and DNA methylation regulation to its transcription and expression of O6-methylguanine-DNA methyltransferase gene (MGMT) in NaAsO2-treated HaCaT cells. Methods HaCaT cells were treated 72 hours at intervals and repeatedly by 3.13, 6.25,12.50, and 25.00 μmol/L NaAsO2, MGMT gene promoter region was amplified in the transcription initiation site - 329 - + 93 region by bisulfate-sequencing polymerase chain reaction (BSP), the mRNA transcription and the protein expression of MGMT was detected by real-time quantitative PCR and Western blotting. NaAsO2-untreated HaCaT cell was set as a blank control, and human epidermal squamous carcinoma cell strain A431 was set as a positive control. Results Among the groups of HaCaT cells treated with 3.13, 6.25, 12.50 and 25.00 μmol/L NaAsO2, the positive rates of the DNA methylation of promoter region in MGMT gene were 0.63%(l/160), 6.25% (10/160), 10.63%( 17/160) and 18.75% (30/160), respectively, and methylated CpG sites were mainly located in - 249--146 region relative to transcription start site. There was no DNA methylation in the blank control. There were significant differences between the blank control and the NaAsO2-treated cells (x2 = 76.687, P< 0.05). Average levels of MGMT mRNA were 1.518 31 ± 0.180 54, 1.425 22 ± 0.180 39, 1.014 54 ± 0.096 79 and 0.887 72 ± 0.020 00, respectively among the groups of HaCaT cells treated with 3.13, 6.25, 12.50 and 25.00 μmol/L NaAsO2, compared with the blank control cells(1.198 29 ± 0.159 97), there were significant differences(F = 37.359, P < 0.05). Average levels of MGMT protein were 1.174 47 ± 0.064 75, 0.848 83 ± 0.057 01, 0.471 63 ± 0.023 34 and 0.240 34 ± 0.014 43, respectively among the groups of HaCaT cells treated with 3.13, 6.25, 12.50 and 25.00 μmol/L NaAsO2, compared with the blank control cells (1.066 19 ± 0.061 24), there were significant differences(F = 20.687, P < 0.05). Conclusions Arsenic can cause Cp

  13. Crystallization of recombinant 1-amino cyclo propane-1-carboxylate (Acc) oxidase

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, L.; Arni, R.K. [UNESP, Sao Jose do Rio Preto, SP (Brazil). Dept. de Fisica; Dilley, D. [Michigan State Univ., East Lansing, MI (United States). Dept. of Biophysics

    1996-12-31

    Full text. Ethylene is an important harmone in plant biology because it activates gene expression with consequences at all phases of plant growth and development spanning seed germination to fruit ripening and senesense of plant organs. In climacteric fruits, the sharp increase in ethylene production at the onset of ripening is throught to trigger the changes in colour, aroma, texture and flavour. The final step in ethylene biosynthesis is catalyzed by ACC oxidase. Biothechnological methods have been used to inhibit ethylene biosynthesis and ripening in tomato by down-regulating ACC synthase and ACC oxidase gene expression using the antisense RNA strategy. A similar goal has been achieved by overexpressing a bacterial ACC deaminase or a viral-S-adenosylmethionine hydrolase gene, which reduces the availability of the ethylene precursors., ACC and S-adenosylmethionine, respectively. C0{sub 2} at concentrations commonly found in the intracellular space of plant tissues is required to active ACC oxidase to produce ethylene and can elevate enzyme activity 20-fold in a concentration dependent manner. Consequently, the intracellular ethylene level is modulated from low inactive levels when C0{sub 2} is not limiting and this may alter gene expression. ACC oxidase undergoes catalytic inactivation as the reaction to make ethylene procedes and this too may involve CO{sub 2}. It has been suggested that CO{sub 2}acts as a modulator of ACC oxidase activity and therby helps regulate ethylene levels in the cell and thus may explain many ethylene related phenomena in plant biology. CO{sub 2} is know to affect O{sub 2} binding in hemoglobin and ribulose bisphosphate carboxylase-oxygenase (Rubisco). Catalytic inactivation is a common phenomena in enzyme turnover, ACC oxidase is a Fe{sup +2}/ascorbate requiring enzyme and this makes it a prime candidate for metal ion oxidation-based inactivation. Charentais melon with an antisense ACC oxidase cDNA. A trangenic line exhibits reduction

  14. Photocatalytic oxidation and removal of arsenite by titanium dioxide supported on granular activated carbon.

    Science.gov (United States)

    Yao, Shu Hua; Jia, Yong Feng; Zhao, Shan Lin

    2012-01-01

    Arsenic contamination in drinking water is a worldwide concern. Photocatalysis can rapidly oxidize arsenite, i.e. As(III), to less labile arsenate, i.e. As(V), which then can be removed by adsorption on to various adsorbents. This study investigated the photocatalytic oxidation of arsenite in aqueous solution by granular activated carbon supporting a titanium dioxide photocatalyst (GAC-TiO2). The effects of photocatalyst dosage, solution pH values, initial concentration of As(III) and co-anions (SO4(2-), PO4(3-), SiO3(2-) and Cl-) on the oxidation of As(III) were studied. The photocatalytic oxidation of As(III) took place in minutes and followed first-order kinetics. The presence of phosphate and silicate significantly decreased As(III) oxidation, while the effect of sulphate, chloride was insignificant. The oxidation efficiency of As(III) was observed to increase with increasing pH. The results suggest that the supported photocatalyst developed in this study is an ideal candidate for pre-oxidation treatment of arsenic-contaminated water.

  15. Effect of sodium arsenite on spermatogenesis,plasma gonadotrophins and testosterone in rats

    Institute of Scientific and Technical Information of China (English)

    MahitoshSarkar; GargiRayChaudhuri; AlokeChattopadhyay; NarendraMohanBiswas

    2003-01-01

    Aim:To investigate the effect of arsenic on spermatogenesis.Methods:Mature(4 months old)Wistar rats were intraperitoneally administered sodium arsenite at doses of 4,5 or 6mg·kg-1·day-1 for 26 days.Different varieties of germ cells at stage Ⅶ seminiferous epithelium cycle,namely,type A spermatogonia(ASg),preleptotene spermatocytes(pLSc),midpachytene spermatocytes(mPSc) and step 7 spermatids(7Sd) were quantitatively evaluated, along with radioimmunoassay of plasma follicle-stimulating hormone(FSH),lutuneizing hormone(LH),testosterone and assessment of the epididymal sperm count.Results:In the 5 and 6 mg/kg groups,there were significant dosedependent decreases in the accessory sex organ weights,epididymal sperm count and plasma concentrations of LH,FSH and testosterone with massive degeneration of all the germ cells at stage Ⅶ,The changes were insignificant in the 4 mg/kg group.Conclusion:Arsenite has a suppressive influence on spermatogenesis and gonadotrophin and testosterone release in rats.

  16. In Vitro Protective Potentials of Annona muricata Leaf Extracts Against Sodium Arsenite-induced Toxicity.

    Science.gov (United States)

    George, Vazhappilly Cijo; Kumar, Devanga Ragupathi Naveen; Suresh, Palamadai Krishnan; Kumar, Rangasamy Ashok

    2015-01-01

    Sodium arsenite (NaAsO2) is a metalloid which is present widely in the environment and its chronic exposure can contribute to the induction of oxidative stress, resulting in disturbances in various metabolic functions including liver cell death. Hence, there is a need to develop drugs from natural sources, which can reduce arsenic toxicity. While there have been reports regarding the antioxidant and protective potentials of Annona muricataleaf extracts, our study is the first ofits kind to extend these findings by specifically evaluating its ability to render protection against sodium arsenite (NaAsO2) induced toxicity (10 μM) in WRL-68 (human hepatic cells) and human erythrocytes by employing XTT and haemolysis inhibition assays respectively. The methanolic extract exhibited higher activity than the aqueous extract in both assays. The results showed a dose-dependent decrease in arsenic toxicity in both WRL-68 cells and erythrocytes, suggesting the protective nature of Annona muricatato mitigate arsenic toxicity. Hence the bioactive extracts can further be scrutinized for the identification and characterization of their principal contributors.

  17. The inhibition of tissue respiration and alcoholic fermentation at different catabolic levels by ethyl carbamate (urethan) and arsenite

    NARCIS (Netherlands)

    Florijn, E.; Gruber, M.; Leijnse, B.; Huisman, T.H.J.

    1950-01-01

    1. A hypothesis is given concerning the action of urethan and arsenite on malignant growth. Two assumptionsares made:- (a) the enzyme system responsible for energy production in malignant tumours is working at maximal rate, contrary to the corresponding enzyme system in normal tissues. (b) a give

  18. Fe/Ti co-pillared clay for enhanced arsenite removal and photo oxidation under UV irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yuan [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Guang Dong Electric Power Design Institute, China Energy Engineering Group Co. Ltd., Guangzhou 510663 (China); Cai, Xiaojiao [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Guo, Jingwei [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); The 718th Research Institute of CSIC, Handan 056027 (China); Zhou, Shimin [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Na, Ping, E-mail: naping@tju.edu.cn [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China)

    2015-01-01

    Graphical abstract: - Highlights: • An iron and titanium co-pillared montmorillonite (Fe-Ti/MMT) was synthesized for arsenite removal. • Variety of characterization results indicated that Fe and Ti species were pillared in MMT. • A possible mechanism of arsenite adsorption/oxidation with UV light was established. • The participation of Fe component can promote the process of photocatalytic oxidation in Fe-Ti/MMT + As(III) system. • Fe-Ti/MMT can function as both photocatalyst and adsorbent for arsenite removal. - Abstract: A series of iron and titanium co-pillared montmorillonites (Fe-Ti/MMT) were prepared using hydrolysis of inserted titanium and different iron content in montmorillonite (MMT). The Fe-Ti/MMT were characterized by X-ray fluorescence, N{sub 2} adsorption and desorption, X-ray diffraction, scanning electron microscopy (SEM) and transmission electron microscopy (TEM), confirming the effective insertion of Fe species and TiO{sub 2} in the MMT. The Fe-Ti/MMT was used to remove arsenite (As(III)) from aqueous solutions under different conditions. The result of As(III) adsorption under UV irradiation showed that the photo activity can be enhanced by incorporating Fe and Ti in MMT. Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analysis indicated that the hydroxyl groups bonded to metal oxide (M–OH) played an important role in the adsorption of As(III)

  19. Fate of arsenite and arsenate in flooded and not flooded soils of southwest Bangladesh irrigated with arsenic contaminated water.

    Science.gov (United States)

    Martin, Maria; Violante, Antonio; Barberis, Elisabetta

    2007-10-01

    In Bangladesh and West Bengal, India, tons of arsenic are added every year to wide extensions of agricultural soils after irrigation with arsenic polluted groundwater, and the fate of the added arsenic in these water-soil environments is not yet clear. This work was aimed to investigate the accumulation and potential release of arsenite [As(III)] and arsenate [As(V)] in two adjacent soils of Bangladesh, irrigated with arsenic contaminated groundwater and cultivated under flooded or not flooded conditions. Both soils showed a scarce As accumulation, in spite of a good adsorption capacity, higher for As(III) than for As(V). The poorly ordered Fe oxides dominated As adsorption in the topsoil of the flooded soil, whereas the crystalline forms were more important in the well aerated soil. A high percentage of the native arsenic was exchangeable with phosphate and the freshly added arsenate or arsenite were even much more mobile. In our experimental conditions, the high As mobility was not dependent on the surface coverage, and, in the flooded soil, 60-70% of the freshly added arsenite or arsenate were desorbed with an infinite sink method, while in the not flooded soil arsenate was less desorbed than arsenite. Depending on their characteristics, some soils, in particular when cultivated under flooded conditions, can represent only a temporary sink for the added As, that can be easily released to waters and possibly enter the food chain from the water-soil system.

  20. Arsenite binding-induced zinc loss from PARP-1 is equivalent to zinc deficiency in reducing PARP-1 activity, leading to inhibition of DNA repair

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Xi; Zhou, Xixi [Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM 87131 (United States); Du, Libo [Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Liu, Wenlan [Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM 87131 (United States); Liu, Yang [Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Hudson, Laurie G. [Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM 87131 (United States); Liu, Ke Jian, E-mail: kliu@salud.unm.edu [Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM 87131 (United States)

    2014-01-15

    Inhibition of DNA repair is a recognized mechanism for arsenic enhancement of ultraviolet radiation-induced DNA damage and carcinogenesis. Poly(ADP-ribose) polymerase-1 (PARP-1), a zinc finger DNA repair protein, has been identified as a sensitive molecular target for arsenic. The zinc finger domains of PARP-1 protein function as a critical structure in DNA recognition and binding. Since cellular poly(ADP-ribosyl)ation capacity has been positively correlated with zinc status in cells, we hypothesize that arsenite binding-induced zinc loss from PARP-1 is equivalent to zinc deficiency in reducing PARP-1 activity, leading to inhibition of DNA repair. To test this hypothesis, we compared the effects of arsenite exposure with zinc deficiency, created by using the membrane-permeable zinc chelator TPEN, on 8-OHdG formation, PARP-1 activity and zinc binding to PARP-1 in HaCat cells. Our results show that arsenite exposure and zinc deficiency had similar effects on PARP-1 protein, whereas supplemental zinc reversed these effects. To investigate the molecular mechanism of zinc loss induced by arsenite, ICP-AES, near UV spectroscopy, fluorescence, and circular dichroism spectroscopy were utilized to examine arsenite binding and occupation of a peptide representing the first zinc finger of PARP-1. We found that arsenite binding as well as zinc loss altered the conformation of zinc finger structure which functionally leads to PARP-1 inhibition. These findings suggest that arsenite binding to PARP-1 protein created similar adverse biological effects as zinc deficiency, which establishes the molecular mechanism for zinc supplementation as a potentially effective treatment to reverse the detrimental outcomes of arsenic exposure. - Highlights: • Arsenite binding is equivalent to zinc deficiency in reducing PARP-1 function. • Zinc reverses arsenic inhibition of PARP-1 activity and enhancement of DNA damage. • Arsenite binding and zinc loss alter the conformation of zinc finger

  1. 基于线粒体CO Ⅰ基因的闪蛱蝶亚科系统发育关系研究%Phylogeny of Apaturinae Butterflies (Lepidoptera: Nymphalidae) Based on Mitochondrial Cytochrome OxidaseGene

    Institute of Scientific and Technical Information of China (English)

    张敏; 曹天文; 张睿; 郭亚平; 段毅豪; 马恩波

    2007-01-01

    The phylogenetic relationships of genera in the subfamily Apaturinae were examined using mtDNA sequence data from 1,471 bp of cytochrome oxidase subunit Ⅰ (COI). The mitochondrial COI gene from a total of 16 species in 11 genera were sequenced to obtain mtDNA data, along with those of 4 species obtained from GenBank, to construct the MP and the NJ trees using Athyma jina, Penthema adelma, Polyura nepenthes, and Charaxes bernardus as outgroups. The transitions at the third codon positions of the COI data set were found saturated, but they were retained for analysis, because they contain the majority of the phylogenetic information. The impacts of equal weight assumptions for all characters in the parsimonious analysis were assessed by potential alternations in clades in response to different transition/transversion weighting schemes. The results indicated four distinct major groups in Apaturinae. Moreover, several well supported and stable clades were found in the Apaturinae. The study also identified undetermined taxon groups whose positions were weakly supported and were subject to changes under different weighting schemes. Within the Apaturinae, the clustering results are approximately identical to the classical morphological classification. The mtDNA data suggest the genus Mimathyma as a monophyletic group. Lelecella limenitoides and Dilipa fenestra have close relationship with very strong support in all phylogenetic trees. It also supports the taxonomic revision of removing several species from Apatura to other genera, namely Mimathyma schrenckii, M. chevana, M. nycteis, Chitoria subcaerulea, C. fasciola, C. pallas, and Helcyra subalba.%测定了重要林业害虫闪蛱蝶亚科Apaturinae 11属17种蝶类的线粒体细胞色素氧化酶Ⅰ的部分序列,并结合由GenBank下载的该亚科4种蝶类的相应序列进行分析,探讨了闪蛱蝶亚科各属间的系统发育关系.以玉杵带蛱蝶Athyma jina,白斑眼蝶Penthema adelma

  2. A desregulação dos genes relógio modifica o estado redox das células β pancreáticas e modula a secreção de insulina estimulada pela glicose via NADPH oxidase.

    OpenAIRE

    2015-01-01

    Os genes relógio são responsáveis pelo ritmo circadiano e homeostase de diversos sistemas biológicos, incluindo o pâncreas endócrino. Nas células β são de grande importância para a regulação do metabolismo e da secreção de insulina (SI), e sua ausência pode levar ao desenvolvimento do diabetes. A NADPH oxidase (NOX) é um complexo enzimático responsável pela produção do ânion superóxido através da redução do oxigênio molecular. Em ilhotas pancreáticas, a NOX participa da regulação do meta...

  3. A broad distribution of the alternative oxidase in microsporidian parasites.

    Directory of Open Access Journals (Sweden)

    Bryony A P Williams

    2010-02-01

    Full Text Available Microsporidia are a group of obligate intracellular parasitic eukaryotes that were considered to be amitochondriate until the recent discovery of highly reduced mitochondrial organelles called mitosomes. Analysis of the complete genome of Encephalitozoon cuniculi revealed a highly reduced set of proteins in the organelle, mostly related to the assembly of iron-sulphur clusters. Oxidative phosphorylation and the Krebs cycle proteins were absent, in keeping with the notion that the microsporidia and their mitosomes are anaerobic, as is the case for other mitosome bearing eukaryotes, such as Giardia. Here we provide evidence opening the possibility that mitosomes in a number of microsporidian lineages are not completely anaerobic. Specifically, we have identified and characterized a gene encoding the alternative oxidase (AOX, a typically mitochondrial terminal oxidase in eukaryotes, in the genomes of several distantly related microsporidian species, even though this gene is absent from the complete genome of E. cuniculi. In order to confirm that these genes encode functional proteins, AOX genes from both A. locustae and T. hominis were over-expressed in E. coli and AOX activity measured spectrophotometrically using ubiquinol-1 (UQ-1 as substrate. Both A. locustae and T. hominis AOX proteins reduced UQ-1 in a cyanide and antimycin-resistant manner that was sensitive to ascofuranone, a potent inhibitor of the trypanosomal AOX. The physiological role of AOX microsporidia may be to reoxidise reducing equivalents produced by glycolysis, in a manner comparable to that observed in trypanosomes.

  4. Differential binding of monomethylarsonous acid compared to arsenite and arsenic trioxide with zinc finger peptides and proteins.

    Science.gov (United States)

    Zhou, Xixi; Sun, Xi; Mobarak, Charlotte; Gandolfi, A Jay; Burchiel, Scott W; Hudson, Laurie G; Liu, Ke Jian

    2014-04-21

    Arsenic is an environmental toxin that enhances the carcinogenic effect of DNA-damaging agents, such as ultraviolet radiation and benzo[a]pyrene. Interaction with zinc finger proteins has been shown to be an important molecular mechanism for arsenic toxicity and cocarcinogenesis. Arsenicals such as arsenite, arsenic trioxide (ATO), and monomethylarsonous acid (MMA(III)) have been reported to interact with cysteine residues of zinc finger domains, but little is known about potential differences in their selectivity of interaction. Herein we analyzed the interaction of arsenite, MMA(III), and ATO with C2H2, C3H1, and C4 configurations of zinc fingers using UV-vis, cobalt, fluorescence, and mass spectrometry. We observed that arsenite and ATO both selectively bound to C3H1 and C4 zinc fingers, while MMA(III) interacted with all three configurations of zinc finger peptides. Structurally and functionally, arsenite and ATO caused conformational changes and zinc loss on C3H1 and C4 zinc finger peptide and protein, respectively, whereas MMA(III) changed conformation and displaced zinc on all three types of zinc fingers. The differential selectivity was also demonstrated in zinc finger proteins isolated from cells treated with these arsenicals. Our results show that trivalent inorganic arsenic compounds, arsenite and ATO, have the same selectivity and behavior when interacting with zinc finger proteins, while methylation removes the selectivity. These findings provide insights on the molecular mechanisms underlying the differential effects of inorganic versus methylated arsenicals, as well as the role of in vivo arsenic methylation in arsenic toxicity and carcinogenesis.

  5. REGULATION OF THE EXPRESSION OF MITOCHONDRIAL PROTEINS - RELATIONSHIP BETWEEN MTDNA COPY NUMBER AND CYTOCHROME-C-OXIDASE ACTIVITY IN HUMAN-CELLS AND TISSUES

    NARCIS (Netherlands)

    VANDENBOGERT, C; DEVRIES, H; HOLTROP, M; MUUS, P; DEKKER, HL; VANGALEN, MJM; BOLHUIS, PA; TAANMAN, JW

    1993-01-01

    The relationship between the relative amounts of nuclear and mitochondrial genes for cytochrome-c oxidase subunits and their transcripts and cytochrome-c oxidase activity was investigated in several human tissues and cell lines to get more insight into the regulation of the expression of this mitoch

  6. Modular assembly of yeast cytochrome oxidase.

    Science.gov (United States)

    McStay, Gavin P; Su, Chen Hsien; Tzagoloff, Alexander

    2013-02-01

    Previous studies of yeast cytochrome oxidase (COX) biogenesis identified Cox1p, one of the three mitochondrially encoded core subunits, in two high-molecular weight complexes combined with regulatory/assembly factors essential for expression of this subunit. In the present study we use pulse-chase labeling experiments in conjunction with isolated mitochondria to identify new Cox1p intermediates and place them in an ordered pathway. Our results indicate that before its assimilation into COX, Cox1p transitions through five intermediates that are differentiated by their compositions of accessory factors and of two of the eight imported subunits. We propose a model of COX biogenesis in which Cox1p and the two other mitochondrial gene products, Cox2p and Cox3p, constitute independent assembly modules, each with its own complement of subunits. Unlike their bacterial counterparts, which are composed only of the individual core subunits, the final sequence in which the mitochondrial modules associate to form the holoenzyme may have been conserved during evolution.

  7. Investigation of the Interaction Between Sodium(meta) Arsenite and Catechin via ESI Tandem Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    CUI Sheng-yun; WEN Jin-feng; KIM Seung-jin; LEE Yong-ill

    2007-01-01

    Catechin, one of the main components of green tea, is considered to have the remedy effect of arsenic poison,although the chemical mechanism is not well known. In this study, sodium(meta) selenite, which is used as herbisolution to investigate the interaction between toxic inorganic arsenic compound and catechin via ESI tandem mass spectrometry. The interaction products of mono-methylated arsenic with catechin in the presence of methanol were identified in the negative mode. Collission induced dissociation(CID) mass spectrometric measurements indicate that monomethylated arsenic was "alkylated" strongly by conjugation at the sites of C2' and C5' in the phenyl ring B of the catechin. The interaction mechanism between sodium(meta) arsenite and catechin was proposed. The results provide useful information to understand the chemical pathway of the detoxification of the arsenic toxicity by catechin.

  8. The oxidative and adsorptive effectiveness of hydrous manganese dioxide for arsenite removal

    Institute of Scientific and Technical Information of China (English)

    Liu Ruiping; Yuan Baoling; Li Xing; Xia Shengji; Yang Yanling; Li Guibai

    2006-01-01

    This study focuses on the effectiveness of hydrous manganese dioxides (δMnO2) removing arsenite (As(Ⅲ)) from aqueous solution. Effects of such factors as permanganate oxidation, pH, humic acid and Ca2+ on As removal and possible mechanisms involved in have been investigated. Permanganate oxidation increases As removal to a certain extent; the higher pH results in the formation of more easily adsorbed As species, contributing to higher As removal; humic acid occupies adsorbing sites and decreases ζ potential of δMnO2, therefore inhibiting As removal; Ca2+ facilitates As adsorption on δMnO2, mainly through increasing ζ potential and decreasing repulsive forces between As and surface sites. δMnO2 exhibits oxidative and adsorptive potential for As(Ⅲ), and may be employed as adsorbents or filter coating for As removal in water treatment process.

  9. Comparative Molecular Docking Studies with ABCC1 and Aquaporin 9 in the Arsenite Complex Efflux

    Science.gov (United States)

    Poojan, Shiv; Dhasmana, Anupam; Jamal, Qazi Mohammad Sajid; Haneef, Mohd; Lohani, Mohtashim

    2014-01-01

    Arsenic is the most toxic metalloid present in the natural environment in both organic and inorganic arsenic forms. Inorganic arsenic is often more hazardous than the organic form. Arsenite and arsenate compounds are the major inorganic forms which are toxic causing severe human health dysfunction including cancer. Excretion of arsenic from the system is found elusive. Therefore, it is of interest to screen channel proteins with the arsenic complex in the different combination of arsenic, GSH (glutathione) and arsenic, selenium using docking methods. The mode of arsenic removal. The complex structure revealed the mode of arsenic binding efficiency with the receptor aquaporine 9 and ABCC1 channel protein. This provides insights to understand the mechanism of arsenic efflux. These inferences find application in the design, identification and development of novel nutracetucal or any other formulation useful in the balance of arsenic efflux. PMID:25258480

  10. Comparative Molecular Docking Studies with ABCC1 and Aquaporin 9 in the Arsenite Complex Efflux.

    Science.gov (United States)

    Poojan, Shiv; Dhasmana, Anupam; Jamal, Qazi Mohammad Sajid; Haneef, Mohd; Lohani, Mohtashim

    2014-01-01

    Arsenic is the most toxic metalloid present in the natural environment in both organic and inorganic arsenic forms. Inorganic arsenic is often more hazardous than the organic form. Arsenite and arsenate compounds are the major inorganic forms which are toxic causing severe human health dysfunction including cancer. Excretion of arsenic from the system is found elusive. Therefore, it is of interest to screen channel proteins with the arsenic complex in the different combination of arsenic, GSH (glutathione) and arsenic, selenium using docking methods. The mode of arsenic removal. The complex structure revealed the mode of arsenic binding efficiency with the receptor aquaporine 9 and ABCC1 channel protein. This provides insights to understand the mechanism of arsenic efflux. These inferences find application in the design, identification and development of novel nutracetucal or any other formulation useful in the balance of arsenic efflux.

  11. Sodium arsenite reduces severity of dextran sulfate sodium-induced ulcerative colitis in rats

    Institute of Scientific and Technical Information of China (English)

    Joshua J. MALAGO; Hortensia NONDOLI

    2008-01-01

    The histopathological features and the associated clinical findings of ulcerative colitis (UC) are due to persistent inflammatory response in the colon mucosa. Interventions that suppress this response benefit UC patients. We tested whether sodium arsenite (SA) benefits rats with dextran sulfate sodium (DSS)-colitis. The DSS-colitis was induced by 5% DSS in drinking water. SA (10 mg/kg; intraperitoneally) was given 8 h before DSS treatment and then every 48 h for 3 cycles of 7,14 or 21 d. At the end of each cycle rats were sacrificed and colon sections processed for histological examination. DSS induced diarrhea, loose stools, hemoccult positive stools, gross bleeding, loss of body weight, loss of epithelium, crypt damage, depletion of goblet cells and infiltration of inflammatory cells. The severity of these changes increased ir the order of Cycles 1,2 and 3. Treatment of rats with SA significantly reduced this severity and improved the weight gain.

  12. Characterization of adsorption of aqueous arsenite and arsenate onto charred dolomite in microcolumn systems.

    Science.gov (United States)

    Salameh, Yousef; Al-Muhtaseb, Ala'a H; Mousa, Hasan; Walker, Gavin M; Ahmad, Mohammad N M

    2014-01-01

    In this work, the removal of arsenite, As(III), and arsenate, As(V), from aqueous solutions onto thermally processed dolomite (charred dolomite) via microcolumn was evaluated. The effects of mass of adsorbent (0.5-2 g), initial arsenic concentration (50-2000 ppb) and particle size (dolomite in a microcolumn were investigated. It was found that the adsorption of As(V) and As(III) onto charred dolomite exhibited a characteristic 'S' shape. The adsorption capacity increased as the initial arsenic concentration increased. A slow decrease in the column adsorption capacity was noted as the particle size increased from>0.335 to 0.710-2.00 mm. For the binary system, the experimental data show that the adsorption of As(V) and As(III) was independent of both ions in solution. The experimental data obtained from the adsorption process were successfully correlated with the Thomas Model and Bed Depth Service Time Model.

