Sample records for basic helix-loop-helix protein-mediated

  1. Challenges in Targeting a Basic Helix-Loop-Helix Transcription Factor with Hydrocarbon-Stapled Peptides

    NARCIS (Netherlands)

    Edwards, Amanda L; Meijer, Dimphna H; Guerra, Rachel M; Molenaar, Remco J; Alberta, John A; Bernal, Federico; Bird, Gregory H; Stiles, Charles D; Walensky, Loren D


    Basic helix-loop-helix (bHLH) transcription factors play critical roles in organism development and disease by regulating cell proliferation and differentiation. Transcriptional activity, whether by bHLH homo- or heterodimerization, is dependent on protein-protein and protein-DNA interactions mediat

  2. Biochemical analysis of the basic helix-loop-helix transcription factor Olig2

    NARCIS (Netherlands)

    Meijer, D.H.M.


    The basic helix-loop-helix (bHLH) transcription factors oligodendrocyte transcription factor 1 (Olig1) and Olig2 are structurally similar and, to a first approximation, coordinately expressed in the developing CNS and postnatal brain. Notwithstanding these similarities, it was apparent from early on

  3. A triple helix-loop-helix/basic helix-loop-helix cascade controls cell elongation downstream of multiple hormonal and environmental signaling pathways in Arabidopsis. (United States)

    Bai, Ming-Yi; Fan, Min; Oh, Eunkyoo; Wang, Zhi-Yong


    Environmental and endogenous signals, including light, temperature, brassinosteroid (BR), and gibberellin (GA), regulate cell elongation largely by influencing the expression of the paclobutrazol-resistant (PRE) family helix-loop-helix (HLH) factors, which promote cell elongation by interacting antagonistically with another HLH factor, IBH1. However, the molecular mechanism by which PREs and IBH1 regulate gene expression has remained unknown. Here, we show that IBH1 interacts with and inhibits a DNA binding basic helix-loop-helix (bHLH) protein, HBI1, in Arabidopsis thaliana. Overexpression of HBI1 increased hypocotyl and petiole elongation, whereas dominant inactivation of HBI1 and its homologs caused a dwarf phenotype, indicating that HBI1 is a positive regulator of cell elongation. In vitro and in vivo experiments showed that HBI1 directly bound to the promoters and activated two EXPANSIN genes encoding cell wall-loosening enzymes; HBI1's DNA binding and transcriptional activities were inhibited by IBH1, but the inhibitory effects of IBH1 were abolished by PRE1. The results indicate that PREs activate the DNA binding bHLH factor HBI1 by sequestering its inhibitor IBH1. Altering each of the three factors affected plant sensitivities to BR, GA, temperature, and light. Our study demonstrates that PREs, IBH1, and HBI1 form a chain of antagonistic switches that regulates cell elongation downstream of multiple external and endogenous signals.

  4. A Classification of Basic Helix-Loop-Helix Transcription Factors of Soybean

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    Karen A. Hudson


    Full Text Available The complete genome sequence of soybean allows an unprecedented opportunity for the discovery of the genes controlling important traits. In particular, the potential functions of regulatory genes are a priority for analysis. The basic helix-loop-helix (bHLH family of transcription factors is known to be involved in controlling a wide range of systems critical for crop adaptation and quality, including photosynthesis, light signalling, pigment biosynthesis, and seed pod development. Using a hidden Markov model search algorithm, 319 genes with basic helix-loop-helix transcription factor domains were identified within the soybean genome sequence. These were classified with respect to their predicted DNA binding potential, intron/exon structure, and the phylogeny of the bHLH domain. Evidence is presented that the vast majority (281 of these 319 soybean bHLH genes are expressed at the mRNA level. Of these soybean bHLH genes, 67% were found to exist in two or more homeologous copies. This dataset provides a framework for future studies on bHLH gene function in soybean. The challenge for future research remains to define functions for the bHLH factors encoded in the soybean genome, which may allow greater flexibility for genetic selection of growth and environmental adaptation in this widely grown crop.

  5. Mutations in TWIST, a basic helix-loop-helix transcription factor, in Saethre-Chotzen syndrome. (United States)

    Howard, T D; Paznekas, W A; Green, E D; Chiang, L C; Ma, N; Ortiz de Luna, R I; Garcia Delgado, C; Gonzalez-Ramos, M; Kline, A D; Jabs, E W


    Saethre-Chotzen syndrome is one of the most common autosomal dominant disorders of craniosynostosis in humans and is characterized by craniofacial and limb anomalies. The locus for Saethre-Chotzen syndrome maps to chromosome 7p21-p22. We have evaluated TWIST, a basic helix-loop-helix transcription factor, as a candidate gene for this condition because its expression pattern and mutant phenotypes in Drosophila and mouse are consistent with the Saethre-Chotzen phenotype. We mapped TWIST to human chromosome 7p21-p22 and mutational analysis reveals nonsense, missense, insertion and deletion mutations in patients. These mutations occur within the basic DNA binding, helix I and loop domains, or result in premature termination of the protein. Studies in Drosophila indicate that twist may affect the transcription of fibroblast growth factor receptors (FGFRs), another gene family implicated in human craniosynostosis. The emerging cascade of molecular components involved in craniofacial and limb development now includes TWIST, which may function as an upstream regulator of FGFRs.

  6. Challenges in Targeting a Basic Helix-Loop-Helix Transcription Factor with Hydrocarbon-Stapled Peptides. (United States)

    Edwards, Amanda L; Meijer, Dimphna H; Guerra, Rachel M; Molenaar, Remco J; Alberta, John A; Bernal, Federico; Bird, Gregory H; Stiles, Charles D; Walensky, Loren D


    Basic helix-loop-helix (bHLH) transcription factors play critical roles in organism development and disease by regulating cell proliferation and differentiation. Transcriptional activity, whether by bHLH homo- or heterodimerization, is dependent on protein-protein and protein-DNA interactions mediated by α-helices. Thus, α-helical decoys have been proposed as potential targeted therapies for pathologic bHLH transcription. Here, we developed a library of stabilized α-helices of OLIG2 (SAH-OLIG2) to test the capacity of hydrocarbon-stapled peptides to disrupt OLIG2 homodimerization, which drives the development and chemoresistance of glioblastoma multiforme, one of the deadliest forms of human brain cancer. Although stapling successfully reinforced the α-helical structure of bHLH constructs of varying length, sequence-specific dissociation of OLIG2 dimers from DNA was not achieved. Re-evaluation of the binding determinants for OLIG2 self-association and stability revealed an unanticipated role of the C-terminal domain. These data highlight potential pitfalls in peptide-based targeting of bHLH transcription factors given the liabilities of their positively charged amino acid sequences and multifactorial binding determinants.

  7. Iron-binding E3 ligase mediates iron response in plants by targeting basic helix-loop-helix transcription factors. (United States)

    Selote, Devarshi; Samira, Rozalynne; Matthiadis, Anna; Gillikin, Jeffrey W; Long, Terri A


    Iron uptake and metabolism are tightly regulated in both plants and animals. In Arabidopsis (Arabidopsis thaliana), BRUTUS (BTS), which contains three hemerythrin (HHE) domains and a Really Interesting New Gene (RING) domain, interacts with basic helix-loop-helix transcription factors that are capable of forming heterodimers with POPEYE (PYE), a positive regulator of the iron deficiency response. BTS has been shown to have E3 ligase capacity and to play a role in root growth, rhizosphere acidification, and iron reductase activity in response to iron deprivation. To further characterize the function of this protein, we examined the expression pattern of recombinant ProBTS::β-GLUCURONIDASE and found that it is expressed in developing embryos and other reproductive tissues, corresponding with its apparent role in reproductive growth and development. Our findings also indicate that the interactions between BTS and PYE-like (PYEL) basic helix-loop-helix transcription factors occur within the nucleus and are dependent on the presence of the RING domain. We provide evidence that BTS facilitates 26S proteasome-mediated degradation of PYEL proteins in the absence of iron. We also determined that, upon binding iron at the HHE domains, BTS is destabilized and that this destabilization relies on specific residues within the HHE domains. This study reveals an important and unique mechanism for plant iron homeostasis whereby an E3 ubiquitin ligase may posttranslationally control components of the transcriptional regulatory network involved in the iron deficiency response.

  8. A Dual Mechanism Controls Nuclear Localization in the Atypical Basic-Helix-Loop-Helix Protein PAR1 of Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    Anahit Galstyan; Jordi Bou-Torrent; Irma Roig-Villanova; Jaime F. Martínez-García


    PAR1 is an atypical basic-helix-loop-helix (bHLH) protein that negatively regulates the shade avoidance syndrome in Arabidopsis thaliana acting as a transcriptional cofactor.Consistently with this function,PAR1 has to be in the nucleus to display biological activity.Previous structure-function analyses revealed that the N-terminal region of PAR1 drives the protein to the nucleus.However,truncated forms of PAR1 lacking this region still display biological activity,implying that PAR1 has additional mechanisms to localize into the nucleus.In this work,we compared the primary structure of PAR1 and various related and unrelated plant bHLH proteins,which led us to suggest that PAR1 contains a non-canonical nuclear localization signal (NLS) in the N-terminal region.By overexpressing truncated and mutated derivatives of PAR1,we have also investigated the importance of other regions of PAR1,such as the acidic and the extended HLH dimerization domains,for its nuclear localization.We found that,in the absence of the N-terminal region,a functional HLH domain is required for nuclear localization.Our results suggest the existence of a dual mechanism for PAR1 nuclear localization:(1) one mediated by the N-terminal non-consensus NLS and (2) a second one that involves interaction with other proteins via the dimerization domain.

  9. Caught red-handed: Rc encodes a basic helix-loop-helix protein conditioning red pericarp in rice. (United States)

    Sweeney, Megan T; Thomson, Michael J; Pfeil, Bernard E; McCouch, Susan


    Rc is a domestication-related gene required for red pericarp in rice (Oryza sativa). The red grain color is ubiquitous among the wild ancestors of O. sativa, in which it is closely associated with seed shattering and dormancy. Rc encodes a basic helix-loop-helix (bHLH) protein that was fine-mapped to an 18.5-kb region on rice chromosome 7 using a cross between Oryza rufipogon (red pericarp) and O. sativa cv Jefferson (white pericarp). Sequencing of the alleles from both mapping parents as well as from two independent genetic stocks of Rc revealed that the dominant red allele differed from the recessive white allele by a 14-bp deletion within exon 6 that knocked out the bHLH domain of the protein. A premature stop codon was identified in the second mutant stock that had a light red pericarp. RT-PCR experiments confirmed that the Rc gene was expressed in both red- and white-grained rice but that a shortened transcript was present in white varieties. Phylogenetic analysis, supported by comparative mapping in rice and maize (Zea mays), showed that Rc, a positive regulator of proanthocyanidin, is orthologous with INTENSIFIER1, a negative regulator of anthocyanin production in maize, and is not in the same clade as rice bHLH anthocyanin regulators.

  10. Phylogeny, Functional Annotation, and Protein Interaction Network Analyses of the Xenopus tropicalis Basic Helix-Loop-Helix Transcription Factors

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    Wuyi Liu


    Full Text Available The previous survey identified 70 basic helix-loop-helix (bHLH proteins, but it was proved to be incomplete, and the functional information and regulatory networks of frog bHLH transcription factors were not fully known. Therefore, we conducted an updated genome-wide survey in the Xenopus tropicalis genome project databases and identified 105 bHLH sequences. Among the retrieved 105 sequences, phylogenetic analyses revealed that 103 bHLH proteins belonged to 43 families or subfamilies with 46, 26, 11, 3, 15, and 4 members in the corresponding supergroups. Next, gene ontology (GO enrichment analyses showed 65 significant GO annotations of biological processes and molecular functions and KEGG pathways counted in frequency. To explore the functional pathways, regulatory gene networks, and/or related gene groups coding for Xenopus tropicalis bHLH proteins, the identified bHLH genes were put into the databases KOBAS and STRING to get the signaling information of pathways and protein interaction networks according to available public databases and known protein interactions. From the genome annotation and pathway analysis using KOBAS, we identified 16 pathways in the Xenopus tropicalis genome. From the STRING interaction analysis, 68 hub proteins were identified, and many hub proteins created a tight network or a functional module within the protein families.

  11. A genome-wide survey on basic helix-loop-helix transcription factors in rat and mouse. (United States)

    Zheng, Xiaodong; Zheng, X; Wang, Yong; Wang, Y; Yao, Qin; Yao, Q; Yang, Zhe; Yang, Z; Chen, Keping; Chen, K


    The basic helix-loop-helix (bHLH) proteins play essential roles in a wide range of developmental processes in higher organisms. bHLH family members have been identified in over 20 organisms, including nematode, fruit fly, and human. Our study identified 114 rat and 14 additional mouse bHLH members in rat and mouse genomes, respectively. Phylogenetic analyses revealed that both rat and mouse had 49, 26, 15, 4, 12, and 4 bHLH members in groups A, B, C, D, E, and F, respectively. Only the rat Mxi1 gene has two copies in the genome. All other rat bHLH genes and all mouse bHLH genes are single-copy genes. The chromosomal distribution pattern of mouse, rat, and human bHLH genes suggests the emergence of some bHLH genes through gene duplication, which probably happened at least before the divergence of vertebrates from invertebrates. The present study provides useful information for future studies using rat as a model animal for mammalian development.

  12. Heterogeneity of myotubes generated by the MyoD and E12 basic helix-loop-helix transcription factors in otherwise non-differentiation growth conditions. (United States)

    Grubišić, Vladimir; Gottipati, Manoj K; Stout, Randy F; Grammer, J Robert; Parpura, Vladimir


    We used a synthetic biology approach to produce myotubes from mammalian C2C12 myoblasts in non-differentiation growth conditions using the expression of basic helix-loop-helix transcription factors, MyoD and E12, in various combinations and configurations. Our approach not only recapitulated the basics of muscle development and physiology, as the obtained myotubes showed qualities similar to those seen in striated muscle fibers in vivo, but also allowed for the synthesis of populations of myotubes which assumed distinct morphology, myofibrillar development and Ca(2+) dynamics. This fashioned class of biomaterials is suitable for the building blocks of soft actuators in micro-scale biomimetic robotics. This production line strategy can be embraced in reparative medicine as synthetic human myotubes with predetermined morphological/functional properties could be obtained using this very approach. This methodology can be adopted beyond striated muscle for the engineering of other tissue components/cells whose differentiation is governed by the principles of basic helix-loop-helix transcription factors, as in the case, for example, of neural or immune cell types.

  13. Fluorescence Resonance Energy Transfer (FRET as a method to calculate the dimerization strength of basic Helix-Loop-Helix (bHLH proteins

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    Centonze Victoria E.


    Full Text Available Post-translational modifications such as phosphorylation play a vital role in the regulation of protein function. In our study of the basic Helix-loop-Helix (bHLH transcription factor HAND1, we show that HAND1 is phosphorylated during the trophoblast giant cell differentiation on residues residing in Helix I of the bHLH domain. Our hypothesis is that these modifications result in changes in HAND1 dimerization affinities with other bHLH factors. To test this idea, we employed FRET to measure the protein-protein interactions of HAND1 and HAND1 point mutants in HEK293 cells using YFP and CFP fusion proteins and laser scanning confocal microscopy.

  14. Molecular characterization of cold-responsive basic helix-loop-helix transcription factors MabHLHs that interact with MaICE1 in banana fruit. (United States)

    Peng, Huan-Huan; Shan, Wei; Kuang, Jian-Fei; Lu, Wang-Jin; Chen, Jian-Ye


    Basic helix-loop-helix (bHLH) transcription factors (TFs) are ubiquitously involved in the response of higher plants to various abiotic stresses. However, little is known about bHLH TFs involved in the cold stress response in economically important fruits. Here, five novel full-length bHLH genes, designated as MabHLH1-MabHLH5, were isolated and characterized from banana fruit. Gene expression profiles revealed that MabHLH1/2/4 were induced by cold stress and methyl jasmonate (MeJA) treatment. Transient assays in tobacco BY2 protoplasts showed that MabHLH1/2/4 promoters were activated by cold stress and MeJA treatments. Moreover, protein-protein interaction analysis demonstrated that MabHLH1/2/4 not only physically interacted with each other to form hetero-dimers in the nucleus, but also interacted with an important upstream component of cold signaling MaICE1, with different interaction domains at their N-terminus. These results indicate that banana fruit cold-responsive MabHLHs may form a big protein complex in the nucleus with MaICE1. Taken together, our findings advance our understanding of the possible involvement of bHLH TFs in the regulatory network of ICE-CBF cold signaling pathway.

  15. Mutations within or upstream of the basic helix-loop-helix domain of the TWIST gene are specific to Saethre-Chotzen syndrome. (United States)

    El Ghouzzi, V; Lajeunie, E; Le Merrer, M; Cormier-Daire, V; Renier, D; Munnich, A; Bonaventure, J


    Saethre-Chotzen syndrome (ACS III) is an autosomal dominant craniosynostosis syndrome recently ascribed to mutations in the TWIST gene, a basic helix-loop-helix (b-HLH) transcription factor regulating head mesenchyme cell development during cranial neural tube formation in mouse. Studying a series of 22 unrelated ACS III patients, we have found TWIST mutations in 16/22 cases. Interestingly, these mutations consistently involved the b-HLH domain of the protein. Indeed, mutant genotypes included frameshift deletions/insertions, nonsense and missense mutations, either truncating or disrupting the b-HLH motif of the protein. This observation gives additional support to the view that most ACS III cases result from loss-of-function mutations at the TWIST locus. The P250R recurrent FGFR 3 mutation was found in 2/22 cases presenting mild clinical manifestations of the disease but 4/22 cases failed to harbour TWIST or FGFR 3 mutations. Clinical re-examination of patients carrying TWIST mutations failed to reveal correlations between the mutant genotype and severity of the phenotype. Finally, since no TWIST mutations were detected in 40 cases of isolated coronal craniosynostosis, the present study suggests that TWIST mutations are specific to Saethre-Chotzen syndrome.

  16. Elevated endogenous expression of the dominant negative basic helix-loop-helix protein ID1 correlates with significant centrosome abnormalities in human tumor cells

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    Gutmann Anja


    Full Text Available Abstract Background ID proteins are dominant negative inhibitors of basic helix-loop-helix transcription factors that have multiple functions during development and cellular differentiation. Ectopic (over-expression of ID1 extends the lifespan of primary human epithelial cells. High expression levels of ID1 have been detected in multiple human malignancies, and in some have been correlated with unfavorable clinical prognosis. ID1 protein is localized at the centrosomes and forced (over-expression of ID1 results in errors during centrosome duplication. Results Here we analyzed the steady state expression levels of the four ID-proteins in 18 tumor cell lines and assessed the number of centrosome abnormalities. While expression of ID1, ID2, and ID3 was detected, we failed to detect protein expression of ID4. Expression of ID1 correlated with increased supernumerary centrosomes in most cell lines analyzed. Conclusions This is the first report that shows that not only ectopic expression in tissue culture but endogenous levels of ID1 modulate centrosome numbers. Thus, our findings support the hypothesis that ID1 interferes with centrosome homeostasis, most likely contributing to genomic instability and associated tumor aggressiveness.

  17. Basic helix-loop-helix transcription factor Bmsage is involved in regulation of fibroin H-chain gene via interaction with SGF1 in Bombyx mori. (United States)

    Zhao, Xiao-Ming; Liu, Chun; Li, Qiong-Yan; Hu, Wen-Bo; Zhou, Meng-Ting; Nie, Hong-Yi; Zhang, Yin-Xia; Peng, Zhang-Chuan; Zhao, Ping; Xia, Qing-You


    Silk glands are specialized in the synthesis of several secretory proteins. Expression of genes encoding the silk proteins in Bombyx mori silk glands with strict territorial and developmental specificities is regulated by many transcription factors. In this study, we have characterized B. mori sage, which is closely related to sage in the fruitfly Drosophila melanogaster. It is termed Bmsage; it encodes transcription factor Bmsage, which belongs to the Mesp subfamily, containing a basic helix-loop-helix motif. Bmsage transcripts were detected specifically in the silk glands of B. mori larvae through RT-PCR analysis. Immunoblotting analysis confirmed the Bmsage protein existed exclusively in B. mori middle and posterior silk gland cells. Bmsage has a low level of expression in the 4th instar molting stages, which increases gradually in the 5th instar feeding stages and then declines from the wandering to the pupation stages. Quantitative PCR analysis suggested the expression level of Bmsage in a high silk strain was higher compared to a lower silk strain on day 3 of the larval 5th instar. Furthermore, far western blotting and co-immunoprecipitation assays showed the Bmsage protein interacted with the fork head transcription factor silk gland factor 1 (SGF1). An electrophoretic mobility shift assay showed the complex of Bmsage and SGF1 proteins bound to the A and B elements in the promoter of fibroin H-chain gene(fib-H), respectively. Luciferase reporter gene assays confirmed the complex of Bmsage and SGF1 proteins increased the expression of fib-H. Together, these results suggest Bmsage is involved in the regulation of the expression of fib-H by being together with SGF1 in B. mori PSG cells.

  18. A genome-wide identification and analysis of the basic helix-loop-helix transcription factors in the ponerine ant, Harpegnathos saltator

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    Liu Ake


    Full Text Available Abstract Background The basic helix-loop-helix (bHLH transcription factors and their homologs form a superfamily that plays essential roles in transcriptional networks of multiple developmental processes. bHLH family members have been identified in over 20 organisms, including fruit fly, zebrafish, human and mouse. Result In this study, we conducted a genome-wide survey for bHLH sequences, and identified 57 bHLH sequences encoded in complete genome sequence of the ponerine ant, Harpegnathos saltator. Phylogenetic analysis of the bHLH domain sequences classified these genes into 38 bHLH families with 23, 14, 10, 1, 8 and 1 members in group A, B, C, D, E and F, respectively. The number of PabHLHs (ponerine ant bHLHs with introns is higher than many other insect species, and they are found to have introns with average lengths only inferior to those of pea aphid. In addition, two H. saltator bHLHs named PaCrp1 and PaSide locate on two separate contigs in the genome. Conclusions A putative full set of PabHLH genes is comparable with other insect species and genes encoding Oligo, MyoRb and Figα were not found in genomes of all insect species of which bHLH family members have been identified. Moreover, in-family phylogenetic analyses indicate that the PabHLH genes are more closely related with Apis mellifera than others. The present study will serve as a solid foundation for further investigations into the structure and function of bHLH proteins in the regulation of H. saltator development.

  19. Intermolecular recognition revealed by the complex structure of human CLOCK-BMAL1 basic helix-loop-helix domains with E-box DNA

    Institute of Scientific and Technical Information of China (English)

    Zixi Wang; Yaling Wu; Lanfen Li; Xiao-Dong Su


    CLOCK (circadian locomotor output cycles kaput) and BMAL1 (brain and muscle ARNT-like 1) are both transcription factors of the circadian core loop in mammals.Recently published mouse CLOCK-BMAL1 bHLH (basic helix-loop-helix)-PAS (period-ARNT-single-minded) complex structure sheds light on the mechanism for heterodimer formation,but the structural details of the protein-DNA recognition mechanisms remain elusive.Here we have elucidated the crystal structure of human CLOCK-BMAL1 bHLH domains bound to a canonical E-box DNA.We demonstrate that CLOCK and BMAL1 bHLH domains can be mutually selected,and that hydrogen-bonding networks mediate their E-box recognition.We identified a hydrophobic contact between BMAL1 Ile80 and a fianking thymine nucleotide,suggesting that CLOCK-BMAL1 actually reads 7-bp DNA and not the previously believed 6-bp DNA.To find potential non-canonical E-boxes that could be recognized by CLOCK-BMAL1,we constructed systematic single-nucleotide mutations on the E-box and measured their relevant affinities.We defined two non-canonical E-box patterns with high affinities,AACGTGA and CATGTGA,in which the flanking A7-T7' base pair is indispensable for recognition.These results will help us to identify functional CLOCK-BMAL1-binding sites in vivo and to search for clock-controlled genes.Furthermore,we assessed the inhibitory role of potential phosphorylation sites in bHLH regions.We found that the phospho-mimicking mutation on BMAL1 Ser78 could efficiently block DNA binding as well as abolish normal circadian oscillation in cells.We propose that BMAL1 Ser78 should be a key residue mediating input signal-regulated transcriptional inhibition for external cues to entrain the circadian clock by kinase cascade.

  20. Functional diversity of human basic helix-loop-helix transcription factor TCF4 isoforms generated by alternative 5' exon usage and splicing.

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    Mari Sepp

    Full Text Available BACKGROUND: Transcription factor 4 (TCF4 alias ITF2, E2-2, ME2 or SEF2 is a ubiquitous class A basic helix-loop-helix protein that binds to E-box DNA sequences (CANNTG. While involved in the development and functioning of many different cell types, recent studies point to important roles for TCF4 in the nervous system. Specifically, human TCF4 gene is implicated in susceptibility to schizophrenia and TCF4 haploinsufficiency is the cause of the Pitt-Hopkins mental retardation syndrome. However, the structure, expression and coding potential of the human TCF4 gene have not been described in detail. PRINCIPAL FINDINGS: In the present study we used human tissue samples to characterize human TCF4 gene structure and TCF4 expression at mRNA and protein level. We report that although widely expressed, human TCF4 mRNA expression is particularly high in the brain. We demonstrate that usage of numerous 5' exons of the human TCF4 gene potentially yields in TCF4 protein isoforms with 18 different N-termini. In addition, the diversity of isoforms is increased by alternative splicing of several internal exons. For functional characterization of TCF4 isoforms, we overexpressed individual isoforms in cultured human cells. Our analysis revealed that subcellular distribution of TCF4 isoforms is differentially regulated: Some isoforms contain a bipartite nuclear localization signal and are exclusively nuclear, whereas distribution of other isoforms relies on heterodimerization partners. Furthermore, the ability of different TCF4 isoforms to regulate E-box controlled reporter gene transcription is varied depending on whether one or both of the two TCF4 transcription activation domains are present in the protein. Both TCF4 activation domains are able to activate transcription independently, but act synergistically in combination. CONCLUSIONS: Altogether, in this study we have described the inter-tissue variability of TCF4 expression in human and provided evidence

  1. OsbHLH148, a basic helix-loop-helix protein, interacts with OsJAZ proteins in a jasmonate signaling pathway leading to drought tolerance in rice. (United States)

    Seo, Ju-Seok; Joo, Joungsu; Kim, Min-Jeong; Kim, Yeon-Ki; Nahm, Baek Hie; Song, Sang Ik; Cheong, Jong-Joo; Lee, Jong Seob; Kim, Ju-Kon; Choi, Yang Do


    Jasmonates play important roles in development, stress responses and defense in plants. Here, we report the results of a study using a functional genomics approach that identified a rice basic helix-loop-helix domain gene, OsbHLH148, that conferred drought tolerance as a component of the jasmonate signaling module in rice. OsbHLH148 transcript levels were rapidly increased by treatment with methyl jasmonate (MeJA) or abscisic acid, and abiotic stresses including dehydration, high salinity, low temperature and wounding. Transgenic over-expression of OsbHLH148 in rice confers plant tolerance to drought stress. Expression profiling followed by DNA microarray and RNA gel-blot analyses of transgenic versus wild-type rice identified genes that are up-regulated by OsbHLH148 over-expression. These include OsDREB and OsJAZ genes that are involved in stress responses and the jasmonate signaling pathway, respectively. OsJAZ1, a rice ZIM domain protein, interacted with OsbHLH148 in yeast two-hybrid and pull-down assays, but it interacted with the putative OsCOI1 only in the presence of coronatine. Furthermore, the OsJAZ1 protein was degraded by rice and Arabidopsis extracts in the presence of coronatine, and its degradation was inhibited by MG132, a 26S proteasome inhibitor, suggesting 26S proteasome-mediated degradation of OsJAZ1 via the SCF(OsCOI1) complex. The transcription level of OsJAZ1 increased upon exposure of rice to MeJA. These results show that OsJAZ1 could act as a transcriptional regulator of the OsbHLH148-related jasmonate signaling pathway leading to drought tolerance. Thus, our study suggests that OsbHLH148 acts on an initial response of jasmonate-regulated gene expression toward drought tolerance, constituting the OsbHLH148-OsJAZ-OsCOI1 signaling module in rice.

  2. Ectopic expression of a basic helix-loop-helix gene transactivates parallel pathways of proanthocyanidin biosynthesis. structure, expression analysis, and genetic control of leucoanthocyanidin 4-reductase and anthocyanidin reductase genes in Lotus corniculatus. (United States)

    Paolocci, Francesco; Robbins, Mark P; Madeo, Laura; Arcioni, Sergio; Martens, Stefan; Damiani, Francesco


    Proanthocyanidins (PAs) are plant secondary metabolites and are composed primarily of catechin and epicatechin units in higher plant species. Due to the ability of PAs to bind reversibly with plant proteins to improve digestion and reduce bloat, engineering this pathway in leaves is a major goal for forage breeders. Here, we report the cloning and expression analysis of anthocyanidin reductase (ANR) and leucoanthocyanidin 4-reductase (LAR), two genes encoding enzymes committed to epicatechin and catechin biosynthesis, respectively, in Lotus corniculatus. We show the presence of two LAR gene families (LAR1 and LAR2) and that the steady-state levels of ANR and LAR1 genes correlate with the levels of PAs in leaves of wild-type and transgenic plants. Interestingly, ANR and LAR1, but not LAR2, genes produced active proteins following heterologous expression in Escherichia coli and are affected by the same basic helix-loop-helix transcription factor that promotes PA accumulation in cells of palisade and spongy mesophyll. This study provides direct evidence that the same subclass of transcription factors can mediate the expression of the structural genes of both branches of PA biosynthesis.

  3. A single amino acid substitution in IIIf subfamily of basic helix-loop-helix transcription factor AtMYC1 leads to trichome and root hair patterning defects by abolishing its interaction with partner proteins in Arabidopsis. (United States)

    Zhao, Hongtao; Wang, Xiaoxue; Zhu, Dandan; Cui, Sujuan; Li, Xia; Cao, Ying; Ma, Ligeng


    Plant trichomes and root hairs are powerful models for the study of cell fate determination. In Arabidopsis thaliana, trichome and root hair initiation requires a combination of three groups of proteins, including the WD40 repeat protein transparent TESTA GLABRA1 (TTG1), R2R3 repeat MYB protein GLABRA1 (GL1), or werewolf (WER) and the IIIf subfamily of basic helix-loop-helix (bHLH) protein GLABRA3 (GL3) or enhancer of GLABRA3 (EGL3). The bHLH component acts as a docking site for TTG1 and MYB proteins. Here, we isolated a mutant showing defects in trichome and root hair patterning that carried a point mutation (R173H) in AtMYC1 that encodes the fourth member of IIIf bHLH family protein. Genetic analysis revealed partial redundant yet distinct function between AtMYC1 and GL3/EGL3. GLABRA2 (GL2), an important transcription factor involved in trichome and root hair control, was down-regulated in Atmyc1 plants, suggesting the requirement of AtMYC1 for appropriate GL2 transcription. Like its homologs, AtMYC1 formed a complex with TTG1 and MYB proteins but did not dimerized. In addition, the interaction of AtMYC1 with MYB proteins and TTG1 was abrogated by the R173H substitution in Atmyc1-1. We found that this amino acid (Arg) is conserved in the AtMYC1 homologs GL3/EGL3 and that it is essential for their interaction with MYB proteins and for their proper functions. Our findings indicate that AtMYC1 is an important regulator of trichome and root hair initiation, and they reveal a novel amino acid necessary for protein-protein interactions and gene function in IIIf subfamily bHLH transcription factors.

  4. The neurogenic basic helix-loop-helix transcription factor NeuroD6 enhances mitochondrial biogenesis and bioenergetics to confer tolerance of neuronal PC12-NeuroD6 cells to the mitochondrial stressor rotenone

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, Kristin Kathleen; Uittenbogaard, Martine [Department of Anatomy and Regenerative Biology, George Washington University Medical Center, Washington, DC (United States); Chiaramello, Anne, E-mail: [Department of Anatomy and Regenerative Biology, George Washington University Medical Center, Washington, DC (United States)


    The fundamental question of how and which neuronal specific transcription factors tailor mitochondrial biogenesis and bioenergetics to the need of developing neuronal cells has remained largely unexplored. In this study, we report that the neurogenic basic helix-loop-helix transcription factor NeuroD6 possesses mitochondrial biogenic properties by amplifying the mitochondrial DNA content and TFAM expression levels, a key regulator for mitochondrial biogenesis. NeuroD6-mediated increase in mitochondrial biogenesis in the neuronal progenitor-like PC12-NEUROD6 cells is concomitant with enhanced mitochondrial bioenergetic functions, including increased expression levels of specific subunits of respiratory complexes of the electron transport chain, elevated mitochondrial membrane potential and ATP levels produced by oxidative phosphorylation. Thus, NeuroD6 augments the bioenergetic capacity of PC12-NEUROD6 cells to generate an energetic reserve, which confers tolerance to the mitochondrial stressor, rotenone. We found that NeuroD6 induces an adaptive bioenergetic response throughout rotenone treatment involving maintenance of the mitochondrial membrane potential and ATP levels in conjunction with preservation of the actin network. In conclusion, our results support the concept that NeuroD6 plays an integrative role in regulating and coordinating the onset of neuronal differentiation with acquisition of adequate mitochondrial mass and energetic capacity to ensure energy demanding events, such as cytoskeletal remodeling, plasmalemmal expansion, and growth cone formation. -- Highlights: Black-Right-Pointing-Pointer NeuroD6 induces mitochondrial biogenesis in neuroprogenitor-like cells. Black-Right-Pointing-Pointer NeuroD6 augments the bioenergetic reserve of the neuronal PC12-NeuroD6 cells. Black-Right-Pointing-Pointer NeuroD6 increases the mitochondrial membrane potential and ATP levels. Black-Right-Pointing-Pointer NeuroD6 confers tolerance to rotenone via an adaptive

  5. Dynamic antagonism between phytochromes and PIF family basic helix-loop-helix factors induces selective reciprocal responses to light and shade in a rapidly responsive transcriptional network in Arabidopsis. (United States)

    Leivar, Pablo; Tepperman, James M; Cohn, Megan M; Monte, Elena; Al-Sady, Bassem; Erickson, Erika; Quail, Peter H


    Plants respond to shade-modulated light signals via phytochrome (phy)-induced adaptive changes, termed shade avoidance. To examine the roles of Phytochrome-Interacting basic helix-loop-helix Factors, PIF1, 3, 4, and 5, in relaying such signals to the transcriptional network, we compared the shade-responsive transcriptome profiles of wild-type and quadruple pif (pifq) mutants. We identify a subset of genes, enriched in transcription factor-encoding loci, that respond rapidly to shade, in a PIF-dependent manner, and contain promoter G-box motifs, known to bind PIFs. These genes are potential direct targets of phy-PIF signaling that regulate the primary downstream transcriptional circuitry. A second subset of PIF-dependent, early response genes, lacking G-box motifs, are enriched for auxin-responsive loci, and are thus potentially indirect targets of phy-PIF signaling, mediating the rapid cell expansion induced by shade. Comparing deetiolation- and shade-responsive transcriptomes identifies another subset of G-box-containing genes that reciprocally display rapid repression and induction in response to light and shade signals. These data define a core set of transcriptional and hormonal processes that appear to be dynamically poised to react rapidly to light-environment changes via perturbations in the mutually antagonistic actions of the phys and PIFs. Comparing the responsiveness of the pifq and triple pif mutants to light and shade confirms that the PIFs act with overlapping redundancy on seedling morphogenesis and transcriptional regulation but that each PIF contributes differentially to these responses.