  13. Molecular basis of arsenite (As+3-induced acute cytotoxicity in human cervical epithelial carcinoma cells

    Directory of Open Access Journals (Sweden)

    Muhammad Nauman Arshad

    2015-04-01

    Full Text Available Background: Rapid industrialization is discharging toxic heavy metals into the environment, disturbing human health in many ways and causing various neurologic, cardiovascular, and dermatologic abnormalities and certain types of cancer. The presence of arsenic in drinking water from different urban and rural areas of the major cities of Pakistan, for example, Lahore, Faisalabad, and Kasur, was found to be beyond the permissible limit of 10 parts per billion set by the World Health Organization. Therefore the present study was initiated to examine the effects of arsenite (As+3 on DNA biosynthesis and cell death. Methods: After performing cytotoxic assays on a human epithelial carcinoma cell line, expression analysis was done by quantitative polymerase chain reaction, western blotting, and flow cytometry. Results: We show that As+3 ions have a dose- and time-dependent cytotoxic effect through the activation of the caspase-dependent apoptotic pathway. In contrast to previous research, the present study was designed to explore the early cytotoxic effects produced in human cells during exposure to heavy dosage of As+3 (7.5 µg/ml. Even treatment for 1 h significantly increased the mRNA levels of p21 and p27 and caspases 3, 7, and 9. It was interesting that there was no change in the expression levels of p53, which plays an important role in G2/M phase cell cycle arrest. Conclusion: Our results indicate that sudden exposure of cells to arsenite (As+3 resulted in cytotoxicity and mitochondrial-mediated apoptosis resulting from up-regulation of caspases.

  14. The C-terminal region controls correct folding of genus Trametes pyranose 2-oxidases.

    Science.gov (United States)

    Maresová, Helena; Palyzová, Andrea; Kyslík, Pavel

    2007-06-30

    The pyranose 2-oxidases from Trametes ochracea and Trametes pubescens share markedly similar amino acid sequences with identity of 93.4%. When expressed from the recombinant plasmids based on the same vector in the Escherichia coli host strain BL21(DE3) at higher growth temperatures, they differ strikingly in the formation of the inclusion bodies. Upon overexpression in the cultures performed at 28 degrees C, the specific activity of pyranose 2-oxidase from T. pubescens was eight times higher than that from T. ochracea: 93% of pyranose 2-oxidase from T. ochracea and only 15% of that from T. pubescens was present in the form of inclusion bodies. To ascertain the cause of this difference, both cloned genes were shuffled. Site-directed recombination of p2o cDNAs revealed that DNA constructs ending with 3' end of p2o cDNA from T. pubescens code for proteins that are folded into an active form to the greater extent, regardless of the gene expression level. "In silicio" analysis of physico-chemical properties of the protein sequences of pyranose 2-oxidases revealed that the sequence of amino acid residues 368-430, constituting the small, head domain of pyranose 2-oxidase from T. pubescens, affects positively the enzyme folding at higher cultivation temperatures. The domain differs in six amino acid residues from that of T. ochracea.

  15. 1-Aminocyclopropane-1-Carboxylate Oxidase Activity Limits Ethylene Biosynthesis in Rumex palustris during Submergence

    Science.gov (United States)

    Vriezen, Wim H.; Hulzink, Raymond; Mariani, Celestina; Voesenek, Laurentius A.C.J.

    1999-01-01

    Submergence strongly stimulates petiole elongation in Rumex palustris, and ethylene accumulation initiates and maintains this response in submerged tissues. cDNAs from R. palustris corresponding to a 1-aminocyclopropane-1-carboxylate (ACC) oxidase gene (RP-ACO1) were isolated from elongating petioles and used to study the expression of the corresponding gene. An increase in RP-ACO1 messenger was observed in the petioles and lamina of elongating leaves 2 h after the start of submergence. ACC oxidase enzyme activity was measured in homogenates of R. palustris shoots, and a relevant increase was observed within 12 h under water with a maximum after 24 h. We have shown previously that the ethylene production rate of submerged shoots does not increase significantly during the first 24 h of submergence (L.A.C.J. Voesenek, M. Banga, R.H. Thier, C.M. Mudde, F.M. Harren, G.W.M. Barendse, C.W.P.M. Blom [1993] Plant Physiol 103: 783–791), suggesting that under these conditions ACC oxidase activity is inhibited in vivo. We found evidence that this inhibition is caused by a reduction of oxygen levels. We hypothesize that an increased ACC oxidase enzyme concentration counterbalances the reduced enzyme activity caused by low oxygen concentration during submergence, thus sustaining ethylene production under these conditions. Therefore, ethylene biosynthesis seems to be limited at the level of ACC oxidase activity rather than by ACC synthase in R. palustris during submergence. PMID:10482674

  16. EFFECTS OF ARSENITE IN TELOMERE AND TELOMERASE IN RELATION TO CELL PROLIFERATION AND APOPTOSIS IN HUMAN KERATINOCYTES AND LEUKEMIA CELLS IN VITRO

    Science.gov (United States)

    Telomeres are critical in maintaining chromosome and genomic stability. Arsenic, a human carcinogen as well as an anticancer agent, is known for its clastogenicity. To better understand molecular mechanisms of arsenic actions, we investigated arsenite effects on telomere and telo...

  17. Vanillyl-alcohol oxidase, a tasteful biocatalyst

    NARCIS (Netherlands)

    Heuvel, Robert H.H. van den; Fraaije, Marco W.; Mattevi, Andrea; Laane, Colja; Berkel, Willem J.H. van

    2001-01-01

    The covalent flavoenzyme vanillyl-alcohol oxidase (VAO) is a versatile biocatalyst. It converts a wide range of phenolic compounds by catalysing oxidation, deamination, demethylation, dehydrogenation and hydroxylation reactions. The production of natural vanillin, 4-hydroxybenzaldehyde, coniferyl al

  18. Subunit II of Bacillus subtilis cytochrome c oxidase is a lipoprotein

    NARCIS (Netherlands)

    Bengtsson, J; Tjalsma, H; Rivolta, C; Hederstedt, L

    1999-01-01

    The sequence of the N-terminal end of the deduced ctaC gene product of Bacillus species has the features of a bacterial lipoprotein. CtaC is the subunit II of cytochrome caa(3), which is a cytochrome c oxidase. Using Bacillus subtilis mutants blocked in lipoprotein synthesis, we show that CtaC is a

  19. 乳糖诱导重组大肠杆菌表达胆固醇氧化酶的研究%Expression Cholesterol Oxidase Gene in Recombinant Escherichia coli Using Lactose as Inducer

    Institute of Scientific and Technical Information of China (English)

    李闯; 孙艳; 张玲; 杨海麟; 王武

    2011-01-01

    Lactose was used to induce cholesterol oxidase (COD) expression in Escherichia coli BL21 (DE3) in this manuscript. Effect of different nutrient and environmental conditions,including media ingredients, lactose concentration, lactose addition time, and the culture temperature on COD expression were carefully investigated. Under the optimum induced conditions, the maximal activity of COD reached at 15.2 U/mL. The results confirmed that lactose could be used as an inducer in the fermentation process.%采用乳糖诱导胆固醇氧化酶(COD)基因在大肠杆菌BL21(DE3)中表达,研究了培养基成分、乳糖浓度、诱导时间和诱导温度对胆固醇氧化酶表达的影响.结果显示,在对诱导条件进行优化控制的前提下,胆固醇氧化酶酶活达到15.2 U/mL.研究结果为乳糖作为诱导剂最终应用于重组基因工程药物的工业化生产提供了有益的参考和借鉴.

  20. H2O2-Forming NADH Oxidase with Diaphorase (Cytochrome) Activity from Archaeoglobus fulgidus

    OpenAIRE

    Reed, David W.; Millstein, Jack; Hartzell, Patricia L.

    2001-01-01

    An enzyme exhibiting NADH oxidase (diaphorase) activity was isolated from the hyperthermophilic sulfate-reducing anaerobe Archaeoglobus fulgidus. N-terminal sequence of the protein indicates that it is coded for by open reading frame AF0395 in the A. fulgidus genome. The gene AF0395 was cloned and its product was purified from Escherichia coli. Like the native NADH oxidase (NoxA2), the recombinant NoxA2 (rNoxA2) has an apparent molecular mass of 47 kDa, requires flavin adenine dinucleotide fo...

  1. Alkalilimnicola ehrlichii sp. nov., a novel, arsenite-oxidizing haloalkaliphilic gammaproteobacterium capable of chemoautotrophic or heterotrophic growth with nitrate or oxygen as the electron acceptor

    Science.gov (United States)

    Hoeft, S.E.; Blum, J.S.; Stolz, J.F.; Tabita, F.R.; Witte, B.; King, G.M.; Santini, J.M.; Oremland, R.S.

    2007-01-01

    A facultative chemoautotrophic bacterium, strain MLHE-1T, was isolated from Mono Lake, an alkaline hypersaline soda lake in California, USA. Cells of strain MLHE-1T were Gram-negative, short motile rods that grew with inorganic electron donors (arsenite, hydrogen, sulfide or thiosulfate) coupled with the reduction of nitrate to nitrite. No aerobic growth was attained with arsenite or sulfide, but hydrogen sustained both aerobic and anaerobic growth. No growth occurred when nitrite or nitrous oxide was substituted for nitrate. Heterotrophic growth was observed under aerobic and anaerobic (nitrate) conditions. Cells of strain MLHE-1T could oxidize but not grow on CO, while CH4 neither supported growth nor was it oxidized. When grown chemoautotrophically, strain MLHE-1T assimilated inorganic carbon via the Calvin-Benson-Bassham reductive pentose phosphate pathway, with the activity of ribulose 1,5-bisphosphate carboxylase (RuBisCO) functioning optimally at 0.1 M NaCl and at pH 7.3. Strain MLHE-1T grew over broad ranges of pH (7.3-10.0; optimum, 9.3), salinity (115-190 g l-1; optimum 30 g l-1) and temperature (113-40 ??C; optimum, 30 ??C). Phylogenetic analysis of 16S rRNA gene sequences placed strain MLHE-1T in the class Gammaproteobacteria (family Ectothiorhodospiraceae) and most closely related to Alkalispirillum mobile (98.5%) and Alkalilimnicola halodurans (98.6%), although none of these three haloalkaliphilic micro-organisms were capable of photoautotrophic growth and only strain MLHE-1T was able to oxidize As(III). On the basis of physiological characteristics and DNA-DNA hybridization data, it is suggested that strain MLHE-1T represents a novel species within the genus Alkalilimnicola for which the name Alkalilimnicola ehrlichii is proposed. The type strain is MLHE-1T (=DSM 17681T =ATCC BAA-1101T). Aspects of the annotated full genome of Alkalilimnicola ehrlichii are discussed in the light of its physiology. ?? 2007 IUMS.

  2. Purification and characterization of methylamine oxidase induced in Aspergillus niger AKU 3302.

    Science.gov (United States)

    Frébort, I; Matsushita, K; Toyama, H; Lemr, K; Yamada, M; Adachi, O

    1999-01-01

    Crude extract of Aspergillus niger AKU 3302 mycelia incubated with methylamine showed a single amine oxidase activity band in a developed polyacrylamide gel that weakly cross-reacted with the antibody against a copper/topa quinone-containing amine oxidase (AO-II) from the same strain induced by n-butylamine. Since the organism cannot grow on methylamine and the already known quinoprotein amine oxidases of the organism cannot catalyze oxidation of methylamine, the organism was forced to produce another enzyme that could oxidize methylamine when the mycelia were incubated with methylamine. The enzyme was separated and purified from the already known two quinoprotein amine oxidases formed in the same mycelia. The purified enzyme showed a sharp symmetric sedimentation peak in analytical ultracentrifugation showing S20,w0 of 6.5s. The molecular mass of 133 kDa estimated by gel chromatography and 66.6 kDa found by SDS-PAGE confirmed the dimeric structure of the enzyme. The purified enzyme was pink in color with an absorption maximum at 494 nm. The enzyme readily oxidized methylamine, n-hexylamine, and n-butylamine, but not benzylamine, histamine, or tyramine, favorite substrates for the already known two quinoprotein amine oxidases. Inactivation by carbonyl reagents and copper chelators suggested the presence of a copper/topa quinone cofactor. Spectrophotometric titration by p-nitrophenylhydrazine showed one reactive carbonyl group per subunit and redox-cyclic quinone staining confirmed the presence of a quinone cofactor. pH-dependent shift of the absorption spectrum of the enzyme-p-nitrophenylhydrazone (469 nm at neutral to 577 nm at alkaline pH) supported the identity of the cofactor with topaquinone. Nothern blot analysis indicated that the methylamine oxidase encoding gene is largely different from the already known amine oxidase in the organism.

  3. Alternative oxidase in the branched mitochondrial respiratory network: an overview on structure, function, regulation, and role

    Directory of Open Access Journals (Sweden)

    Sluse F.E.

    1998-01-01

    Full Text Available Plants and some other organisms including protists possess a complex branched respiratory network in their mitochondria. Some pathways of this network are not energy-conserving and allow sites of energy conservation to be bypassed, leading to a decrease of the energy yield in the cells. It is a challenge to understand the regulation of the partitioning of electrons between the various energy-dissipating and -conserving pathways. This review is focused on the oxidase side of the respiratory chain that presents a cyanide-resistant energy-dissipating alternative oxidase (AOX besides the cytochrome pathway. The known structural properties of AOX are described including transmembrane topology, dimerization, and active sites. Regulation of the alternative oxidase activity is presented in detail because of its complexity. The alternative oxidase activity is dependent on substrate availability: total ubiquinone concentration and its redox state in the membrane and O2 concentration in the cell. The alternative oxidase activity can be long-term regulated (gene expression or short-term (post-translational modification, allosteric activation regulated. Electron distribution (partitioning between the alternative and cytochrome pathways during steady-state respiration is a crucial measurement to quantitatively analyze the effects of the various levels of regulation of the alternative oxidase. Three approaches are described with their specific domain of application and limitations: kinetic approach, oxygen isotope differential discrimination, and ADP/O method (thermokinetic approach. Lastly, the role of the alternative oxidase in non-thermogenic tissues is discussed in relation to the energy metabolism balance of the cell (supply in reducing equivalents/demand in energy and carbon and with harmful reactive oxygen species formation.

  4. DNA-based diagnosis of isolated sulfite oxidase deficiency by denaturing high-performance liquid chromatography.

    Science.gov (United States)

    Lam, Ching-Wan; Li, Chi-Keung; Lai, Chi-Kong; Tong, Sui-Fan; Chan, Kwok-Yin; Ng, Grace Sui-Fun; Yuen, Yuet-Ping; Cheng, Anna Wai-Fun; Chan, Yan-Wo

    2002-01-01

    Isolated sulfite oxidase deficiency is a rare autosomal recessive disease, characterized by severe neurological abnormalities, seizures, mental retardation, and dislocation of the ocular lenses, that often leads to death in infancy. There is a special demand for prenatal diagnosis, since no effective treatment is available for isolated sulfite oxidase deficiency. Until now, the cDNA sequence of the sulfite oxidase (SUOX) gene has been available, but the genomic sequence of the SUOX gene has not been published. In this study, we have performed a DNA-based diagnosis of isolated sulfite oxidase deficiency in a Chinese patient. To do so, we designed oligonucleotide primers for amplification of the predicted exons and intron-exon boundaries of the SUOX gene obtained from the completed draft version of the human genome. Using overlapping PCR products, we confirmed the flanking intronic sequences of the coding exons and that the entire 466-residue mature peptide is encoded by the last exon of the gene. We then performed mutation detection using denaturing high-performance liquid chromatography (DHPLC). The DHPLC chromatogram of exon 2b showed the presence of heteroduplex peaks only after mixing of the mutant DNA with the wild-type DNA, indicating the presence of a homozygous mutation. Direct DNA sequencing showed a homozygous base substitution at codon 160, changing the codon from CGG to CAG, which changes the amino acid from arginine to glutamine, i.e., R160Q. The DNA-based diagnosis of isolated sulfite oxidase deficiency will enable us to make an accurate determination of carrier status and to perform prenatal diagnosis of this disease. The availability of the genomic sequences of human genes from the completed draft human genome sequence will simplify the development of molecular genetic diagnoses of human diseases from peripheral blood DNA.

  5. Differential Expression of the Three Multicopper Oxidases from Myxococcus xanthus▿

    Science.gov (United States)

    Sánchez-Sutil, María Celestina; Gómez-Santos, Nuria; Moraleda-Muñoz, Aurelio; Martins, Lígia O.; Pérez, Juana; Muñoz-Dorado, José

    2007-01-01

    Myxococcus xanthus is a soil bacterium that undergoes a unique life cycle among the prokaryotes upon starvation, which includes the formation of macroscopic structures, the fruiting bodies, and the differentiation of vegetative rods into coccoid myxospores. This peculiarity offers the opportunity to study the copper response in this bacterium in two different stages. In fact, M. xanthus vegetative rods exhibit 15-fold-greater resistance against copper than developing cells. However, cells preadapted to this metal reach the same levels of resistance during both stages. Analysis of the M. xanthus genome reveals that many of the genes involved in copper resistance are redundant, three of which encode proteins of the multicopper oxidase family (MCO). Each MCO gene exhibits a different expression profile in response to external copper addition. Promoters of cuoA and cuoB respond to Cu(II) ions during growth and development; however, they show a 10-fold-increased copper sensitivity during development. The promoter of cuoC shows copper-independent induction upon starvation, but it is copper up-regulated during growth. Phenotypic analyses of deletion mutants reveal that CuoB is involved in the primary copper-adaptive response; CuoA and CuoC are necessary for the maintenance of copper tolerance; and CuoC is required for normal development. These roles seem to be carried out through cuprous oxidase activity. PMID:17483223

  6. Evaluation of the toxic effects of arsenite, chromate, cadmium, and copper using a battery of four bioassays

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Kyung-Seok; Lee, Pyeong-Koo [Korea Institute of Geoscience and Mineral Resources (KIGAM), Daejeon (Korea, Republic of). Geologic Environment Div.; Kong, In Chul [Yeungnam Univ., Kyungbuk (Korea, Republic of). Dept. of Environmental Engineering

    2012-09-15

    The sensitivities of four different kinds of bioassays to the toxicities of arsenite, chromate, cadmium, and copper were compared. The different bioassays exhibited different sensitivities, i.e., they responded to different levels of toxicity of each of the different metals. However, with the exception of the {alpha}-glucosidase enzyme activity, arsenite was the most toxic compound towards all the tested organisms, exhibiting the highest toxic effect on the seeds of Lactuca, with an EC{sub 50} value of 0.63 mg/L. The sensitivities of Lactuca and Raphanus were greater than the sensitivities of two other kinds of seeds tested. Therefore, these were the seeds appropriate for use in a seed germination assay. A high revertant mutagenic ratio (5:1) of Salmonella typhimurium was observed with an arsenite concentration of 0.1 {mu}g/plate, indicative of a high possibility of mutagenicity. These different results suggested that a battery of bioassays, rather than one bioassay alone, is needed as a more accurate and better tool for the bioassessment of environmental pollutants. (orig.)

  7. In vitro development of resistance to arsenite and chromium-VI in Lactobacilli strains as perspective attenuation of gastrointestinal disorder.

    Science.gov (United States)

    Upreti, Raj K; Sinha, Vartika; Mishra, Ritesh; Kannan, Ambrose

    2011-05-01

    Inadvertent intake of inorganic arsenic and chromium through drinking water and food causing their toxic insults is a major health problem. Intestinal bacteria including Lactobacilli play important regulatory roles on intestinal homeostasis, and their loss is known to cause gastrointestinal (GI) disorders. Probiotic Lactobacilli resistance to arsenite and chromium-VI could be an importantfactorfor the perspective attenuation of Gl-disorders caused by these toxic metals/metalloid. In the present study resistance of arsenite (up to 32 ppm), Cr-VI (up to 64 ppm), and arsenite plus Cr-VI (32 ppm each) were developed under in vitro condition following chronological chronic exposures in Lactobacilli strains. Comparative study of biochemical parameters such as membrane transport enzymes and structural constituents; dehydrogenase and esterase activity tests, which are respective indicators for respiratory and energy producing processes, and the general heterotrophic activity of cells, of resistant strains showed similarities with their respective normal parent strains. The resistant strains were also found to be sensitive to antibiotics. Findings indicate that these resistant probiotic Lactobacilli would be useful in the prophylactic interventions of arsenic and chromium GI-toxicity.

  8. Auxin and its transport play a role in plant tolerance to arsenite-induced oxidative stress in Arabidopsis thaliana.

    Science.gov (United States)

    Krishnamurthy, Aparna; Rathinasabapathi, Bala

    2013-10-01

    The role of auxin in plant development is well known; however, its possible function in root response to abiotic stress is poorly understood. In this study, we demonstrate a novel role of auxin transport in plant tolerance to oxidative stress caused by arsenite. Plant response to arsenite [As(III)] was evaluated by measuring root growth and markers for stress on seedlings treated with control or As(III)-containing medium. Auxin transporter mutants aux1, pin1 and pin2 were significantly more sensitive to As(III) than the wild type (WT). Auxin transport inhibitors significantly reduced plant tolerance to As(III) in the WT, while exogenous supply of indole-3-acetic acid improved As(III) tolerance of aux1 and not that of WT. Uptake assays using H(3) -IAA showed As(III) affected auxin transport in WT roots. As(III) increased the levels of H2 O2 in WT but not in aux1, suggesting a positive role for auxin transport through AUX1 on plant tolerance to As(III) stress via reactive oxygen species (ROS)-mediated signalling. Compared to the WT, the mutant aux1 was significantly more sensitive to high-temperature stress and salinity, also suggesting auxin transport influences a common element shared by plant tolerance to arsenite, salinity and high-temperature stress.

  9. Arsenite evokes IL-6 secretion, autocrine regulation of STAT3 signaling, and miR-21 expression, processes involved in the EMT and malignant transformation of human bronchial epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Fei; Xu, Yuan [Institute of Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University (China); The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University (China); Ling, Min [Jiangsu Center for Disease Control and Prevention, Nanjing 211166, Jiangsu (China); Zhao, Yue; Xu, Wenchao [Institute of Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University (China); The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University (China); Liang, Xiao [Mental Health Center of Xuhui-CDC, Shanghai 200232 (China); Jiang, Rongrong; Wang, Bairu [Institute of Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University (China); The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University (China); Bian, Qian [Jiangsu Center for Disease Control and Prevention, Nanjing 211166, Jiangsu (China); Liu, Qizhan, E-mail: drqzliu@hotmail.com [Institute of Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University (China); The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University (China)

    2013-11-15

    Arsenite is an established human carcinogen, and arsenite-induced inflammation contributes to malignant transformation of cells, but the molecular mechanisms by which cancers are produced remain to be established. The present results showed that, evoked by arsenite, secretion of interleukin-6 (IL-6), a pro-inflammatory cytokine, led to the activation of STAT3, a transcription activator, and to increased levels of a microRNA, miR-21. Blocking IL-6 with anti-IL-6 antibody and inhibiting STAT3 activation reduced miR-21 expression. For human bronchial epithelial cells, cultured in the presence of anti-IL-6 antibody for 3 days, the arsenite-induced EMT and malignant transformation were reversed. Thus, IL-6, acting on STAT3 signaling, which up-regulates miR-21in an autocrine manner, contributes to the EMT induced by arsenite. These data define a link from inflammation to EMT in the arsenite-induced malignant transformation of HBE cells. This link, mediated through miRNAs, establishes a mechanism for arsenite-induced lung carcinogenesis. - Highlights: • Arsenite evokes IL-6 secretion. • IL-6 autocrine mediates STAT3 signaling and up-regulates miR-21expression. • Inflammation is involved in arsenite-induced EMT.

  10. Deletion of glucose oxidase changes the pattern of organic acid production in Aspergillus carbonarius.

    Science.gov (United States)

    Yang, Lei; Lübeck, Mette; Lübeck, Peter S

    2014-01-01

    Aspergillus carbonarius has potential as a cell factory for the production of different organic acids. At pH 5.5, A.carbonarius accumulates high amounts of gluconic acid when it grows on glucose based medium whereas at low pH, it produces citric acid. The conversion of glucose to gluconic acid is carried out by secretion of the enzyme, glucose oxidase. In this work, the gene encoding glucose oxidase was identified and deleted from A. carbonarius with the aim of changing the carbon flux towards other organic acids. The effect of genetic engineering was examined by testing glucose oxidase deficient (Δgox) mutants for the production of different organic acids in a defined production medium. The results obtained showed that the gluconic acid accumulation was completely inhibited and increased amounts of citric acid, oxalic acid and malic acid were observed in the Δgox mutants.

  11. Rat pristanoyl-CoA oxidase. cDNA cloning and recognition of its C-terminal (SQL) by the peroxisomal-targeting signal 1 receptor.

    Science.gov (United States)

    Vanhooren, J C; Fransen, M; de Béthune, B; Baumgart, E; Baes, M; Torrekens, S; Van Leuven, F; Mannaerts, G P; Van Veldhoven, P P

    1996-07-15

    The composite pristanoyl-CoA oxidase cDNA sequence, derived from two overlapping clones from a rat liver cDNA library and a 5'-RACE (rapid amplification of cDNA ends) PCR fragment, consisted of 2600 bases and contained an open reading frame of 2100 bases, encoding a protein of 700 amino acids with a calculated molecular mass of 78445 Da. This value is somewhat larger than the reported molecular mass of 70 kDa as determined earlier by SDS-gel electrophoresis. The amino acid identity with rat palmitoyl-CoA oxidase was rather low (28%) and barely higher than that with the yeast acyl-CoA oxidases (20%), suggesting that the palmitoyl-CoA oxidase/pristanoyl-CoA oxidase duplication occurred early in evolution. The carboxy-terminal tripeptide of pristanoyl-CoA oxidase was SQL. In vitro studies with the bacterially expressed human peroxisomal-targeting signal-1 import receptor indicated that SQL functions as a peroxisome-targeting signal. Northern analysis of tissues from control and clofibrate treated rats demonstrated that the pristanoyl-CoA oxidase gene is transcribed in liver and extrahepatic tissues and that transcription is not enhanced by treatment of rats with peroxisome proliferators. No mRNA could be detected by northern analysis of human tissues, suggesting that the human pristanoyl-CoA oxidase gene, if present, is only poorly or not transcribed.

  12. FASTKD2 Nonsense Mutation in an Infantile Mitochondrial Encephalomyopathy Associated with Cytochrome C Oxidase Deficiency

    OpenAIRE

    2008-01-01

    In two siblings we found a mitochondrial encephalomyopathy, characterized by developmental delay, hemiplegia, convulsions, asymmetrical brain atrophy, and low cytochrome c oxidase (COX) activity in skeletal muscle. The disease locus was identified on chromosome 2 by homozygosity mapping; candidate genes were prioritized for their known or predicted mitochondrial localization and then sequenced in probands and controls. A homozygous nonsense mutation in the KIAA0971 gene segregated with the di...

  13. Gibberellin metabolism in Vitis vinifera L. during bloom and fruit-set: functional characterization and evolution of grapevine gibberellin oxidases.

    Science.gov (United States)

    Giacomelli, Lisa; Rota-Stabelli, Omar; Masuero, Domenico; Acheampong, Atiako Kwame; Moretto, Marco; Caputi, Lorenzo; Vrhovsek, Urska; Moser, Claudio

    2013-11-01

    Gibberellins (GAs) are involved in the regulation of flowering and fruit-set in grapes (Vitis vinifera L.), but the molecular mechanisms behind this process are mostly unknown. In this work, the family of grapevine GA oxidases involved in the biosynthesis and deactivation of GAs was characterized. Six putative GA 20-oxidase (GA20ox), three GA 3-oxidase (GA3ox), and eight GA 2-oxidase (GA2ox) proteins, the latter further divided into five C19-GA 2ox and three C20-GA2ox proteins, were identified. Phylogenetic analyses suggest a common origin of the GA3ox and C19-GA2ox groups and challenge previous evolutionary models. In vitro analysis revealed that all GA3ox and GA20ox enzymes prefer substrates of the non-13-hydroxylation pathway. In addition, ectopic expression of GA2ox genes in Arabidopsis thaliana confirmed the activity of their encoded proteins in vivo. The results show that bioactive GA1 accumulates in opening grapevine flowers, whereas at later developmental stages only GA4 is detected in the setting fruit. By studying the expression pattern of the grapevine GA oxidase genes in different organs, and at different stages of flowering and fruit-set, it is proposed that the pool of bioactive GAs is controlled by a fine regulation of the abundance and localization of GA oxidase transcripts.