  6. Molecular recognition in helix-loop-helix and helix-loop-helix-leucine zipper domains. Design of repertoires and selection of high affinity ligands for natural proteins. (United States)

    Ciarapica, Roberta; Rosati, Jessica; Cesareni, Gianni; Nasi, Sergio


    Helix-loop-helix (HLH) and helix-loop-helix-leucine zipper (HLHZip) are dimerization domains that mediate selective pairing among members of a large transcription factor family involved in cell fate determination. To investigate the molecular rules underlying recognition specificity and to isolate molecules interfering with cell proliferation and differentiation control, we assembled two molecular repertoires obtained by directed randomization of the binding surface in these two domains. For this strategy we selected the Heb HLH and Max Zip regions as molecular scaffolds for the randomization process and displayed the two resulting molecular repertoires on lambda phage capsids. By affinity selection, many domains were isolated that bound to the proteins Mad, Rox, MyoD, and Id2 with different levels of affinity. Although several residues along an extended surface within each domain appeared to contribute to dimerization, some key residues critically involved in molecular recognition could be identified. Furthermore, a number of charged residues appeared to act as switch points facilitating partner exchange. By successfully selecting ligands for four of four HLH or HLHZip proteins, we have shown that the repertoires assembled are rather general and possibly contain elements that bind with sufficient affinity to any natural HLH or HLHZip molecule. Thus they represent a valuable source of ligands that could be used as reagents for molecular dissection of functional regulatory pathways.

  7. The basic helix-loop-helix/leucine zipper transcription factor USF2 integrates serum-induced PAI-1 expression and keratinocyte growth. (United States)

    Qi, Li; Higgins, Craig E; Higgins, Stephen P; Law, Brian K; Simone, Tessa M; Higgins, Paul J


    Plasminogen activator inhibitor type-1 (PAI-1), a major regulator of the plasmin-dependent pericellular proteolytic cascade, is prominently expressed during the tissue response to injury although the factors that impact PAI-1 induction and their role in the repair process are unclear. Kinetic modeling using established biomarkers of cell cycle transit (c-MYC; cyclin D1; cyclin A) in synchronized human (HaCaT) keratinocytes, and previous cytometric assessments, indicated that PAI-1 transcription occurred early after serum-stimulation of quiescent (G0) cells and prior to G1 entry. It was established previously that differential residence of USF family members (USF1→USF2 switch) at the PE2 region E box (CACGTG) characterized the G0  → G1 transition period and the transcriptional status of the PAI-1 gene. A consensus PE2 E box motif (5'-CACGTG-3') at nucleotides -566 to -561 was required for USF/E box interactions and serum-dependent PAI-1 transcription. Site-directed CG → AT substitution at the two central nucleotides inhibited formation of USF/probe complexes and PAI-1 promoter-driven reporter expression. A dominant-negative USF (A-USF) construct or double-stranded PE2 "decoy" attenuated serum- and TGF-β1-stimulated PAI-1 synthesis. Tet-Off induction of an A-USF insert reduced both PAI-1 and PAI-2 transcripts while increasing the fraction of Ki-67(+) cells. Conversely, overexpression of USF2 or adenoviral-delivery of a PAI-1 vector inhibited HaCaT colony expansion indicating that the USF1 → USF2 transition and subsequent PAI-1 transcription are critical events in the epithelial go-or-grow response. Collectively, these data suggest that USF2, and its target gene PAI-1, regulate serum-stimulated keratinocyte growth, and likely the cadence of cell cycle progression in replicatively competent cells as part of the injury repair program.

  8. Human variants in the neuronal basic helix-loop-helix/Per-Arnt-Sim (bHLH/PAS transcription factor complex NPAS4/ARNT2 disrupt function.

    Directory of Open Access Journals (Sweden)

    David C Bersten

    Full Text Available Neuronal Per-Arnt-Sim homology (PAS Factor 4 (NPAS4 is a neuronal activity-dependent transcription factor which heterodimerises with ARNT2 to regulate genes involved in inhibitory synapse formation. NPAS4 functions to maintain excitatory/inhibitory balance in neurons, while mouse models have shown it to play roles in memory formation, social interaction and neurodegeneration. NPAS4 has therefore been implicated in a number of neuropsychiatric or neurodegenerative diseases which are underpinned by defects in excitatory/inhibitory balance. Here we have explored a broad set of non-synonymous human variants in NPAS4 and ARNT2 for disruption of NPAS4 function. We found two variants in NPAS4 (F147S and E257K and two variants in ARNT2 (R46W and R107H which significantly reduced transcriptional activity of the heterodimer on a luciferase reporter gene. Furthermore, we found that NPAS4.F147S was unable to activate expression of the NPAS4 target gene BDNF due to reduced dimerisation with ARNT2. Homology modelling predicts F147 in NPAS4 to lie at the dimer interface, where it appears to directly contribute to protein/protein interaction. We also found that reduced transcriptional activation by ARNT2 R46W was due to disruption of nuclear localisation. These results provide insight into the mechanisms of NPAS4/ARNT dimerisation and transcriptional activation and have potential implications for cognitive phenotypic variation and diseases such as autism, schizophrenia and dementia.

  9. Functional diversification of the potato R2R3 MYB anthocyanin activators AN1, MYBA1, and MYB113 and their interaction with basic helix-loop-helix cofactors. (United States)

    Liu, Yuhui; Lin-Wang, Kui; Espley, Richard V; Wang, Li; Yang, Hongyu; Yu, Bin; Dare, Andrew; Varkonyi-Gasic, Erika; Wang, Jing; Zhang, Junlian; Wang, Di; Allan, Andrew C


    In potato (Solanum tuberosum L.), R2R3 MYBs are involved in the regulation of anthocyanin biosynthesis. We examined sequences of these MYBs in cultivated potatoes, which are more complex than diploid potato due to ploidy and heterozygosity. We found amino acid variants in the C-terminus of the MYB StAN1, termed R0, R1, and R3, due to the presence of a repeated 10-amino acid motif. These variant MYBs showed some expression in both white and pigmented tubers. We found several new alleles or gene family members of R2R3 MYBs,StMYBA1 and StMYB113, which were also expressed in white potato tubers. From functional analysis in tobacco, we showed that the presence of a C-terminal 10-amino acid motif is optimal for activating anthocyanin accumulation. Engineering a motif back into a MYB lacking this sequence enhanced its activating ability. Versions of StMYBA1 and StMYB113 can also activate anthocyanin accumulation in tobacco leaves, with the exception of StMYB113-3, which has a partial R2R3 domain. We isolated five family members of potato StbHLH1, and one StJAF13, to test their ability to interact with MYB variants. The results showed that two alleles of StbHLH1 from white skin and red skin are non-functional, while three other StbHLH1s have different co-regulating abilities, and need to be activated by StJAF13. Combined with expression analysis in potato tuber, results suggest that StbHLH1 and StJAF13a re key co-regulators of anthocyanin biosynthesis, while the transcripts of MYB variants StAN1,StMYBA1, and StMYB113 are well expressed, even in the absence of pigmentation.

  10. Responses of a triple mutant defective in three iron deficiency-induced Basic Helix-Loop-Helix genes of the subgroup Ib(2) to iron deficiency and salicylic acid. (United States)

    Maurer, Felix; Naranjo Arcos, Maria Augusta; Bauer, Petra


    Plants are sessile organisms that adapt to external stress by inducing molecular and physiological responses that serve to better cope with the adverse growth condition. Upon low supply of the micronutrient iron, plants actively increase the acquisition of soil iron into the root and its mobilization from internal stores. The subgroup Ib(2) BHLH genes function as regulators in this response, however their concrete functions are not fully understood. Here, we analyzed a triple loss of function mutant of BHLH39, BHLH100 and BHLH101 (3xbhlh mutant). We found that this mutant did not have any iron uptake phenotype if iron was provided. However, under iron deficiency the mutant displayed a more severe leaf chlorosis than the wild type. Microarray-based transcriptome analysis revealed that this mutant phenotype resulted in the mis-regulation of 198 genes, out of which only 15% were associated with iron deficiency regulation itself. A detailed analysis revealed potential targets of the bHLH transcription factors as well as genes reflecting an exaggerated iron deficiency response phenotype. Since the BHLH genes of this subgroup have been brought into the context of the plant hormone salicylic acid, we investigated whether the 3xbhlh mutant might have been affected by this plant signaling molecule. Although a very high number of genes responded to SA, also in a differential manner between mutant and wild type, we did not find any indication for an association of the BHLH gene functions in SA responses upon iron deficiency. In summary, our study indicates that the bHLH subgroup Ib(2) transcription factors do not only act in iron acquisition into roots but in other aspects of the adaptation to iron deficiency in roots and leaves.

  11. Responses of a triple mutant defective in three iron deficiency-induced Basic Helix-Loop-Helix genes of the subgroup Ib(2 to iron deficiency and salicylic acid.

    Directory of Open Access Journals (Sweden)

    Felix Maurer

    Full Text Available Plants are sessile organisms that adapt to external stress by inducing molecular and physiological responses that serve to better cope with the adverse growth condition. Upon low supply of the micronutrient iron, plants actively increase the acquisition of soil iron into the root and its mobilization from internal stores. The subgroup Ib(2 BHLH genes function as regulators in this response, however their concrete functions are not fully understood. Here, we analyzed a triple loss of function mutant of BHLH39, BHLH100 and BHLH101 (3xbhlh mutant. We found that this mutant did not have any iron uptake phenotype if iron was provided. However, under iron deficiency the mutant displayed a more severe leaf chlorosis than the wild type. Microarray-based transcriptome analysis revealed that this mutant phenotype resulted in the mis-regulation of 198 genes, out of which only 15% were associated with iron deficiency regulation itself. A detailed analysis revealed potential targets of the bHLH transcription factors as well as genes reflecting an exaggerated iron deficiency response phenotype. Since the BHLH genes of this subgroup have been brought into the context of the plant hormone salicylic acid, we investigated whether the 3xbhlh mutant might have been affected by this plant signaling molecule. Although a very high number of genes responded to SA, also in a differential manner between mutant and wild type, we did not find any indication for an association of the BHLH gene functions in SA responses upon iron deficiency. In summary, our study indicates that the bHLH subgroup Ib(2 transcription factors do not only act in iron acquisition into roots but in other aspects of the adaptation to iron deficiency in roots and leaves.

  12. Antagonistic regulation of growth and immunity by the Arabidopsis basic helix-loop-helix transcription factor homolog of brassinosteroid enhanced expression2 interacting with increased leaf inclination1 binding bHLH1

    DEFF Research Database (Denmark)

    Malinovsky, Frederikke Gro; Batoux, Martine; Schwessinger, Benjamin;


    Plants need to finely balance resources allocated to growth and immunity to achieve optimal fitness. A tradeoff between pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) and brassinosteroid (BR)-mediated growth was recently reported, but more information about the underlying...... to different PAMPs. HBI1 overexpression leads to reduced PAMP-triggered responses. This inhibition correlates with reduced steady-state expression of immune marker genes, leading to increased susceptibility to the bacterium Pseudomonas syringae. Overexpression of the HBI1-related bHLHs brassinosteroid enhanced...... expression2 (BEE2) and cryptochrome-interacting bHLH (CIB1) partially inhibits immunity, indicating that BEE2 and CIB1 may act redundantly with HBI1. In contrast to its expression pattern upon PAMP treatment, HBI1 expression is enhanced by BR treatment. Also, HBI1-overexpressing plants are hyperresponsive...

  13. Protein (Viridiplantae): 297852830 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)


  14. Effect of phosphorylation of phosphatidylinositol on myelin basic protein-mediated binding of actin filaments to lipid bilayers in vitro. (United States)

    Boggs, Joan M; Rangaraj, Godha; Dicko, Awa


    Myelin basic protein (MBP) binds to negatively charged lipids on the cytosolic surface of oligodendrocytes and is believed to be responsible for adhesion of these surfaces in the multilayered myelin sheath. It can also assemble actin filaments and tether them to lipid bilayers through electrostatic interactions. Here we investigate the effect of increased negative charge of the lipid bilayer due to phosphorylation of phosphatidylinositol (PI) on MBP-mediated binding of actin to the lipid bilayer, by substituting phosphatidylinositol 4-phosphate or phosphatidylinositol 4,5-bisphosphate for PI in phosphatidylcholine/phosphatidylglycerol lipid vesicles. Phosphorylation of PI caused dissociation of the MBP/actin complex from the lipid vesicles due to repulsion of the negatively charged complex from the negatively charged membrane surface. An effect of phosphorylation could be detected even if the inositol lipid was only 2mol% of the total lipid. Calcium-calmodulin dissociated actin from the MBP-lipid vesicles and phosphorylation of PI increased the amount dissociated. These results show that changes to the lipid composition of myelin, which could occur during signaling or other physiological events, could regulate the ability of MBP to act as a scaffolding protein and bind actin filaments to the lipid bilayer.

  15. Rbms3, an RNA-binding protein, mediates the expression of Ptf1a by binding to its 3'UTR during mouse pancreas development. (United States)

    Lu, Chung-Kuang; Lai, Yi-Chyi; Chen, Hau-Ren; Chiang, Ming-Ko


    The development of the pancreas is a complicated process that is regulated on several levels. Pancreas transcription factor 1, alpha subunit (Ptf1a), also known as p48, is a pancreas-specific basic helix-loop-helix transcription factor that is critical for both exocrine pancreas development and maintenance of acinar cell differentiation. Based on a differential screening assay, we identified Rbms3, a gene encoding a glycine-rich RNA-binding protein, to be specifically expressed in the neural tube and the pancreatic rudiment of e10.5 embryos. The presence of Rbms3 in the early developing pancreas suggests that specific post-transcriptional regulation mechanisms play an important role in controlling pancreas development. In this study, we show that Rbms3 binds to the 3'UTR of Ptf1a mRNA, but not the 3'UTR of Pdx1, which is another pancreatic transcription factor. The ectopic expression of Rbms3 stimulates the translation of a reporter gene carrying the Ptf1a 3'UTR. In addition, when Rbms3 expression is suppressed in the AR42J-B13 pancreatic exocrine cell line, the expression of Ptf1a is also down-regulated. These results suggest that binding of Rbms3 to the 3'UTR of Ptf1a regulates the production of the Ptf1a protein and, thereby, indirectly regulates the expression of the Ptf1a downstream target genes.

  16. EST Table: FS845099 [KAIKOcDNA[Archive

    Lifescience Database Archive (English)

    Full Text Available PREDICTED: similar to class b basic helix-loop-helix protein (bhlhb) (differentially expressed in chondrocytes) (mdec) (sharp...lar to class b basic helix-loop-helix protein (bhlhb) (differentially expressed in chondrocytes) (mdec) (sharp) [Tribolium castaneum] FS845099 fner ...

  17. EST Table: FS816912 [KAIKOcDNA[Archive

    Lifescience Database Archive (English)

    Full Text Available milar to class b basic helix-loop-helix protein (bhlhb) (differentially expressed in chondrocytes) (mdec) (sharp...asic helix-loop-helix protein (bhlhb) (differentially expressed in chondrocytes) (mdec) (sharp) [Tribolium castaneum] FS845099 fmgV ...

  18. Identifying Novel Helix-Loop-Helix Genes in "Caenorhabditis elegans" through a Classroom Demonstration of Functional Genomics (United States)

    Griffin, Vernetta; McMiller, Tracee; Jones, Erika; Johnson, Casonya M.


    A 14-week, undergraduate-level Genetics and Population Biology course at Morgan State University was modified to include a demonstration of functional genomics in the research laboratory. Students performed a rudimentary sequence analysis of the "Caenorhabditis elegans" genome and further characterized three sequences that were predicted to encode…

  19. Mutations in the basic domain and the loop-helix II junction of TWIST abolish DNA binding in Saethre-Chotzen syndrome. (United States)

    El Ghouzzi, V; Legeai-Mallet, L; Benoist-Lasselin, C; Lajeunie, E; Renier, D; Munnich, A; Bonaventure, J


    Saethre-Chotzen syndrome is an autosomal dominant skull disorder resulting from premature fusion of coronal sutures (craniosynostosis). It is caused by mutations in the TWIST gene encoding a basic Helix-Loop-Helix transcription factor. Here we report on the identification of a novel mutation affecting a highly conserved residue of the basic domain. Unlike nonsense and missense mutations lying within helices, this mutation does not affect protein stability or heterodimerisation of TWIST with its partner E12. However, it does abolish TWIST binding capacity to a target E-box as efficiently as two missense mutations in the loop-helix II junction. By contrast, elongation of the loop through a 7 amino acid insertion appears not to hamper binding to the DNA target. We conclude that loss of TWIST protein function in Saethre-Chotzen patients can occur at three different levels, namely protein stability, dimerisation, and DNA binding and that the loop-helix II junction is essential for effective protein-DNA interaction.

  20. SREBP-1 dimerization specificity maps to both the helix-loop-helix and leucine zipper domains: use of a dominant negative

    DEFF Research Database (Denmark)

    Rishi, Vikas; Gal, Jozsef; Krylov, Dmitry


    The mammalian SREBP family contains two genes that code for B-HLH-ZIP proteins that bind sequence-specific DNA to regulate the expression of genes involved in lipid metabolism. We have designed a dominant negative (DN), termed A-SREBP-1, that inhibits the DNA binding of either SREBP protein. A...

  1. Marked induction of the helix-loop-helix protein Id3 promotes the gammadelta T cell fate and renders their functional maturation Notch independent

    DEFF Research Database (Denmark)

    Lauritsen, Jens Peter Holst; Wong, Gladys W; Lee, Sang-Yun


    alphabeta and gammadelta T cells arise from a common thymocyte progenitor during development in the thymus. Emerging evidence suggests that the pre-T cell receptor (pre-TCR) and gammadelta T cell receptor (gammadeltaTCR) play instructional roles in specifying the alphabeta and gammadelta T-lineag...

  2. A smallest 6 kda metalloprotease, mini-matrilysin, in living world: a revolutionary conserved zinc-dependent proteolytic domain- helix-loop-helix catalytic zinc binding domain (ZBD

    Directory of Open Access Journals (Sweden)

    Yu Wei-Hsuan


    Full Text Available Abstract Background The Aim of this study is to study the minimum zinc dependent metalloprotease catalytic folding motif, helix B Met loop-helix C, with proteolytic catalytic activities in metzincin super family. The metzincin super family share a catalytic domain consisting of a twisted five-stranded β sheet and three long α helices (A, B and C. The catalytic zinc is at the bottom of the cleft and is ligated by three His residues in the consensus sequence motif, HEXXHXXGXXH, which is located in helix B and part of the adjacent Met turn region. An interesting question is - what is the minimum portion of the enzyme that still possesses catalytic and inhibitor recognition?” Methods We have expressed a 60-residue truncated form of matrilysin which retains only the helix B-Met turn-helix C region and deletes helix A and the five-stranded β sheet which form the upper portion of the active cleft. This is only 1/4 of the full catalytic domain. The E. coli derived 6 kDa MMP-7 ZBD fragments were purified and refolded. The proteolytic activities were analyzed by Mca-Pro-Leu-Gly-Leu-Dpa-Ala-Arg-NH2 peptide assay and CM-transferrin zymography analysis. SC44463, BB94 and Phosphoramidon were computationally docked into the 3day structure of the human MMP7 ZBD and TAD and thermolysin using the docking program GOLD. Results This minimal 6 kDa matrilysin has been refolded and shown to have proteolytic activity in the Mca-Pro-Leu-Gly-Leu-Dpa-Ala-Arg-NH2 peptide assay. Triton X-100 and heparin are important factors in the refolding environment for this mini-enzyme matrilysin. This minienzyme has the proteolytic activity towards peptide substrate, but the hexamer and octamer of the mini MMP-7 complex demonstrates the CM-transferrin proteolytic activities in zymographic analysis. Peptide digestion is inhibited by SC44463, specific MMP7 inhibitors, but not phosphorimadon. Interestingly, the mini MMP-7 can be processed by autolysis and producing ~ 6 ~ 7 kDa fragments. Thus, many of the functions of the enzyme are retained indicating that the helix B-Met loop-helix C is the minimal functional “domain” found to date for the matrixin family. Conclusions The helix B-Met loop-helix C folding conserved in metalloprotease metzincin super family is able to facilitate proteolytic catalysis for specific substrate and inhibitor recognition. The autolysis processing and producing 6 kDa mini MMP-7 is the smallest metalloprotease in living world.

  3. Structure-Function Analysis of the v-Myc Oncoprotein (United States)


    transcription activation domain (TAD) and a carboxy-terminal basic helix-loop-helix/ leucine zipper (bHLH/LZ) motif (Henriksson and Luscher , 1996). Work by...U. (1996). Active repression mechanisms of eukaryotic transcription repressors. Trends in Genetics 12: 229-234. Henriksson, M. and Luscher , B. (1996

  4. Protein: MPA6 [TP Atlas

    Lifescience Database Archive (English)

    Full Text Available MPA6 SREBBP1c SREBF1 BHLHD1, SREBP1 Sterol regulatory element-binding protein 1 D basic helix-loop-helix protein 1, Sterol regulatory element-binding transcription factor 1 9606 Homo sapiens P36956 6720 1AM9 6720 P36956 ...

  5. AcEST: DK950560 [AcEST

    Lifescience Database Archive (English)

    Full Text Available A0|UVRC_SYNWW UvrABC system protein C OS=Syntrophomonas w... 36 0.28 sp|Q9NX45|SOLH2_HUMAN Spermatogenesis- and oogenesis...HUMAN Spermatogenesis- and oogenesis-specific basic helix-loop-helix-containing protein 2 OS=Homo sapiens GN

  6. Translational control of TWIST1 expression in MCF-10A cell lines recapitulating breast cancer progression

    DEFF Research Database (Denmark)

    Nairismägi, Maarja-Liisa; Vislovukh, Andrii; Meng, Q


    TWIST1 is a highly conserved basic helix-loop-helix transcription factor that promotes epithelial–mesenchymal transition (EMT). Its misregulation has been observed in various types of tumors. Using the MCF-10A-series of cell lines that recapitulate the early stages of breast cancer formation...

  7. Domain Modeling: NP_005797.1 [SAHG[Archive

    Lifescience Database Archive (English)

    Full Text Available NP_005797.1 chr21 Crystal Structure of the basic-helix-loop-helix domains of the he...terodimer E47/NeuroD1 bound to DNA p2ql2d_ chr21/NP_005797.1/NP_005797.1_holo_110-166.pdb blast 113I,114N,11

  8. The window period of NEUROGENIN3 during human gestation

    NARCIS (Netherlands)

    R.J. Salisbury (Rachel J.); J. Blaylock (Jennifer); A.A. Berry (Andrew A.); R.E. Jennings (Rachel E.); R.R. de Krijger (Ronald); K.P. Hanley (Karen Piper); N.A. Hanley (Neil A)


    textabstractThe basic helix-loop-helix transcription factor, NEUROG3, is critical in causing endocrine commitment from a progenitor cell population in the developing pancreas. In human, NEUROG3 has been detected from 8 weeks postconception (wpc). However, the profile of its production and when it ce

  9. Functionally Similar WRKY Proteins Regulate Vacuolar Acidification in Petunia and Hair Development in Arabidopsis

    NARCIS (Netherlands)

    Verweij, W.; Spelt, C.E.; Bliek, M.; de Vries, M.; Wit, N.; Faraco, M.; Koes, R.; Quattrocchio, F.


    The WD40 proteins ANTHOCYANIN11 (AN11) from petunia (Petunia hybrida) and TRANSPARENT TESTA GLABRA1 (TTG1) fromArabidopsis thalianaand associated basic helix-loop-helix (bHLH) and MYB transcription factors activate a variety of differentiation processes. In petunia petals, AN11 and the bHLH protein

  10. AcEST: DK944591 [AcEST

    Lifescience Database Archive (English)

    Full Text Available e-15 sp|P0C7P8|Y1615_ARATH Uncharacterized basic helix-loop-helix pro... 79 2e-14 sp|P49259|PLA2R...TEKQGEKTWICFVVEGQNNKVMHRMDILWSLVQ 725 >sp|P49259|PLA2R_BOVIN Secretory phospholipase A2 receptor OS=Bos taurus GN=PLA2R

  11. Upregulation of the transcription factor TFEB in t(6;11)(p21;q13)-positive renal cell carcinomas due to promoter substitution

    NARCIS (Netherlands)

    Kuiper, RP; Schepens, M; Thijssen, J; van Asseldonk, M; van den Berg, E; Bridge, J; Schuuring, E; Schoenmakers, EFPM; van Kessel, AG


    The MITF/TFE subfamily of basic helix-loop-helix leucine-zipper (bHLH-LZ) transcription factors consists of four closely related members, TFE3, TFEB, TFEC and MITF, which can form both homo- and heterodimers. Previously, we demonstrated that in t(X;1)(p11;q21)-positive renal cell carcinomas (RCCs),

  12. Domain Modeling: NP_004307.2 [SAHG[Archive

    Lifescience Database Archive (English)

    Full Text Available NP_004307.2 chr12 Crystal Structure of the basic-helix-loop-helix domains of the he...terodimer E47/NeuroD1 bound to DNA p2ql2d_ chr12/NP_004307.2/NP_004307.2_holo_119-175.pdb psi-blast 120V,122

  13. Protein-mediated surface structuring in biomembranes

    Directory of Open Access Journals (Sweden)

    Maggio B.


    Full Text Available The lipids and proteins of biomembranes exhibit highly dissimilar conformations, geometrical shapes, amphipathicity, and thermodynamic properties which constrain their two-dimensional molecular packing, electrostatics, and interaction preferences. This causes inevitable development of large local tensions that frequently relax into phase or compositional immiscibility along lateral and transverse planes of the membrane. On the other hand, these effects constitute the very codes that mediate molecular and structural changes determining and controlling the possibilities for enzymatic activity, apposition and recombination in biomembranes. The presence of proteins constitutes a major perturbing factor for the membrane sculpturing both in terms of its surface topography and dynamics. We will focus on some results from our group within this context and summarize some recent evidence for the active involvement of extrinsic (myelin basic protein, integral (Folch-Lees proteolipid protein and amphitropic (c-Fos and c-Jun proteins, as well as a membrane-active amphitropic phosphohydrolytic enzyme (neutral sphingomyelinase, in the process of lateral segregation and dynamics of phase domains, sculpturing of the surface topography, and the bi-directional modulation of the membrane biochemical reactivity.

  14. Id transcriptional regulators in adipogenesis and adipose tissue metabolism. (United States)

    Patil, Mallikarjun; Sharma, Bal Krishan; Satyanarayana, Ande


    Id proteins (Id1-Id4) are helix-loop-helix (HLH) transcriptional regulators that lack a basic DNA binding domain. They act as negative regulators of basic helix-loop-helix (bHLH) transcription factors by forming heterodimers and inhibit their DNA binding and transcriptional activity. Id proteins are implicated in the regulation of various cellular mechanisms such as cell proliferation, cellular differentiation, cell fate determination, angiogenesis and tumorigenesis. A handful of recent studies also disclosed that Id proteins have critical functions in adipocyte differentiation and adipose tissue metabolism. Here, we reviewed the progress made thus far in understanding the specific functions of Id proteins in adipose tissue differentiation and metabolism. In addition to reviewing the known mechanisms of action, we also discuss possible additional mechanisms in which Id proteins might participate in regulating adipogenic and metabolic pathways.

  15. Altered Twist1 and Hand2 dimerization is associated with Saethre-Chotzen syndrome and limb abnormalities. (United States)

    Firulli, Beth A; Krawchuk, Dayana; Centonze, Victoria E; Vargesson, Neil; Virshup, David M; Conway, Simon J; Cserjesi, Peter; Laufer, Ed; Firulli, Anthony B


    Autosomal dominant mutations in the gene encoding the basic helix-loop-helix transcription factor Twist1 are associated with limb and craniofacial defects in humans with Saethre-Chotzen syndrome. The molecular mechanism underlying these phenotypes is poorly understood. We show that ectopic expression of the related basic helix-loop-helix factor Hand2 phenocopies Twist1 loss of function in the limb and that the two factors have a gene dosage-dependent antagonistic interaction. Dimerization partner choice by Twist1 and Hand2 can be modulated by protein kinase A- and protein phosphatase 2A-regulated phosphorylation of conserved helix I residues. Notably, multiple Twist1 mutations associated with Saethre-Chotzen syndrome alter protein kinase A-mediated phosphorylation of Twist1, suggesting that misregulation of Twist1 dimerization through either stoichiometric or post-translational mechanisms underlies phenotypes of individuals with Saethre-Chotzen syndrome.

  16. Genomic pathways modulated by Twist in breast cancer


    Vesuna, Farhad; Bergman, Yehudit; Raman, Venu


    Background The basic helix-loop-helix transcription factor TWIST1 (Twist) is involved in embryonic cell lineage determination and mesodermal differentiation. There is evidence to indicate that Twist expression plays a role in breast tumor formation and metastasis, but the role of Twist in dysregulating pathways that drive the metastatic cascade is unclear. Moreover, many of the genes and pathways dysregulated by Twist in cell lines and mouse models have not been validated against data obtaine...

  17. NOTCH Signaling and ATOH1 in Colorectal Cancers



    The Notch receptor signaling pathway regulates expression of the basic helix-loop-helix transcription factor ATOH1 (Math1/Hath1) to determine cell fate in the intestine. In differentiating intestinal stem cells, high levels of Notch activity specify absorptive enterocyte/colonocyte differentiation, whereas high ATOH1 activity specifies secretory (goblet, enteroendocrine, and Paneth) cell differentiation. In colorectal cancer, ATOH1 is a tumor suppressor that is silenced in most tumors, while ...

  18. Id4 Promotes Senescence and Sensitivity to Doxorubicin-induced Apoptosis in DU145 Prostate Cancer Cells


    Carey, Jason P; Knowell, Ashley Evans; Chinaranagari, Swathi; Chaudhary, Jaideep


    Inhibitor of differentiation proteins (Id1, 2, 3 and 4) are dominant negative regulators of basic helix loop helix transcription factors and play dominant roles in cancer cells, spanning several molecular pathways including senescence, invasion, metastasis, proliferation and apoptosis. In contrast to high Id1, Id2 and Id3 expression, the expression of Id4 is epigenetically silenced in prostate cancer. In the present study we demonstrated a novel role of Id4, that of promotion of cellular sene...

  19. Proneural proteins Achaete and Scute associate with nuclear actin to promote formation of external sensory organs. (United States)

    Hsiao, Yun-Ling; Chen, Yu-Ju; Chang, Yi-Jie; Yeh, Hsiao-Fong; Huang, Yi-Chun; Pi, Haiwei


    Basic helix-loop-helix (bHLH) proneural proteins promote neurogenesis through transcriptional regulation. Although much is known about the tissue-specific regulation of proneural gene expression, how proneural proteins interact with transcriptional machinery to activate downstream target genes is less clear. Drosophila proneural proteins Achaete (Ac) and Scute (Sc) induce external sensory organ formation by activating neural precursor gene expression. Through co-immunoprecipitation and mass spectrometric analyses, we found that nuclear but not cytoplasmic actin associated with the Ac and Sc proteins in Drosophila S2 cells. Daughterless (Da), the common heterodimeric partner of Drosophila bHLH proteins, was observed to associate with nuclear actin through proneural proteins. A yeast two-hybrid assay revealed that the binding specificity between actin and Ac or Sc was conserved in yeast nuclei without the presence of additional Drosophila factors. We further show that actin is required in external sensory organ formation. Reduction in actin gene activity impaired proneural-protein-dependent expression of the neural precursor genes, as well as formation of neural precursors. Furthermore, increased nuclear actin levels, obtained by expression of nucleus-localized actin, elevated Ac-Da-dependent gene transcription as well as Ac-mediated external sensory organ formation. Taken together, our in vivo and in vitro observations suggest a novel link for actin in proneural-protein-mediated transcriptional activation and neural precursor differentiation.

  20. ABC-F Proteins Mediate Antibiotic Resistance through Ribosomal Protection. (United States)

    Sharkey, Liam K R; Edwards, Thomas A; O'Neill, Alex J


    Members of the ABC-F subfamily of ATP-binding cassette proteins mediate resistance to a broad array of clinically important antibiotic classes that target the ribosome of Gram-positive pathogens. The mechanism by which these proteins act has been a subject of long-standing controversy, with two competing hypotheses each having gained considerable support: antibiotic efflux versus ribosomal protection. Here, we report on studies employing a combination of bacteriological and biochemical techniques to unravel the mechanism of resistance of these proteins, and provide several lines of evidence that together offer clear support to the ribosomal protection hypothesis. Of particular note, we show that addition of purified ABC-F proteins to anin vitrotranslation assay prompts dose-dependent rescue of translation, and demonstrate that such proteins are capable of displacing antibiotic from the ribosomein vitro To our knowledge, these experiments constitute the first direct evidence that ABC-F proteins mediate antibiotic resistance through ribosomal protection.IMPORTANCEAntimicrobial resistance ranks among the greatest threats currently facing human health. Elucidation of the mechanisms by which microorganisms resist the effect of antibiotics is central to understanding the biology of this phenomenon and has the potential to inform the development of new drugs capable of blocking or circumventing resistance. Members of the ABC-F family, which includelsa(A),msr(A),optr(A), andvga(A), collectively yield resistance to a broader range of clinically significant antibiotic classes than any other family of resistance determinants, although their mechanism of action has been controversial since their discovery 25 years ago. Here we present the first direct evidence that proteins of the ABC-F family act to protect the bacterial ribosome from antibiotic-mediated inhibition.

  1. Prostacyclin-induced hyperthermia - Implication of a protein mediator (United States)

    Kandasamy, S. B.; Williams, B. A.


    The mechanism of the prostacyclin-linked hyperthermia is studied in rabbits. Results show that intracerebroventricular administration of prostacyclin (PGI2) induces dose-related hyperthermia at room temperature (21 C), as well as at low (4 C) and high (30 C) ambient temperatures. It is found that this PGI2-induced hyperthermia is not mediated by its stable metabolite 6-keto prostaglandin F-1(alpha). Only one of the three anion transport systems, the liver transport system, appears to be important to the central inactivation of pyrogen, prostaglandin E2, and PGI2. Phenoxybenzamine and pimozide have no thermolytic effect on PGI2-induced hyperthermia, while PGI2 still induces hyperthermia after norepinephrine (NE) and dopamine levels are depleted by 6-hydroxydopamine. Indomethacin and SC-19220 (a PG antagonist) do not antagonize PGI2 induced hyperthermia, while theophylline does not accentuate the PGI2-induced hyperthermia. However, the hyperthermic response to PGI2 is attenuated by central administration of the protein synthesis inhibitor, anisomycin. It is concluded that PGI2-induced hyperthermia is not induced by NE, dopamine, or cyclic AMP, but rather that a protein mediator is implicated in the induction of fever by PG12.