  14. Evidence for toxicity differences between inorganic arsenite and thioarsenicals in human bladder cancer cells.

    Science.gov (United States)

    Naranmandura, Hua; Ogra, Yasumitsu; Iwata, Katsuya; Lee, Jane; Suzuki, Kazuo T; Weinfeld, Michael; Le, X Chris

    2009-07-15

    Arsenic toxicity is dependent on its chemical species. In humans, the bladder is one of the primary target organs for arsenic-induced carcinogenicity. However, little is known about the mechanisms underlying arsenic-induced carcinogenicity, and what arsenic species are responsible for this carcinogenicity. The present study aimed at comparing the toxic effect of DMMTA(V) with that of inorganic arsenite (iAs(III)) on cell viability, uptake efficiency and production of reactive oxygen species (ROS) toward human bladder cancer EJ-1 cells. The results were compared with those of a previous study using human epidermoid carcinoma A431 cells. Although iAs(III) was known to be toxic to most cells, here we show that iAs(III) (LC(50)=112 microM) was much less cytotoxic than DMMTA(V) (LC(50)=16.7 microM) in human bladder EJ-1 cells. Interestingly, pentavalent sulfur-containing DMMTA(V) generated a high level of intracellular ROS in EJ-1 cells. However, this was not observed in the cells exposed to trivalent inorganic iAs(III) at their respective LC(50) dose. Furthermore, the presence of N-acetyl-cysteine completely inhibited the cytotoxicity of DMMTA(V) but not iAs(III), suggesting that production of ROS was the main cause of cell death from exposure to DMMTA(V), but not iAs(III). Because the cellular uptake of iAs(III) is mediated by aquaporin proteins, and because the resistance of cells to arsenite can be influenced by lower arsenic uptake due to lower expression of aquaporin proteins (AQP 3, 7 and 9), the expression of several members of the aquaporin family was also examined. In human bladder EJ-1 cells, mRNA/proteins of AQP3, 7 and 9 were not detected by reverse transcription polymerase chain reaction (RT-PCR)/western blotting. In A431 cells, only mRNA and protein of AQP3 were detected. The large difference in toxicity between the two cell lines could be related to their differences in uptake of arsenic species.

  15. Arsenite activates NFκB through induction of C-reactive protein

    Energy Technology Data Exchange (ETDEWEB)

    Druwe, Ingrid L.; Sollome, James J.; Sanchez-Soria, Pablo; Hardwick, Rhiannon N.; Camenisch, Todd D.; Vaillancourt, Richard R., E-mail: vaillancourt@pharmacy.arizona.edu

    2012-06-15

    C-reactive protein (CRP) is an acute phase protein in humans. Elevated levels of CRP are produced in response to inflammatory cytokines and are associated with atherosclerosis, hypertension, cardiovascular disease and insulin resistance. Exposure to inorganic arsenic, a common environmental toxicant, also produces cardiovascular disorders, namely atherosclerosis and is associated with insulin-resistance. Inorganic arsenic has been shown to contribute to cardiac toxicities through production of reactive oxygen species (ROS) that result in the activation of NFκB. In this study we show that exposure of the hepatic cell line, HepG2, to environmentally relevant levels of arsenite (0.13 to 2 μM) results in elevated CRP expression and secretion. ROS analysis of the samples showed that a minimal amount of ROS are produced by HepG2 cells in response to these concentrations of arsenic. In addition, treatment of FvB mice with 100 ppb sodium arsenite in the drinking water for 6 months starting at weaning age resulted in dramatically higher levels of CRP in both the liver and inner medullary region of the kidney. Further, mouse Inner Medullary Collecting Duct cells (mIMCD-4), a mouse kidney cell line, were stimulated with 10 ng/ml CRP which resulted in activation of NFκB. Pretreatment with 10 nM Y27632, a known Rho-kinase inhibitor, prior to CRP exposure attenuated NFκB activation. These data suggest that arsenic causes the expression and secretion of CRP and that CRP activates NFκB through activation of the Rho-kinase pathway, thereby providing a novel pathway by which arsenic can contribute to metabolic syndrome and cardiovascular disease. -- Highlights: ► Exposure to arsenic can induce the expression and secretion of CRP. ► Mice treated with NaAsO{sub 2} showed higher levels of CRP in both the liver and kidney. ► mIMCD-3 were stimulated with CRP which resulted in activation of NFκB. ► CRP activates NFκB through activation of the Rho-kinase pathway. ► Data

  16. 黄河裸裂尻鱼细胞色素C氧化酶Ⅰ、Ⅱ和Ⅲ亚基基因的克隆及序列特征分析%Cloning and Sequence Analysis of Genes Encoding mtDNA Cytochrome C Oxidase Subunits I, I and Ⅲ in Schizopygopsis pylzovi

    Institute of Scientific and Technical Information of China (English)

    晁燕; 祁得林; 申志新; 王国杰; 杨成

    2011-01-01

    The complete sequences of genes encoding cytochrome C oxidase subunits I, li and ill were cloned in Schizopygopsis pylzovi by RT-PCR method. The sequence analysis showed that the complete sequence of CO I was 1 551 bp, which consisted of the open reading frame (ORF) encoding 516 amino acid residues; the CO Ⅱ gene was 691 bp and contained a 690-nucleotide ORF encoding 230 amino acid residues; and the CO Ⅲ gene was 786 bp, which was composed of the ORF encoding 261 amino acid residues. The homologous analysis of sequences showed high similarity both in DNA and corresponding amino acid sequences of CO I, CO Ⅱ and CO Ⅲ between S. pylzovi and other 9 species from family Cyprinidae. Although there were sequence differences in subunit genes among different species, the corresponding amino acids tended to be consistent, suggesting functional stability of cytochrome C oxidase in electron transfer of mitochondrial respiration chain. S. pylzovi and Sinocyclocheilus grahami clustered together in the phylogenetic trees based on gene and amino acid sequences of CO I , and gene sequences of CO Ⅱ and CO Ⅲ, coupled with the same types, positions and numbers of functional sites in CO I and CO Ⅱ , suggesting that there is a relatively close relationship between them, which is consistent with the conclusion that the subfamily Schizothoracinae is originated from one of the primitive Barbinae fishes widely distributed in warm drainages in Qinghai-Tibetan Plateau during the Tertiary Period.%采用RT-PCR技术克隆获得了黄河裸裂尻鱼(Schizopygopsis pylzovi)CO Ⅰ、Ⅱ、Ⅲ基因的编码序列,并对此进行了初步分析.结果表明,黄河裸裂尻鱼CO I基因全长为1 551 bp,开放阅读框(ORF)由基因全长组成,编码516个氨基酸;COⅡ基因全长为691 bp,开放阅读框为690 bp,编码230个氨基酸;COⅢ基因全长为786 bp,其开放阅读框也是由基因全长组成,编码261个氨基酸.序列同源性分析显示

  17. Alternative oxidase: distribution, induction, properties, structure, regulation, and functions.

    Science.gov (United States)

    Rogov, A G; Sukhanova, E I; Uralskaya, L A; Aliverdieva, D A; Zvyagilskaya, R A

    2014-12-01

    The respiratory chain in the majority of organisms with aerobic type metabolism features the concomitant existence of the phosphorylating cytochrome pathway and the cyanide- and antimycin A-insensitive oxidative route comprising a so-called alternative oxidase (AOX) as a terminal oxidase. In this review, the history of AOX discovery is described. Considerable evidence is presented that AOX occurs widely in organisms at various levels of organization and is not confined to the plant kingdom. This enzyme has not been found only in Archaea, mammals, some yeasts and protists. Bioinformatics research revealed the sequences characteristic of AOX in representatives of various taxonomic groups. Based on multiple alignments of these sequences, a phylogenetic tree was constructed to infer their possible evolution. The ways of AOX activation, as well as regulatory interactions between AOX and the main respiratory chain are described. Data are summarized concerning the properties of AOX and the AOX-encoding genes whose expression is either constitutive or induced by various factors. Information is presented on the structure of AOX, its active center, and the ubiquinone-binding site. The principal functions of AOX are analyzed, including the cases of cell survival, optimization of respiratory metabolism, protection against excess of reactive oxygen species, and adaptation to variable nutrition sources and to biotic and abiotic stress factors. It is emphasized that different AOX functions complement each other in many instances and are not mutually exclusive. Examples are given to demonstrate that AOX is an important tool to overcome the adverse aftereffects of restricted activity of the main respiratory chain in cells and whole animals. This is the first comprehensive review on alternative oxidases of various organisms ranging from yeasts and protists to vascular plants.

  18. Pyruvate oxidase is a determinant of Avery's rough morphology.

    Science.gov (United States)

    Belanger, Aimee E; Clague, Melissa J; Glass, John I; Leblanc, Donald J

    2004-12-01

    In pioneering studies, Avery et al. identified DNA as the hereditary material (A. T. Avery, C. M. MacLeod, and M. McCarty, J. Exp. Med. 79:137-158, 1944). They demonstrated, by means of variation in colony morphology, that this substance could transform their rough type 2 Streptococcus pneumoniae strain R36A into a smooth type 3 strain. It has become accepted as fact, from modern textbook accounts of these experiments, that smooth pneumococci make capsule, while rough strains do not. We found that rough-to-smooth morphology conversion did not occur in rough strains R36A and R6 when the ability to synthesize native type 2 capsule was restored. The continued rough morphology of these encapsulated strains was attributed to a second, since-forgotten, morphology-affecting mutation that was sustained by R36A during strain development. We used a new genome-PCR-based approach to identify spxB, the gene encoding pyruvate oxidase, as the mutated locus in R36A and R6 that, with unencapsulation, gives rise to rough colony morphology, as we know it. The variant spxB allele of R36A and R6 is associated with increased cellular pyruvate oxidase activity relative to the ancestral strain D39. Increased pyruvate oxidase activity alters colony shape by mediating cell death. R36A requires a wild-type spxB allele for the expression of smooth type 2 morphology but not for the expression of smooth type 3 morphology, the phenotype monitored by Avery et al. Thus, the mutated spxB allele did not impact their use of smooth morphology to identify the transforming principle.

  19. Cloning and Expression Analysis of ent-kaurene Oxidase Gene CKO in Cucumber%黄瓜贝壳杉烯氧化酶基因CKO的克隆及其表达分析

    Institute of Scientific and Technical Information of China (English)

    胡宏敏; 蒋芳玲; 曹雪; 吴震; 王广龙

    2012-01-01

    With homologous cloning and RACE technology, ent-Kaurene oxidase (KO), a key enzyme in the pathway of gibberellins biosynthesis, was cloned from the shoot tip of' Deltastal' ( Cucumis sativus L. ) and named CKO (GenBank accession number: JN792591 ) . The full eDNA was 1 895 bp in length with an open reading frame (ORF) encoding a protein of 519 amino acids. The protein molecular weight and isoelectric point were predicted to be 59.211 kD and 8.45 respectively. Amino acids homology analysis indicated that the sequence had 84% similarity with that of Momordica charantia. Sequence analysis showed that CKO belonged to cytochrome P450 superfamily and contained cysteine hemeiron ligand signature (FXXGXRXCXG) and transmembrane region. The fluorescent quantitative RT-PCR result showed that the expression level of CKO was the highest in leggy seedling under shading treatment, being 5.18 times of the normal one. While the expression of CKO significantly reduced after spraying paclobutrazol at shading.%以‘戴多星’黄瓜为试材,应用同源克隆和RACE技术从茎尖中得到赤霉素合成的关键酶——贝壳杉烯氧化酶(KO)基因cDNA全长序列,命名为CKO,GenBank登录号为JN792591,其长度为l895bp,开放阅读框(ORF)编码519个氨基酸,相对分子量为59.211kD,等电点(PI)8.45。氨基酸同源性分析发现,CKO与苦瓜的KO同源性最高,达84%:序列结构分析表明,CKO属于细胞色素超家族P450系,具有细胞色素P450的血红素结构域FXXGXRXCXG和跨膜结构域。实时荧光定量分析表明,CKO在遮荫的徒长苗中表达量最高,是正常苗的5.18倍,在遮阴条件下喷施多效唑可降低期表达。

  20. Development of a biosorbent for arsenite: structural modeling based on X-ray spectroscopy.

    Science.gov (United States)

    Teixeira, Monica Cristina; Ciminelli, Virginia S T

    2005-02-01

    This work describes a biological route for direct sorption of aqueous As(III) species, which are the most toxic and mobile arsenic species found in soils. Based upon the biochemical mechanisms that explain arsenic toxicity, we propose that a waste biomass with a high fibrous protein content obtained from chicken feathers can be used for selective As(III) adsorption. Prior to adsorption, the disulfide bridges present in the biomass are reduced by thioglycolate. Our investigations demonstrated that As(III) is specifically adsorbed on the biomass and, contrary to the behavior observed with inorganic sorbents, the lower is the pH the more effective is the removal. Arsenic uptake reaches values of up to 270 micromol As(III)/g of biomass. Analyses by synchrotron light techniques, such as XANES, demonstrated that arsenic is adsorbed in its trivalent state, an advantage over conventional techniques for As uptake, which usually require a previous oxidation stage. EXAFS analyses showed that each As atom is directly bound to three S atoms with an estimated distance of 2.26 A. The uptake mechanism is explained in terms of the structural similarities between the As(III)-biomass complex structure and that of arsenite ions and Ars-Operon system encoded proteins and phytochelatins. The biological route presented here offers the perspective of a direct removal of arsenic in its reduced form.

  1. Protective effects of phyllanthus emblica leaf extract on sodium arsenite-mediated adverse effects in mice.

    Science.gov (United States)

    Sayed, Sadia; Ahsan, Nazmul; Kato, Masashi; Ohgami, Nobutaka; Rashid, Abdur; Akhand, Anwarul Azim

    2015-02-01

    Groundwater contamination of arsenic is the major cause of a serious health hazard in Bangladesh. No specific treatment is yet available to manage the large number of individuals exposed to arsenic. In this study, we evaluated the protective effects of Phyllanthus emblica (Indian gooseberry or Amla) leaf extract (PLE) on arsenic-mediated toxicity in experimental mice. Male Swiss albino mice were divided into three different groups (n=6/group). 'Control' mice received arsenic free water together with normal feed. Mice in the remaining two groups designated 'SA' and 'SA+PLE' were exposed to sodium arsenite (SA, 10 µg/g body weight/day) through drinking water in addition to receiving normal feed and PLE-supplemented feed, respectively. The weight gain of SA-exposed mice was decreased compared with the controls; however, this decrease in body weight gain was prevented when the feed was supplemented with PLE. A secondary effect of arsenic was enlargement of the liver, kidney and spleen of SA-group mice. Deposition of arsenic in those organs was demonstrated by ICP-MS. When PLE was supplemented in the feed the enlargement of the organs was minimized; however, the deposition of arsenic was not significantly reduced. These results indicated that PLE may not block arsenic deposition in tissue directly but rather may play a protective role to reduce arsenic-induced toxicity. Therefore, co-administration of PLE in arsenic-exposed animals might have a future therapeutic application for protecting against arsenic-mediated toxicity.

  2. Arsenite-loaded nanoparticles inhibit PARP-1 to overcome multidrug resistance in hepatocellular carcinoma cells

    Science.gov (United States)

    Liu, Hanyu; Zhang, Zongjun; Chi, Xiaoqin; Zhao, Zhenghuan; Huang, Dengtong; Jin, Jianbin; Gao, Jinhao

    2016-08-01

    Hepatocellular carcinoma (HCC) is one of the highest incidences in cancers; however, traditional chemotherapy often suffers from low efficiency caused by drug resistance. Herein, we report an arsenite-loaded dual-drug (doxorubicin and arsenic trioxide, i.e., DOX and ATO) nanomedicine system (FeAsOx@SiO2-DOX, Combo NP) with significant drug synergy and pH-triggered drug release for effective treatment of DOX resistant HCC cells (HuH-7/ADM). This nano-formulation Combo NP exhibits the synergistic effect of DNA damage by DOX along with DNA repair interference by ATO, which results in unprecedented killing efficiency on DOX resistant cancer cells. More importantly, we explored the possible mechanism is that the activity of PARP-1 is inhibited by ATO during the treatment of Combo NP, which finally induces apoptosis of HuH-7/ADM cells by poly (ADP-ribosyl) ation suppression and DNA lesions accumulation. This study provides a smart drug delivery strategy to develop a novel synergistic combination therapy for effectively overcome drug- resistant cancer cells.

  3. Adsorption of Arsenite by Six Submerged Plants from Nansi Lake, China

    Directory of Open Access Journals (Sweden)

    Zhibin Zhang

    2014-01-01

    Full Text Available Nansi Lake is the largest and the most important freshwater lake in north China for the South-North Water Transfer Project. Due to long-time and large-scale fish farming of history, the excess fish food and excretion usually release pentavalent arsenic, which is converted into trivalent arsenic (As (III in the lake sediment and released into lake water. Adsorption of arsenite using six submerged plants (Mimulicalyx rosulatus, Potamogeton maackianus, Hydrilla, Watermifoil, Pteris vittata, and Potamogeton crispus as adsorbing materials was investigated. The experimental data obtained have been analyzed using Langmuir, Freundlich, and Dubinin-Radushkevich isotherm models and the pseudo-first-order, pseudo-second-order, and intraparticle diffusion kinetics models. According to the results, the As (III equilibrium data agreed well with the Freundlich isotherm model. The adsorption capacity of the plants was in the following order: Potamogeton crispus > Pteris vittata > Potamogeton maackianus > Mimulicalyx rosulatus > Hydrilla > Watermifoil. The sorption system with the six submerged plants was better described by pseudo-second-order than by first-order kinetics. Moreover, the adsorption with Potamogeton crispus could follow intraparticle diffusion (IPD model. The initial adsorption and rate of IPD using Potamogeton crispus and Pteris vittata were higher than those using other plants studied.

  4. Bacterial community succession during the enrichment of chemolithoautotrophic arsenite oxidizing bacteria at high arsenic concentrations

    Institute of Scientific and Technical Information of China (English)

    Nguyen Ai Le; Akiko Sato; Daisuke Inoue; Kazunari Sei; Satoshi Soda; Michihiko Ike

    2012-01-01

    To generate cost-effective technologies for the removal of arsenic from water,we developed an enrichment culture of chemolithoautotrophic arsenite oxidizing bacteria (CAOs) that could effectively oxidize widely ranging concentrations of As(Ⅲ) to As(Ⅴ).In addition,we attempted to elucidate the enrichment process and characterize the microbial composition of the enrichment culture.A CAOs enrichment culture capable of stably oxidizing As(Ⅲ) to As(Ⅴ) was successfully constructed through repeated batch cultivation for more than 700 days,during which time the initial As(Ⅲ) concentrations were increased in a stepwise manner from l to 10-12 mmol/L.As(Ⅲ) oxidation activity of the enrichment culture gradually improved,and 10-12 mmol/L As(Ⅲ) was almost completely oxidized within four days.Terminal restriction fragment length polymorphism analysis showed that the dominant bacteria in the enrichment culture varied drastically during the enrichment process depending on the As(Ⅲ) concentration.Isolation and characterization of bacteria in the enrichment culture revealed that the presence of multiple CAOs with various As(Ⅲ) oxidation abilities enabled the culture to adapt to a wide range of As(Ⅲ) concentrations.The CAOs enrichment culture constructed here may he useful for pretreatment of water from which arsenic is being removed.

  5. The GA5 locus of Arabidopsis thaliana encodes a multifunctional gibberellin 20-oxidase: Molecular cloning and functional expression

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yun-Ling; Li, Li; Wu, Keqiang [Michigan State Univ., East Lansing, MI (United States)] [and others

    1995-07-03

    The biosynthesis of gibberellins (GAs) after GA{sub 12}-aldehyde involves a series of oxidative steps that lead to the formation of bioactive GAs. Previously, a cDNA clone encoding a GA 20-oxidase [gibberellin, 2-oxoglutarate:oxygen oxidoreductase (20-hydroxylating, oxidizing), EC 1.14.11-] was isolated by immunoscreening a cDNA library from liquid endosperm of pumpkin (Cucurbita maxima L.) with antibodies against partially purified GA 20-oxidase. Here, we report isolation of a genomic clone for GA 20-oxidase from a genomic library of the long-day species Arabidopsis thaliana Heynh., strain Columbia, by using the pumpkin cDNA clone as a heterologous probe. This genomic clone contains a GA 20-oxidase gene that consists of three exons and two introns. The three exons are 1131-bp long and encode 377 amino acid residues. A cDNA clone corresponding to the putative GA 20-oxidase genomic sequence was constructed with the reverse transcription-PCR method, and the identity of the cDNA clone was confirmed by analyzing the capability of the fusion protein expressed in Escherichia coli to convert GA{sub 53} to GA{sub 44} and GA{sub 19} to GA{sub 20}. The Arabidopsis GA 20-oxidase shares 55% identity and >80% similarity with the pumpkin GA 20-oxidase at the derived amino acid level. Both GA 20-oxidases share high homology with other 2-oxoglutarate-dependent dioxygenases (2-ODDs), but the highest homology was found between the two GA 20-oxidases. Mapping results indicated tight linkage between the cloned GA 20-oxidase and the GA locus of Arabidopsis. The ga5 semidwarf mutant contains a G {yields} A point mutation that inserts a translational stop codon in the protein-coding sequence, thus confirming that the GA5 locus encodes GA 20-oxidase. Expression of the GA5 gene in Arabidopsis leaves was enhanced after plants were transferred from short to long days; it was reduced by GA{sub 4} treatment, suggesting end-product repression in the GA biosynthetic pathway. 28 refs., 6 figs.

  6. Evidence for Interplay between Genes and Parenting on Infant Temperament in the First Year of Life: Monoamine Oxidase a Polymorphism Moderates Effects of Maternal Sensitivity on Infant Anger Proneness

    Science.gov (United States)

    Pickles, Andrew; Hill, Jonathan; Breen, Gerome; Quinn, John; Abbott, Kate; Jones, Helen; Sharp, Helen

    2013-01-01

    Background: The low expression polymorphism of the MAOA gene in interaction with adverse environments (G × E) is associated with antisocial behaviour disorders. These have their origins in early life, but it is not known whether MAOA G × E occurs in infants. We therefore examined whether MAOA G × E predicts infant anger proneness, a temperamental…

  7. Accumulation of heme oxygenase-1 (HSP32) in Xenopus laevis A6 kidney epithelial cells treated with sodium arsenite, cadmium chloride or proteasomal inhibitors.

    Science.gov (United States)

    Music, Ena; Khan, Saad; Khamis, Imran; Heikkila, John J

    2014-11-01

    The present study examined the effect of sodium arsenite, cadmium chloride, heat shock and the proteasomal inhibitors MG132, withaferin A and celastrol on heme oxygenase-1 (HO-1; also known as HSP32) accumulation in Xenopus laevis A6 kidney epithelial cells. Immunoblot analysis revealed that HO-1 accumulation was not induced by heat shock but was enhanced by sodium arsenite and cadmium chloride in a dose- and time-dependent fashion. Immunocytochemistry revealed that these metals induced HO-1 accumulation in a granular pattern primarily in the cytoplasm. Additionally, in 20% of the cells arsenite induced the formation of large HO-1-containing perinuclear structures. In cells recovering from sodium arsenite or cadmium chloride treatment, HO-1 accumulation initially increased to a maximum at 12h followed by a 50% reduction at 48 h. This initial increase in HO-1 levels was likely the result of new synthesis as it was inhibited by cycloheximide. Interestingly, treatment of cells with a mild heat shock enhanced HO-1 accumulation induced by low concentrations of sodium arsenite and cadmium chloride. Finally, we determined that HO-1 accumulation was induced in A6 cells by the proteasomal inhibitors, MG132, withaferin A and celastrol. An examination of heavy metal and proteasomal inhibitor-induced HO-1 accumulation in amphibians is of importance given the presence of toxic heavy metals in aquatic habitats.

  8. FILOGENIA DE ESPECIES DEL SUBGENERO Parides (LEPIDOPTERA: PAPILIONIDAE BASADA EN SECUENCIAS DEL GEN CITOCROMO OXIDASA I Species phylogeny of the Subgenus Parides (Lepidoptera: Papilionidae Based in Sequences of Citochrome Oxidase I Gene

    Directory of Open Access Journals (Sweden)

    INGRID MARCELA GUTIÉRREZ R

    2012-12-01

    Colombia where the biota of North and South America converge. This work presents a phylogenetic hypothesis of these butterflies and proposes a more robust definition of some taxa. For this, 15 taxa of the subgenus Parides were analyzed as ingroup; species of other two genera of Troidini, closer to Parides , were used as out-group. DNA was extracted using the Pascual et al. (1997 protocol and Quiagen DNAeasy kit. A terminal fragment of Cytochrome Oxidase I gen (476 bp were amplified. We obtained a phylogenetic approximation using maximum parsimony and evaluated the branch support with Jackknife and absolute Bremer support. We also conducted a bayesian analysis. The resulting phylogenetic hypothesis suggested that Parides is a paraphyletic group; the molecular evidence support one species and five subspecies. The analyzed taxa were divided in three principal groups coincident with the Lysander (group 1 and Aeneas (groups 1 and 2 groups proposed by Rothschild and Jordan (1906.

  9. Role of NADPH Oxidase-4 in Human Endothelial Progenitor Cells

    Science.gov (United States)

    Hakami, Nora Y.; Ranjan, Amaresh K.; Hardikar, Anandwardhan A.; Dusting, Greg J.; Peshavariya, Hitesh M.

    2017-01-01

    Introduction: Endothelial progenitor cells (EPCs) display a unique ability to promote angiogenesis and restore endothelial function in injured blood vessels. NADPH oxidase 4 (NOX4)-derived hydrogen peroxide (H2O2) serves as a signaling molecule and promotes endothelial cell proliferation and migration as well as protecting against cell death. However, the role of NOX4 in EPC function is not completely understood. Methods: EPCs were isolated from human saphenous vein and mammary artery discarded during bypass surgery. NOX4 gene and protein expression in EPCs were measured by real time-PCR and Western blot analysis respectively. NOX4 gene expression was inhibited using an adenoviral vector expressing human NOX4 shRNA (Ad-NOX4i). H2O2 production was measured by Amplex red assay. EPC migration was evaluated using a transwell migration assay. EPC proliferation and viability were measured using trypan blue counts. Results: Inhibition of NOX4 using Ad-NOX4i reduced Nox4 gene and protein expression as well as H2O2 formation in EPCs. Inhibition of NOX4-derived H2O2 decreased both proliferation and migration of EPCs. Interestingly, pro-inflammatory cytokine tumor necrosis factor alpha (TNFα) decreased NOX4 expression and reduced survival of EPCs. However, the survival of EPCs was further diminished by TNF-α in NOX4-knockdown cells, suggesting that NOX4 has a protective role in EPCs. Conclusion: These findings suggest that NOX4-type NADPH oxidase is important for proliferation and migration functions of EPCs and protects against pro-inflammatory cytokine induced EPC death. These properties of NOX4 may facilitate the efficient function of EPCs which is vital for successful neovascularization.

  10. Kinetic mechanism of putrescine oxidase from Rhodococcus erythropolis

    NARCIS (Netherlands)

    Kopacz, Malgorzata; Heuts, Dominic P. H. M.; Fraaije, Marco W.

    2014-01-01

    Putrescine oxidase from Rhodococcus erythropolis (PuO) is a flavin-containing amine oxidase from the monoamine oxidase family that performs oxidative deamination of aliphatic diamines. In this study we report pre-steady-state kinetic analyses of the enzyme with the use of single-and double-mixing st

  11. Bilirubin Oxidase Activity of Bacillus subtilis CotA

    OpenAIRE

    Sakasegawa, S; Ishikawa, H.; Imamura, S.; Sakuraba, H.; Goda, S.; Ohshima, T.

    2006-01-01

    The spore coat protein CotA from Bacillus subtilis was previously identified as a laccase. We have now found that CotA also shows strong bilirubin oxidase activity and markedly higher affinity for bilirubin than conventional bilirubin oxidase. This is the first characterization of bilirubin oxidase activity in a bacterial protein.

  12. THERMOSTABILITY OF RESPIRATORY TERMINAL OXIDASES IN THE LIPID ENVIRONMENT

    NARCIS (Netherlands)

    Elferink, Marieke G.L.; Bosmal, Tjibbe; Lolkema, Juke S.; Gleiszner, Michael; Driessen, Arnold J.M.; Konings, Wil N.

    1995-01-01

    The effect of the lipid environment on the thermostability of three respiratory terminal oxidases was determined. Cytochrome-e oxidase from beef heart and Bacillus stearothermophilus were used as representative proteins from mesophilic and thermophilic origin, respectively. Quinol oxidase from the a

  13. 21 CFR 866.2420 - Oxidase screening test for gonorrhea.

    Science.gov (United States)

    2010-04-01

    ... Section 866.2420 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2420 Oxidase... ingredient that will react with cytochrome oxidase. When cytochrome oxidase is present, the swab turns a...

  14. A colorimetric assay for cytokinin oxidase.

    Science.gov (United States)

    Libreros-Minotta, C A; Tipton, P A

    1995-11-01

    A simple and rapid colorimetric assay for cytokinin oxidase is described. The assay is based on the formation of a Schiff base between the enzymatic reaction product 3-methyl-2-butenal and p-aminophenol. The assay is effective in the submicromolar concentration range and can be used in crude plant extracts as well as in more highly purified preparations.

  15. Spectrophotometric Assay of Immobilized Glucose Oxidase

    Directory of Open Access Journals (Sweden)

    Nojan Noorbehesht

    2016-06-01

    Full Text Available Enzyme results in change the substrate of product. Each enzyme may act on specific substrates, resulting in product or different products. The enzyme glucose oxidase (GOX is a bio catalyst. It accelerates the process of transforming glucose into hydrogen peroxide (H2O2 . These enzymes are used in the chemical industry, food industry, cosmetics and kits for diagnosis of glucose. There are many researches about immobilizations of Glucose Oxide to increase specifications such as repeated use, recovery, stability, shelf life and other features In this work, glucose oxidase enzyme using covalent bonding is placed on the carrier of carbon nanotubes. In this study, multi-walled carbon nanotubes have been used as adsorbents. Also, carbon nanotubes have been functionalized by sulfuric acid and nitric acid with a high concentration. Glucose oxidase is a biological biocatalyst enzyme. It accelerates changing glucose to H2O2. This enzyme is used in the chemical industry, food industry, cosmetics and glucose diagnostic kits. For example, as a result of ongoing research working focuses on the development of glucose biosensors, GOX in practice as standard enzyme has been revealed for immobilization of oxidative enzyme.GOX correct fixation on the MWNTs carrier is a way to reuse enzyme and miniature of biosensor devices and structures. In this study, a spectrophotometer was used to determine the absorbance of the enzyme glucose oxidase (GOX to review its activities after stabilizing the carbon nanotubes.

  16. Lysyl oxidase mediates hypoxic control of metastasis

    DEFF Research Database (Denmark)

    Erler, Janine Terra; Giaccia, Amato J

    2006-01-01

    Hypoxic cancer cells pose a great challenge to the oncologist because they are especially aggressive, metastatic, and resistant to therapy. Recently, we showed that elevation of the extracellular matrix protein lysyl oxidase (LOX) correlates with metastatic disease and is essential for hypoxia...

  17. EFFECTS OF Sulfite oxidase GENE OVEREXPRESSION ON IMPROVEMENT OF OXIDATION OF SULFITE IN TRANSGENIC TOMATO%超表达亚硫酸氧化酶基因对促进番茄果实亚硫酸盐氧化的研究

    Institute of Scientific and Technical Information of China (English)

    吴自明; 韩瑞才; 陈慧珍; 谭雪明; 石庆华; 潘晓华

    2011-01-01

    本研究以亚硫酸氧化酶基因(SO)超表达系(OE)、干扰系(Ri)及野生型(WT)的绿熟番茄果实为材料,经SO2熏蒸后,12℃低温贮藏,研究亚硫酸氧化酶基因的超表达,对番茄贮藏期间相对电导率、亚硫酸盐含量、番茄红素含量及成熟度的变化。结果表明,经SO2熏蒸后,Ri果实较WT果实表现为相对电导率增加,亚硫酸盐残留较多,番茄红素含量增加较慢,红熟加快,接种病菌后的第4天果实组织溃烂,菌丝生长明显,组织病斑较大;相反,OE果实较WT果实表现为相对电导率下降,亚硫酸盐残留较少,番茄红素明显增加,红熟延迟,接种病菌后第4天的果实无明显病斑,软化腐烂较小。亚硫酸氧化酶基因超表达,能够有效减少SO2熏蒸后贮藏番茄中亚硫酸盐的残留。%The sulfite oxidase gene(SO) overexpressed(OE),RNA interferred(Ri) and wild type tomato were used as materials.The mature green unripe tomato fruits were fumigated with SO2,then stored at 12℃.The effects of sulfite oxidase overexpression on the relative electrical conductivity,sulfite content,lyconpene and maturity diffrence in transgenic tomato were studied.The results showed that electrical conductivity and sulfite residual of Ri fruits increased,lycopene content decreased,fruit color change accelerated.Tissue rotting and fungal growth of Ri fruit appeared 4d after B.cinerea inoculation,and surrounding pericarp tissue developed.In contrast,the relative electrical conductivity and sulfite residual of OE fruits decreased,lycopene level remained normal,fruit color change delayed.The growth of fungus in OE fruits was limited to the puncture sites and soft rot symptoms did not develop after B.cinerea inoculation for 4d.The study showed that sulfite oxidase gene overexpression in fruit could decrease sulfite residual,and improve the quality and storage properties of the tomato with SO2 fumigation.

  18. [Molecular phylogenetic study of several eelpout fishes (Perciformes, Zoarcoidei) from far eastern seas on the basis of the nucleotide sequence of the mitochondrial cytochrome oxidase 1 gene (Co-1)].

    Science.gov (United States)

    Turanov, S V; kartavtseva, Iu F; Zemnukhov, V V

    2012-02-01

    A total of 95 nucleotide sequences of a Co-1 gene fragment of approximately 650 bp were analyzed for fishes of the orders Perciformes and Scorpaeniformes (outgroup). Gene trees based on four algorithms (BA, NJ, MP, and ML) were similar in topology of solved branches. An emphasis was placed on the species and generic levels, but a significant phylogenetic signal was obtained for higher taxonomic ranks as well. For instance, a monophyletic origin was confirmed for the family Zoarcidae and the subfamily Opisthocentrinae (Stichaeidae). The proportion of different nucleotides in the sequences compared (p-distances) significantly increased with increasing taxonomic rank. The p-distances were estimated for four hierarchic levels and were (1) 0.15 0.06% for the within-species hierarchic level, (2) 6.33 0.37% for the within-genus level, (3) 11.83 0.06% for the within-family level, and (4) 15.22 0.05% for the within-order level. The difference in the Co-1 gene fragments between levels (1) and (2) allows almost errorless species identification on the basis of this kind of a molecular bar code.

  19. A diminution in ascorbate oxidase activity affects carbon allocation and improves yield in tomato under water deficit.

    Science.gov (United States)

    Garchery, Cécile; Gest, Noé; Do, Phuc T; Alhagdow, Moftah; Baldet, Pierre; Menard, Guillaume; Rothan, Christophe; Massot, Capucine; Gautier, Hélène; Aarrouf, Jawad; Fernie, Alisdair R; Stevens, Rebecca

    2013-01-01

    The regulation of carbon allocation between photosynthetic source leaves and sink tissues in response to stress is an important factor controlling plant yield. Ascorbate oxidase is an apoplastic enzyme, which controls the redox state of the apoplastic ascorbate pool. RNA interference was used to decrease ascorbate oxidase activity in tomato (Solanum lycopersicum L.). Fruit yield was increased in these lines under three conditions where assimilate became limiting for wild-type plants: when fruit trusses were left unpruned, when leaves were removed or when water supply was limited. Several alterations in the transgenic lines could contribute to the improved yield and favour transport of assimilate from leaves to fruits in the ascorbate oxidase lines. Ascorbate oxidase plants showed increases in stomatal conductance and leaf and fruit sugar content, as well as an altered apoplastic hexose:sucrose ratio. Modifications in gene expression, enzyme activity and the fruit metabolome were coherent with the notion of the ascorbate oxidase RNAi lines showing altered sink strength. Ascorbate oxidase may therefore be a target for strategies aimed at improving water productivity in crop species.

  20. Thermostable Xanthine Oxidase Activity from Bacillus pumilus RL-2d Isolated from Manikaran Thermal Spring: Production and Characterization.

    Science.gov (United States)

    Sharma, Nirmal Kant; Thakur, Shikha; Thakur, Neerja; Savitri; Bhalla, Tek Chand

    2016-03-01

    Xanthine oxidase is an important enzyme of purine metabolism that catalyzes the hydroxylation of hypoxanthine to xanthine and then xanthine to uric acid. A thermostable xanthine oxidase is being reported from a thermophilic organism RL-2d isolated from the Manikaran (Kullu) hot spring of Himachal Pradesh (India). Based on the morphology, physiological tests, and 16S rDNA gene sequence, RL-2d was identified as Bacillus pumilus. Optimization of physiochemical parameters resulted into 4.1-fold increase in the xanthine oxidase activity from 0.051 U/mg dcw (dry cell weight) to 0.209 U/mg dcw. The xanthine oxidase of B. pumilus RL-2d has exhibited very good thermostability and its t1/2 at 70 and 80 °C were 5 and 1 h, respectively. Activity of this enzyme was strongly inhibited by Hg(2+), Ag(+) and allopurinol. The investigation showed that B. pumilus RL-2d exhibited highest xanthine oxidase activity and remarkable thermostability among the other xanthine oxidases reported so far.

  1. The elusive third subunit IIa of the bacterial B-type oxidases: the enzyme from the hyperthermophile Aquifex aeolicus.

    Directory of Open Access Journals (Sweden)

    Laurence Prunetti

    Full Text Available The reduction of molecular oxygen to water is catalyzed by complicated membrane-bound metallo-enzymes containing variable numbers of subunits, called cytochrome c oxidases or quinol oxidases. We previously described the cytochrome c oxidase II from the hyperthermophilic bacterium Aquifex aeolicus as a ba(3-type two-subunit (subunits I and II enzyme and showed that it is included in a supercomplex involved in the sulfide-oxygen respiration pathway. It belongs to the B-family of the heme-copper oxidases, enzymes that are far less studied than the ones from family A. Here, we describe the presence in this enzyme of an additional transmembrane helix "subunit IIa", which is composed of 41 amino acid residues with a measured molecular mass of 5105 Da. Moreover, we show that subunit II, as expected, is in fact longer than the originally annotated protein (from the genome and contains a transmembrane domain. Using Aquifex aeolicus genomic sequence analyses, N-terminal sequencing, peptide mass fingerprinting and mass spectrometry analysis on entire subunits, we conclude that the B-type enzyme from this bacterium is a three-subunit complex. It is composed of subunit I (encoded by coxA(2 of 59000 Da, subunit II (encoded by coxB(2 of 16700 Da and subunit IIa which contain 12, 1 and 1 transmembrane helices respectively. A structural model indicates that the structural organization of the complex strongly resembles that of the ba(3 cytochrome c oxidase from the bacterium Thermus thermophilus, the IIa helical subunit being structurally the lacking N-terminal transmembrane helix of subunit II present in the A-type oxidases. Analysis of the genomic context of genes encoding oxidases indicates that this third subunit is present in many of the bacterial oxidases from B-family, enzymes that have been described as two-subunit complexes.

  2. Adsorption kinetics and isotherms of arsenite and arsenate on hematite nanoparticles and aggregates.

    Science.gov (United States)

    Dickson, Dionne; Liu, Guangliang; Cai, Yong

    2017-01-15

    Iron (Fe) nanoparticles, e.g., zerovalent iron (ZVI) and iron oxide nanoparticles (IONP), have been used for remediation and environmental management of arsenic (As) contamination. These Fe nanoparticles, although originally nanosized, tend to form aggregates, in particular in the environment. The interactions of As with both nanoparticles and micron-sized aggregates should be considered when these Fe nanomaterials are used for mitigation of As issue. The objective of this study was to compare the adsorption kinetics and isotherm of arsenite (As(III)) and arsenate (As(V)) on bare hematite nanoparticles and aggregates and how this affects the fate of arsenic in the environment. The adsorption kinetic process was investigated with regards to the aggregation of the nanoparticles and the type of sorbed species. Kinetic data were best described by a pseudo second-order model. Both As species had similar rate constants, ranging from 3.82 to 6.45 × 10(-4) g/(μg·h), as rapid adsorption occurred within the first 8 h regardless of particle size. However, hematite nanoparticles and aggregates showed a higher affinity to adsorb larger amounts of As(V) (4122 ± 62.79 μg/g) than As(III) (2899 ± 71.09 μg/g) at equilibrium. We were able to show that aggregation and sedimentation of hematite nanoparticles occurs during the adsorption process and this might cause the immobilization and reduced bioavailability of arsenic. Isotherm studies were described by the Freundlich model and it confirmed that hematite nanoparticles have a significantly higher adsorption capacity for both As(V) and As(III) than hematite aggregates. This information is useful and can assist in predicting arsenic adsorption behavior and assessing the role of iron oxide nanoparticles in the biogeochemical cycling of arsenic.

  3. Arsenite alters heme synthesis in long-term cultures of adult rat hepatocytes.

    Science.gov (United States)

    Aguilar-González, M G; Hernández, A; López, M L; Mendoza-Figueroa, T; Albores, A

    1999-06-01

    Arsenite (As[III]) effects on the intermediate steps of heme biosynthesis were studied in adult rat hepatocytes seeded on a feeder layer of 3T3 cells (3T3-hepatocytes) and maintained for 2 weeks with culture medium non-supplemented or supplemented with 150 microM 5-aminolevulinic acid (ALA). The activities of the intracellular enzymes porphobilinogen deaminase (PBG-D), uroporphyrinogen III synthase (UROIII-S), and uroporphyrinogen III decarboxylase (URO-D), and the intermediary uroporphyrins (URO), coproporphyrins (COPRO) and protoporphyrin IX (PROTO) were determined in these cultures. The 3T3-hepatocytes maintained the activities of PBG-D, UROIII-S and URO-D during 2 weeks and ALA addition to the culture medium increased PBG-D (2-3-fold) and UROIII-S (50%) activities and porphyrin production, which accumulated as PROTO. Exposure to 3.9 microM As(III) inhibited UROIII-S activity (down to 34%), and PBG-D and URO-D activities to a lower extent; these effects were magnified by ALA supplementation. As(III) also produced an intracellular accumulation and a decreased excretion of PROTO, and a 31% reduction of the COPRO/URO ratio in the culture medium. Additionally, As(III) caused cytoplasmic vacuolization and lipid accumulation. Our results show that As(III) exposure selectively inhibits several intermediary enzymes of heme metabolism and affects the intra- and extracellular content of porphyrins and their ratio in the culture medium. They also confirm that 3T3-hepatocytes are a suitable in vitro model to study hepatic heme metabolism and its alterations by hepatotoxic chemicals.

  4. Arsenite Removal from Simulated Groundwater by Biogenic Schwertmannite: A Column Trial

    Institute of Scientific and Technical Information of China (English)

    XIE Yue; ZHOU Li-Xiang

    2013-01-01

    To assess the feasibility of biogenic schwertmannite to act as a sorbent for removing arsenite from groundwater,a series of biogenic schwertmannite-packed column adsorption experiments were conducted on simulated As(Ⅲ)-containing groundwater.Empty bed contact time (EBCT),As(Ⅲ) concentration in effluent,and the removal efficiency of As(Ⅲ) through the column were investigated at pH 8.0 and temperature 25 ± 0.5 ℃.The results showed that the breakthrough curves were mainly dependent on EBCT values when the influent As(Ⅲ) concentration was 500 μg L-1 and the optimum EBCT was 4.0 min.When the effluent As(Ⅲ) concentration reached 10 and 50 μg L-1,the breakthrough volumes for the schwertmannite adsorption column were 4200 and 5600 bed volume (BV),with As(Ⅲ) adsorption capacity of 2.1 and 2.8 mg g-1,respectively.Biogenic schwertmannite could be regenerated by 1.0 mol L-1 NaOH solution,and more than 80% of As(Ⅲ) adsorbed on the surface of schwertmannite could be released after 3 successive regenerations.The breakthrough volume for the regenerated schwertmannite-packed column still maintained 4 000-4 200 BV when the As(Ⅲ) concentration in effluent was below 10 μg L-1.Compared with other sorbents for As(Ⅲ) removal,the biogenic schwertmannitepacked column had a higher breakthrough volume and a much higher adsorption capacity,implying that biogenic schwertmannite was a highly efficient and potential sorbent to purify As(Ⅲ)-contaminated groundwater.

  5. Study on the Correlation between Single Nucleotide Polymorphism of Monoamine Oxidase A Gene and Anger Regulation%单胺氧化酶A基因单核苷酸多态性与愤怒调节的关系研究

    Institute of Scientific and Technical Information of China (English)

    闫秀娟; 詹向红; 侯俊林; 刘永; 王淑玲; 李伟; 闫国立; 王友杰; 杨丽萍

    2012-01-01

    目的 研究单胺氧化酶A( monoamine oxidase A,MAOA)基因单核苷酸多态性(single nucleotide polymorphism,SNP)与怒的调节关系.方法 以某学院健康大学生为研究对象,根据状态-特质愤怒表达量表2(State-Trait Anger Expression Inventory-Ⅱ,STAXI-2)特质怒得分筛选受试者,其中高特质怒者225名,低特质怒者221名,经采血后,采用酚-氯仿法提取DNA,聚合酶链反应-连接酶检测反应(PCR-LDR)法对MAOA基因上的4个tag SNP位点(rs5906957、rs2235186、rs1181275和rs5905613)进行基因分型,对高、低特质怒不同性别组MAOA基因4个tag SNP位点不同基因型受试者怒的表达量表得分和怒的控制量表得分进行统计分析.结果 低特质怒女性MAOA基因rs2235186位点不同基因型组控制发怒得分比较,差异有统计学意义(P =0.037),其余3个tag SNP位点的不同基因型受试者在怒的表达及控制得分上比较,差异均无统计学意义(P>0.05).结论 MAOA基因tag SNP rs2235186多态性与我国健康大学生低特质怒女性的控制发怒特质有关.%Objective To study the correlation between single nucleotide polymorphism (SNP) of monoamine oxidase A gene (MAOA) and anger regulation. Methods Enrolled were healthy students from some college , including 225 of the high trait anger and 221 of the low trait anger. Subjects were recruited referring to the State-Trait Anger Expression Inventory 2 (STAXI-2) and their blood sampled. The DNA was extracted using phenol-chloroform method, 4 tag SNPs of MAOA (rs5906957, rs2235186, rs1181275, and rs5905613) were genotyped by PCR-based ligase detection reaction (PCR-LDR). The scores for trait anger expression inventory and the scores for trait anger expression control at the 4 tag SNPs of MAOA in the different sexes groups of the high and the low trait anger were statistical analyzed. Results There was statistical difference in anger control score of locus rs2235186 of MAOA gene group (P=0.037). There was no

  6. Synergism between arsenite and proteasome inhibitor MG132 over cell death in myeloid leukaemic cells U937 and the induction of low levels of intracellular superoxide anion

    Energy Technology Data Exchange (ETDEWEB)

    Lombardo, Tomás [Laboratorio de Immunotoxicologia (LaITO), IDEHU-CONICET, Hospital de Clínicas, José de San Martín, Universidad de Buenos Aires (UBA), Buenos Aires (Argentina); Cavaliere, Victoria; Costantino, Susana N. [Laboratorio de Inmunología Tumoral (LIT), IDEHU-CONICET, Facultad de Farmacia y Bioquímica, UBA, Buenos Aires (Argentina); Kornblihtt, Laura [Servicio de Hematología, Hospital de Clínicas, José de San Martín (UBA), Buenos Aires (Argentina); Alvarez, Elida M. [Laboratorio de Inmunología Tumoral (LIT), IDEHU-CONICET, Facultad de Farmacia y Bioquímica, UBA, Buenos Aires (Argentina); Blanco, Guillermo A., E-mail: gblanco@ffyb.uba.ar [Laboratorio de Immunotoxicologia (LaITO), IDEHU-CONICET, Hospital de Clínicas, José de San Martín, Universidad de Buenos Aires (UBA), Buenos Aires (Argentina)

    2012-02-01

    Increased oxygen species production has often been cited as a mechanism determining synergism on cell death and growth inhibition effects of arsenic-combined drugs. However the net effect of drug combination may not be easily anticipated solely from available knowledge of drug-induced death mechanisms. We evaluated the combined effect of sodium arsenite with the proteasome inhibitor MG132, and the anti-leukaemic agent CAPE, on growth-inhibition and cell death effect in acute myeloid leukaemic cells U937 and Burkitt's lymphoma-derived Raji cells, by the Chou–Talalay method. In addition we explored the association of cytotoxic effect of drugs with changes in intracellular superoxide anion (O{sub 2}{sup −}) levels. Our results showed that combined arsenite + MG132 produced low levels of O{sub 2}{sup −} at 6 h and 24 h after exposure and were synergic on cell death induction in U937 cells over the whole dose range, although the combination was antagonistic on growth inhibition effect. Exposure to a constant non-cytotoxic dose of 80 μM hydrogen peroxide together with arsenite + MG132 changed synergism on cell death to antagonism at all effect levels while increasing O{sub 2}{sup −} levels. Arsenite + hydrogen peroxide also resulted in antagonism with increased O{sub 2}{sup −} levels in U937 cells. In Raji cells, arsenite + MG132 also produced low levels of O{sub 2}{sup −} at 6 h and 24 h but resulted in antagonism on cell death and growth inhibition. By contrast, the combination arsenite + CAPE showed high levels of O{sub 2}{sup −} production at 6 h and 24 h post exposure but resulted in antagonism over cell death and growth inhibition effects in U937 and Raji cells. We conclude that synergism between arsenite and MG132 in U937 cells is negatively associated to O{sub 2}{sup −} levels at early time points after exposure. -- Highlights: ► Arsenic combined cytotoxic and anti-proliferative effects by Chou–Talalay method. ► Cytotoxic effect

  7. Combined effects of fluoride and arsenite on the expression of Runx-related transcription 2 mRNA in bone of rats

    Institute of Scientific and Technical Information of China (English)

    郑冲

    2014-01-01

    Objective To explore the combined effects of fluoride and arsenite on the expression of Runx-related transcription 2(Runx2)mRNA in bone of Sprague Dawley(SD)rats.Methods Fifty four SD rats were selected[body mass(109.71±10.52)g,half male and half female].3×3 Factorial experimental design was used to evaluate the combined effects of fluoride and arsenite on the expression of Runx2 mRNA by random number table.

  8. NADPH oxidases in lung biology and pathology: host defense enzymes, and more.

    Science.gov (United States)

    van der Vliet, Albert

    2008-03-15

    The deliberate production of reactive oxygen species (ROS) by phagocyte NADPH oxidase is widely appreciated as a critical component of antimicrobial host defense. Recently, additional homologs of NADPH oxidase (NOX) have been discovered throughout the animal and plant kingdoms, which appear to possess diverse functions in addition to host defense, in cell proliferation, differentiation, and in regulation of gene expression. Several of these NOX homologs are also expressed within the respiratory tract, where they participate in innate host defense as well as in epithelial and inflammatory cell signaling and gene expression, and fibroblast and smooth muscle cell proliferation, in response to bacterial or viral infection and environmental stress. Inappropriate expression or activation of NOX/DUOX during various lung pathologies suggests their specific involvement in respiratory disease. This review summarizes the current state of knowledge regarding the general functional properties of mammalian NOX enzymes, and their specific importance in respiratory tract physiology and pathology.

  9. Cloning and Expression Analysis of GA20-Oxidase Gene from Sugar Apple (Annona squamosa)%番荔枝GA20氧化酶基因的克隆与表达分析

    Institute of Scientific and Technical Information of China (English)

    刘锴栋; 袁长春; 黎海利; 刘金祥; 陈燕; 莫亿伟; 李华富

    2015-01-01

    A full-length cDNA sequence of homologousGA20ox gene was cloned by employing homology gene cloning and RACE-PCR from sugar apple (Annona squamosa L.), which was named asAsGA20ox(Gen-Bank accession KR676623). Sequence analysis showed that theAsGA20oxgene has a 1 257 bp open reading frame (ORF) encoding 418 amino acids. Sequence alignment displayed that it was a similarity of 71% and 70% with GA20ox ofElaeis guineensis andPhoenix dactylifera, respectively. The phylogenetic tree showed that sugar appleAsGA20ox andDasypyrum villosum GA20ox are closest in molecular evolution distance, followed byMusa acuminatasubsp. Malaccensis GA20ox. It was speculated that AsGA20ox protein is located in the extracellular matrix and peroxisomal. It do not have a signal peptide. The putative protein molecular weight was 47.2 kDa and its theoretical isoelectric point was 6.21. The real-time PCR results suggested thatAsGA20ox gene showed a high transcription level in lfower buds I, immature seeds, young stems of fruiting branches and pistils. The results laid a solid foundation for further research on AsGA20ox protein structure and the relation-ship between the gene and plant lfower development.%本研究利用同源克隆和RACE-PCR的方法获得番荔枝GA20ox基因的全长cDNA序列,命名为AsGA20ox, GenBank登录号为KR676623。序列分析表明,克隆获得的番荔枝AsGA20ox基因编码区长为1257 bp,编码418个氨基酸。序列比对显示与油棕和海枣等GA20ox的相似度分别为71%和70%。构建类似蛋白系统进化树显示,番荔枝AsGA20ox与簇毛麦、香蕉等分子进化距离较近。预测AsGA20ox蛋白定位在细胞外基质和过氧化物酶体中,不具备信号肽。蛋白质分子量为47.2 kDa,等电点为6.21。实时定量RT-PCR结果表明,在不同的组织、不同的器官中,AsGA20ox的表达量存在差异,其中在花蕾期I、未成熟的种子、结果枝的幼嫩茎段和雌蕊中的表达量相对较高。

  10. Dynamic 1-Aminocyclopropane-1-Carboxylate-Synthase and -Oxidase Transcript Accumulation Patterns during Pollen Tube Growth in Tobacco Styles1

    Science.gov (United States)

    Weterings, Koen; Pezzotti, Mario; Cornelissen, Marc; Mariani, Celestina

    2002-01-01

    In flowering plants, pollination of the stigma sets off a cascade of responses in the distal flower organs. Ethylene and its biosynthetic precursor 1-aminocyclopropane-1-carboxylate (ACC) play an important role in regulating these responses. Because exogenous application of ethylene or ACC does not invoke the full postpollination syndrome, the pollination signal probably consists of a more complex set of stimuli. We set out to study how and when the pollination signal moves through the style of tobacco (Nicotiana tabacum) by analyzing the expression patterns of pistil-expressed ACC-synthase and -oxidase genes. Results from this analysis showed that pollination induces high ACC-oxidase transcript levels in all cells of the transmitting tissue. ACC-synthase mRNA accumulated only in a subset of transmitting tract cells and to lower levels as compared with ACC-oxidase. More significantly, we found that although ACC-oxidase transcripts accumulate to uniform high levels, the ACC-synthase transcripts accumulate in a wave-like pattern in which the peak coincides with the front of the ingrowing pollen tube tips. This wave of ACC-synthase expression can also be induced by incongruous pollination and (partially) by wounding. This indicates that wounding-like features of pollen tube invasion might be part of the stimuli evoking the postpollination response and that these stimuli are interpreted differently by the regulatory mechanisms of the ACC-synthase and -oxidase genes. PMID:12427986

  11. DNA primers for amplification of mitochondrial cytochrome c oxidase subunit I from diverse metazoan invertebrates.

    Science.gov (United States)

    Folmer, O; Black, M; Hoeh, W; Lutz, R; Vrijenhoek, R

    1994-10-01

    We describe "universal" DNA primers for polymerase chain reaction (PCR) amplification of a 710-bp fragment of the mitochondrial cytochrome c oxidase subunit I gene (COI) from 11 invertebrate phyla: Echinodermata, Mollusca, Annelida, Pogonophora, Arthropoda, Nemertinea, Echiura, Sipuncula, Platyhelminthes, Tardigrada, and Coelenterata, as well as the putative phylum Vestimentifera. Preliminary comparisons revealed that these COI primers generate informative sequences for phylogenetic analyses at the species and higher taxonomic levels.

  12. Plasma diamine oxidase activity in asthmatic children

    Directory of Open Access Journals (Sweden)

    Kyoichiro Toyoshima

    1996-01-01

    Full Text Available Histamine plays an important role in the development of asthmatic symptoms. Diamine oxidase (DAO histaminase, which inactivates histamine, is located in the intestine and kidney and is released into plasma. Plasma DAO activity in asthmatic children was measured by a recently developed high performance liquid chromatographic method using histamine as the DAO substrate. Diamine oxidase activity was higher in severely asthmatic children than in those with mild asthma. A time course study during the acute exacerbation phase revealed that DAO activity rose during acute asthmatic attacks and then decreased gradually over several days. Although the mechanisms of plasma DAO activity increase during acute asthmatic attacks could not be explained, data showed that plasma DAO activity is an important index of histamine metabolism in asthmatics and may relate to some mechanisms of acute exacerbation of airway inflammation. Consequently, fluctuations in plasma DAO can be used as one of various indices of instability in management of asthma.

  13. Xanthine oxidase biosensor for monitoring meat spoilage

    Science.gov (United States)

    Vanegas, D. C.; Gomes, C.; McLamore, E. S.