  2. Morphology, biophysical properties and protein-mediated fusion of archaeosomes.

    Directory of Open Access Journals (Sweden)

    Vid Šuštar

    Full Text Available As variance from standard phospholipids of eubacteria and eukaryotes, archaebacterial diether phospholipids contain branched alcohol chains (phytanol linked to glycerol exclusively with ether bonds. Giant vesicles (GVs constituted of different species of archaebacterial diether phospholipids and glycolipids (archaeosomes were prepared by electroformation and observed under a phase contrast and/or fluorescence microscope. Archaebacterial lipids and different mixtures of archaebacterial and standard lipids formed GVs which were analysed for size, yield and ability to adhere to each other due to the mediating effects of certain plasma proteins. GVs constituted of different proportions of archaeal or standard phosphatidylcholine were compared. In nonarchaebacterial GVs (in form of multilamellar lipid vesicles, MLVs the main transition was detected at T(m = 34. 2°C with an enthalpy of ΔH = 0.68 kcal/mol, whereas in archaebacterial GVs (MLVs we did not observe the main phase transition in the range between 10 and 70°C. GVs constituted of archaebacterial lipids were subject to attractive interaction mediated by beta 2 glycoprotein I and by heparin. The adhesion constant of beta 2 glycoprotein I-mediated adhesion determined from adhesion angle between adhered GVs was in the range of 10(-8 J/m(2. In the course of protein mediated adhesion, lateral segregation of the membrane components and presence of thin tubular membranous structures were observed. The ability of archaebacterial diether lipids to combine with standard lipids in bilayers and their compatibility with adhesion-mediating molecules offer further evidence that archaebacterial lipids are appropriate for the design of drug carriers.

  3. Gene expression profiling of human neural progenitor cells following the serum-induced astrocyte differentiation. (United States)

    Obayashi, Shinya; Tabunoki, Hiroko; Kim, Seung U; Satoh, Jun-ichi


    Neural stem cells (NSC) with self-renewal and multipotent properties could provide an ideal cell source for transplantation to treat spinal cord injury, stroke, and neurodegenerative diseases. However, the majority of transplanted NSC and neural progenitor cells (NPC) differentiate into astrocytes in vivo under pathological environments in the central nervous system, which potentially cause reactive gliosis. Because the serum is a potent inducer of astrocyte differentiation of rodent NPC in culture, we studied the effect of the serum on gene expression profile of cultured human NPC to identify the gene signature of astrocyte differentiation of human NPC. Human NPC spheres maintained in the serum-free culture medium were exposed to 10% fetal bovine serum (FBS) for 72 h, and processed for analyzing on a Whole Human Genome Microarray of 41,000 genes, and the microarray data were validated by real-time RT-PCR. The serum elevated the levels of expression of 45 genes, including ID1, ID2, ID3, CTGF, TGFA, METRN, GFAP, CRYAB and CSPG3, whereas it reduced the expression of 23 genes, such as DLL1, DLL3, PDGFRA, SOX4, CSPG4, GAS1 and HES5. Thus, the serum-induced astrocyte differentiation of human NPC is characterized by a counteraction of ID family genes on Delta family genes. Coimmunoprecipitation analysis identified ID1 as a direct binding partner of a proneural basic helix-loop-helix (bHLH) transcription factor MASH1. Luciferase assay indicated that activation of the DLL1 promoter by MASH1 was counteracted by ID1. Bone morphogenetic protein 4 (BMP4) elevated the levels of ID1 and GFAP expression in NPC under the serum-free culture conditions. Because the serum contains BMP4, these results suggest that the serum factor(s), most probably BMP4, induces astrocyte differentiation by upregulating the expression of ID family genes that repress the proneural bHLH protein-mediated Delta expression in human NPC.

  4. Increased bone formation and decreased osteocalcin expression induced by reduced Twist dosage in Saethre-Chotzen syndrome



    The Saethre-Chotzen syndrome is characterized by premature fusion of cranial sutures resulting from mutations in Twist, a basic helix-loop-helix (bHLH) transcription factor. We have identified Twist target genes using human mutant calvaria osteoblastic cells from a child with Saethre-Chotzen syndrome with a Twist mutation that introduces a stop codon upstream of the bHLH domain. We observed that Twist mRNA and protein levels were reduced in mutant cells and that the Twist mutation increased c...

  5. Yas3p, an Opi1 Family Transcription Factor, Regulates Cytochrome P450 Expression in Response to n-Alkanes in Yarrowia lipolytica*


    Hirakawa, Kiyoshi; Kobayashi, Satoshi; Inoue, Takuro; Endoh-Yamagami, Setsu; Fukuda, Ryouichi; Ohta, Akinori


    In the alkane-assimilating yeast Yarrowia lipolytica, the expression of ALK1, a gene encoding cytochrome P450 that catalyzes the first step of n-alkane oxidation, is induced by n-alkanes. We previously demonstrated that two basic helix-loop-helix proteins, Yas1p and Yas2p, activate the transcription of ALK1 in an alkane-dependent manner by forming a heterocomplex and binding to alkane-responsive element 1 (ARE1), a cis-acting element in the ALK1 promoter. Here we i...

  6. Twist1 activity thresholds define multiple functions in limb development


    Krawchuk, Dayana; Weiner, Shoshana J; Chen, You-Tzung; Lu, Benson; Costantini, Frank; Behringer, Richard R.; Laufer, Ed


    The basic helix-loop-helix transcription factor Twist1 is essential for normal limb development. Twist1−/− embryos die at midgestation. However, studies on early limb buds found that Twist1−/− mutant limb mesenchyme has an impaired response to FGF signaling from the apical ectodermal ridge, which disrupts the feedback loop between the mesenchyme and AER, and reduces and shifts anteriorly Shh expression in the zone of polarizing activity. We have combined Twist1 null, hypomorph and conditional...

  7. Progress of transcription factor Twist expression in breast cancer and its biological effect

    Institute of Scientific and Technical Information of China (English)

    Tian Qian


    Breast cancer is the most common malignant tumor in women and the pathogenesis is not fully elucidated. Proliferation, invasion, epithelial-mesenchymal transition and angiogenesis are the links closely related to the occurrence and development of breast cancer. Twist is a type of basic helix-loop-helix transcription factor that can affect cell proliferation and invasion process, epithelial-mesenchymal transition process and angiogenesis process through regulating the transcription of downstream target genes. In the research, the study of transcription factor Twist expression in breast cancer and its biological effect is reviewed.

  8. Gibberellins control fruit patterning in Arabidopsis thaliana. (United States)

    Arnaud, Nicolas; Girin, Thomas; Sorefan, Karim; Fuentes, Sara; Wood, Thomas A; Lawrenson, Tom; Sablowski, Robert; Østergaard, Lars


    The Arabidopsis basic helix-loop-helix (bHLH) proteins INDEHISCENT (IND) and ALCATRAZ (ALC) specify tissues required for fruit opening that have major roles in seed dispersal and plant domestication. Here, we show that synthesis of the phytohormone gibberellin is a direct and necessary target of IND, and that ALC interacts directly with DELLA repressors, which antagonize ALC function but are destabilized by gibberellin. Thus, the gibberellin/DELLA pathway has a key role in patterning the Arabidopsis fruit, and the interaction between DELLA and bHLH proteins, previously shown to connect gibberellin and light responses, is a versatile regulatory module also used in tissue patterning.

  9. Calcium binding protein-mediated regulation of voltage-gated calcium channels linked to human diseases

    Institute of Scientific and Technical Information of China (English)

    Nasrin NFJATBAKHSH; Zhong-ping FENG


    Calcium ion entry through voltage-gated calcium channels is essential for cellular signalling in a wide variety of cells and multiple physiological processes. Perturbations of voltage-gated calcium channel function can lead to pathophysiological consequences. Calcium binding proteins serve as calcium sensors and regulate the calcium channel properties via feedback mechanisms. This review highlights the current evidences of calcium binding protein-mediated channel regulation in human diseases.

  10. Mixed lineage kinase phosphorylates transcription factor E47 and inhibits TrkB expression to link neuronal death and survival pathways. (United States)

    Pedraza, Neus; Rafel, Marta; Navarro, Isis; Encinas, Mario; Aldea, Martí; Gallego, Carme


    E47 is a basic helix-loop-helix transcription factor involved in neuronal differentiation and survival. We had previously shown that the basic helix-loop-helix protein E47 binds to E-box sequences within the promoter of the TrkB gene and activates its transcription. Proper expression of the TrkB receptor plays a key role in development and function of the vertebrate nervous system, and altered levels of TrkB have been associated with important human diseases. Here we show that E47 interacts with MLK2, a mixed lineage kinase (MLK) involved in JNK-mediated activation of programmed cell death. MLK2 enhances phosphorylation of the AD2 activation domain of E47 in vivo in a JNK-independent manner and phosphorylates in vitro defined serine and threonine residues within a loop-helix structure of AD2 that also contains a putative MLK docking site. Although these residues are essential for MLK2-mediated inactivation of E47, inhibition of MLKs by CEP11004 causes up-regulation of TrkB at a transcriptional level in cerebellar granule neurons and differentiating neuroblastoma cells. These findings allow us to propose a novel mechanism by which MLK regulates TrkB expression through phosphorylation of an activation domain of E47. This molecular link would explain why MLK inhibitors not only prevent activation of cell death processes but also enhance cell survival signaling as a key aspect of their neuroprotective potential.

  11. Down-regulation of ubiquitin ligase Cbl induced by twist haploinsufficiency in Saethre-Chotzen syndrome results in increased PI3K/Akt signaling and osteoblast proliferation. (United States)

    Guenou, Hind; Kaabeche, Karim; Dufour, Cécilie; Miraoui, Hichem; Marie, Pierre J


    Genetic mutations of Twist, a basic helix-loop-helix transcription factor, induce premature fusion of cranial sutures in Saethre-Chotzen syndrome (SCS). We report here a previously undescribed mechanism involved in the altered osteoblastogenesis in SCS. Cranial osteoblasts from an SCS patient with a Twist mutation causing basic helix-loop-helix deletion exhibited decreased expression of E3 ubiquitin ligase Cbl compared with wild-type osteoblasts. This was associated with decreased ubiquitin-mediated degradation of phosphatidyl inositol 3 kinase (PI3K) and increased PI3K expression and PI3K/Akt signaling. Increased PI3K immunoreactivity was also found in osteoblasts in histological sections of affected cranial sutures from SCS patients. Transfection with Twist or Cbl abolished the increased PI3K/Akt signaling in Twist mutant osteoblasts. Forced overexpression of Cbl did not correct the altered expression of osteoblast differentiation markers in Twist mutant cells. In contrast, pharmacological inhibition of PI3K/Akt, but not ERK signaling, corrected the increased cell growth in Twist mutant osteoblasts. The results show that Twist haploinsufficiency results in decreased Cbl-mediated PI3K degradation in osteoblasts, causing PI3K accumulation and activation of PI3K/Akt-dependent osteoblast growth. This provides genetic and biochemical evidence for a role for Cbl-mediated PI3K signaling in the altered osteoblast phenotype induced by Twist haploinsufficiency in SCS.

  12. A juvenile hormone transcription factor Bmdimm-fibroin H chain pathway is involved in the synthesis of silk protein in silkworm, Bombyx mori. (United States)

    Zhao, Xiao-Ming; Liu, Chun; Jiang, Li-Jun; Li, Qiong-Yan; Zhou, Meng-Ting; Cheng, Ting-Cai; Mita, Kazuei; Xia, Qing-You


    The genes responsible for silk biosynthesis are switched on and off at particular times in the silk glands of Bombyx mori. This switch appears to be under the control of endogenous and exogenous hormones. However, the molecular mechanisms by which silk protein synthesis is regulated by the juvenile hormone (JH) are largely unknown. Here, we report a basic helix-loop-helix transcription factor, Bmdimm, its silk gland-specific expression, and its direct involvement in the regulation of fibroin H-chain (fib-H) by binding to an E-box (CAAATG) element of the fib-H gene promoter. Far-Western blots, enzyme-linked immunosorbent assays, and co-immunoprecipitation assays revealed that Bmdimm protein interacted with another basic helix-loop-helix transcription factor, Bmsage. Immunostaining revealed that Bmdimm and Bmsage proteins are co-localized in nuclei. Bmdimm expression was induced in larval silk glands in vivo, in silk glands cultured in vitro, and in B. mori cell lines after treatment with a JH analog. The JH effect on Bmdimm was mediated by the JH-Met-Kr-h1 signaling pathway, and Bmdimm expression did not respond to JH by RNA interference with double-stranded BmKr-h1 RNA. These data suggest that the JH regulatory pathway, the transcription factor Bmdimm, and the targeted fib-H gene contribute to the synthesis of fibroin H-chain protein in B. mori.

  13. Experimental determination of the evolvability of a transcription factor. (United States)

    Maerkl, Sebastian J; Quake, Stephen R


    Sequence-specific binding of a transcription factor to DNA is the central event in any transcriptional regulatory network. However, relatively little is known about the evolutionary plasticity of transcription factors. For example, the exact functional consequence of an amino acid substitution on the DNA-binding specificity of most transcription factors is currently not predictable. Furthermore, although the major structural families of transcription factors have been identified, the detailed DNA-binding repertoires within most families have not been characterized. We studied the sequence recognition code and evolvability of the basic helix-loop-helix transcription factor family by creating all possible 95 single-point mutations of five DNA-contacting residues of Max, a human helix-loop-helix transcription factor and measured the detailed DNA-binding repertoire of each mutant. Our results show that the sequence-specific repertoire of Max accessible through single-point mutations is extremely limited, and we are able to predict 92% of the naturally occurring diversity at these positions. All naturally occurring basic regions were also found to be accessible through functional intermediates. Finally, we observed a set of amino acids that are functional in vitro but are not found to be used naturally, indicating that functionality alone is not sufficient for selection.

  14. 酵母双杂交诱饵载体pGBKT7_MYC2构建及表达鉴定%Construction and Expressional Identification of Yeast Two - hybrid Bait Expression Vector pGBKT7_MYC2

    Institute of Scientific and Technical Information of China (English)

    刘武; 肖牧; 阮颖; 刘春林


    MYC2是一类含有helix - loop - helix (bHLH)结构域的转录因子.为进一步研究MYC2因子在植物防御抗性中的作用及其参与植物JA,SA等信号途径的作用机制,克隆了拟南芥的MYC2基因,以此构建了pGBKT7_MYC2酵母双杂交载体,通过Western blotting验证表明,该载体能在酵母细胞里正常表达.%MYC2, a basic helix - loop - helix (bHLH) domain - containing TF, acts as a positive regulator of abseisic acid - dependent drought responses and is also induced in JA - mediated responses. Taking the cDNA from Arabidophsis as the template, full - length COS of MYC2 had been cloned and then was ligated into the bait expression vector pG-BKT7. After verified by digestion, the bait vector was transformed into Clod yeast cells, and the expression of MYC2 gene was checked by Western blotting. As a result, the bait expression vector pGBKT7_MYC2 was constructed successfully, which laid the foundation for screening target proteins interacting and mapping the network with the MYC2 protein.

  15. Analysis of the DNA-binding and dimerization activities of Neurospora crassa transcription factor NUC-1. (United States)

    Peleg, Y; Metzenberg, R L


    NUC-1, a positive regulatory protein of Neurospora crassa, controls the expression of several unlinked target genes involved in phosphorus acquisition. The carboxy-terminal end of the NUC-1 protein has sequence similarity to the helix-loop-helix family of transcription factors. Bacterially expressed and in vitro-synthesized proteins, which consist of the carboxy-terminal portion of NUC-1, bind specifically to upstream sequences of two of its target genes, pho2+ and pho-4+. These upstream sequences contain the core sequence, CACGTG, a target for many helix-loop-helix proteins. A large loop region (47 amino acids) separates the helix I and helix II domains. Mutations and deletion within the loop region did not interfere with the in vitro or in vivo functions of the protein. Immediately carboxy-proximal to the helix II domain, the NUC-1 protein contains an atypical zipper domain which is essential for function. This domain consists of a heptad repeat of alanine and methionine rather than leucine residues. Analysis of mutant NUC-1 proteins suggests that the helix II and the zipper domains are essential for the protein dimerization, whereas the basic and the helix I domains are involved in DNA binding. The helix I domain, even though likely to participate in dimer formation while NUC-1 is bound to DNA, is not essential for in vitro dimerization.

  16. Asthma Basics (United States)

    ... Old Feeding Your 1- to 2-Year-Old Asthma Basics KidsHealth > For Parents > Asthma Basics A A ... Asthma Categories en español Asma: aspectos fundamentales About Asthma Asthma is a common lung condition in kids ...