    2014-05-01

    In this study, we have designed an electrochemical biosensor for real-time detection of specific biomarkers of bacterial metabolism related to meat spoilage (hypoxanthine and xanthine). The selective biosensor was developed by assembling a `sandwich' of nanomaterials and enzymes on a platinum-iridium electrode (1.6 mm tip diameter). The materials deposited on the sensor tip include amorphous platinum nanoclusters (i.e. Pt black), reduced graphene oxide, nanoceria, and xanthine oxidase. Xanthine oxidase was encapsulated in laponite hydrogel and used for the biorecognition of hypoxanthine and xanthine (two molecules involved in the rotting of meat by spoilage microorganisms). The developed biosensor demonstrated good electrochemical performance toward xanthine with sensitivity of 2.14 +/- 1.48 μA/mM, response time of 5.2 +/- 1.5 sec, lower detection limit of 150 +/- 39 nM, and retained at least 88% of its activity after 7 days of continuous use.

  14. The inhibition of monoamine oxidase by esomeprazole

    OpenAIRE

    2013-01-01

    Virtual screening of a library of drugs has suggested that esomeprazole, the S-enantiomer of omeprazole, may possess binding affinities for the active sites of the monoamine oxidase (MAO) A and B enzymes. Based on this finding, the current study examines the MAO inhibitory properties of esomeprazole. Using recombinant human MAO-A and MAO-B, IC50 values for the inhibition of these enzymes by esomeprazole were experimentally determined. To examine the reversibility of MAO inhibition by esomepra...

  15. Stress-induced Start Codon Fidelity Regulates Arsenite-inducible Regulatory Particle-associated Protein (AIRAP) Translation*

    Science.gov (United States)

    Zach, Lolita; Braunstein, Ilana; Stanhill, Ariel

    2014-01-01

    Initial steps in protein synthesis are highly regulated processes as they define the reading frame of the translation machinery. Eukaryotic translation initiation is a process facilitated by numerous factors (eIFs), aimed to form a “scanning” mechanism toward the initiation codon. Translation initiation of the main open reading frame (ORF) in an mRNA transcript has been reported to be regulated by upstream open reading frames (uORFs) in a manner of re-initiation. This mode of regulation is governed by the phosphorylation status of eIF2α and controlled by cellular stresses. Another mode of translational initiation regulation is leaky scanning, and this regulatory process has not been extensively studied. We have identified arsenite-inducible regulatory particle-associated protein (AIRAP) transcript to be translationally induced during arsenite stress conditions. AIRAP transcript contains a single uORF in a poor-kozak context. AIRAP translation induction is governed by means of leaky scanning and not re-initiation. This induction of AIRAP is solely dependent on eIF1 and the uORF kozak context. We show that eIF1 is phosphorylated under specific conditions that induce protein misfolding and have biochemically characterized this site of phosphorylation. Our data indicate that leaky scanning like re-initiation is responsive to stress conditions and that leaky scanning can induce ORF translation by bypassing poor kozak context of a single uORF transcript. PMID:24898249

  16. 利用两种不同引物扩增金龟子COI序列片段的研究与对比%Research and comparison of the scarab mitochondrial cytochrome C oxidase Ⅰ (COI) gene fragment sequence cloned by two different primers

    Institute of Scientific and Technical Information of China (English)

    田雷雷; 席景会; 李克斌; 孙昊雨; 尹姣; 曹雅忠

    2013-01-01

    Universal primer (L1490, H2198) and specific primer (Pat, Jerry) were used for cloning the mitochondrial cytochrome C oxidase I (COI ) gene fragments of four common scarabs. The homologous sequences were compared and partial nucleotide sequences of COI (689 bp, 775 bp) obtained. The genetic distances of these sequences were analysed and the sequences used to produce three kinds of phylogenetic trees. The results show that the stability and differentials of interspecific distance of the sequences amplified with specific primers are clearly higher than those of sequences amplified with a universal primer. The phylogenetic trees constructed from sequences amplified with the specific primer are more consistent with the current morphological taxonomy of these scarab species. We conclude that sequences amplified with specific primer are more accurate for scarab classification.%利用两类不同的引物,即通用引物(L1490,H219S)与特异引物(Pat,Jerry)分别对4种常见金龟子线粒体细胞色素C氧化酶I(COI)基因片段序列进行扩增和测序,获得长度为689 bp与775 bp的序列.对测序结果进行遗传距离分析,并构建了4种金龟子系统进化树.结果表明,特异引物扩增序列的遗传距离在种内稳定性与种间的差异性都明显优于通用引物扩增序列,利用特异引物扩增序列所构建的系统进化树最符合实际情况,因此利用特异引物扩增序列更能够准确的对金龟子进行分类.

  17. Complexation of arsenite with dissolved organic matter: conditional distribution coefficients and apparent stability constants.

    Science.gov (United States)

    Liu, Guangliang; Cai, Yong

    2010-11-01

    The complexation of arsenic (As) with dissolved organic matter (DOM), although playing an important role in regulating As mobility and transformation, is poorly characterized, as evidenced by scarce reporting of fundamental parameters of As-DOM complexes. The complexation of arsenite (AsIII) with Aldrich humic acid (HA) at different pHs was characterized using a recently developed analytical technique to measure both free and DOM-bound As. Conditional distribution coefficient (KD), describing capacity of DOM in binding AsIII from the mass perspective, and apparent stability constant (Ks), describing stability of resulting AsIII-DOM complexes, were calculated to characterize AsIII-DOM complexation. LogKD of AsIII ranged from 3.7 to 2.2 (decreasing with increase of As/DOM ratio) at pH 5.2, from 3.6 to 2.6 at pH 7, and from 4.3 to 3.2 at pH=9.3, respectively. Two-site ligand binding models can capture the heterogeneity of binding sites and be used to calculate Ks by classifying the binding sites into strong (S1) and weak (S2) groups. LogKs for S1 sites are 7.0, 6.5, and 5.9 for pH 5.2, 7, and 9.3, respectively, which are approximately 1-2 orders of magnitude higher than for weak S2 sites. The results suggest that AsIII complexation with DOM increases with pH, as evidenced by significant spikes in concentrations of DOM-bound AsIII and in KD values at pH 9.3. In contrary to KD, logKs decreased with pH, in particular for S1 sites, probably due to the presence of negatively charged H2AsO3- and the involvement of metal-bridged AsIII-DOM complexation at pH 9.3.

  18. Sodium meta-arsenite prevents the development of autoimmune diabetes in NOD mice

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Y.S.; Kim, D.; Lee, E.K. [Lee Gil Ya Cancer and Diabetes Institute, Gachon University, 7-45 Songdo-dong, Yeonsu-ku, Incheon 406-840 (Korea, Republic of); Kim, S. [Komipharm International Co. Ltd., 3188, Seongnam-dong, Jungwon-gu, Seongnam-si, Gyeonggi-do 462-827 (Korea, Republic of); Choi, C.S. [Lee Gil Ya Cancer and Diabetes Institute, Gachon University, 7-45 Songdo-dong, Yeonsu-ku, Incheon 406-840 (Korea, Republic of); Endocrinology, Internal Medicine, Gachon University Gil Medical Center, 1198 Guwol-Dong, Namdong-Gu, Incheon 405-760 (Korea, Republic of); Gachon Medical Research Institute, Gil Hospital, 1198 Guwol-Dong, Namdong-Gu, Incheon 405-760 (Korea, Republic of); Jun, H.S., E-mail: hsjun@gachon.ac.kr [Lee Gil Ya Cancer and Diabetes Institute, Gachon University, 7-45 Songdo-dong, Yeonsu-ku, Incheon 406-840 (Korea, Republic of); College of Pharmacy and Gachon Institute of Pharmaceutical Science, Gachon University, 7-45 Songdo-dong, Yeonsu-ku, Incheon 406-840 (Korea, Republic of); Gachon Medical Research Institute, Gil Hospital, 1198 Guwol-Dong, Namdong-Gu, Incheon 405-760 (Korea, Republic of)

    2015-04-15

    Sodium meta-arsenite (SA) is an orally available arsenic compound. We investigated the effects of SA on the development of autoimmune type 1 diabetes. Female non-obese diabetic (NOD) mice were orally intubated with SA (5 mg/kg/day) from 8 weeks of age for 8 weeks. The cumulative incidence of diabetes was monitored until 30 weeks of age, islet histology was examined, and lymphocytes including T cells, B cells, CD4+ IFN-γ+ cells, CD8+ IFN-γ+ cells, CD4+ IL-4+ cells, and regulatory T cells were analyzed. We also investigated the diabetogenic ability of splenocytes using an adoptive transfer model and the effect of SA on the proliferation, activation, and expression of glucose transporter 1 (Glut1) in splenocytes treated with SA in vitro and splenocytes isolated from SA-treated mice. SA treatment decreased the incidence of diabetes and delayed disease onset. SA treatment reduced the infiltration of immunocytes in islets, and splenocytes from SA-treated mice showed a reduced ability to transfer diabetes. The number of total splenocytes and T cells and both the number and the proportion of CD4+ IFN-γ+ and CD8+ IFN-γ+ T cells in the spleen were significantly reduced in SA-treated NOD mice compared with controls. The number, but not the proportion, of regulatory T cells was decreased in SA-treated NOD mice. Treatment with SA either in vitro or in vivo inhibited proliferation of splenocytes. In addition, the expression of Glut1 and phosphorylated ERK1/2 was decreased by SA treatment. These results suggest that SA reduces proliferation and activation of T cells, thus preventing autoimmune diabetes in NOD mice. - Highlights: • SA prevents the development of diabetes and delays the age of onset in NOD mice. • SA decreases the number but not the proportion of T lymphocytes in NOD mice. • SA reduces IFN-γ-producing T lymphocytes in NOD mice. • SA reduces proliferation and activation of T lymphocytes in vitro and in vivo. • SA reduces the expression of glucose

  19. Purine-induced expression of urate oxidase and enzyme activity in Atlantic salmon (Salmo salar). Cloning of urate oxidase liver cDNA from three teleost species and the African lungfish Protopterus annectens.

    Science.gov (United States)

    Andersen, Øivind; Aas, Turid S; Skugor, Stanko; Takle, Harald; van Nes, Solveig; Grisdale-Helland, Barbara; Helland, Ståle J; Terjesen, Bendik F

    2006-07-01

    The peroxisomal enzyme urate oxidase plays a pivotal role in the degradation of purines in both prokaryotes and eukaryotes. However, knowledge about the purine-induced expression of the encoding gene is lacking in vertebrates. These are the first published sequences of fish urate oxidase, which were predicted from PCR amplified liver cDNAs of Atlantic salmon (Salmo salar), Atlantic cod (Gadus morhua), Atlantic halibut (Hippoglossus hippoglossus) and African lungfish (Protopterus annectens). Sequence alignment of different vertebrate urate oxidases revealed amino acid substitutions of putative functional importance in the enzyme of chicken and lungfish. In the adult salmon, expression of urate oxidase mRNA predominated in liver, but was also identified in several nonhepatic organs including brain, but not in skeletal muscle and kidney. Juvenile salmon fed diets containing bacterial protein meal (BPM) rich in nucleic acids showed a significant increase in liver urate oxidase enzyme activity, and urea concentrations in plasma, muscle and liver were elevated. Whereas salmon fed the 18% BPM diet showed a nonsignificant increase in liver mRNA levels of urate oxidase compared with the 0% BPM-fed fish, no further increase in mRNA levels was found in fish receiving 36% BPM. The discrepancy between urate oxidase mRNA and enzyme activity was explained by rapid mRNA degradation or alternatively, post-translational control of the activity. Although variable plasma and liver levels of urate were detected, the substrate increased only slightly in 36% BPM-fed fish, indicating that the uricolytic pathway of Atlantic salmon is intimately regulated to handle high dietary purine levels.

  20. ARSENATE AND ARSENITE REMOVAL BY ZERO-VALENT IRON: EFFECTS OF PHOSPHATE, SILICATE, CARBONATE, BORATE, SULFATE, CHROMATE, MOLYBDATE, AND NITRATE, RELATIVE TO CHLORIDE

    Science.gov (United States)

    Batch tests were performed to evaluate the effects of inorganic anion competition on the kinetics of arsenate (As(V)) and arsenite (As(III)) removal by zerovalent iron (Peerless Fe0) in aqueous solution. The oxyanions underwent either sorption-dominated reactions (phosphate, sil...

  1. Ribosomal protein S7 regulates arsenite-induced GADD45α expression by attenuating MDM2-mediated GADD45α ubiquitination and degradation.

    Science.gov (United States)

    Gao, Ming; Li, Xiaoguang; Dong, Wen; Jin, Rui; Ma, Hanghang; Yang, Pingxun; Hu, Meiru; Li, Yi; Hao, Yi; Yuan, Shengtao; Huang, Junjian; Song, Lun

    2013-05-01

    The stress-responding protein, GADD45α, plays important roles in cell cycle checkpoint, DNA repair and apoptosis. In our recent study, we demonstrate that GADD45α undergoes a dynamic ubiquitination and degradation in vivo, which process can be blocked by the cytotoxic reagent, arsenite, resulting in GADD45α accumulation to activate JNKs cell death pathway, thereby revealing a novel mechanism for the cellular GADD45α functional regulation. But the factors involved in GADD45α stability modulations are unidentified. Here, we demonstrated that MDM2 was an E3 ubiquitin ligase for GADD45α. One of MDM2-binding partner, ribosomal protein S7, interacted with and stabilized GADD45α through preventing the ubiquitination and degradation of GADD45α mediated by MDM2. This novel function of S7 is unrelated to p53 but seems to depend on S7/MDM2 interaction, for the S7 mutant lacking MDM2-binding ability lost its function to stabilize GADD45α. Further investigations indicated that arsenite treatment enhanced S7-MDM2 interaction, resulting in attenuation of MDM2-dependent GADD45α ubiquitination and degradation, thereby leading to GADD45α-dependent cell death pathway activation. Silencing S7 expression suppressed GADD45α-dependent cytotoxicity induced by arsenite. Our findings thus identify a novel function of S7 in control of GADD45α stabilization under both basal and stress conditions and its significance in mediating arsenite-induced cellular stress.

  2. Data on cytochrome c oxidase assembly in mice and human fibroblasts or tissues induced by SURF1 defect.

    Science.gov (United States)

    Kovářová, Nikola; Pecina, Petr; Nůsková, Hana; Vrbacký, Marek; Zeviani, Massimo; Mráček, Tomáš; Viscomi, Carlo; Houštěk, Josef

    2016-06-01

    This paper describes data related to a research article entitled "Tissue- and species-specific differences in cytochrome c oxidase assembly induced by SURF1 defects" [1]. This paper includes data of the quantitative analysis of individual forms of respiratory chain complexes I, III and IV present in SURF1 knockout (SURF1 (-/-) ) and control (SURF1 (+/+) ) mouse fibroblasts and tissues and in fibroblasts of human control and patients with SURF1 gene mutation. Also it includes data demonstrating response of complex IV, cytochrome c oxidase (COX), to reversible inhibition of mitochondrial translation in SURF1 (-/-) mouse and SURF1 patient fibroblast cell lines.

  3. Pathological changes in platelet histamine oxidases in atopic eczema

    Directory of Open Access Journals (Sweden)

    Reinhold Kiehl

    1993-01-01

    Full Text Available Increased plasma histamine levels were associated with significantly lowered diamine and type B monoamine oxidase activities in platelet-rich plasma of atopic eczema (AE patients. The diamine oxidase has almost normal cofactor levels (pyridoxal phosphate and Cu2+ but the cofactor levels for type B monoamine oxidase (flavin adenine dinucleotide and Fe2+ are lowered. The biogenic amines putrescine, cadaverine, spermidine, spermine, tyramine and serotonin in the sera, as well as dopamine and epinephrine in EDTA-plasma were found to be normal. It is unlikely, therefore, that these amines are responsible for the decreased activities of monoamine and diamine oxidase in these patients. The most likely causative factors for the inhibition of the diamine oxidase are nicotine, alcohol, food additives and other environmental chemicals, or perhaps a genetic defect of the diamine oxidase.

  4. Experimental Evidence for a Revision in the Annotation of Putative Pyridoxamine 5'-Phosphate Oxidases P(N/MP from Fungi.

    Directory of Open Access Journals (Sweden)

    Tatiana Domitrovic

    Full Text Available Pyridoxinamine 5'-phosphate oxidases (P(N/MP oxidases that bind flavin mononucleotide (FMN and oxidize pyridoxine 5'-phosphate or pyridoxamine 5'-phosphate to form pyridoxal 5'-phosphate (PLP are an important class of enzymes that play a central role in cell metabolism. Failure to generate an adequate supply of PLP is very detrimental to most organisms and is often clinically manifested as a neurological disorder in mammals. In this study, we analyzed the function of YLR456W and YPR172W, two homologous genes of unknown function from S. cerevisiae that have been annotated as putative P(N/MP oxidases based on sequence homology. Different experimental approaches indicated that neither protein catalyzes PLP formation nor binds FMN. On the other hand, our analysis confirmed the enzymatic activity of Pdx3, the S. cerevisiae protein previously implicated in PLP biosynthesis by genetic and structural characterization. After a careful sequence analysis comparing the putative and confirmed P(N/MP oxidases, we found that the protein domain (PF01243 that led to the YLR456W and YPR172W annotation is a poor indicator of P(N/MP oxidase activity. We suggest that a combination of two Pfam domains (PF01243 and PF10590 present in Pdx3 and other confirmed P(N/MP oxidases would be a stronger predictor of this molecular function. This work exemplifies the importance of experimental validation to rectify genome annotation and proposes a revision in the annotation of at least 400 sequences from a wide variety of fungal species that are homologous to YLR456W and are currently misrepresented as putative P(N/MP oxidases.

  5. Prolonged inorganic arsenite exposure suppresses insulin-stimulated AKT S473 phosphorylation and glucose uptake in 3T3-L1 adipocytes: Involvement of the adaptive antioxidant response

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Peng [The Hamner Institutes for Health Sciences, Research Triangle Park, NC 27709 (United States); School of Public Health, China Medical University, Shenyang 110001 (China); Hou, Yongyong; Zhang, Qiang; Woods, Courtney G.; Yarborough, Kathy; Liu, Huiyu [The Hamner Institutes for Health Sciences, Research Triangle Park, NC 27709 (United States); Sun, Guifan [School of Public Health, China Medical University, Shenyang 110001 (China); Andersen, Melvin E. [The Hamner Institutes for Health Sciences, Research Triangle Park, NC 27709 (United States); Pi, Jingbo, E-mail: jpi@thehamner.org [The Hamner Institutes for Health Sciences, Research Triangle Park, NC 27709 (United States)

    2011-04-08

    Highlights: {yields} In 3T3-L1 adipocytes iAs{sup 3+} decreases insulin-stimulated glucose uptake. {yields} iAs{sup 3+} attenuates insulin-induced phosphorylation of AKT S473. {yields} iAs{sup 3+} activates the cellular adaptive oxidative stress response. {yields} iAs{sup 3+} impairs insulin-stimulated ROS signaling. {yields} iAs{sup 3+} decreases expression of adipogenic genes and GLUT4. -- Abstract: There is growing evidence that chronic exposure of humans to inorganic arsenic, a potent environmental oxidative stressor, is associated with the incidence of type 2 diabetes (T2D). One critical feature of T2D is insulin resistance in peripheral tissues, especially in mature adipocytes, the hallmark of which is decreased insulin-stimulated glucose uptake (ISGU). Despite the deleterious effects of reactive oxygen species (ROS), they have been recognized as a second messenger serving an intracellular signaling role for insulin action. Nuclear factor erythroid 2-related factor 2 (NRF2) is a central transcription factor regulating cellular adaptive response to oxidative stress. This study proposes that in response to arsenic exposure, the NRF2-mediated adaptive induction of endogenous antioxidant enzymes blunts insulin-stimulated ROS signaling and thus impairs ISGU. Exposure of differentiated 3T3-L1 cells to low-level (up to 2 {mu}M) inorganic arsenite (iAs{sup 3+}) led to decreased ISGU in a dose- and time-dependent manner. Concomitant to the impairment of ISGU, iAs{sup 3+} exposure significantly attenuated insulin-stimulated intracellular ROS accumulation and AKT S473 phosphorylation, which could be attributed to the activation of NRF2 and induction of a battery of endogenous antioxidant enzymes. In addition, prolonged iAs{sup 3+} exposure of 3T3-L1 adipocytes resulted in significant induction of inflammatory response genes and decreased expression of adipogenic genes and glucose transporter type 4 (GLUT4), suggesting chronic inflammation and reduction in GLUT4

  6. The nature of CuA in cytochrome c oxidase

    OpenAIRE

    Stevens, Tom H.; Martin, Craig T.; Wang, Hsin; Brudvig, Gary W.; Scholes, Charles P.; Chan, Sunney I.

    1982-01-01

    The isolation and purification of yeast cytochrome c oxidase is described. Characterization of the purified protein indicates that it is spectroscopically identical with cytochrome c oxidase isolated from beef heart. Preparations of isotopically substituted yeast cytochrome c oxidase are obtained incorporating [1,3-15N2]histidine or [beta,beta- 2H2]cysteine. Electron paramagnetic resonance and electron nuclear double resonance spectra of the isotopically substituted proteins identify unambigu...

  7. Kinetic Results for Mutations of Conserved Residues H304 and R309 of Human Sulfite Oxidase Point to Mechanistic Complexities

    Science.gov (United States)

    Davis, Amanda C.; Johnson-Winters, Kayunta; Arnold, Anna R.; Tollin, Gordon; Enemark, John H.

    2014-01-01

    Several point mutations in the gene of human sulfite oxidase (hSO) result in isolated sulfite oxidase deficiency, an inherited metabolic disorder. Three conserved residues (H304, R309, K322) are hydrogen bonded to the phosphate group of the molybdenum cofactor, and the R309H and K322R mutations are responsible for isolated sulfite oxidase deficiency. The kinetic effects of the K322R mutation have been previously reported (Rajapakshe et al. 2012, Chem. Biodiversity 9, 1621-1634); here we investigate several mutants of H304 and R309 by steady-state kinetics, laser flash photolysis studies of intramolecular electron transfer (IET), and spectroelectrochemistry. An unexpected result is that all of the mutants show decreased rates of IET but increased steady-state rates of catalysis. However, in all cases the rate of IET is greater than the overall turnover rate, showing that IET is not the rate determining step for any of the mutations. PMID:24968320

  8. DNA cloning of human liver monoamine oxidase A and B: Molecular basis of differences in enzymatic properties

    Energy Technology Data Exchange (ETDEWEB)

    Back, A.W.J.; Lan, N.C.; Johnson, D.L.; Abell, C.W.; Bembenek, M.E.; Kwan, S.W.; Seeburg, P.H.; Shih, J.C. (Univ. of Heidelberg (West Germany))

    1988-07-01

    The monoamine oxidases play a vital role in the metabolism of biogenic amines in the central nervous system and in peripheral tissues. Using oligonucleotide probes derived from three sequenced peptide fragments, the authors have isolated cDNA clones that encode the A and B forms of monoamine oxidase and have determined the nucleotide sequences of these cDNAs. Comparison of the deduced amino acid sequences shows that the A and B forms have subunit molecular weights of 59,700 and 58,800, respectively, and have 70% sequence identity. Both sequences contain the pentapeptide Ser-Gly-Gly-Cys-Tyr, in which the obligatory cofactor FAD is covalently bound to cysteine. Based on differences in primary amino acid sequences and RNA gel blot analysis of mRNAs, the A and B forms of monoamine oxidase appear to be derived from separate genes.

  9. COPPER AMINE OXIDASE1 (CuA01)of Arabidopsis thaliana Contributes to Abscisic Acid-and Polyamine-Induced Nitric Oxide Biosynthesis and Abscisic Acid Signal Transduction

    Institute of Scientific and Technical Information of China (English)

    Rinukshi Wimalasekera; Corina Villar; Tahmina Begum; Günther F. E. Scherer

    2011-01-01

    Polyamines (PA), polyamine oxidases, copper amine oxidases, and nitric oxide (NO)play important roles in physiology and stress responses in plants. NO biosynthesis as a result of catabolism of PA by polyamine oxidases and copper amine oxidases may explain in part PA-mediated responses. Involvement of a copper amine oxidase gene, COPPER AMINE OXIDASE1 (CuA01), of Arabidopsis was tested for its role in stress responses using the knockouts cuaol.1 and cuaol-2. PA-induced and ABA-induced NO production investigated by fluorometry and fluorescence microscopy showed that the cuaol-1 and cuaol-2 are impaired in NO production, suggesting a function of CuAO1 in PA and ABA-mediated NO production. Furthermore, we found a PA-dependent increase in protein S-nitrosylation. The addition of PA and ABA also resulted in HO increases, cuaol-1 and cuaol-2 showed less sensitivity to exogenous ABA supplementation during ger-mination, seedling establishment, and root growth inhibition as compared to wild-type. In response to ABA treatment,expression levels of the stress-responsive genes RD29A and ADH1 were significantly lower in the knockouts. These obser-vations characterize cuaol-1 and cuaol-2 as ABA-insensitive mutants. Taken together, our findings extend the ABA signal transduction network to include CuAO1 as one potential contributor to enhanced NO production by ABA.

  10. Involvement of NADPH oxidase NtrbohD in the rapid production of H2O2 induced by ABA in cultured tobacco cell line BY-2

    Institute of Scientific and Technical Information of China (English)

    Fushun Hao; Jinguang Zhang; Zhonglian Yu; Jia Chen

    2008-01-01

    The mechanisms for the production of hydrogen peroxide (H2O2) induced by abscisic acid (ABA) were investigated in suspension culture cells of tobacco BY-2 cells. The results showed that the immediate generation of H2O2, which was mainly derived from super-oxide dismutase-catalyzed dismutation of superoxide radical, was significantly induced by ABA. Furthermore, treatment of the cultured tobacco cells with ABA resulted in a time-dependent quick increase in plasma membrane (PM) NADPH oxidase activity, which coincided on time and magnitude with the elevation in ABA-induced accumulation of H2O2. Moreover, these enhanced effects were pronouncedly inhibited by two NADPH oxidase inhibitors, diphenylene iodonium and imidazole, suggesting that PM NADPH oxidase is involved in the rapid accumulation of H2O2 in cultured tobacco cells. In addition, analysis of the expression level of NtrbohD, a PM NADPH oxidase gene in tobacco, by RT-PCR and protein gel blot revealed that the gene at both mRNA and protein levels was upregulated by ABA, indicating that NtrbohD participates in the ABA-stimulated rapid production of H2O2 in tobacco culture cells. Taken together, these findings suggest that ABA induces the rapid accumulation of reactive oxygen species via NADPH oxidase in suspension culture cells of tobacco, and that NADPH oxidase and H2O2 appear to be important components in ABA signal transduction pathway in plants.

  11. Nanoparticle strategies for cancer therapeutics: Nucleic acids, polyamines, bovine serum amine oxidase and iron oxide nanoparticles (Review).

    Science.gov (United States)

    Agostinelli, Enzo; Vianello, Fabio; Magliulo, Giuseppe; Thomas, Thresia; Thomas, T J

    2015-01-01

    Nanotechnology for cancer gene therapy is an emerging field. Nucleic acids, polyamine analogues and cytotoxic products of polyamine oxidation, generated in situ by an enzyme-catalyzed reaction, can be developed for nanotechnology-based cancer therapeutics with reduced systemic toxicity and improved therapeutic efficacy. Nucleic acid-based gene therapy approaches depend on the compaction of DNA/RNA to nanoparticles and polyamine analogues are excellent agents for the condensation of nucleic acids to nanoparticles. Polyamines and amine oxidases are found in higher levels in tumours compared to that of normal tissues. Therefore, the metabolism of polyamines spermidine and spermine, and their diamine precursor, putrescine, can be targets for antineoplastic therapy since these naturally occurring alkylamines are essential for normal mammalian cell growth. Intracellular polyamine concentrations are maintained at a cell type-specific set point through the coordinated and highly regulated interplay between biosynthesis, transport, and catabolism. In particular, polyamine catabolism involves copper-containing amine oxidases. Several studies showed an important role of these enzymes in developmental and disease-related processes in animals through the control of polyamine homeostasis in response to normal cellular signals, drug treatment, and environmental and/or cellular stress. The production of toxic aldehydes and reactive oxygen species (ROS), H2O2 in particular, by these oxidases suggests a mechanism by which amine oxidases can be exploited as antineoplastic drug targets. The combination of bovine serum amine oxidase (BSAO) and polyamines prevents tumour growth, particularly well if the enzyme has been conjugated with a biocompatible hydrogel polymer. The findings described herein suggest that enzymatically formed cytotoxic agents activate stress signal transduction pathways, leading to apoptotic cell death. Consequently, superparamagnetic nanoparticles or other

  12. NADH/NADPH Oxidase and Vascular Function.

    Science.gov (United States)

    Griendling, K K; Ushio-Fukai, M

    1997-11-01

    The vascular NADH/NADPH oxidase has been shown to be the major source of superoxide in the vessel wall. Recent work has provided insight into its structure and activity in vascular cells. This enzyme is involved in both vascular smooth muscle hypertrophy and in some forms of impaired endothelium-dependent relaxation. Because oxidative stress in general participates in the pathogenesis of hypertension and atherosclerosis, the enzymes that produce reactive oxygen species may be important determinants of the course of vascular disease. (Trends Cardiovasc Med 1997;7:301-307). © 1997, Elsevier Science Inc.

  13. NADPH oxidase: an enzyme for multicellularity?

    Science.gov (United States)

    Lalucque, Hervé; Silar, Philippe

    2003-01-01

    Multicellularity has evolved several times during the evolution of eukaryotes. One evolutionary pressure that permits multicellularity relates to the division of work, where one group of cells functions as nutrient providers and the other in specialized roles such as defence or reproduction. This requires signalling systems to ensure harmonious development of multicellular structures. Here, we show that NADPH oxidases are specifically present in organisms that differentiate multicellular structures during their life cycle and are absent from unicellular life forms. The biochemical properties of these enzymes make them ideal candidates for a role in intercellular signalling.

  14. OXIDASE REACTION OF VARIOUS GROUPS OF BACTERIA.

    Science.gov (United States)

    Felton, L D

    1923-08-31

    1. A simple technique is described for studying the oxidase action of bacteria by means of the oxidation of p-aminoleucomalachite green. 2. It is shown that pneumococci under aerobic conditions produced an oxidase when grown on suitable medium. The sera of any of seven different animal species constitute such a medium, the degree of oxidation by the pneumococcus depending upon the animal from which the serum was taken-rat, guinea pig, rabbit, horse, man, cat, and chicken in order of diminishing suitability. 3. Conditions favoring the oxidation of p-aminoleucomalachite green by a single strain of pneumococci are: the presence of a slight amount of hemoglobin, dextrose, H ion concentration on the add side, and heating of fresh serum for 30 minutes at 56 degrees C. Conditions preventing the oxidation are: sterilized meat infusion, 1 per cent peptone, plain broth, a high concentration of hemoglobin, and absence of oxygen. In a quantitative fashion, meat infusion, 1 per cent peptone, and plain broth interfere with the suitability of serum as a substratum of oxidase production by the pneumococcus. 4. Twenty-three microbic species were studied with reference to oxidative power. They were grown upon 10 per cent horse serum, with and without dextrose, upon 10 per cent guinea pig serum, and upon plain broth. Only three of the twenty-three gave evidence of oxidative power as tested by p-aminoleucomalachite green; namely, the pneumococcus, Streptococcus viridans, and Streptococcus haemolyticus. Among the strains, of these three pneumococci gave the most intense reaction, after which Streptococcus viridans and Streptococcus haemolyticus follow in the order named, but with a noticeable variation among the different strains of Streptococcus haemolyticus. 5. Hemolytic streptococci of human and bovine origin were studied. The only variation in the type of reaction was manifested by the streptococci of milk and cheese origin. Strains from these sources showed definitely the least

  15. Functional characterization of a C-4 sterol methyl oxidase from the endomycorrhizal fungus Glomus intraradices.

    Science.gov (United States)

    Oger, Elodie; Ghignone, Stefano; Campagnac, Estelle; Fontaine, Joël; Grandmougin-Ferjani, Anne; Lanfranco, Luisa

    2009-01-01

    Sterols are crucial components of eukaryotic membranes that control membrane fluidity and permeability. They play an important role in cell signaling, polarity and sorting. Since many steps in the pathway are essential, sterol biosynthesis inhibitors (SBI) are widely used as antifungal agents. This work reports the identification and the characterization of a C-4 sterol methyl oxidase (SMO), the first gene involved in the sterol biosynthetic pathway, so far described from an arbuscular mycorrhizal fungus. The sequence, called GintSMO, shows a primary structure, a hydrophobicity profile and a pattern of histidine-rich motifs which are typical of C-4 methyl sterol oxidases. The complementation assay in a Saccharomyces cerevisiae mutant strain demonstrates that GintSMO encodes a functional SMO. Changes in GintSMO transcript levels and in the amount of the sterol precursor squalene were observed in in vitro grown extraradical structures exposed to the fenpropimorph SBI fungicide.

  16. Multicopper oxidase-1 orthologs from diverse insect species have ascorbate oxidase activity.

    Science.gov (United States)

    Peng, Zeyu; Dittmer, Neal T; Lang, Minglin; Brummett, Lisa M; Braun, Caroline L; Davis, Lawrence C; Kanost, Michael R; Gorman, Maureen J

    2015-04-01

    Members of the multicopper oxidase (MCO) family of enzymes can be classified by their substrate specificity; for example, ferroxidases oxidize ferrous iron, ascorbate oxidases oxidize ascorbate, and laccases oxidize aromatic substrates such as diphenols. Our previous work on an insect multicopper oxidase, MCO1, suggested that it may function as a ferroxidase. This hypothesis was based on three lines of evidence: RNAi-mediated knock down of Drosophila melanogaster MCO1 (DmMCO1) affects iron homeostasis, DmMCO1 has ferroxidase activity, and DmMCO1 has predicted iron binding residues. In our current study, we expanded our focus to include MCO1 from Anopheles gambiae, Tribolium castaneum, and Manduca sexta. We verified that MCO1 orthologs have similar expression profiles, and that the MCO1 protein is located on the basal surface of cells where it is positioned to oxidize substrates in the hemolymph. In addition, we determined that RNAi-mediated knock down of MCO1 in A. gambiae affects iron homeostasis. To further characterize the enzymatic activity of MCO1 orthologs, we purified recombinant MCO1 from all four insect species and performed kinetic analyses using ferrous iron, ascorbate and two diphenols as substrates. We found that all of the MCO1 orthologs are much better at oxidizing ascorbate than they are at oxidizing ferrous iron or diphenols. This result is surprising because ascorbate oxidases are thought to be specific to plants and fungi. An analysis of three predicted iron binding residues in DmMCO1 revealed that they are not required for ferroxidase or laccase activity, but two of the residues (His374 and Asp380) influence oxidation of ascorbate. These two residues are conserved in MCO1 orthologs from insects and crustaceans; therefore, they are likely to be important for MCO1 function. The results of this study suggest that MCO1 orthologs function as ascorbate oxidases and influence iron homeostasis through an unknown mechanism.

  17. Biogenesis of photosynthetic complexes in the chloroplast of Chlamydomonas reinhardtii requires ARSA1, a homolog of prokaryotic arsenite transporter and eukaryotic TRC40 for guided entry of tail-anchored proteins.

    Science.gov (United States)

    Formighieri, Cinzia; Cazzaniga, Stefano; Kuras, Richard; Bassi, Roberto

    2013-03-01

    as1, for antenna size mutant 1, was obtained by insertion mutagenesis of the unicellular green alga Chlamydomonas reinhardtii. This strain has a low chlorophyll content, 8% with respect to the wild type, and displays a general reduction in thylakoid polypeptides. The mutant was found to carry an insertion into a homologous gene, prokaryotic arsenite transporter (ARSA), whose yeast and mammal counterparts were found to be involved in the targeting of tail-anchored (TA) proteins to cytosol-exposed membranes, essential for several cellular functions. Here we present the characterization in a photosynthetic organism of an insertion mutant in an ARSA-homolog gene. The ARSA1 protein was found to be localized in the cytosol, and yet its absence in as1 leads to a small chloroplast and a strongly decreased chlorophyll content per cell. ARSA1 appears to be required for optimal biogenesis of photosynthetic complexes because of its involvement in the accumulation of TOC34, an essential component of the outer chloroplast membrane translocon (TOC) complex, which, in turn, catalyzes the import of nucleus-encoded precursor polypeptides into the chloroplast. Remarkably, the effect of the mutation appears to be restricted to biogenesis of chlorophyll-binding polypeptides and is not compensated by the other ARSA homolog encoded by the C. reinhardtii genome, implying a non-redundant function.

  18. A possible relationship between bumblefoot responsive to potassium arsenite and micrococci in the blood of three birds of prey.

    Science.gov (United States)

    Tarello, W

    2002-01-01

    Pododermatitis (bumblefoot) is a major health problem of falcons world-wide because healing processes in the talons are difficult and lengthy. A peregrine (Falco peregrinus), a merlin (Falco columbarius) and a saker falcon (Falco cherrug) with bumblefoot at different stages ranging from III to V, were all found to be carriers of micrococcus-like organisms in the blood and two of them were successfully treated with 0.5% potassium arsenite in low dosage given intravenously. A number of considerations are made on the immune dysfunction aspects of bumblefoot in birds of prey and on the emerging role of arsenic-based medicaments in the treatment of animal and human immune dysfunction syndromes.

  19. Genome Sequence of the Photoarsenotrophic Bacterium Ectothiorhodospira sp. Strain BSL-9, Isolated from a Hypersaline Alkaline Arsenic-Rich Extreme Environment

    Science.gov (United States)

    Hernandez-Maldonado, Jaime; Stoneburner, Brendon; Boren, Alison; Miller, Laurence; Rosen, Michael; Oremland, Ronald S.

    2016-01-01

    The full genome sequence of Ectothiorhodospira sp. strain BSL-9 is reported here. This purple sulfur bacterium encodes an arxA-type arsenite oxidase within the arxB2AB1CD gene island and is capable of carrying out “photoarsenotrophy” anoxygenic photosynthetic arsenite oxidation. Its genome is composed of 3.5 Mb and has approximately 63% G+C content. PMID:27738045

  20. A Raman spectroscopic study of arsenite and thioarsenite species in aqueous solution at 25°C

    Directory of Open Access Journals (Sweden)

    Janecky David R

    2002-02-01

    Full Text Available The Raman spectra of thioarsenite and arsenite species in aqueous solution were obtained at room temperature. Solutions at constant ΣAs + ΣS of 0.1 and 0.5 mol kg-1 were prepared with various ΣS/ΣAs ratios (0.1–9.0 and pH values (~7–13.2. Our data suggest that the speciation of As under the conditions investigated is more complicated than previously thought. The Raman measurements offer evidence for at least six separate S-bearing As species whose principal bands are centered near 365, 385, 390, 400, 415 and 420 cm-1. The data suggest that at least two different species may give rise to bands at 385 cm-1, bringing the probable minimum number of species to seven. Several additional species are possible but could not be resolved definitively. In general, the relative proportions of these species are dependent on total As concentration, ΣS/ΣAs ratio and pH. At very low ΣS/ΣAs ratios we also observe Raman bands attributable to the dissociation products of H3AsO3(aq. Although we were unable to assign precise stoichiometries for the various thioarsenite species, we were able to map out general pH and ΣS/ΣAs conditions under which the various thioarsenite and arsenite species are predominant. This study provides a basis for more detailed Raman spectroscopic and other types of investigations of the nature of thioarsenite species.

  1. Enzymatic Characterization and In Vivo Function of Five Terminal Oxidases in Pseudomonas aeruginosa

    OpenAIRE

    Arai, Hiroyuki; Kawakami, Takuro; Osamura, Tatsuya; Hirai, Takehiro; Sakai, Yoshiaki; Ishii, Masaharu

    2014-01-01

    The ubiquitous opportunistic pathogen Pseudomonas aeruginosa has five aerobic terminal oxidases: bo3-type quinol oxidase (Cyo), cyanide-insensitive oxidase (CIO), aa3-type cytochrome c oxidase (aa3), and two cbb3-type cytochrome c oxidases (cbb3-1 and cbb3-2). These terminal oxidases are differentially regulated under various growth conditions and are thought to contribute to the survival of this microorganism in a wide variety of environmental niches. Here, we constructed multiple mutant str...

  2. 利用细胞色素氧化酶亚单位Ⅰ分析青海藏区细粒棘球绦虫系统发育学%Phylogeny of Qinghai Plateau Echinococcus g ranulosus isolates inferred by cytochrome oxidasegene sequences

    Institute of Scientific and Technical Information of China (English)

    曹得萍; 樊海宁; 毋德芳; 赵海龙; 白海燕

    2014-01-01

    目的:囊型包虫病是一种广泛流行且危害严重的人兽共患寄生虫病。本文旨在分析流行于青南地区细粒棘球绦虫系统发育学及基因多态性。方法本文利用线粒体 DNA细胞色素氧化酶亚单位Ⅰ(COX Ⅰ)分子对收集到的流行于青海省的59例包虫病样本进行测序。总计71条序列(其中12条来自GenBank)碱基通过Clustal X软件比对,构建贝叶斯进化树。结果流行于青海省包虫病样本大部分与细粒棘球绦虫G1型聚在一枝,还有三个样本与多房棘球绦虫(AB018440)聚在一枝。虽大部分棘球绦虫基因型属于G1型,但各自的基因型各不相同,具有丰富的多样性。结论流行于青海省细粒棘球绦虫系统发育学比我们想象复杂。%Cystic echinococcosis is one of the most widespread and severe zoonotic helminthic diseases .To understand the phylogeny and genetic polymorphism Echinococcus granulosus (E .granulosus) prevailed in south region of Qinghai Prov-ince ,partial fragment of cytochrome oxidase Ⅰ (COX Ⅰ ) gene sequences were used to infer the phylogenetic relationship of 59 collected samples of E .granulosus in Qinghai Province .Total 72 sequences (13 sequences from GenBank) were aligned using CLUSTAL X ,and then ,Bayesian analyses were performed in Mrbayes-3 .1 .2 .The results revealed that Echinococcus spp .isolates did not form a monophyletic group .The most samples clustered with E . granulosus strain (G1) (AB297617) , but showed high genetic polymorphism .Another three samples clustered with E .multilocularis (AB018440) ,while they showed complex phylogenetic relationships among them ,further indicating that Echinococcus spp .isolates from Qinghai Prov-ince may has a more complex evolutionary history than expected .

  3. Endothelins and NADPH oxidases in the cardiovascular system.

    Science.gov (United States)

    Dammanahalli, Karigowda J; Sun, Zhongjie

    2008-01-01

    1. The endothelin (ET) system and NADPH oxidase play important roles in the regulation of cardiovascular function, as well as in the pathogenesis of hypertension and other cardiovascular diseases. 2. Endothelins activate NADPH oxidases and thereby increase superoxide production, resulting in oxidative stress and cardiovascular dysfunction. Thus, NADPH oxidases may mediate the role of endothelins in some cardiovascular diseases. However, the role of reactive oxygen species (ROS) in mediating ET-induced vasoconstriction and cardiovascular disease remains under debate, as evidenced by conflicting reports from different research teams. Conversely, activation of NADPH oxidase can stimulate ET secretion via ROS generation, which further enhances the cardiovascular effects of NADPH oxidase. However, little is known about how ROS activate the endothelin system. It seems that the relationship between ET-1 and ROS may vary with cardiovascular disorders. 3. Endothelins activate NADPH oxidase via the ET receptor-proline-rich tyrosine kinase-2 (Pyk2)-Rac1 pathway. Rac1 is an important regulator of NADPH oxidase. There is ample evidence supporting direct stimulation by Rac1 of NADPH oxidase activity. In addition, Rac1-induced cardiomyocyte hypertrophy is mediated by the generation of ROS.

  4. Laboratory-evolved vanillyl-alcohol oxidase produces natural vanillin

    NARCIS (Netherlands)

    Heuvel, van den R.H.H.; Berg, van den W.A.M.; Rovida, S.; Berkel, van W.J.H.

    2004-01-01

    The flavoenzyme vanillyl-alcohol oxidase was subjected to random mutagenesis to generate mutants with enhanced reactivity to creosol (2-methoxy-4-methylphenol). The vanillyl-alcohol oxidase-mediated conversion of creosol proceeds via a two-step process in which the initially formed vanillyl alcohol

  5. D-氨基酸氧化酶激活剂基因多态性与精神分裂症的关联研究%Association of D-amino acid oxidase activator gene polymorphisms with schizophrenia in a Chinese Han sample

    Institute of Scientific and Technical Information of China (English)

    杨丽; 邵静茹; 阮冶; 吴艳瑞; 周利国; 张勇辉; 伍星; 郑冰蓉; 肖春杰

    2011-01-01

    Objective To investigate the association between single nucleotide polymorphisms (SNPs) of D-amino acid oxidase activator (DAOA) gene and schizophrenia in Han population from Yunnan Province.Methods Two hundred and seventy-six schizophrenic patients and 312 healthy controls were recruited.Genotyping was performed using polymerase chain reaction(PCR)-restriction fragment length polymerase(RFLP).Odds ratios(ORs)and 95%confidence intervals(CIs)were calculated to evaluate the relationship between the gene polymorphisms and schizophrenia.Results (1)No significant differences of rs2391191,rs947267 and rs778294 allele frequencies were observed between the patients and controls,and the same results existed in the females.(2)In males,there was no significant difference in the allele frequency of rs2391191(P>0.05)between the two groups.The frequencies of rs947267 C allele and rs778294 A allele(0.406 and 0.184,respectively)were higher in patients compared to that in controls (0.327 and 0.103,respectively)[adjusted OR=1.41,95%CI=1.00-1.99,P=0.049;adjusted OR=1.91,95%CI=1.21-3.20,P=0.006].(3)In males,the frequency of haplotype GAA was significantly higher in controls than that in patients(P=0.008).Conclusions The DAOA gene rs947267 and rs778294 polymorphisms may be associated with schizophrenia in males.Rs947267 C allele and rs778294 A allele are possibly risk factors for schizophrenia in Yunnan Han male population.Haplotype GAA may be associated with schizophrenia as a protective factor in males.%目的 探讨D-氨基酸氧化酶激活剂(D-amino acid oxidase activator,DAOA)基因rs2391191、rs947267、rs778294多态性与云南汉族人群精神分裂症发病的相关性.方法 采用聚合酶链式反应-限制性片段长度多态(PCR-RFLP)方法,对276例精神分裂症患者(患者组)和312名健康对照(对照组)DAOA基因rs2391191、rs947267和rs778294 3个位点的多态进行检测,在混合群体和性别分层群体中进行多态性与精

  6. Modulation of NADPH oxidase activity by known uraemic retention solutes

    DEFF Research Database (Denmark)

    Schulz, Anna Marta; Terne, Cindy; Jankowski, Vera

    2014-01-01

    as the strongest inhibitor of NADPH oxidase (90% of DPI inhibition). Surprisingly, none of the uraemic retention solutes we investigated was found to increase NADPH oxidase activity. Furthermore, plasma from patients with CKD-5D before dialysis caused significantly higher inhibitory effect on NADPH oxidase...... inhibitory effect on NADPH oxidase activity in the presence of plasma from patients with CKD-5D after dialysis compared with before dialysis, we investigated the effect of 48 known and commercially available uraemic retention solutes on the enzymatic activity of NADPH oxidase. METHODS: Mononuclear leucocytes...... isolated from buffy coats of healthy volunteers were isolated, lysed and incubated with NADH in the presence of plasma from healthy controls and patients with CKD-5D. Furthermore, the leucocytes were lysed and incubated in the presence of uraemic retention solute of interest and diphenyleneiodonium...

  7. The NADH oxidase-Prx system in Amphibacillus xylanus.

    Science.gov (United States)

    Niimura, Youichi

    2007-01-01

    Amphibacillus NADH oxidase belongs to a growing new family of peroxiredoxin-linked oxidoreductases including alkyl hydroperoxide reductase F (AhpF). Like AhpF it displays extremely high hydroperoxide reductase activity in the presence of a Prx, thus making up the NADH oxidase-Prx system. The NADH oxidase primarily catalyzes the reduction of oxygen by NADH to form H2O2, while the Prx immediately reduces H2O2 (or ROOH) to water (or ROH). Consequently, the NADH oxidase-Prx system catalyzes the reduction of both oxygen and hydrogen peroxide to water with NADH as the preferred electron donor. The NADH oxidase-Prx system is widely distributed in aerobically growing bacteria lacking a respiratory chain and catalase, and plays an important role not only in scavenging hydroperoxides but also in regenerating NAD in these bacteria.

  8. Gene

    Data.gov (United States)

    U.S. Department of Health & Human Services — Gene integrates information from a wide range of species. A record may include nomenclature, Reference Sequences (RefSeqs), maps, pathways, variations, phenotypes,...

  9. The moderating effect of monoamine oxidase A gene polymorphism in relationship between childhood abuse of male adolescents and externalizing behaviors%单胺氧化酶A基因多态性对男性青少年儿童期虐待与外化性行为关系的调节效应

    Institute of Scientific and Technical Information of China (English)

    明庆森; 姚树桥; 张芸; 陈海燕

    2012-01-01

    Objective To explore the relationship between male adolescents' childhood abuse and externalizing behaviors,and the moderating effect of monoamine oxidase A (MAOA) gene promoter region variable number tandem repeat (VNTR) polymorphism.Methods Through random cluster sampling,352 Han male middle school students from Changsha were tested by Achenbach child behavior checklist-youth self reports (CBCL-YSR)and childhood trauma questionnaire-28 item short form (CTQ-SF),their MAOA genotypes were also identified.A hierarchical multiple regression analysis was used to test the moderating effect.Results ( 1 ) Compared participates with high activity MAOA gene and that with low activity MAOA gene,there were no significant differences on age ( ( 15.82 ± 1.52) vs ( 15.94 ± 1.62 ) ),externalizing behaviors ( ( 15.13 ± 10.14 ) vs ( 14.33 ± 9.70 ) ),total abuse ( (52.59 ± 10.46) vs (51.39 ± 7.56 ) ),emotional abuse( ( 7.63 ± 3.31 ) vs ( 7.11 ± 2.68 ) ),physical abuse ( ( 6.40 ± 2.82) vs (6.12 ± 2.05 ) ),sexual abuse ( ( 6.42 ± 3.24 ) vs ( 5.94 ± 1.72 ) ),emotional neglect ((13.44±5.12) vs (13.16 ±4.83) ),physical neglect( (10.27 ±2.64) vs (10.44±2.53))(t=-1.789~0.678,P > 0.05 ).(2)Except emotional neglect and physical neglect,emotional abuse,physical abuse and sexual abuse could predict externalizing behaviors( Sβ =0.141 ~0.347,P < 0.01 ).(3) MAOA gene was not directly related to externalizing behaviors( Sβ =- 0.023,P > 0.05 ).There was a significant interaction between MAOA gene and emotional abuse( Sβ =-0.148,P < 0.01 ).The interaction between MAOA gene and physical abuse or sexual abuse showed no statistical significance( Sβ =- 0.067,- 0.005,P > 0.05 ).Conclusion MAOA gene polymorphism can moderate the relationship between male adolescents'childhood emotional abuse and externalizing behaviors.%目的 探讨男性青少年的儿童期虐待与外化性行为的关系以及单胺氧化酶A (MAOA)基因启动子区域可变重复序列(VNTR)多态

  10. Loss of lysyl oxidase-like 3 causes cleft palate and spinal deformity in mice.

    Science.gov (United States)

    Zhang, Jian; Yang, Rui; Liu, Ziyi; Hou, Congzhe; Zong, Wen; Zhang, Aizhen; Sun, Xiaoyang; Gao, Jiangang

    2015-11-01

    In mammals, embryonic development are highly regulated morphogenetic processes that are tightly controlled by genetic elements. Failure of any one of these processes can result in embryonic malformation. The lysyl oxidase (LOX) family genes are closely related to human diseases. In this study, we investigated the essential role of lysyl oxidase-like 3 (LOXL3), a member of the LOX family, in embryonic development. Mice lacking LOXL3 exhibited perinatal lethality, and the deletion of the Loxl3 gene led to impaired development of the palate shelves, abnormalities in the cartilage primordia of the thoracic vertebrae and mild alveolar shrinkage. We found that the obvious decrease of collagen cross-links in palate and spine that was induced by the lack of LOXL3 resulted in cleft palate and spinal deformity. Thus, we provide critical in vivo evidence that LOXL3 is indispensable for mouse palatogenesis and vertebral column development. The Loxl3 gene may be a candidate disease gene resulting in cleft palate and spinal deformity.

  11. Glucose oxidase immobilization onto carbon nanotube networking

    CERN Document Server

    Karachevtsev, V A; Zarudnev, E S; Karachevtsev, M V; Leontiev, V S; Linnik, A S; Lytvyn, O S; Plokhotnichenko, A M; Stepanian, S G

    2012-01-01

    When elaborating the biosensor based on single-walled carbon nanotubes (SWNTs), it is necessary to solve such an important problem as the immobilization of a target biomolecule on the nanotube surface. In this work, the enzyme (glucose oxidase (GOX)) was immobilized on the surface of a nanotube network, which was created by the deposition of nanotubes from their solution in 1,2-dichlorobenzene by the spray method. 1-Pyrenebutanoic acid succinimide ester (PSE) was used to form the molecular interface, the bifunctional molecule of which provides the covalent binding with the enzyme shell, and its other part (pyrene) is adsorbed onto the nanotube surface. First, the usage of such a molecular interface leaves out the direct adsorption of the enzyme (in this case, its activity decreases) onto the nanotube surface, and, second, it ensures the enzyme localization near the nanotube. The comparison of the resonance Raman (RR) spectrum of pristine nanotubes with their spectrum in the PSE environment evidences the creat...

  12. NADPH Oxidases in Chronic Liver Diseases

    Directory of Open Access Journals (Sweden)

    Joy X. Jiang

    2014-01-01

    Full Text Available Oxidative stress is a common feature observed in a wide spectrum of chronic liver diseases including viral hepatitis, alcoholic, and nonalcoholic steatohepatitis. The nicotinamide adenine dinucleotide phosphate (NADPH oxidases (NOXs are emerging as major sources of reactive oxygen species (ROS. Several major isoforms are expressed in the liver, including NOX1, NOX2, and NOX4. While the phagocytic NOX2 has been known to play an important role in Kupffer cell and neutrophil phagocytic activity and inflammation, the nonphagocytic NOX homologues are increasingly recognized as key enzymes in oxidative injury and wound healing. In this review, we will summarize the current advances in knowledge on the regulatory pathways of NOX activation, their cellular distribution, and their role in the modulation of redox signaling in liver diseases.

  13. SK channels mediate NADPH oxidase-independent reactive oxygen species production and apoptosis in granulocytes.

    Science.gov (United States)

    Fay, Alex J; Qian, Xiang; Jan, Yuh Nung; Jan, Lily Yeh

    2006-11-14

    Neutrophils are immune cells that bind to, engulf, and destroy bacterial and fungal pathogens in infected tissue, and their clearance by apoptosis is essential for the resolution of inflammation. Killing involves both oxidative and nonoxidative processes, the oxidative pathway requiring electrogenic production of superoxide by the membrane-bound NADPH oxidase complex. A variety of stimuli, from bacterial chemotactic peptides to complement- or IgG-opsonized microbes, can induce the production of reactive oxygen species (ROS) by neutrophils, presumably by means of NADPH oxidase. We report here that 1-ethyl-2-benzimidazolinone (1-EBIO), an activator of Ca2+-activated potassium channels of small conductance (SK) and intermediate conductance (IK), causes production of superoxide and hydrogen peroxide by neutrophils and granulocyte-differentiated PLB-985 cells. This response can be partially inhibited by the SK blocker apamin, which inhibits a Ca2+-activated K+ current in these cells. Analysis of RNA transcripts indicates that channels encoded by the SK3 gene carry this current. The effects of 1-EBIO and apamin are independent of the NADPH oxidase pathway, as demonstrated by using a PLB-985 cell line lacking the gp91phox subunit. Rather, 1-EBIO and apamin modulate mitochondrial ROS production. Consistent with the enhanced ROS production and K+ efflux mediated by 1-EBIO, we found that this SK opener increased apoptosis of PLB-985 cells. Together, these findings suggest a previously uncharacterized mechanism for the regulation of neutrophil ROS production and programmed cell death.