  17. Ultramild protein-mediated click chemistry creates efficient oligonucleotide probes for targeting and detecting nucleic acids

    DEFF Research Database (Denmark)

    Nåbo, Lina J.; Madsen, Charlotte Stahl; Jensen, Knud Jørgen


    results by electronic structure calculations. Functionalized oligonucleotides were prepared in good yields by protein-mediated CuAAC click reactions for the first time with a human copper-binding chaperon. The carbohydrate, peptide, and fluorescent derivatives display high binding affinity and selectivity...... targeting and detection properties. We focus in particular on the pH sensitivity of these new probes and their high target specificity. For the first time, human copper(I)-binding chaperon Cox17 was applied to effectively catalyze click labeling of oligonucleotides. This was performed under ultramild...... conditions with fluorophore, peptide, and carbohydrate azide derivatives. In thermal denaturation studies, the modified probes showed specific binding to complementary DNA and RNA targets. Finally, we demonstrated the pH sensitivity of the new rhodamine-based fluorescent probes in vitro and rationalize our...

  18. Basic electrotechnology

    CERN Document Server

    Ashen, R A


    BASIC Electrotechnology discusses the applications of Beginner's All-purpose Symbolic Instruction Code (BASIC) in engineering, particularly in solving electrotechnology-related problems. The book is comprised of six chapters that cover several topics relevant to BASIC and electrotechnology. Chapter 1 provides an introduction to BASIC, and Chapter 2 talks about the use of complex numbers in a.c. circuit analysis. Chapter 3 covers linear circuit analysis with d.c. and sinusoidal a.c. supplies. The book also discusses the elementary magnetic circuit theory. The theory and performance of two windi

  19. Brain Basics

    Medline Plus

    Full Text Available ... Basics will introduce you to some of this science, such as: How the brain develops How genes and the environment affect the brain The basic structure of the brain How different parts of the brain communicate and work with each other How changes in the brain ...

  20. Natural Products Induce a G Protein-Mediated Calcium Pathway Activating p53 in Cancer Cells (United States)

    van Ginkel, Paul R.; Yan, Michael B.; Bhattacharya, Saswati; Polans, Arthur S.; Kenealey, Jason D.


    Paclitaxel, etoposide, vincristine and doxorubicin are examples of natural products being used as chemotherapeutics but with adverse side effects that limit their therapeutic window. Natural products derived from plants and having low toxicity, such as quercetin, resveratrol, epigallocatechin gallate and piceatannol, have been shown to inhibit tumor cell growth both in vitro and in pre-clinical models of cancer, but their mechanisms of action have not been fully elucidated, thus restricting their use as prototypes for developing synthetic analogs with improved anti-cancer properties. We and others have demonstrated that one of the earliest and consistent events upon exposure of tumor cells to these less toxic natural products is a rise in cytoplasmic calcium, activating several pro-apoptotic pathways. We describe here a G protein/inositol 1,4,5-trisphosphate pathway (InsP3) in MDA-MB-231 human breast cancer cells that mediates between these less toxic natural products and the release of calcium from the endoplasmic reticulum. Further, we demonstrate that this elevation of intracellular calcium modulates p53 activity and the subsequent transcription of several pro-apoptotic genes encoding PIG8, CD95, PIDD, TP53INP, RRM2B, Noxa, p21 and PUMA. We conclude from our findings that less toxic natural products likely bind to a G protein coupled receptor that activates a G protein-mediated and calcium-dependent pathway resulting selectively in tumor cell death. PMID:26341291

  1. Two kinesin-like proteins mediate actin-based chloroplast movement in Arabidopsis thaliana. (United States)

    Suetsugu, Noriyuki; Yamada, Noboru; Kagawa, Takatoshi; Yonekura, Hisashi; Uyeda, Taro Q P; Kadota, Akeo; Wada, Masamitsu


    Organelle movement is essential for efficient cellular function in eukaryotes. Chloroplast photorelocation movement is important for plant survival as well as for efficient photosynthesis. Chloroplast movement generally is actin dependent and mediated by blue light receptor phototropins. In Arabidopsis thaliana, phototropins mediate chloroplast movement by regulating short actin filaments on chloroplasts (cp-actin filaments), and the chloroplast outer envelope protein CHUP1 is necessary for cp-actin filament accumulation. However, other factors involved in cp-actin filament regulation during chloroplast movement remain to be determined. Here, we report that two kinesin-like proteins, KAC1 and KAC2, are essential for chloroplasts to move and anchor to the plasma membrane. A kac1 mutant showed severely impaired chloroplast accumulation and slow avoidance movement. A kac1kac2 double mutant completely lacked chloroplast photorelocation movement and showed detachment of chloroplasts from the plasma membrane. KAC motor domains are similar to those of the kinesin-14 subfamily (such as Ncd and Kar3) but do not have detectable microtubule-binding activity. The C-terminal domain of KAC1 could interact with F-actin in vitro. Instead of regulating microtubules, KAC proteins mediate chloroplast movement via cp-actin filaments. We conclude that plants have evolved a unique mechanism to regulate actin-based organelle movement using kinesin-like proteins.

  2. Natural products induce a G protein-mediated calcium pathway activating p53 in cancer cells. (United States)

    van Ginkel, Paul R; Yan, Michael B; Bhattacharya, Saswati; Polans, Arthur S; Kenealey, Jason D


    Paclitaxel, etoposide, vincristine and doxorubicin are examples of natural products being used as chemotherapeutics but with adverse side effects that limit their therapeutic window. Natural products derived from plants and having low toxicity, such as quercetin, resveratrol, epigallocatechin gallate and piceatannol, have been shown to inhibit tumor cell growth both in vitro and in pre-clinical models of cancer, but their mechanisms of action have not been fully elucidated, thus restricting their use as prototypes for developing synthetic analogs with improved anti-cancer properties. We and others have demonstrated that one of the earliest and consistent events upon exposure of tumor cells to these less toxic natural products is a rise in cytoplasmic calcium, activating several pro-apoptotic pathways. We describe here a G protein/inositol 1,4,5-trisphosphate pathway (InsP3) in MDA-MB-231 human breast cancer cells that mediates between these less toxic natural products and the release of calcium from the endoplasmic reticulum. Further, we demonstrate that this elevation of intracellular calcium modulates p53 activity and the subsequent transcription of several pro-apoptotic genes encoding PIG8, CD95, PIDD, TP53INP, RRM2B, Noxa, p21 and PUMA. We conclude from our findings that less toxic natural products likely bind to a G protein coupled receptor that activates a G protein-mediated and calcium-dependent pathway resulting selectively in tumor cell death.

  3. The TIM Barrel Architecture Facilitated the Early Evolution of Protein-Mediated Metabolism. (United States)

    Goldman, Aaron David; Beatty, Joshua T; Landweber, Laura F


    The triosephosphate isomerase (TIM) barrel protein fold is a structurally repetitive architecture that is present in approximately 10% of all enzymes. It is generally assumed that this ubiquity in modern proteomes reflects an essential historical role in early protein-mediated metabolism. Here, we provide quantitative and comparative analyses to support several hypotheses about the early importance of the TIM barrel architecture. An information theoretical analysis of protein structures supports the hypothesis that the TIM barrel architecture could arise more easily by duplication and recombination compared to other mixed α/β structures. We show that TIM barrel enzymes corresponding to the most taxonomically broad superfamilies also have the broadest range of functions, often aided by metal and nucleotide-derived cofactors that are thought to reflect an earlier stage of metabolic evolution. By comparison to other putatively ancient protein architectures, we find that the functional diversity of TIM barrel proteins cannot be explained simply by their antiquity. Instead, the breadth of TIM barrel functions can be explained, in part, by the incorporation of a broad range of cofactors, a trend that does not appear to be shared by proteins in general. These results support the hypothesis that the simple and functionally general TIM barrel architecture may have arisen early in the evolution of protein biosynthesis and provided an ideal scaffold to facilitate the metabolic transition from ribozymes, peptides, and geochemical catalysts to modern protein enzymes.

  4. Blood Group Antigen Recognition via the Group A Streptococcal M Protein Mediates Host Colonization (United States)

    De Oliveira, David M. P.; Hartley-Tassell, Lauren; Everest-Dass, Arun; Day, Christopher J.; Dabbs, Rebecca A.; Ve, Thomas; Kobe, Bostjan; Nizet, Victor; Packer, Nicolle H.; Walker, Mark J.; Jennings, Michael P.


    ABSTRACT Streptococcus pyogenes (group A streptococcus [GAS]) is responsible for over 500,000 deaths worldwide each year. The highly virulent M1T1 GAS clone is one of the most frequently isolated serotypes from streptococcal pharyngitis and invasive disease. The oral epithelial tract is a niche highly abundant in glycosylated structures, particularly those of the ABO(H) blood group antigen family. Using a high-throughput approach, we determined that a strain representative of the globally disseminated M1T1 GAS clone 5448 interacts with numerous, structurally diverse glycans. Preeminent among GAS virulence factors is the surface-expressed M protein. M1 protein showed high affinity for several terminal galactose blood group antigen structures. Deletion mutagenesis shows that M1 protein mediates glycan binding via its B repeat domains. Association of M1T1 GAS with oral epithelial cells varied significantly as a result of phenotypic differences in blood group antigen expression, with significantly higher adherence to those cells expressing H antigen structures compared to cells expressing A, B, or AB antigen structures. These data suggest a novel mechanism for GAS attachment to host cells and propose a link between host blood group antigen expression and M1T1 GAS colonization. PMID:28119471

  5. Basic hydraulics

    CERN Document Server

    Smith, P D


    BASIC Hydraulics aims to help students both to become proficient in the BASIC programming language by actually using the language in an important field of engineering and to use computing as a means of mastering the subject of hydraulics. The book begins with a summary of the technique of computing in BASIC together with comments and listing of the main commands and statements. Subsequent chapters introduce the fundamental concepts and appropriate governing equations. Topics covered include principles of fluid mechanics; flow in pipes, pipe networks and open channels; hydraulic machinery;

  6. Brain Basics

    Medline Plus

    Full Text Available ... depression. The Growing Brain Inside the Brain: Neurons & Neural Circuits Neurons are the basic working unit of ... but sometimes give rise to disabilities or diseases. neural circuit —A network of neurons and their interconnections. ...

  7. Brain Basics

    Medline Plus

    Full Text Available ... Real Life Brain Basics in Real Life—How Depression affects the Brain Meet Sarah Sarah is a ... blues" from time to time. In contrast, major depression is a serious disorder that lasts for weeks. ...

  8. Schizophrenia Basics (United States)

    ... I know with schizophrenia? For More Information Share Schizophrenia Basics Download PDF Download ePub Order a free hardcopy What is schizophrenia? Schizophrenia is a serious mental disorder that affects ...

  9. Brain Basics

    Medline Plus

    Full Text Available ... News About Us Home > Health & Education > Educational Resources Brain Basics Introduction The Growing Brain The Working Brain ... to mental disorders, such as depression. The Growing Brain Inside the Brain: Neurons & Neural Circuits Neurons are ...

  10. Brain Basics (United States)

    ... News About Us Home > Health & Education > Educational Resources Brain Basics Introduction The Growing Brain The Working Brain ... to mental disorders, such as depression. The Growing Brain Inside the Brain: Neurons & Neural Circuits Neurons are ...

  11. Fluoridation Basics (United States)

    ... Page Basic Information About Fluoride Benefits: Strong Teeth History of Fluoride in Water Cost: Saves Money, Saves Teeth Fluoride in the Water Today The mineral fluoride occurs naturally on earth and is released from rocks into the soil, ...

  12. Basic Finance (United States)

    Vittek, J. F.


    A discussion of the basic measures of corporate financial strength, and the sources of the information is reported. Considered are: balance sheet, income statement, funds and cash flow, and financial ratios.

  13. Brain Basics

    Medline Plus

    Full Text Available ... science, such as: How the brain develops How genes and the environment affect the brain The basic ... that with brain development in people mental disorders. Genes and environmental cues both help to direct this ...

  14. Brain Basics

    Medline Plus

    Full Text Available ... in the anatomy, physiology, and chemistry of the nervous system. When the brain cannot effectively coordinate the billions ... the basic working unit of the brain and nervous system. These cells are highly specialized for the function ...

  15. Protein Mediated Oxidative Stress in Patients with Diabetes and its Associated Neuropathy: Correlation with Protein Carbonylation and Disease Activity Markers (United States)

    Almogbel, Ebtehal


    Introduction Free radicals have been implicated as Diabetes Mellitus (DM) contributors in type 2 DM and its associated Diabetes Mellitus Neuropathy (DMN). However, the potential for protein mediated oxidative stress to contribute disease pathogenesis remains largely unexplored. Aim To investigate the status and contribution of protein mediated oxidative stress in patients with DM or DMN and to explore whether oxidative protein modification has a role in DM progression to DM associated neuropathy. Materials and Methods Sera from 42 DM and 37 DMN patients with varying levels of disease activities biomarkers (HbA1C, patients’ age or disease duration) and 21 age- and sex-matched healthy controls were evaluated for serum levels of protein mediated oxidative stress. Results Serum analysis showed significantly higher levels of protein carbonyl contents in both DM and DMN patients compared with healthy controls. Importantly, not only was there an increased number of subjects positive for protein carbonylation, but also the levels of protein carbonyl contents were significantly higher among DM and DMN patients, whose HbA1C were ≥8.8 as compared with patients with lower HbA1C (HbA1Cdiabetes to diabetes neuropathy. Conclusion These findings support an association between protein oxidation and DM or DMN progression. The stronger response observed in patients with higher HbA1C or patients’ ages or disease durations suggests, that protein mediated oxidative stress may be useful in evaluating the progression of DM and its associated DMN and in elucidating the mechanisms of these disorders pathogenesis.

  16. Basic electronics

    CERN Document Server

    Holbrook, Harold D


    Basic Electronics is an elementary text designed for basic instruction in electricity and electronics. It gives emphasis on electronic emission and the vacuum tube and shows transistor circuits in parallel with electron tube circuits. This book also demonstrates how the transistor merely replaces the tube, with proper change of circuit constants as required. Many problems are presented at the end of each chapter. This book is comprised of 17 chapters and opens with an overview of electron theory, followed by a discussion on resistance, inductance, and capacitance, along with their effects on t

  17. Ethanol Basics

    Energy Technology Data Exchange (ETDEWEB)



    Ethanol is a widely-used, domestically-produced renewable fuel made from corn and other plant materials. More than 96% of gasoline sold in the United States contains ethanol. Learn more about this alternative fuel in the Ethanol Basics Fact Sheet, produced by the U.S. Department of Energy's Clean Cities program.

  18. Body Basics (United States)

    ... more about how the body works, what basic human anatomy is, and what happens when parts of the body don't function properly. Blood Bones, Muscles, and Joints Brain and Nervous System Digestive System Endocrine System Eyes Female Reproductive System Heart and Circulatory System Immune ...

  19. Brain Basics

    Medline Plus

    Full Text Available ... such as depression. The Growing Brain Inside the Brain: Neurons & Neural Circuits Neurons are the basic working unit ... final destination. Chemical signals from other cells guide neurons in forming various brain structures. Neighboring neurons make connections with each other ...

  20. Insulin Basics (United States)

    ... Honor Become a Member En Español Type 1 Type 2 About Us Online Community Meal Planning Sign In Search: Search More Sites Search ≡ Are You At Risk? Diabetes Basics Living with Diabetes Food & Fitness In My ... Diabetes and Learning About Prediabetes Type 2 Diabetes Risk Test Lower Your Risk Healthy ...

  1. Wavelet basics

    CERN Document Server

    Chan, Y T


    Since the study of wavelets is a relatively new area, much of the research coming from mathematicians, most of the literature uses terminology, concepts and proofs that may, at times, be difficult and intimidating for the engineer. Wavelet Basics has therefore been written as an introductory book for scientists and engineers. The mathematical presentation has been kept simple, the concepts being presented in elaborate detail in a terminology that engineers will find familiar. Difficult ideas are illustrated with examples which will also aid in the development of an intuitive insight. Chapter 1 reviews the basics of signal transformation and discusses the concepts of duals and frames. Chapter 2 introduces the wavelet transform, contrasts it with the short-time Fourier transform and clarifies the names of the different types of wavelet transforms. Chapter 3 links multiresolution analysis, orthonormal wavelets and the design of digital filters. Chapter 4 gives a tour d'horizon of topics of current interest: wave...

  2. Basic electronics

    CERN Document Server

    Tayal, DC


    The second edition of this book incorporates the comments and suggestions of my friends and students who have critically studied the first edition. In this edition the changes and additions have been made and subject matter has been rearranged at some places. The purpose of this text is to provide a comprehensive and up-to-date study of the principles of operation of solid state devices, their basic circuits and application of these circuits to various electronic systems, so that it can serve as a standard text not only for universities and colleges but also for technical institutes. This book

  3. Regression Basics

    CERN Document Server

    Kahane, Leo H


    Using a friendly, nontechnical approach, the Second Edition of Regression Basics introduces readers to the fundamentals of regression. Accessible to anyone with an introductory statistics background, this book builds from a simple two-variable model to a model of greater complexity. Author Leo H. Kahane weaves four engaging examples throughout the text to illustrate not only the techniques of regression but also how this empirical tool can be applied in creative ways to consider a broad array of topics. New to the Second Edition Offers greater coverage of simple panel-data estimation:

  4. Direct detection of transcription factors in cotyledons during seedling development using sensitive silicon-substrate photonic crystal protein arrays. (United States)

    Jones, Sarah I; Tan, Yafang; Shamimuzzaman, Md; George, Sherine; Cunningham, Brian T; Vodkin, Lila


    Transcription factors control important gene networks, altering the expression of a wide variety of genes, including those of agronomic importance, despite often being expressed at low levels. Detecting transcription factor proteins is difficult, because current high-throughput methods may not be sensitive enough. One-dimensional, silicon-substrate photonic crystal (PC) arrays provide an alternative substrate for printing multiplexed protein microarrays that have greater sensitivity through an increased signal-to-noise ratio of the fluorescent signal compared with performing the same assay upon a traditional aminosilanized glass surface. As a model system to test proof of concept of the silicon-substrate PC arrays to directly detect rare proteins in crude plant extracts, we selected representatives of four different transcription factor families (zinc finger GATA, basic helix-loop-helix, BTF3/NAC [for basic transcription factor of the NAC family], and YABBY) that have increasing transcript levels during the stages of seedling cotyledon development. Antibodies to synthetic peptides representing the transcription factors were printed on both glass slides and silicon-substrate PC slides along with antibodies to abundant cotyledon proteins, seed lectin, and Kunitz trypsin inhibitor. The silicon-substrate PC arrays proved more sensitive than those performed on glass slides, detecting rare proteins that were below background on the glass slides. The zinc finger transcription factor was detected on the PC arrays in crude extracts of all stages of the seedling cotyledons, whereas YABBY seemed to be at the lower limit of their sensitivity. Interestingly, the basic helix-loop-helix and NAC proteins showed developmental profiles consistent with their transcript patterns, indicating proof of concept for detecting these low-abundance proteins in crude extracts.

  5. Type I bHLH Proteins Daughterless and Tcf4 Restrict Neurite Branching and Synapse Formation by Repressing Neurexin in Postmitotic Neurons

    Directory of Open Access Journals (Sweden)

    Mitchell D’Rozario


    Full Text Available Proneural proteins of the class I/II basic-helix-loop-helix (bHLH family are highly conserved transcription factors. Class I bHLH proteins are expressed in a broad number of tissues during development, whereas class II bHLH protein expression is more tissue restricted. Our understanding of the function of class I/II bHLH transcription factors in both invertebrate and vertebrate neurobiology is largely focused on their function as regulators of neurogenesis. Here, we show that the class I bHLH proteins Daughterless and Tcf4 are expressed in postmitotic neurons in Drosophila melanogaster and mice, respectively, where they function to restrict neurite branching and synapse formation. Our data indicate that Daughterless performs this function in part by restricting the expression of the cell adhesion molecule Neurexin. This suggests a role for these proteins outside of their established roles in neurogenesis.

  6. Functional interconnection of MYC2 and SPA1 in the photomorphogenic seedling development of Arabidopsis. (United States)

    Gangappa, Sreeramaiah N; Prasad, V Babu Rajendra; Chattopadhyay, Sudip


    MYC2 is a basic helix-loop-helix transcription factor that cross talks with light, abscisic acid (ABA), and jasmonic acid (JA) signaling pathways. Here, we have shown that Arabidopsis (Arabidopsis thaliana) MYC2 directly binds to the G-box present in the SUPPRESSOR OF PHYTOCHROME A1 (SPA1) promoter and that it controls the expression of SPA1 in a COP1-dependent manner. Analyses of atmyc2 spa1 double mutants suggest that whereas MYC2 and SPA1 act redundantly to suppress photomorphogenic growth in the dark, they function synergistically for the suppression of photomorphogenic growth in the light. Our studies have also revealed that MYC2-mediated ABA and JA responses are further modulated by SPA1. Taken together, this study demonstrates the molecular and physiological interrelations of MYC2 and SPA1 in light, ABA, and JA signaling pathways.

  7. Transcriptional control of GABAergic neuron development in the dorsal spinal cord

    Institute of Scientific and Technical Information of China (English)

    Huang Jing; Wu Shengxi


    GABAergic neurons are the major inhibitory interneurons that powerfully control the function of spinal neuronalnet works. In recent years, tremendous progresses have been made in understanding the transcriptional control of GABAergic neuron development in the dorsal spinal cord. New experimental approaches provide a relatively high throughput way to study the molecular regulation of subgroup fate determination. Our understanding of the molecular mechanisms on GABAergic neuron development in the dorsal spinal cord is rapidly expanding. Recent studies have defined several transcription factors that play essential roles in GABAergic neuron development in the spinal dorsal horn. Here, we review results of very recent analyses of the mechanisms that specify the GABAergic neuron development in the dorsal spinal cord, especially the progresses in the homeodomain (HD) and basic-helix-loop-helix(bHLH) containing transcription factors.

  8. Inhibition of Tcf3 binding by I-mfa domain proteins. (United States)

    Snider, L; Thirlwell, H; Miller, J R; Moon, R T; Groudine, M; Tapscott, S J


    We have determined that I-mfa, an inhibitor of several basic helix-loop-helix (bHLH) proteins, and XIC, a Xenopus ortholog of human I-mf domain-containing protein that shares a highly conserved cysteine-rich C-terminal domain with I-mfa, inhibit the activity and DNA binding of the HMG box transcription factor XTcf3. Ectopic expression of I-mfa or XIC in early Xenopus embryos inhibited dorsal axis specification, the expression of the Tcf3/beta-catenin-regulated genes siamois and Xnr3, and the ability of beta-catenin to activate reporter constructs driven by Lef/Tcf binding sites. I-mfa domain proteins can regulate both the Wnt signaling pathway and a subset of bHLH proteins, possibly coordinating the activities of these two critical developmental pathways.

  9. Structural basis of nucleic acid recognition by FK506-binding protein 25 (FKBP25), a nuclear immunophilin. (United States)

    Prakash, Ajit; Shin, Joon; Rajan, Sreekanth; Yoon, Ho Sup


    The nuclear immunophilin FKBP25 interacts with chromatin-related proteins and transcription factors and is suggested to interact with nucleic acids. Currently the structural basis of nucleic acid binding by FKBP25 is unknown. Here we determined the nuclear magnetic resonance (NMR) solution structure of full-length human FKBP25 and studied its interaction with DNA. The FKBP25 structure revealed that the N-terminal helix-loop-helix (HLH) domain and C-terminal FK506-binding domain (FKBD) interact with each other and that both of the domains are involved in DNA binding. The HLH domain forms major-groove interactions and the basic FKBD loop cooperates to form interactions with an adjacent minor-groove of DNA. The FKBP25-DNA complex model, supported by NMR and mutational studies, provides structural and mechanistic insights into the nuclear immunophilin-mediated nucleic acid recognition.

  10. Network theory inspired analysis of time-resolved expression data reveals key players guiding P. patens stem cell development. (United States)

    Busch, Hauke; Boerries, Melanie; Bao, Jie; Hanke, Sebastian T; Hiss, Manuel; Tiko, Theodhor; Rensing, Stefan A


    Transcription factors (TFs) often trigger developmental decisions, yet, their transcripts are often only moderately regulated and thus not easily detected by conventional statistics on expression data. Here we present a method that allows to determine such genes based on trajectory analysis of time-resolved transcriptome data. As a proof of principle, we have analysed apical stem cells of filamentous moss (P. patens) protonemata that develop from leaflets upon their detachment from the plant. By our novel correlation analysis of the post detachment transcriptome kinetics we predict five out of 1,058 TFs to be involved in the signaling leading to the establishment of pluripotency. Among the predicted regulators is the basic helix loop helix TF PpRSL1, which we show to be involved in the establishment of apical stem cells in P. patens. Our methodology is expected to aid analysis of key players of developmental decisions in complex plant and animal systems.

  11. Feedback regulation of NEUROG2 activity by MTGR1 is required for progression of neurogenesis. (United States)

    Aaker, Joshua D; Patineau, Andrea L; Yang, Hyun-Jin; Ewart, David T; Gong, Wuming; Li, Tongbin; Nakagawa, Yasushi; McLoon, Steven C; Koyano-Nakagawa, Naoko


    The sequential steps of neurogenesis are characterized by highly choreographed changes in transcription factor activity. In contrast to the well-studied mechanisms of transcription factor activation during neurogenesis, much less is understood regarding how such activity is terminated. We previously showed that MTGR1, a member of the MTG family of transcriptional repressors, is strongly induced by a proneural basic helix-loop-helix transcription factor, NEUROG2 in developing nervous system. In this study, we describe a novel feedback regulation of NEUROG2 activity by MTGR1. We show that MTGR1 physically interacts with NEUROG2 and represses transcriptional activity of NEUROG2. MTGR1 also prevents DNA binding of the NEUROG2/E47 complex. In addition, we provide evidence that proper termination of NEUROG2 activity by MTGR1 is necessary for normal progression of neurogenesis in the developing spinal cord. These results highlight the importance of feedback regulation of proneural gene activity in neurodevelopment.

  12. Dose-dependent regulation of target gene expression and cell proliferation by c-Myc levels. (United States)

    Schuhmacher, Marino; Eick, Dirk


    The proto-oncogene c-myc encodes a basic helix-loop-helix leucine zipper transcription factor (c-Myc). c-Myc plays a crucial role in cell growth and proliferation. Here, we examined how expression of c-Myc target genes and cell proliferation depend on variation of c-Myc protein levels. We show that proliferation rates, the number of cells in S-phase, and cell size increased in a dose-dependent manner in response to increasing c-Myc levels. Likewise, the mRNA levels of c-Myc responsive genes steadily increased with rising c-Myc levels. Strikingly, steady-state mRNA levels of c-Myc target genes did not saturate even at highest c-Myc concentrations. These characteristics predestine c-Myc levels as a cellular rheostat for the control and fine-tuning of cell proliferation and growth rates.

  13. Grasses use an alternatively wired bHLH transcription factor network to establish stomatal identity. (United States)

    Raissig, Michael T; Abrash, Emily; Bettadapur, Akhila; Vogel, John P; Bergmann, Dominique C


    Stomata, epidermal valves facilitating plant-atmosphere gas exchange, represent a powerful model for understanding cell fate and pattern in plants. Core basic helix-loop-helix (bHLH) transcription factors regulating stomatal development were identified in Arabidopsis, but this dicot's developmental pattern and stomatal morphology represent only one of many possibilities in nature. Here, using unbiased forward genetic screens, followed by analysis of reporters and engineered mutants, we show that stomatal initiation in the grass Brachypodium distachyon uses orthologs of stomatal regulators known from Arabidopsis but that the function and behavior of individual genes, the relationships among genes, and the regulation of their protein products have diverged. Our results highlight ways in which a kernel of conserved genes may be alternatively wired to produce diversity in patterning and morphology and suggest that the stomatal transcription factor module is a prime target for breeding or genome modification to improve plant productivity.

  14. RNA profiling and chromatin immunoprecipitation-sequencing reveal that PTF1a stabilizes pancreas progenitor identity via the control of MNX1/HLXB9 and a network of other transcription factors

    DEFF Research Database (Denmark)

    Thompson, Nancy; Gésina, Emilie; Scheinert, Peter;


    Pancreas development is initiated by the specification and expansion of a small group of endodermal cells. Several transcription factors are crucial for progenitor maintenance and expansion, but their interactions and the downstream targets mediating their activity are poorly understood. Among...... those factors, PTF1a, a basic helix-loop-helix (bHLH) transcription factor which controls pancreas exocrine cell differentiation, maintenance, and functionality, is also needed for the early specification of pancreas progenitors. We used RNA profiling and chromatin immunoprecipitation (ChIP) sequencing...... to identify a set of targets in pancreas progenitors. We demonstrate that Mnx1, a gene that is absolutely required in pancreas progenitors, is a major direct target of PTF1a and is regulated by a distant enhancer element. Pdx1, Nkx6.1, and Onecut1 are also direct PTF1a targets whose expression is promoted...

  15. Functional domains of the transcriptional activator NUC-1 in Neurospora crassa. (United States)

    Kang, S


    The NUC-1 regulatory protein directly controls the transcription of these genes and how the activity enzymes in Neurospora crassa. To understand how NUC-1 regulates the transcription of these genes and how the activity of NUC-1 is modulated by other regulatory proteins, two putative functional domains of NUC-1 were analysed: the DNA-binding domain and the regulatory domain. The DNA-binding activity of NUC-1 has not been directly demonstrated; however, results of deletion analysis, sequence analysis of the nuc-1 mutant alleles, and strong sequence similarity with the Saccharomyces cerevisiae PHO4 protein strongly suggest that the basic helix-loop-helix motif of NUC-1 forms a DNA-binding domain. Deletion and mutant analyses revealed that 39 amino acid (aa) residues (aa 463 to 501), or fewer, of NUC-1 are interacting with the negative regulatory factor(s), the PREG and/or PGOV proteins.

  16. Translocation of Neurospora crassa transcription factor NUC-1 into the nucleus is induced by phosphorus limitation. (United States)

    Peleg, Y; Addison, R; Aramayo, R; Metzenberg, R L


    NUC-1, a basic helix-loop-helix zipper protein, activates the expression of several genes involved in phosphorus acquisition in Neurospora crassa. In the present study we investigated whether posttranscriptional mechanisms control the activity of NUC-1. The NUC-1 level was higher (up to fivefold) in wild-type cells grown at low external phosphate concentration and in mutant strains expressing the phosphorus acquisition genes constitutively than in a wild-type strain grown at high external phosphate concentration. Using indirect immunofluorescence we demonstrated that NUC-1 is localized at least predominantly in the cytosol when wild-type N. crassa is grown with an adequate supply of phosphate, whereas NUC-1 is largely concentrated in the nucleus upon limitation of external phosphate. In mutant strains expressing the phosphorus acquisition genes constitutively, NUC-1 localization was also primarily in the nucleus. Thus, subcellular compartmentation of regulatory proteins is an important mechanism in regulating gene expression in filamentous fungi.

  17. Waardenburg syndrome type 2 caused by mutations in the human microphthalmia (MITF) gene. (United States)

    Tassabehji, M; Newton, V E; Read, A P


    Waardenburg syndrome type 2 (WS2) is a dominantly inherited syndrome of hearing loss and pigmentary disturbances. We recently mapped a WS2 gene to chromosome 3p12.3-p14.1 and proposed as a candidate gene MITF, the human homologue of the mouse microphthalmia (mi) gene. This encodes a putative basic-helix-loop-helix-leucine zipper transcription factor expressed in adult skin and in embryonic retina, otic vesicle and hair follicles. Mice carrying mi mutations show reduced pigmentation of the eyes and coat, and with some alleles, microphthalmia, hearing loss, osteopetrosis and mast cell defects. Here we show that affected individuals in two WS2 families have mutations affecting splice sites in the MITF gene.

  18. [Research progress of the bHLH transcription factors involved in genic male sterility in plants]. (United States)

    Yongming, Liu; Ling, Zhang; Jianyu, Zhou; Moju, Cao


    Male sterility exists widely in the spermatophytes. It contributes to the study of plant reproductive development and can be used as an effective tool for hybrid seed production in heterosis utilization. Therefore, the study on male sterility is of great value in both theory and application. As one of the largest transcription factor families in plants, basic helix-loop-helix proteins (bHLHs) play a crucial role in regulating plant growth and development. This paper introduces the mechanism of bHLH regulating stamen development in several important model plants. Furthermore, we discuss the molecular mechanisms of genic male sterility resulting from bHLH dysfunction to provide references for crop breeding and theoretical studies.

  19. Circadian transcription factor BMAL1 regulates innate immunity against select RNA viruses. (United States)

    Majumdar, Tanmay; Dhar, Jayeeta; Patel, Sonal; Kondratov, Roman; Barik, Sailen


    BMAL1 (brain and muscle ARNT-like protein 1, also known as MOP3 or ARNT3) belongs to the family of the basic helix-loop-helix (bHLH)-PAS domain-containing transcription factors, and is a key component of the molecular oscillator that generates circadian rhythms. Here, we report that BMAL1-deficient cells are significantly more susceptible to infection by two major respiratory viruses of the Paramyxoviridae family, namely RSV and PIV3. Embryonic fibroblasts from Bmal1(-/-) mice produced nearly 10-fold more progeny virus than their wild type controls. These results were supported by animal studies whereby pulmonary infection of RSV produced a more severe disease and morbidity in Bmal1(-/-)mice. These results show that BMAL1 can regulate cellular innate immunity against specific RNA viruses.

  20. Hypoxia-inducible factor-1α increased the expression of peroxisome proliferator activated receptor α in lung cancer cell A549

    Institute of Scientific and Technical Information of China (English)

    张惠兰; 张珍祥; 徐永健


    @@ Hypoxia plays a fundamental role in many pathologic processes. Hypoxia-inducible factor-1 (HIF-1) is a heterodimeric basic helix-loop-helix-per-aryl hydrocarbon receptor ARNT-sim (PAS) domain protein, consisting of α and β subunits and is precisely regulated by cellular oxygen levels.1 The peroxisome proliferator-activated receptors (PPARs) are family nuclear hormone-binding proteins with increasing diverse functions as transcriptional regulators, owning three subtypes (α, β, and γ).2 PPARα plays a critical physiological role as lipid sensors and regulators of proliferation.3 Hypoxia can elicit up-regulation of PPAR-α expression.4 Herein, we report the results of an investigation on the correlation of HIF-1α and PPARα.

  1. Iron assimilation and transcription factor controlled synthesis of riboflavin in plants. (United States)

    Vorwieger, A; Gryczka, C; Czihal, A; Douchkov, D; Tiedemann, J; Mock, H-P; Jakoby, M; Weisshaar, B; Saalbach, I; Bäumlein, H


    Iron homeostasis is vital for many cellular processes and requires a precise regulation. Several iron efficient plants respond to iron starvation with the excretion of riboflavin and other flavins. Basic helix-loop-helix transcription factors (TF) are involved in the regulation of many developmental processes, including iron assimilation. Here we describe the isolation and characterisation of two Arabidopsis bHLH TF genes, which are strongly induced under iron starvation. Their heterologous ectopic expression causes constitutive, iron starvation independent excretion of riboflavin. The results show that both bHLH TFs represent an essential component of the regulatory pathway connecting iron deficiency perception and riboflavin excretion and might act as integrators of various stress reactions.