  14. Cell Wall Amine Oxidases: New Players in Root Xylem Differentiation under Stress Conditions

    Directory of Open Access Journals (Sweden)

    Sandip A. Ghuge

    2015-07-01

    Full Text Available Polyamines (PAs are aliphatic polycations present in all living organisms. A growing body of evidence reveals their involvement as regulators in a variety of physiological and pathological events. They are oxidatively deaminated by amine oxidases (AOs, including copper amine oxidases (CuAOs and flavin adenine dinucleotide (FAD-dependent polyamine oxidases (PAOs. The biologically-active hydrogen peroxide (H2O2 is a shared compound in all of the AO-catalyzed reactions, and it has been reported to play important roles in PA-mediated developmental and stress-induced processes. In particular, the AO-driven H2O2 biosynthesis in the cell wall is well known to be involved in plant wound healing and pathogen attack responses by both triggering peroxidase-mediated wall-stiffening events and signaling modulation of defense gene expression. Extensive investigation by a variety of methodological approaches revealed high levels of expression of cell wall-localized AOs in root xylem tissues and vascular parenchyma of different plant species. Here, the recent progresses in understanding the role of cell wall-localized AOs as mediators of root xylem differentiation during development and/or under stress conditions are reviewed. A number of experimental pieces of evidence supports the involvement of apoplastic H2O2 derived from PA oxidation in xylem tissue maturation under stress-simulated conditions.

  15. Heterologous expression of two FAD-dependent oxidases with (S)-tetrahydroprotoberberine oxidase activity from Arge mone mexicana and Berberis wilsoniae in insect cells.

    Science.gov (United States)

    Gesell, Andreas; Chávez, Maria Luisa Díaz; Kramell, Robert; Piotrowski, Markus; Macheroux, Peter; Kutchan, Toni M

    2011-06-01

    Berberine, palmatine and dehydrocoreximine are end products of protoberberine biosynthesis. These quaternary protoberberines are elicitor inducible and, like other phytoalexins, are highly oxidized. The oxidative potential of these compounds is derived from a diverse array of biosynthetic steps involving hydroxylation, intra-molecular C-C coupling, methylenedioxy bridge formation and a dehydrogenation reaction as the final step in the biosynthesis. For the berberine biosynthetic pathway, the identification of the dehydrogenase gene is the last remaining uncharacterized step in the elucidation of the biosynthesis at the gene level. An enzyme able to catalyze these reactions, (S)-tetrahydroprotoberberine oxidase (STOX, EC 1.3.3.8), was originally purified in the 1980s from suspension cells of Berberis wilsoniae and identified as a flavoprotein (Amann et al. 1984). We report enzymatic activity from recombinant STOX expressed in Spodoptera frugiperda Sf9 insect cells. The coding sequence was derived successively from peptide sequences of purified STOX protein. Furthermore, a recombinant oxidase with protoberberine dehydrogenase activity was obtained from a cDNA library of Argemone mexicana, a traditional medicinal plant that contains protoberberine alkaloids. The relationship of the two enzymes is discussed regarding their enzymatic activity, phylogeny and the alkaloid occurrence in the plants. Potential substrate binding and STOX-specific amino acid residues were identified based on sequence analysis and homology modeling.

  16. Structural characterization and regulatory element analysis of the heart isoform of cytochrome c oxidase VIa

    Science.gov (United States)

    Wan, B.; Moreadith, R. W.; Blomqvist, C. G. (Principal Investigator)

    1995-01-01

    In order to investigate the mechanism(s) governing the striated muscle-specific expression of cytochrome c oxidase VIaH we have characterized the murine gene and analyzed its transcriptional regulatory elements in skeletal myogenic cell lines. The gene is single copy, spans 689 base pairs (bp), and is comprised of three exons. The 5'-ends of transcripts from the gene are heterogeneous, but the most abundant transcript includes a 5'-untranslated region of 30 nucleotides. When fused to the luciferase reporter gene, the 3.5-kilobase 5'-flanking region of the gene directed the expression of the heterologous protein selectively in differentiated Sol8 cells and transgenic mice, recapitulating the pattern of expression of the endogenous gene. Deletion analysis identified a 300-bp fragment sufficient to direct the myotube-specific expression of luciferase in Sol8 cells. The region lacks an apparent TATA element, and sequence motifs predicted to bind NRF-1, NRF-2, ox-box, or PPAR factors known to regulate other nuclear genes encoding mitochondrial proteins are not evident. Mutational analysis, however, identified two cis-elements necessary for the high level expression of the reporter protein: a MEF2 consensus element at -90 to -81 bp and an E-box element at -147 to -142 bp. Additional E-box motifs at closely located positions were mutated without loss of transcriptional activity. The dependence of transcriptional activation of cytochrome c oxidase VIaH on cis-elements similar to those found in contractile protein genes suggests that the striated muscle-specific expression is coregulated by mechanisms that control the lineage-specific expression of several contractile and cytosolic proteins.

  17. Upregulation of Mitochondrial Content in Cytochrome c Oxidase Deficient Fibroblasts.

    Science.gov (United States)

    Kogot-Levin, Aviram; Saada, Ann; Leibowitz, Gil; Soiferman, Devorah; Douiev, Liza; Raz, Itamar; Weksler-Zangen, Sarah

    2016-01-01

    Cytochrome-c-oxidase (COX) deficiency is a frequent cause of mitochondrial disease and is associated with a wide spectrum of clinical phenotypes. We studied mitochondrial function and biogenesis in fibroblasts derived from the Cohen (CDs) rat, an animal model of COX deficiency. COX activity in CDs-fibroblasts was 50% reduced compared to control rat fibroblasts (P<0.01). ROS-production in CDs fibroblasts increased, along with marked mitochondrial fragmentation and decreased mitochondrial membrane-potential, indicating mitochondrial dysfunction. Surprisingly, cellular ATP content, oxygen consumption rate (OCR) and the extracellular acidification rate (ECAR) were unchanged. To clarify the discrepancy between mitochondrial dysfunction and ATP production, we studied mitochondrial biogenesis and turnover. The content of mitochondria was higher in CDs-fibroblasts. Consistently, AMPK activity and the expression of NRF1-target genes, NRF2 and PGC1-α that mediate mitochondrial biogenesis were increased (P<0.01 vs control fibroblast). In CDs-fibrobalsts, the number of autophagosomes (LC3+ puncta) containing mitochondria in CDs fibroblasts was similar to that in control fibroblasts, suggesting that mitophagy was intact. Altogether, our findings demonstrate that mitochondrial dysfunction and oxidative stress are associated with an increase in mitochondrial biogenesis, resulting in preservation of ATP generation.

  18. Elevated connexin 43 expression in arsenite-and cadmium-transformed human bladder cancer cells, tumor transplants and selected high grade human bladder cancers.

    Science.gov (United States)

    Zhang, Ruowen; Wang, Liping; Garrett, Scott H; Sens, Donald A; Dunlevy, Jane R; Zhou, Xu Dong; Somji, Seema

    2016-10-01

    Connexin 43 has been shown to play a role in cell migration and invasion; however, its role in bladder cancer is not well defined. Previous studies from our laboratory have shown that the environmental pollutants arsenite and cadmium can cause malignant transformation of the immortalized urothelial cell line UROtsa. These transformed cells can form tumors in immune-compromised mice. The goal of the present study was to determine if connexin 43 is expressed in the normal human bladder, the arsenite and cadmiun-transformed UROtsa cells as well as human urothelial cancer. The results obtained showed that connexin 43 is not expressed in the epithelial cells of the human bladder but is expressed in immortalized cultures of human urothelial cells and the expression is variable in the arsenite and cadmium- transformed urothelial cell lines derived from these immortalized cells. Tumor heterotransplants generated from the transformed cells expressed connexin 43 and the expression was localized to areas of squamous differentiation. Immuno-histochemical analysis of human bladder cancers also showed that the expression of connexin 43 was localized to areas of the tumor that showed early features of squamous differentiation. Treatment of UROtsa cells with various concentrations of arsenite or cadmium did not significantly alter the expression level of connexin 43. In conclusion, our results show that the expression of connexin 43 is localized to the areas of the tumor that show squamous differentiation, which may be an indicator of poor prognosis. This suggests that connexin 43 has the potential to be developed as a biomarker for bladder cancer that may have the ability to invade and metastasize.

  19. Nuclear localization of human spermine oxidase isoforms - possible implications in drug response and disease etiology.

    Science.gov (United States)

    Murray-Stewart, Tracy; Wang, Yanlin; Goodwin, Andrew; Hacker, Amy; Meeker, Alan; Casero, Robert A

    2008-06-01

    The recent discovery of the direct oxidation of spermine via spermine oxidase (SMO) as a mechanism through which specific antitumor polyamine analogues exert their cytotoxic effects has fueled interest in the study of the polyamine catabolic pathway. A major byproduct of spermine oxidation is H2O2, a source of toxic reactive oxygen species. Recent targeted small interfering RNA studies have confirmed that SMO-produced reactive oxygen species are directly responsible for oxidative stress capable of inducing apoptosis and potentially mutagenic DNA damage. In the present study, we describe a second catalytically active splice variant protein of the human spermine oxidase gene, designated SMO5, which exhibits substrate specificities and affinities comparable to those of the originally identified human spermine oxidase-1, SMO/PAOh1, and, as such, is an additional source of H2O2. Importantly, overexpression of either of these SMO isoforms in NCI-H157 human non-small cell lung carcinoma cells resulted in significant localization of SMO protein in the nucleus, as determined by confocal microscopy. Furthermore, cell lines overexpressing either SMO/PAOh1 or SMO5 demonstrated increased spermine oxidation in the nucleus, with accompanying alterations in individual nuclear polyamine concentrations. This increased oxidation of spermine in the nucleus therefore increases the production of highly reactive H2O2 in close proximity to DNA, as well as decreases nuclear spermine levels, thus altering the protective roles of spermine in free radical scavenging and DNA shielding, and resulting in an overall increased potential for oxidative DNA damage in these cells. The results of these studies therefore have considerable significance both with respect to targeting polyamine oxidation as an antineoplastic strategy, and in regard to the potential role of spermine oxidase in inflammation-induced carcinogenesis.

  20. Acyl-CoA oxidase complexes control the chemical message produced by Caenorhabditis elegans.

    Science.gov (United States)

    Zhang, Xinxing; Feng, Likui; Chinta, Satya; Singh, Prashant; Wang, Yuting; Nunnery, Joshawna K; Butcher, Rebecca A

    2015-03-31

    Caenorhabditis elegans uses ascaroside pheromones to induce development of the stress-resistant dauer larval stage and to coordinate various behaviors. Peroxisomal β-oxidation cycles are required for the biosynthesis of the fatty acid-derived side chains of the ascarosides. Here we show that three acyl-CoA oxidases, which catalyze the first step in these β-oxidation cycles, form different protein homo- and heterodimers with distinct substrate preferences. Mutations in the acyl-CoA oxidase genes acox-1, -2, and -3 led to specific defects in ascaroside production. When the acyl-CoA oxidases were expressed alone or in pairs and purified, the resulting acyl-CoA oxidase homo- and heterodimers displayed different side-chain length preferences in an in vitro activity assay. Specifically, an ACOX-1 homodimer controls the production of ascarosides with side chains with nine or fewer carbons, an ACOX-1/ACOX-3 heterodimer controls the production of those with side chains with seven or fewer carbons, and an ACOX-2 homodimer controls the production of those with ω-side chains with less than five carbons. Our results support a biosynthetic model in which β-oxidation enzymes act directly on the CoA-thioesters of ascaroside biosynthetic precursors. Furthermore, we identify environmental conditions, including high temperature and low food availability, that induce the expression of acox-2 and/or acox-3 and lead to corresponding changes in ascaroside production. Thus, our work uncovers an important mechanism by which C. elegans increases the production of the most potent dauer pheromones, those with the shortest side chains, under specific environmental conditions.

  1. Direct regulation of cytochrome c oxidase by calcium ions.

    Directory of Open Access Journals (Sweden)

    Tatiana Vygodina

    Full Text Available Cytochrome c oxidase from bovine heart binds Ca(2+ reversibly at a specific Cation Binding Site located near the outer face of the mitochondrial membrane. Ca(2+ shifts the absorption spectrum of heme a, which allowed previously to determine the kinetics and equilibrium characteristics of the binding. However, no effect of Ca(2+ on the functional characteristics of cytochrome oxidase was revealed earlier. Here we report that Ca(2+ inhibits cytochrome oxidase activity of isolated bovine heart enzyme by 50-60% with Ki of ∼1 µM, close to Kd of calcium binding with the oxidase determined spectrophotometrically. The inhibition is observed only at low, but physiologically relevant, turnover rates of the enzyme (∼10 s(-1 or less. No inhibitory effect of Ca(2+ is observed under conventional conditions of cytochrome c oxidase activity assays (turnover number >100 s(-1 at pH 8, which may explain why the effect was not noticed earlier. The inhibition is specific for Ca(2+ and is reversed by EGTA. Na(+ ions that compete with Ca(2+ for binding with the Cation Binding Site, do not affect significantly activity of the enzyme but counteract the inhibitory effect of Ca(2+. The Ca(2+-induced inhibition of cytochrome c oxidase is observed also with the uncoupled mitochondria from several rat tissues. At the same time, calcium ions do not inhibit activity of the homologous bacterial cytochrome oxidases. Possible mechanisms of the inhibition are discussed as well as potential physiological role of Ca(2+ binding with cytochrome oxidase. Ca(2+- binding at the Cation Binding Site is proposed to inhibit proton-transfer through the exit part of the proton conducting pathway H in the mammalian oxidases.

  2. Multilayered polyelectrolyte microcapsules: interaction with the enzyme cytochrome C oxidase.

    Science.gov (United States)

    Pastorino, Laura; Dellacasa, Elena; Noor, Mohamed R; Soulimane, Tewfik; Bianchini, Paolo; D'Autilia, Francesca; Antipov, Alexei; Diaspro, Alberto; Tofail, Syed A M; Ruggiero, Carmelina

    2014-01-01

    Cell-sized polyelectrolyte capsules functionalized with a redox-driven proton pump protein were assembled for the first time. The interaction of polyelectrolyte microcapsules, fabricated by electrostatic layer-by-layer assembly, with cytochrome c oxidase molecules was investigated. We found that the cytochrome c oxidase retained its functionality, that the functionalized microcapsules interacting with cytochrome c oxidase were permeable and that the permeability characteristics of the microcapsule shell depend on the shell components. This work provides a significant input towards the fabrication of an integrated device made of biological components and based on specific biomolecular functions and properties.

  3. Multilayered polyelectrolyte microcapsules: interaction with the enzyme cytochrome C oxidase.

    Directory of Open Access Journals (Sweden)

    Laura Pastorino

    Full Text Available Cell-sized polyelectrolyte capsules functionalized with a redox-driven proton pump protein were assembled for the first time. The interaction of polyelectrolyte microcapsules, fabricated by electrostatic layer-by-layer assembly, with cytochrome c oxidase molecules was investigated. We found that the cytochrome c oxidase retained its functionality, that the functionalized microcapsules interacting with cytochrome c oxidase were permeable and that the permeability characteristics of the microcapsule shell depend on the shell components. This work provides a significant input towards the fabrication of an integrated device made of biological components and based on specific biomolecular functions and properties.

  4. Alternative oxidase involvement in Daucus carota somatic embryogenesis.

    Science.gov (United States)

    Frederico, António Miguel; Campos, Maria Doroteia; Cardoso, Hélia Guerra; Imani, Jafargholi; Arnholdt-Schmitt, Birgit

    2009-12-01

    Plant alternative oxidase (AOX) is a mitochondrial inner membrane enzyme involved in alternative respiration. The critical importance of the enzyme during acclimation upon stress of plant cells is not fully understood and is still an issue of intensive research and discussion. Recently, a role of AOX was suggested for the ability of plant cells to change easily its fate upon stress. In order to get new insights about AOX involvement in cell reprogramming, quantitative real-time polymerase chain reaction (PCR) and inhibitor studies were performed during cell redifferentiation and developmental stages of Daucus carota L. somatic embryogenesis. Transcript level analysis shows that D. carota AOX genes (DcAOX1a and DcAOX2a) are differentially expressed during somatic embryogenesis. DcAOX1a shows lower expression levels, being mainly down-regulated, whereas DcAOX2a presented a large up-regulation during initiation of the realization phase of somatic embryogenesis. However, when globular embryos start to develop, both genes are down-regulated, being this state transient for DcAOX2a. In addition, parallel studies were performed using salicylhydroxamic acid (SHAM) in order to inhibit AOX activity during the realization phase of somatic embryogenesis. Embryogenic cells growing in the presence of the inhibitor were unable to develop embryogenic structures and its growth rate was diminished. This effect was reversible and concentration dependent. The results obtained contribute to the hypothesis that AOX activity supports metabolic reorganization as an essential part of cell reprogramming and, thus, enables restructuring and de novo cell differentiation.

  5. Mutations of SURF-1 in Leigh disease associated with cytochrome c oxidase deficiency.

    OpenAIRE

    1998-01-01

    Leigh disease associated with cytochrome c oxidase deficiency (LD[COX-]) is one of the most common disorders of the mitochondrial respiratory chain, in infancy and childhood. No mutations in any of the genes encoding the COX-protein subunits have been identified in LD(COX-) patients. Using complementation assays based on the fusion of LD(COX-) cell lines with several rodent/human rho0 hybrids, we demonstrated that the COX phenotype was rescued by the presence of a normal human chromosome 9. L...

  6. A novel D-amino acid oxidase from a contaminated agricultural soil metagenome and its characterization.

    Science.gov (United States)

    Ou, Qian; Liu, Yao; Deng, Jie; Chen, Gao; Yang, Ying; Shen, Peihong; Wu, Bo; Jiang, Chengjian

    2015-06-01

    A novel D-amino acid oxidase (DAAO) gene designated as daoE was cloned by the sequence-based screening of a plasmid metagenomic library of uncultured microorganisms from contaminated agricultural soil. The deduced amino acid sequence comparison and phylogenetic analysis indicated that daoE and other putative DAAOs are closely related. The putative DAAO gene was subcloned into a pETBlue-2 vector and overexpressed in Escherichia coli Tunner(DE3)pLacI. The recombinant protein was purified to homogeneity. The maximum activity of DaoE protein occurred at pH 8.0 and 37 °C. DaoE recombinant protein had an apparent K m of 2.96 mM, V max of 0.018 mM/min, k cat of 10.9/min, and k cat/K m of 1.16 × 10(4)/mol/min. The identification of this novel DAAO gene demonstrated the importance of metagenomic libraries in exploring new D-amino acid oxidases from environmental microorganisms to optimize their applications.

  7. Properties of recombinant human N1-acetylpolyamine oxidase (hPAO): potential role in determining drug sensitivity.

    Science.gov (United States)

    Wang, Yanlin; Hacker, Amy; Murray-Stewart, Tracy; Frydman, Benjamin; Valasinas, Aldonia; Fraser, Alison V; Woster, Patrick M; Casero, Robert A

    2005-07-01

    The recent cloning of the mammalian gene coding for N(1)-acetylpolyamine oxidase (PAO) provides the opportunity to directly examine the role of human PAO (hPAO) in polyamine homeostasis as well as its potential role in determining cellular response to antitumor polyamine analogues. To facilitate the study of this enzyme, the production, purification, and characterization of the recombinant hPAO is reported. hPAO oxidizes N(1)-acetylspermidine (K(m)=2.1 microM, K(cat)=15.0 s(-1)) and has very high affinity for N(1)-acetylspermine (K(m)=0.85 microM, K(cat)=31.7 s(-1)). The recombinant hPAO does not efficiently oxidize spermine, thereby demonstrating a significant difference in substrate specificity from the previously described human spermine oxidase PAOh1/SMO. Importantly, hPAO demonstrates the ability to oxidize a subset of antitumor polyamine analogues, suggesting that this oxidase activity could have a significant effect on determining tumor sensitivity to these or similar agents. Transfection of A549 human lung cancer cells with an hPAO-expressing plasmid leads to a profound decrease in sensitivity to those analogues which act as substrates, confirming its potential to alter drug response. One similarity that hPAO shares with human PAOh1/SMO, is that certain oligoamine analogues are potent inhibitors of its oxidase activity. The results of these studies demonstrate how changes in polyamine catabolism may affect drug response.

  8. PHYLOGENETIC ANALYSIS OF SOME SPECIES IN PAPILIONINAE ( PAPILIONIDAE,LEPIDOPTERA) BASED ON MITOCHONDRIAL CYTOCHROME OXIDASE I GENE%基于线粒体CO Ⅰ基因的凤蝶亚科部分物种系统发育关系

    Institute of Scientific and Technical Information of China (English)

    林昶东; 梁振; 郝宇; 马恩波; 张敏

    2011-01-01

    The mitochondrial cytochrome oxidase subunit I (COI) gene from a total of 27 species in 11 genera of the subfamily Papilioninae were sequenced and used for phylogenetic analysis with Parnassius apollo as an outgroup. Phylogenetic trees were constructed with the methods of neighbor-joining (NJ), maximum parsimony (MP) , maximum likelihood (ML). The results show that the species in Papilioninae were divided into four clades, namely the tribes of Troidini, Papilionini, Lampropterini and Teinopalpini, which is correspond to the current classification. Besides, the tribe Lampropterini, which was a separate branch ofthe base of the phylogenetic tree, was monophyletic. In the genus Papilio, the subgenera Menelaides and Princeps clustered firstly. Secondly, the phylogenetic relationship of Sinoprinceps and Papilio was closer. Then the two clades dustered together and formed the genus Papilio. These results evidenced the traditional dassification status of the subfamily Papilioninae on the molecular level. The study also offered the basic data for the further study of the taxonomy and the darification of the phylogenetic relationships of the subfamily Papilioninae.%通过对凤蝶亚科Papilioninae 11属27种的线粒体细胞色素c氧化酶Ⅰ基因(CoⅠ)序列测定,以阿波罗绢蝶Parnassius apollo为外群,分别采用邻接法(NJ)、最大简约法(MP)和最大似然法(ML)构建凤蝶亚科的系统发育树,初步探讨了其系统发育关系.结果显示,凤蝶亚科11属27个物种分为4个主要的分支,分别是裳凤蝶族Troidini、凤蝶族Papilionini、燕凤蝶族Lampropterini和喙凤蝶族Teinopalpini,与传统分类学观点一致.其中,燕凤蝶族构成凤蝶亚科系统发育树基部的一个独立分支,且为单系发生.凤蝶属Papilio中美凤蝶亚属Menelaides和翠凤蝶亚属Princeps首先相聚,华凤蝶亚属Sinoprinceps 和凤蝶亚属Papilio亲缘关系较近,随后两分支再聚为一支,构成凤蝶属.本研究结果从分子

  9. 抑郁症单胺氧化酶A基因活性对表情识别脑功能的影响%Influence of monoamine oxidase A gene and brain function in the dynamic facial expression recognition in depressed patients

    Institute of Scientific and Technical Information of China (English)

    唐勇; 张婧; 姚志剑; 刘海燕; 卢青

    2011-01-01

    目的 应用影像基因组学的原理,探讨单胺氧化酶A基因串联重复序列多态性(MAOA-uVNTR)对抑郁症患者及健康对照不同面部表情识别过程中脑功能的影响.方法 28例抑郁症患者及33例性别比例、年限、受教育年限匹配的健康对照,应用聚合酶链式反应(PCR)技术扩增目的 基因,将61名受试者进行基因型分组,并利用1.5T功能核磁共振成像系统检测每个受试在识别喜悦、悲伤、及中性面部表情视频时的脑激活反应.结果 识别悲伤面部表情时,高活性基因型健康组较低活性基因型健康组左楔叶、左额下回、右额中回、左顶下小叶脑区激活显著增强(P<0.005,K≥10).识别喜悦面部表情时,高活性基因型患者组较低活性基因型患者组左右壳核、左中央后回,右颞上回、右丘脑、左梭状回脑区激活降低(P<0.005,K≥10).结论 高活性基因型与健康人群负性情绪识别的优先激活趋势及抑郁症患者正性情绪的抑制状态均存在关联性,该基因型可能是健康者罹患抑郁症的危险因素之一,同时部分导致该类患者情绪症状较为显著.%Objective To explore the impact of the variable number of tandem repeats of monoamine oxidase A gene (MAOA-uVNTR) on the intensity of brain activation during the recognition of facial expression in patients with depression and healthy controls.Methods 28 cases of depression,as well as 33 healthy controls who were matched in gender, age and years of education were divided into different genotypes with the methods of polymerase chain reaction (PCR) amplification and 1.5% agarose gel electrophoresis separation.61 cases were scanned to compare the intensity of brain activation in the recognition of happy, sad and neutral facial expression.Results In healthy controls,cases with high-activity genotype showed increased activation in left cuneus,left inferior frontal gyrus, right medial frontal gyrus and left inferior

  10. Aldehyde-induced xanthine oxidase activity in raw milk.

    Science.gov (United States)

    Steffensen, Charlotte L; Andersen, Henrik J; Nielsen, Jacob H

    2002-12-04

    In the present study, the aldehyde-induced pro-oxidative activity of xanthine oxidase was followed in an accelerated raw milk system using spin-trap electron spin resonance (ESR) spectroscopy. The aldehydes acetaldehyde, propanal, hexanal, trans-2-hexenal, trans-2-heptenal, trans-2-nonenal, and 3-methyl-2-butenal were all found to initiate radical reactions when added to milk. Formation of superoxide through aldehyde-induced xanthine oxidase activity is suggested as the initial reaction, as all tested aldehydes were shown to trigger superoxide formation in an ultrahigh temperature (UHT) milk model system with added xanthine oxidase. It was found that addition of aldehydes to milk initially increased the ascorbyl radical concentration with a subsequent decay due to ascorbate depletion, which renders the formation of superoxide in milk with added aldehyde. The present study shows for the first time potential acceleration of oxidative events in milk through aldehyde-induced xanthine oxidase activity.

  11. Activation of the neutrophil NADPH oxidase by Aspergillus fumigatus.

    Science.gov (United States)

    Boyle, Keith B; Stephens, Len R; Hawkins, Phillip T

    2012-12-01

    Upon infection of the respiratory system with the fungus Aspergillus fumigatus various leukoctytes, in particular neutrophils, are recruited to the lung to mount an immune response. Neutrophils respond by both phagocytosing conidia and mediating extracellular killing of germinated, invasive hyphae. Of paramount importance to an appropriate immune response is the neutrophil NADPH oxidase enzyme, which mediates the production of various reactive oxygen species (ROS). This is evidenced by the acute sensitivity of both oxidase-deficient humans and mice to invasive aspergillosis. Herein we briefly review the mechanisms and functions of oxidase activation and discuss our recent work identifying at least some of the important players in hyphal-induced oxidase activation and neutrophil function. Among these we define the phosphoinositide 3-kinase enzyme and the regulatory protein Vav to be of critical importance and allude to a kinase-independent role for Syk.

  12. Xanthine oxidase in human skeletal muscle following eccentric exercise

    DEFF Research Database (Denmark)

    Hellsten, Ylva; Frandsen, Ulrik; Orthenblad, N.

    1997-01-01

    1. The present study tested the hypothesis that the level of xanthine oxidase is elevated in injured human skeletal muscle in association with inflammatory events. Seven male subjects performed five bouts of strenuous one-legged eccentric exercise. Muscle biopsies from both the exercised and the ......1. The present study tested the hypothesis that the level of xanthine oxidase is elevated in injured human skeletal muscle in association with inflammatory events. Seven male subjects performed five bouts of strenuous one-legged eccentric exercise. Muscle biopsies from both the exercised...... the increase in xanthine oxidase in the muscle there were no detectable changes in the levels of muscle malondialdehyde or in plasma antioxidant capacity up to 4 days post-exercise. 5. It is concluded that eccentric exercise leads to an increased level of xanthine oxidase in human muscle and that the increase...

  13. 基于mtDNA-COI基因序列分析我国中华按蚊种群的遗传结构%Analysis of population genetic structure of Anopheles sinensis based on mitochondrial DNA cytochrome oxidase subunit I gene fragment

    Institute of Scientific and Technical Information of China (English)

    常雪莲; 钟代斌; 李小聪; 黄亚铭; 朱国鼎; 魏星; 夏惠; 陈晓光; 方强

    2015-01-01

    目的:探讨我国中华按蚊种群遗传多样性、遗传分化及种群系统发育关系。方法本实验采用2010-2012年间在我国山东,安徽,江苏,贵州,广西和云南等6个不同地理环境采集的中华按蚊样品,进行线粒体COI基因扩增并测序。采用Bioedit 7.0软件对测序结果进行比对分析;运用DnaSP 5.0软件确定种群遗传结构特点;应用Arlequin 3.1软件计算种群的遗传距离及遗传分化系数;通过IBDWS在线软件来明确遗传距离与地理距离的相关性;使用PHYLIP 3.6软件构建种群系统发育进化树。结果六个中华按蚊种群共123个雌蚊个体的PCR产物成功扩增和测序。PCR扩增中华按蚊线粒体COI基因序列大小为814 bp,平均A+T含量(71.2%)>平均G+C含量(28.8%)。线粒体COI序列分析结果显示,种群具有丰富的遗传多样性;分子变异等级分析表明中华按蚊遗传分化主要来自于种群内部;种群间存在一定的地理隔离现象。中性检验,错配分析及聚类进化树结果显示:中华按蚊种群发展经历扩张状态,而云南种群相对其他种群较独立,在系统树中为孤立一支。结论线粒体COI基因可以作为研究中华按蚊种群遗传结构和系统进化的理想分子标志。云南种群遗传发育较其他地理种群具有一定特殊性。%Objective To study the population genetic variation, genetic diversity and phylogenesis of Anopheles sinensis in China. Methods Anopheles sinensis samples collected from Shandong, Anhui, Jiangsu, Guizhou, and Yunnan Provinces and Guangxi Zhuang Autonomous Region with different geographical conditions between 2010 and 2012 were analyzed by mitochondrial DNA cytochrome oxidase subunit I (mtDNA-COI) gene amplification and sequencing. Bioedit 7.0 and DnaSP 5.0 software was used to compare the gene sequences and analyze the population genetic structure, respectively. Arlequin 3.1 was used to calculate the

  14. Functional coadaptation between cytochrome c and cytochrome c oxidase within allopatric populations of a marine copepod.

    Science.gov (United States)

    Rawson, Paul D; Burton, Ronald S

    2002-10-01

    Geographically isolated populations may accumulate alleles that function well on their own genetic backgrounds but poorly on the genetic backgrounds of other populations. Consequently, interpopulation hybridization may produce offspring of low fitness as a result of incompatibilities arising in allopatry. Genes participating in these epistatic incompatibility systems remain largely unknown. In fact, despite the widely recognized importance of epistatic interactions among gene products, few data directly address the functional consequences of such interactions among natural genetic variants. In the marine copepod, Tigriopus californicus, we found that the cytochrome c variants isolated from two different populations each had significantly higher activity with the cytochrome c oxidase derived from their respective source population. Three amino acid substitutions in the cytochrome c protein appear to be sufficient to confer population specificity. These results suggest that electron transport system (ETS) proteins form coadapted sets of alleles within populations and that disruption of the coadapted ETS gene complex leads to functional incompatibilities that may lower hybrid fitness.

  15. Regulation of the NADPH Oxidase RBOHD During Plant Immunity

    OpenAIRE

    2015-01-01

    Pathogen recognition induces the production of reactive oxygen species (ROS) by NADPH oxidases in both plants and animals. ROS have direct antimicrobial properties, but also serve as signaling molecules to activate further immune outputs. However, ROS production has to be tightly controlled to avoid detrimental effects on host cells, but yet must be produced in the right amount, at the right place and at the right time upon pathogen perception. Plant NADPH oxidases belong to the respiratory b...

  16. Expression of multiple cbb3 cytochrome c oxidase isoforms by combinations of multiple isosubunits in Pseudomonas aeruginosa.

    Science.gov (United States)

    Hirai, Takehiro; Osamura, Tatsuya; Ishii, Masaharu; Arai, Hiroyuki

    2016-10-24

    The ubiquitous opportunistic human pathogen Pseudomonas aeruginosa has five terminal oxidases for aerobic respiration and uses them under different growth conditions. Two of them are cbb3-type cytochrome c oxidases encoded by the gene clusters ccoN1O1Q1P1 and ccoN2O2Q2P2, which are the main terminal oxidases under high- and low-oxygen conditions, respectively. P. aeruginosa also has two orphan gene clusters, ccoN3Q3 and ccoN4Q4, encoding the core catalytic CcoN isosubunits, but the roles of these genes have not been clarified. We found that 16 active cbb3 isoforms could be produced by combinations of four CcoN, two CcoO, and two CcoP isosubunits. The CcoN3- or CcoN4-containing isoforms were produced in the WT cell membrane in response to nitrite and cyanide, respectively. The strains carrying these isoforms were more resistant to nitrite or cyanide under low-oxygen conditions. These results indicate that P. aeruginosa gains resistance to respiratory inhibitors using multiple cbb3 isoforms with different features, which are produced through exchanges of multiple core catalytic isosubunits.

  17. MONOAMINE OXIDASE: RADIOTRACER DEVELOPMENT AND HUMAN STUDIES.

    Energy Technology Data Exchange (ETDEWEB)

    FOWLER,J.S.; LOGAN,J.; VOLKOW,N.D.; WANG,G.J.; MACGREGOR,R.R.; DING,Y.S.

    2000-09-28

    PET is uniquely capable of providing information on biochemical transformations in the living human body. Although most of the studies of monoamine oxidase (MAO) have focused on measurements in the brain, the role of peripheral MAO as a phase 1 enzyme for the metabolism of drugs and xenobiotics is gaining attention (Strolin Benedetti and Tipton, 1998; Castagnoli et al., 1997.). MAO is well suited for this role because its concentration in organs such as kidneys, liver and digestive organs is high sometimes exceeding that in the brain. Knowledge of the distribution of the MAO subtypes within different organs and different cells is important in determining which substrates (and which drugs and xenobiotics) have access to which MAO subtypes. The highly variable subtype distribution with different species makes human studies even more important. In addition, the deleterious side effects of combining MAO inhibitors with other drugs and with foodstuffs makes it important to know the MAO inhibitory potency of different drugs both in the brain and in peripheral organs (Ulus et al., 2000). Clearly PET can play a role in answering these questions, in drug research and development and in discovering some of the factors which contribute to the highly variable MAO levels in different individuals.

  18. Monoamine oxidase inhibitory activities of heterocyclic chalcones.

    Science.gov (United States)

    Minders, Corné; Petzer, Jacobus P; Petzer, Anél; Lourens, Anna C U

    2015-11-15

    Studies have shown that natural and synthetic chalcones (1,3-diphenyl-2-propen-1-ones) possess monoamine oxidase (MAO) inhibition activities. Of particular importance to the present study is a report that a series of furanochalcones acts as MAO-B selective inhibitors. Since the effect of heterocyclic substitution, other than furan (and more recently thiophene, piperidine and quinoline) on the MAO inhibitory properties of the chalcone scaffold remains unexplored, the aim of this study was to synthesise and evaluate further heterocyclic chalcone analogues as inhibitors of the human MAOs. For this purpose, heterocyclic chalcone analogues that incorporate pyrrole, 5-methylthiophene, 5-chlorothiophene and 6-methoxypyridine substitution were examined. Seven of the nine synthesised compounds exhibited IC50 values chalcones are reversible and competitive MAO inhibitors. 4h, however, may exhibit tight-binding to MAO-B, a property linked to its thiophene moiety. We conclude that high potency chalcones such as 4h represent suitable leads for the development of MAO-B inhibitors for the treatment of Parkinson's disease and possibly other neurodegenerative disorders.

  19. Leflunomide, a Reversible Monoamine Oxidase Inhibitor.

    Science.gov (United States)

    Petzer, Jacobus P; Petzer, Anél

    2016-01-01

    A screening study aimed at identifying inhibitors of the enzyme, monoamine oxidase (MAO), among clinically used drugs have indicated that the antirheumatic drug, leflunomide, is an inhibitor of both MAO isoforms. Leflunomide inhibits human MAO-A and MAO-B and exhibits IC50 values of 19.1 μM and 13.7 μM, respectively. The corresponding Ki values are 17.7 μM (MAO-A) and 10.1 μM (MAO-B). Dialyses of mixtures of the MAO enzymes and leflunomide show that inhibition of the MAOs by leflunomide is reversible. The principal metabolite of leflunomide, teriflunomide (A77 1726), in contrast is not an MAO inhibitor. This study concludes that, although leflunomide is only moderately potent as an MAO inhibitor, isoxazole derivatives may represent a general class of MAO inhibitors and this heterocycle may find application in MAO inhibitor design. In this respect, MAO inhibitors are used in the clinic for the treatment of depressive illness and Parkinson's disease, and are under investigation as therapy for certain types of cancer, Alzheimer's disease and age-related impairment of cardiac function.

  20. Prenatal Exposure to Sodium Arsenite Alters Placental Glucose 1, 3, and 4 Transporters in Balb/c Mice

    Directory of Open Access Journals (Sweden)

    Daniela Sarahí Gutiérrez-Torres

    2015-01-01

    Full Text Available Inorganic arsenic (iAs exposure induces a decrease in glucose type 4 transporter (GLUT4 expression on the adipocyte membrane, which may be related to premature births and low birth weight infants in women exposed to iAs at reproductive age. The aim of this study was to analyze the effect of sodium arsenite (NaAsO2 exposure on GLUT1, GLUT3, and GLUT4 protein expression and on placental morphology. Female Balb/c mice (n=15 were exposed to 0, 12, and 20 ppm of NaAsO2 in drinking water from 8th to 18th day of gestation. Morphological changes and GLUT1, GLUT3, and GLUT4 expression were evaluated in placentas by immunohistochemical and image analysis and correlated with iAs and arsenical species concentration, which were quantified by atomic absorption spectroscopy. NaAsO2 exposure induced a significant decrease in fetal and placental weight (P<0.01 and increases in infarctions and vascular congestion. Whereas GLUT1 expression was unchanged in placentas from exposed group, GLUT3 expression was found increased. In contrast, GLUT4 expression was significantly lower (P<0.05 in placentas from females exposed to 12 ppm. The decrease in placental GLUT4 expression might affect the provision of adequate fetal nutrition and explain the low fetal weight observed in the exposed groups.

  1. Arsenate and arsenite exposure modulate antioxidants and amino acids in contrasting arsenic accumulating rice (Oryza sativa L.) genotypes.

    Science.gov (United States)

    Dave, Richa; Tripathi, Rudra Deo; Dwivedi, Sanjay; Tripathi, Preeti; Dixit, Garima; Sharma, Yogesh Kumar; Trivedi, Prabodh Kumar; Corpas, Francisco J; Barroso, Juan B; Chakrabarty, Debasis

    2013-11-15

    Carcinogenic arsenic (As) concentrations are found in rice due to irrigation with contaminated groundwater in South-East Asia. The present study evaluates comparative antioxidant property and specific amino acid accumulation in contrasting rice genotypes corresponding to differential As accumulation during arsenate (As(V)) and arsenite (As(III)) exposures. The study was conducted on two contrasting As accumulating rice genotypes selected from 303 genotype accessions, in hydroponic conditions. Maximum As accumulation was up to 1181 μg g(-1) dw in the roots of high As accumulating genotype (HARG), and 89 μg g(-1) dw in low As accumulating genotype (LARG) under As(III) exposures. The inorganic As was correlated more significantly upon exposures to As(III) than As(V). In the presence of As(V) various antioxidant enzymes guiacol peroxidase (GPX), ascorbate peroxidase (APX) and superoxide dismutase (SOD) were highly stimulated in HARG. The stress responsive amino acids proline, cysteine, glycine, glutamic acid and methionine showed higher accumulation in HARG than LARG. A clear correlation was found between stress responsive amino acids, As accumulation and antioxidative response. The comparisons between the contrasting genotypes helped to determine the significance of antioxidants and specific amino acid response to As stress.

  2. Protective effects of the dietary supplementation of turmeric (Curcuma longa L.) on sodium arsenite-induced biochemical perturbation in mice.

    Science.gov (United States)

    Karim, Md Rezaul; Haque, Abedul; Islam, Khairul; Ali, Nurshad; Salam, Kazi Abdus; Saud, Zahangir Alam; Hossain, Ekhtear; Fajol, Abul; Akhand, Anwarul Azim; Himeno, Seiichiro; Hossain, Khaled

    2010-12-01

    The present study was undertaken to evaluate the protective effect of turmeric powder on arsenic toxicity through mice model. Swiss albino male mice were divided into four groups. The first group was used as control, while groups 2, 3, and 4 were treated with turmeric powder (T, 50 mg/kg body weight/day), sodium arsenite (Sa, 10 mg/kg body weight/day) and turmeric plus Sa (T+Sa), respectively. Results showed that oral administration of Sa reduced the weight gain of the mice compared to the control group and food supplementation of turmeric prevented the reduction of weight gain. Turmeric abrogated the Sa-induced elevation of serum urea, glucose, triglyceride (TG) level and alanine aminotransferase (ALT) activity except the activity of alkaline phosphatase (ALP). Turmeric also prevented the Sa-induced perturbation of serum butyryl cholinesterase activity (BChE). Therefore, ameliorating effect of turmeric on Sa-treated mice suggested the future application of turmeric to reduce or to prevent arsenic toxicity in human.

  3. Photosynthesis is induced in rice plants that associate with arbuscular mycorrhizal fungi and are grown under arsenate and arsenite stress.

    Science.gov (United States)

    de Andrade, Sara Adrian Lopez; Domingues, Adilson Pereira; Mazzafera, Paulo

    2015-09-01

    The metalloid arsenic (As) increases in agricultural soils because of anthropogenic activities and may have phytotoxic effects depending on the available concentrations. Plant performance can be improved by arbuscular mycorrhiza (AM) association under challenging conditions, such as those caused by excessive soil As levels. In this study, the influence of AM on CO2 assimilation, chlorophyll a fluorescence, SPAD-chlorophyll contents and plant growth was investigated in rice plants exposed to arsenate (AsV) or arsenite (AsIII) and inoculated or not with Rhizophagus irregularis. Under AsV and AsIII exposure, AM rice plants had greater biomass accumulation and relative chlorophyll content, increased water-use efficiency, higher carbon assimilation rate and higher stomatal conductance and transpiration rates than non-AM rice plants did. Chlorophyll a fluorescence analysis revealed significant differences in the response of AM-associated and -non-associated plants to As. Mycorrhization increased the maximum and actual quantum yields of photosystem II and the electron transport rate, maintaining higher values even under As exposure. Apart from the negative effects of AsV and AsIII on the photosynthetic rates and PSII efficiency in rice leaves, taken together, these results indicate that AM is able to sustain higher rice photosynthesis efficiency even under elevated As concentrations, especially when As is present as AsV.

  4. Tissue distribution and subcellular binding of arsenic in marmoset monkeys after injection of /sup 74/As-arsenite

    Energy Technology Data Exchange (ETDEWEB)

    Vahter, M.; Marafante, E.; Lindgren, A.; Dencker, L.

    1982-10-01

    The distribution and retention of arsenic in Marmoset monkeys, given /sup 74/As-arsenite (0.4 mg As/kg body weight) i.p., were studied by means of whole-body autoradiography and determination of /sup 74/As-levels in tissues and excreta. Only about 30% of the dose was eliminated over 4 days, mainly via the kidneys. All of the arsenic in urine and tissues was found to be in inorganic form. Tissues with highest accumulation 4 days after dosing were liver (about 20% of the dose), squamous epithelium of oral cavity and esophagus, kidney cortex, skin, testes (mainly tubuli seminiferi) and intestinal wall. As a rule the major part of the arsenic in these tissues was found to be associated with cellular organelles. In the liver about 50% of the arsenic was strongly bound to the rough microsomal membranes. In the soluble extract of tissues, arsenic was mainly associated with macromolecular constituents. The long retention time and tight binding of arsenic could partly be explained by the fact that no biotransformation into methylated arsenic occurred, in contrast to all other species studied so far.

  5. Characterisation of the arsenic resistance genes in Bacillus sp. UWC isolated from maturing fly ash acid mine drainage neutralised solids

    Directory of Open Access Journals (Sweden)

    Donald Cowan

    2010-03-01

    Full Text Available An arsenic resistant Bacillus sp. UWC was isolated from fly ash acid mine drainage (FA-AMD neutralised solids. A genomic library was prepared and screened in an arsenic sensitive mutant Escherichia coli strain for the presence of arsenic resistance (ars genes. Sequence analysis of a clone conferring resistance to both sodium arsenite and sodium arsenate revealed homologues to the arsR (regulatory repressor, arsB (membrane located arsenite pump, arsC (arsenate reductase, arsD (second regulatory repressor and a metallochaperone and arsA (ATPase genes from known arsenic resistance operons. The Bacillus sp. UWC arsRBCDA genes were shown to be arranged in an unusual manner with the arsDA genes immediately downstream of arsC.

  6. Unique role of NADPH oxidase 5 in oxidative stress in human renal proximal tubule cells

    Directory of Open Access Journals (Sweden)

    Peiying Yu

    2014-01-01

    Full Text Available NADPH oxidases are the major sources of reactive oxygen species in cardiovascular, neural, and kidney cells. The NADPH oxidase 5 (NOX5 gene is present in humans but not rodents. Because Nox isoforms in renal proximal tubules (RPTs are involved in the pathogenesis of hypertension, we tested the hypothesis that NOX5 is differentially expressed in RPT cells from normotensive (NT and hypertensive subjects (HT. We found that NOX5 mRNA, total NOX5 protein, and apical membrane NOX5 protein were 4.2±0.7-fold, 5.2±0.7-fold, and 2.8±0.5-fold greater in HT than NT. Basal total NADPH oxidase activity was 4.5±0.2-fold and basal NOX5 activity in NOX5 immunoprecipitates was 6.2±0.2-fold greater in HT than NT (P=<0.001, n=6–14/group. Ionomycin increased total NOX and NOX5 activities in RPT cells from HT (P<0.01, n=4, ANOVA, effects that were abrogated by pre-treatment of the RPT cells with diphenylene-iodonium or superoxide dismutase. Silencing NOX5 using NOX5-siRNA decreased NADPH oxidase activity (−45.1±3.2% vs. mock-siRNA, n=6–8 in HT. D1-like receptor stimulation decreased NADPH oxidase activity to a greater extent in NT (−32.5±1.8% than HT (−14.8±1.8. In contrast to the marked increase in expression and activity of NOX5 in HT, NOX1 mRNA and protein were minimally increased in HT, relative to NT; total NOX2 and NOX4 proteins were not different between HT and NT, while the increase in apical RPT cell membrane NOX1, NOX2, and NOX4 proteins in HT, relative to NT, was much less than those observed with NOX5. Thus, we demonstrate, for the first time, that NOX5 is expressed in human RPT cells and to greater extent than the other Nox isoforms in HT than NT. We suggest that the increased expression of NOX5, which may be responsible for the increased oxidative stress in RPT cells in human essential hypertension, is caused, in part, by a defective renal dopaminergic system.

  7. Decrease in acrolein toxicity based on the decline of polyamine oxidases.

    Science.gov (United States)

    Uemura, Takeshi; Nakamura, Mizuho; Sakamoto, Akihiko; Suzuki, Takehiro; Dohmae, Naoshi; Terui, Yusuke; Tomitori, Hideyuki; Casero, Robert A; Kashiwagi, Keiko; Igarashi, Kazuei

    2016-10-01

    We have shown recently that acrolein is strongly involved in cell damage during brain infarction and chronic renal failure. To study the mechanism of acrolein detoxification, we tried to isolate Neuro2a cells with reduced sensitivity to acrolein toxicity (Neuro2a-ATD cells). In one cell line, Neuro2a-ATD1, the level of glutathione (GSH) was increased. We recently isolated a second cell line, Neuro2a-ATD2, and found that acrolein-producing enzymes [polyamine oxidases (PAO); i.e. acetylpolyamine oxidase (AcPAO), and spermine oxidase (SMO)] are reduced in this cell line due to changes at the level of transcription. In the Neuro2a-ATD2 cells, the IC50 of acrolein increased from 4.2 to 6.8μM, and the levels of FosB and C/EBPβ - transcription factors involved in the transcription of AcPAO and SMO genes - were reduced. Transfection of siRNAs for FosB and C/EBPβ reduced the levels of AcPAO and SMO, respectively. In addition, the synthesis of FosB and AcPAO was also decreased by siRNA for C/EBPβ, because C/EBPβ is one of the transcription factors for the FosB gene. It was also found that transfection of siRNA for C/EBPβ decreased SMO promoter activity in Neuro2a cells but not in ATD2 cells confirming that a decrease in C/EBPβ is involved in the reduced SMO activity in Neuro2a-ATD2 cells. Furthermore, transfection of the cDNA for AcPAO or SMO into Neuro2a cells increased the toxicity of acrolein. These results suggest that acrolein is mainly produced from polyamines by PAO.

  8. Lysyl oxidase-like and lysyl oxidase are present in the dermis and epidermis of a skin equivalent and in human skin and are associated to elastic fibers.

    Science.gov (United States)

    Noblesse, Emmanuelle; Cenizo, Valérie; Bouez, Charbel; Borel, Agnès; Gleyzal, Claudine; Peyrol, Simone; Jacob, Marie-Paule; Sommer, Pascal; Damour, Odile

    2004-03-01

    Elastic fiber formation involves the secretion of tropoelastin which is converted to insoluble elastin by cross-linking, initiated by the oxidative deamination of lysine residues by lysyl oxidase. Five lysyl oxidase genes have been discovered. This study deals with the expression of two isoforms, LOX and LOX-like (LOXL), in human foreskin and in a human skin-equivalent (SE) model that allows the formation of elastic fibers. In this model, keratinocytes are added to a dermal equivalent made of fibroblasts grown on a chitosan-cross-linked collagen-GAG matrix. LOX and LOXL were detected by immunohistochemistry in the dermis and the epidermis of both normal skin and in a SE. This expression was confirmed by in situ hybridization on the SE. LOX and LOXL expression patterns were confirmed in human skin. The ultrastructural localization of LOXL was indicative of its association with elastin-positive materials within the SE and human skin, though interaction with collagen could not be discarded. LOX was found on collagen fibers and could be associated with elastin-positive materials in the SE and human skin. LOXL and LOX were detected in keratinocytes where LOX was mainly expressed by differentiating keratinocytes, in contrast to LOXL that can be found in both proliferating and differentiating fibroblasts. These data favor a role for LOXL in elastic fiber formation, together with LOX, and within the epidermis where both enzymes should play a role in post-translational modification of yet unknown substrates.

  9. Existence of aa3-type ubiquinol oxidase as a terminal oxidase in sulfite oxidation of Acidithiobacillus thiooxidans.

    Science.gov (United States)

    Sugio, Tsuyoshi; Hisazumi, Tomohiro; Kanao, Tadayoshi; Kamimura, Kazuo; Takeuchi, Fumiaki; Negishi, Atsunori

    2006-07-01

    It was found that Acidithiobacillus thiooxidans has sulfite:ubiquinone oxidoreductase and ubiquinol oxidase activities in the cells. Ubiquinol oxidase was purified from plasma membranes of strain NB1-3 in a nearly homogeneous state. A purified enzyme showed absorption peaks at 419 and 595 nm in the oxidized form and at 442 and 605 nm in the reduced form. Pyridine ferrohaemochrome prepared from the enzyme showed an alpha-peak characteristic of haem a at 587 nm, indicating that the enzyme contains haem a as a component. The CO difference spectrum of ubiquinol oxidase showed two peaks at 428 nm and 595 nm, and a trough at 446 nm, suggesting the existence of an aa(3)-type cytochrome in the enzyme. Ubiquinol oxidase was composed of three subunits with apparent molecular masses of 57 kDa, 34 kDa, and 23 kDa. The optimum pH and temperature for ubiquinol oxidation were pH 6.0 and 30 degrees C. The activity was completely inhibited by sodium cyanide at 1.0 mM. In contrast, the activity was inhibited weakly by antimycin A(1) and myxothiazol, which are inhibitors of mitochondrial bc(1) complex. Quinone analog 2-heptyl-4-hydoroxyquinoline N-oxide (HOQNO) strongly inhibited ubiquinol oxidase activity. Nickel and tungstate (0.1 mM), which are used as a bacteriostatic agent for A. thiooxidans-dependent concrete corrosion, inhibited ubiquinol oxidase activity 100 and 70% respectively.

  10. Current status of NADPH oxidase research in cardiovascular pharmacology

    Directory of Open Access Journals (Sweden)

    Rodiño-Janeiro BK

    2013-07-01

    Full Text Available Bruno K Rodiño-Janeiro,1,2 Beatriz Paradela-Dobarro,1 María Isabel Castiñeiras-Landeira,1 Sergio Raposeiras-Roubín,1,3 José R González-Juanatey,1,3,4 Ezequiel Álvarez1,4 1Health Research Institute of Santiago de Compostela, Santiago de Compostela, Spain; 2European Molecular Biology Laboratory, Grenoble, France; 3Cardiology Department, University Clinic Hospital of Santiago de Compostela, Santiago de Compostela, Spain; 4Medicine Department, University of Santiago de Compostela, Santiago de Compostela, Spain Abstract: The implications of reactive oxygen species in cardiovascular disease have been known for some decades. Rationally, therapeutic antioxidant strategies combating oxidative stress have been developed, but the results of clinical trials have not been as good as expected. Therefore, to move forward in the design of new therapeutic strategies for cardiovascular disease based on prevention of production of reactive oxygen species, steps must be taken on two fronts, ie, comprehension of reduction-oxidation signaling pathways and the pathophysiologic roles of reactive oxygen species, and development of new, less toxic, and more selective nicotinamide adenine dinucleotide phosphate (NADPH oxidase inhibitors, to clarify both the role of each NADPH oxidase isoform and their utility in clinical practice. In this review, we analyze the value of NADPH oxidase as a therapeutic target for cardiovascular disease and the old and new pharmacologic agents or strategies to prevent NADPH oxidase activity. Some inhibitors and different direct or indirect approaches are available. Regarding direct NADPH oxidase inhibition, the specificity of NADPH oxidase is the focus of current investigations, whereas the chemical structure-activity relationship studies of known inhibitors have provided pharmacophore models with which to search for new molecules. From a general point of view, small-molecule inhibitors are preferred because of their hydrosolubility

  11. HIF-1α activation by intermittent hypoxia requires NADPH oxidase stimulation by xanthine oxidase.

    Science.gov (United States)

    Nanduri, Jayasri; Vaddi, Damodara Reddy; Khan, Shakil A; Wang, Ning; Makarenko, Vladislav; Semenza, Gregg L; Prabhakar, Nanduri R

    2015-01-01

    Hypoxia-inducible factor 1 (HIF-1) mediates many of the systemic and cellular responses to intermittent hypoxia (IH), which is an experimental model that simulates O2 saturation profiles occurring with recurrent apnea. IH-evoked HIF-1α synthesis and stability are due to increased reactive oxygen species (ROS) generated by NADPH oxidases, especially Nox2. However, the mechanisms by which IH activates Nox2 are not known. We recently reported that IH activates xanthine oxidase (XO) and the resulting increase in ROS elevates intracellular calcium levels. Since Nox2 activation requires increased intracellular calcium levels, we hypothesized XO-mediated calcium signaling contributes to Nox activation by IH. We tested this possibility in rat pheochromocytoma PC12 cells subjected to IH consisting alternating cycles of hypoxia (1.5% O2 for 30 sec) and normoxia (21% O2 for 5 min). Kinetic analysis revealed that IH-induced XO preceded Nox activation. Inhibition of XO activity either by allopurinol or by siRNA prevented IH-induced Nox activation, translocation of the cytosolic subunits p47phox and p67phox to the plasma membrane and their interaction with gp91phox. ROS generated by XO also contribute to IH-evoked Nox activation via calcium-dependent protein kinase C stimulation. More importantly, silencing XO blocked IH-induced upregulation of HIF-1α demonstrating that HIF-1α activation by IH requires Nox2 activation by XO.

  12. Heterologous expression of glucose oxidase in the yeast Kluyveromyces marxianus

    Directory of Open Access Journals (Sweden)

    Gombert Andreas K

    2010-01-01

    Full Text Available Abstract Background In spite of its advantageous physiological properties for bioprocess applications, the use of the yeast Kluyveromyces marxianus as a host for heterologous protein production has been very limited, in constrast to its close relative Kluyveromyces lactis. In the present work, the model protein glucose oxidase (GOX from Aspergillus niger was cloned into K. marxianus CBS 6556 and into K. lactis CBS 2359 using three different expression systems. We aimed at verifying how each expression system would affect protein expression, secretion/localization, post-translational modification, and biochemical properties. Results The highest GOX expression levels (1552 units of secreted protein per gram dry cell weight were achieved using an episomal system, in which the INU1 promoter and terminator were used to drive heterologous gene expression, together with the INU1 prepro sequence, which was employed to drive secretion of the enzyme. In all cases, GOX was mainly secreted, remaining either in the periplasmic space or in the culture supernatant. Whereas the use of genetic elements from Saccharomyces cerevisiae to drive heterologous protein expression led to higher expression levels in K. lactis than in K. marxianus, the use of INU1 genetic elements clearly led to the opposite result. The biochemical characterization of GOX confirmed the correct expression of the protein and showed that K. marxianus has a tendency to hyperglycosylate the protein, in a similar way as already observed for other yeasts, although this tendency seems to be smaller than the one of e.g. K. lactis and S. cerevisiae. Hyperglycosylation of GOX does not seem to affect its affinity for the substrate, nor its activity. Conclusions Taken together, our results indicate that K. marxianus is indeed a good host for the expression of heterologous proteins, not only for its physiologic