  2. Time to pump iron: iron-deficiency-signaling mechanisms of higher plants. (United States)

    Walker, Elsbeth L; Connolly, Erin L


    Iron is an essential nutrient for plants, yet it often limits plant growth. On the contrary, overaccumulation of iron within plant cells leads to oxidative stress. As a consequence, iron-uptake systems are carefully regulated to ensure that iron homeostasis is maintained. In response to iron limitation, plants induce expression of sets of activities that function at the root-soil interface to solubilize iron and subsequently transfer it across the plasma membrane of root cells. Recent advances have revealed key players in the signaling pathways that function to induce these iron-uptake responses. Transcription factors belonging to the basic helix-loop-helix, ABI3/VP1(B3), and NAC families appear to function either directly or indirectly in the upregulation of iron deficiency responses.

  3. The Transcriptional Coregulator LEUNIG_HOMOLOG Inhibits Light-Dependent Seed Germination in Arabidopsis. (United States)

    Lee, Nayoung; Park, Jeongmoo; Kim, Keunhwa; Choi, Giltsu


    PHYTOCHROME-INTERACTING FACTOR1 (PIF1) is a basic helix-loop-helix transcription factor that inhibits light-dependent seed germination in Arabidopsis thaliana. However, it remains unclear whether PIF1 requires other factors to regulate its direct targets. Here, we demonstrate that LEUNIG_HOMOLOG (LUH), a Groucho family transcriptional corepressor, binds to PIF1 and coregulates its targets. Not only are the transcriptional profiles of the luh and pif1 mutants remarkably similar, more than 80% of the seeds of both genotypes germinate in the dark. We show by chromatin immunoprecipitation that LUH binds a subset of PIF1 targets in a partially PIF1-dependent manner. Unexpectedly, we found LUH binds and coregulates not only PIF1-activated targets but also PIF1-repressed targets. Together, our results indicate LUH functions with PIF1 as a transcriptional coregulator to inhibit seed germination.

  4. Transcription of a zebrafish gene of the hairy-Enhancer of split family delineates the midbrain anlage in the neural plate. (United States)

    Müller, M; von Weizsäcker, E; Campos-Ortega, J A


    her5 encodes a basic helix-loop-helix (bHLH) protein with all features characteristic of the Drosophila hairy-E(spl) family. her5 is expressed in a band of cells within the neural anlage from about 90% epiboly on to at least 36 h postfertilization (hpf). After completion of brain morphogenesis, her5-expressing cells are located in the caudal region of the midbrain, at the boundary with the rhombencephalon. Labelling of cells within the her5 expression domain in the neural plate by injection of fluorescein-dextran allows their labelled progeny to be localized in the 36-hpf-old embryo using an anti-fluorescein antibody. This shows that the her5 expression domain corresponds to the midbrain primordium, including both the tectum and the tegmentum, in the neural plate. A possible function for her5 in regionalization of the brain and/or control of the midbrain-hindbrain boundary is discussed.

  5. FHL2 Interacts with and Acts as a Functional Repressor of Id2 in Human Neuroblastoma Cells

    Institute of Scientific and Technical Information of China (English)

    Wei-dong Han; Zhi-qiang Wu; Ya-li Zhao; Yi-ling Si; Xiao-bing Fu


    Objective: Id2 is a natural inhibitor of the basic helix-loop-helix(bHLH) transcription factors. Although it is well known that active Id2 prevents differentiation and promotes cell cycle progression and tumorigenesis, the molecular events that regulate Id2 activity remain to be investigated.Methods: Yeast two-hybrid, mammalian two-hybrid, GST-pulldown and immunoprecipitation (CoIP) assays were used to screen and identify novel Id2 interactors. Luciferase assays were used to detect E47-mediated transcription activity. Colony formation and BrdU incorporation assays were used to determine cellular proliferation abilities. Northorn blot, western blot and quantitative PCR methods were used to measure gene expression levels. Electrophoretic mobility shift assays (EMSAs) were performed to investigate protein/DNA binding.Results: The LIM-only protein FHL2 (four-and-a-half-LIM-only protein 2) was identified to be a novel Id2 interactor. The HLH domain within Id2 is not required for its interaction with FHL2. FHL2 antagonizes the inhibitory effect of Id2 on the basic helix-loop-helix protein E47-mediated transcription. FHL2 prevents the formation of Id2-E47 heterdimer, thus releasing E47 to its target DNA and restoring its transcriptional activity. FHL2 expression was remarkably up-regulated during retinoic acid-induced differentiation of neuroblastoma cells, during which the expression of Id2 is opposite to that. Ectopic FHL2 expression in neuroblastoma cells markedly reduces the transcriptional and cell-cycle promoting functions of Id2.Conclusion: These results indicate that FHL2 is an important repressor of the oncogenic activity of Id2 in neuroblastoma cells.

  6. 细胞功能调控的重要转录因子TFEB%Function and regulation of the transcription factor TFEB

    Institute of Scientific and Technical Information of China (English)

    陈太琪; 姜丛; 王平; 刘宁


    TFEB is a member of the MiTF/TFE (microphthalmia-transcription factor E) subfamily of bHLH-LZ (basic-helix-loop-helix leucine-zipper) factors. And TFEB-related pathway is involved in some of cellular physiological processes and its regulating aberration has been known to contribute to the pathogenesis of several human diseases, such as placenta angiogenesis and renal cell carcinoma. Recent studies have shown that TFEB could regulate autophagy and lysosome function through regulating the expression of the related genes. Future study on the function and mechanism of TFEB will help better understand the pathological process and provide new theory basis and clues for the treatment of TFEB-related diseases.%转录因子TFEB (transcription factor EB)属于亮氨酸拉链bHLH-LZ (basic-helix-loop-helix leucine-zipper)类转录因子中的MiTF/TFE (microphthalmia-transcription factor E)家族成员,参与调控许多重要的细胞生理过程,例如胎盘血管新生、肾癌的发生等.最近研究表明,TFEB能通过调控细胞自噬和溶酶体相关的基因表达而调控细胞自噬以及溶酶体功能.因此,对于TFEB的生物学功能及其相关调控机制的研究,将为进一步阐释其生理病理发生过程及相关疾病的治疗提供重要的线索及理论依据.

  7. Inflation Basics

    Energy Technology Data Exchange (ETDEWEB)

    Green, Dan [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)


    inflation since metrical fluctuations, both scalar and tensor, are also produced in inflationary models. Thus, the time appears to be appropriate for a very basic and simple exposition of the inflationary model written from a particle physics perspective. Only the simplest scalar model will be explored because it is easy to understand and contains all the basic elements of the inflationary model.

  8. Inflation Basics

    Energy Technology Data Exchange (ETDEWEB)

    Green, Dan [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)


    inflation since metrical fluctuations, both scalar and tensor, are also produced in inflationary models. Thus, the time appears to be appropriate for a very basic and simple exposition of the inflationary model written from a particle physics perspective. Only the simplest scalar model will be explored because it is easy to understand and contains all the basic elements of the inflationary model.

  9. ERT basics

    Energy Technology Data Exchange (ETDEWEB)

    Butters, M. [MBC Energy and Environment, Ottawa, ON (Canada)]|[National Round Table on the Environment and the Economy, Ottawa, ON (Canada)


    ERT is an economic instrument which helps power companies achieve emission reduction compliance cost-effectively. This paper presents the basics of ERT with reference to trading concepts, types of systems and types of emissions. The paper also describes the state of the Canadian energy market regarding greenhouse gases (GHG), nitrogen oxides, sulphur dioxide and volatile organic compounds. The association between ERT and district energy is also explained. By 2010, the global market for GHG trading is expected to be worth $10 billion to $3 trillion U.S. Canada has committed to reducing its GHG to 6 per cent below 1990 levels by 2012, but currently emits 705 Mt per year. This is expected to increase to 770 Mt by 2010. Therefore, in order to meet its commitment, GHGs will have to be reduced 200 Mt per year. Canada is currently considering ratifying the Kyoto agreement and a trading system is being developed. There are several abatement technologies currently under consideration for district energy systems, including adding scrubbers, improving efficiency, and fuel switching. The marginal cost of abatement was also discussed. tabs., figs.


    Institute of Scientific and Technical Information of China (English)

    张德昌; 张宽仁


    The effect of nueleoside diphosphate kinase (NDPK) on the activity of guanine nueleotide regulatory protein (G-protein) mediated phospholipase C (PLC) and on the [35S ] GTPTτS binding of G-protein was investigated in this work in order to demonstrate the mechanism behind the regulation of G-protein and its effector PLC by NDPK. The stimulation of PLC in turkey erythrocyte membrane by both GTP and GTPτS indicated that the PLC stimulation was msdiated by G-protein, NDPK alone stimulated PLC activity, as well as the stimulation in the presence of GTP and GDP, in a dose-dependent manner. However, NDPK inhibited GTPτS-stimulated PLC, Furthermore, NDPK inhibited [35S] GTPτS binding of purified Gi-protein in a non-competitive manner. A hypothesis implying an important role of direct interaction of G-protein and NDPK in the regulation of their functions is suggested and discussed.

  11. Citrus tristeza virus p23: a unique protein mediating key virus-host interactions

    Directory of Open Access Journals (Sweden)

    Ricardo eFlores


    Full Text Available The large RNA genome of CTV (ca. 20 kb contains 12 open reading frames (ORFs, with the 3’-terminal one corresponding to a protein of 209 amino acids (p23 that is expressed from an abundant subgenomic RNA. p23, an RNA-binding protein with a putative Zn-finger domain and some basic motifs, is unique to CTV because no homologues have been found in other closteroviruses, including the type species of the genus Beet yellows virus (despite both viruses having many homologous genes. Consequently, p23 might have evolved for the specific interaction of CTV with its citrus hosts. From a functional perspective p23 has been involved in many roles: i regulation of the asymmetrical accumulation of CTV RNA strands, ii induction of the seedling yellows syndrome in sour orange and grapefruit, iii intracellular suppression of RNA silencing, iv elicitation of CTV-like symptoms when expressed ectopically as a transgene in several Citrus spp., and v enhancement of systemic infection (and virus accumulation in sour orange and CTV release from the phloem in p23-expressing transgenic sweet and sour orange. Moreover, transformation of Mexican lime with intron-hairpin constructs designed for the co-inactivation of p23 and the two other CTV silencing suppressors results in complete resistance against the homologous virus. From a cellular point of view, recent data indicate that p23 accumulates preferentially in the nucleolus, being the first closterovirus protein with such a subcellular localization, as well as in plasmodesmata. These major accumulation sites most likely determine some of the functional roles of p23.

  12. Sme4 coiled-coil protein mediates synaptonemal complex assembly, recombinosome relocalization, and spindle pole body morphogenesis. (United States)

    Espagne, Eric; Vasnier, Christelle; Storlazzi, Aurora; Kleckner, Nancy E; Silar, Philippe; Zickler, Denise; Malagnac, Fabienne


    We identify a large coiled-coil protein, Sme4/PaMe4, that is highly conserved among the large group of Sordariales and plays central roles in two temporally and functionally distinct aspects of the fungal sexual cycle: first as a component of the meiotic synaptonemal complex (SC) and then, after disappearing and reappearing, as a component of the spindle pole body (SPB). In both cases, the protein mediates spatial juxtaposition of two major structures: linkage of homolog axes through the SC and a change in the SPB from a planar to a bent conformation. Corresponding mutants exhibit defects, respectively, in SC and SPB morphogenesis, with downstream consequences for recombination and astral-microtubule nucleation plus postmeiotic nuclear migration. Sme4 is also required for reorganization of recombination complexes in which Rad51, Mer3, and Msh4 foci relocalize from an on-axis position to a between-axis (on-SC) position concomitant with SC installation. Because involved recombinosome foci represent total recombinational interactions, these dynamics are irrespective of their designation for maturation into cross-overs or noncross-overs. The defined dual roles for Sme4 in two different structures that function at distinct phases of the sexual cycle also provide more functional links and evolutionary dynamics among the nuclear envelope, SPB, and SC.

  13. Stem Cell Basics (United States)

    ... Tips Info Center Research Topics Federal Policy Glossary Stem Cell Information General Information Clinical Trials Funding Information Current ... Basics » Stem Cell Basics I. Back to top Stem Cell Basics I. Introduction: What are stem cells, and ...

  14. Basics of SCI Rehabilitation (United States)

    ... Donate Experts \\ The Basics of Spinal Cord Injury Rehabilitation Topics Adult Injuries Spinal Cord Injury 101 Spinal ... Injury 101 The Basics of Spinal Cord Injury Rehabilitation The Basics of Spinal Cord Injury Rehabilitation Preventing ...

  15. Basic Research Firing Facility (United States)

    Federal Laboratory Consortium — The Basic Research Firing Facility is an indoor ballistic test facility that has recently transitioned from a customer-based facility to a dedicated basic research...

  16. Body Basics Library (United States)

    ... of Healthy Breakfasts Shyness About the Body Basics Library KidsHealth > For Teens > About the Body Basics Library A A A Did you ever wonder what ... system, part, and process works. Use this medical library to find out about basic human anatomy, how ...

  17. Body Basics Library (United States)

    ... of Healthy Breakfasts Shyness About the Body Basics Library KidsHealth > For Teens > About the Body Basics Library Print A A A Did you ever wonder ... system, part, and process works. Use this medical library to find out about basic human anatomy, how ...

  18. Basic Cake Decorating Workbook. (United States)

    Bogdany, Mel

    Included in this student workbook for basic cake decorating are the following: (1) Drawings of steps in a basic way to ice a layer cake, how to make a paper cone, various sizes of flower nails, various sizes and types of tin pastry tubes, and special rose tubes; (2) recipes for basic decorating icings (buttercream, rose paste, and royal icing);…

  19. Basics of Bayesian Learning - Basically Bayes

    DEFF Research Database (Denmark)

    Larsen, Jan

    Tutorial presented at the IEEE Machine Learning for Signal Processing Workshop 2006, Maynooth, Ireland, September 8, 2006. The tutorial focuses on the basic elements of Bayesian learning and its relation to classical learning paradigms. This includes a critical discussion of the pros and cons...

  20. Basic molecular spectroscopy

    CERN Document Server

    Gorry, PA


    BASIC Molecular Spectroscopy discusses the utilization of the Beginner's All-purpose Symbolic Instruction Code (BASIC) programming language in molecular spectroscopy. The book is comprised of five chapters that provide an introduction to molecular spectroscopy through programs written in BASIC. The coverage of the text includes rotational spectra, vibrational spectra, and Raman and electronic spectra. The book will be of great use to students who are currently taking a course in molecular spectroscopy.

  1. Basic digital signal processing

    CERN Document Server

    Lockhart, Gordon B


    Basic Digital Signal Processing describes the principles of digital signal processing and experiments with BASIC programs involving the fast Fourier theorem (FFT). The book reviews the fundamentals of the BASIC program, continuous and discrete time signals including analog signals, Fourier analysis, discrete Fourier transform, signal energy, power. The text also explains digital signal processing involving digital filters, linear time-variant systems, discrete time unit impulse, discrete-time convolution, and the alternative structure for second order infinite impulse response (IIR) sections.

  2. Basic Research Objectives Reaffirmed

    Institute of Scientific and Technical Information of China (English)

    Guo Haiyan; Zhao Baohua


    @@ As a national institution for scientific research and a component of the national innovation system, CAS should and must make key contributions to the great national rejuvenation of the country. Keeping this in mind, CAS has developed four developmental targets for its basic research. This was revealed at a CAS conference on basic research held June 11-12 in Beijing.

  3. Cycles in basic innovations

    NARCIS (Netherlands)

    Groot, de E.A. (Bert); Franses, P.H.P.H.


    Basic innovations are often believed to be the drivers of economic growth. It has been widely documented that economic growth follows cyclical patterns of varying length. In this paper we examine if such patterns are also present in basic innovations. For an annual time series of count data covering

  4. Basic Science Training Program. (United States)

    Brummel, Clete

    These six learning modules were developed for Lake Michigan College's Basic Science Training Program, a workshop to develop good study skills while reviewing basic science. The first module, which was designed to provide students with the necessary skills to study efficiently, covers the following topics: time management; an overview of a study…

  5. Basic principle of superconductivity


    De Cao, Tian


    The basic principle of superconductivity is suggested in this paper. There have been two vital wrong suggestions on the basic principle, one is the relation between superconductivity and the Bose-Einstein condensation (BEC), and another is the relation between superconductivity and pseudogap.

  6. Basic stress analysis

    CERN Document Server

    Iremonger, M J


    BASIC Stress Analysis aims to help students to become proficient at BASIC programming by actually using it in an important engineering subject. It also enables the student to use computing as a means of learning stress analysis because writing a program is analogous to teaching-it is necessary to understand the subject matter. The book begins by introducing the BASIC approach and the concept of stress analysis at first- and second-year undergraduate level. Subsequent chapters contain a summary of relevant theory, worked examples containing computer programs, and a set of problems. Topics c

  7. Quantum electronics basic theory

    CERN Document Server

    Fain, V M; Sanders, J H


    Quantum Electronics, Volume 1: Basic Theory is a condensed and generalized description of the many research and rapid progress done on the subject. It is translated from the Russian language. The volume describes the basic theory of quantum electronics, and shows how the concepts and equations followed in quantum electronics arise from the basic principles of theoretical physics. The book then briefly discusses the interaction of an electromagnetic field with matter. The text also covers the quantum theory of relaxation process when a quantum system approaches an equilibrium state, and explai

  8. Hybrids of the bHLH and bZIP protein motifs display different DNA-binding activities in vivo vs. in vitro.

    Directory of Open Access Journals (Sweden)

    Hiu-Kwan Chow

    Full Text Available Minimalist hybrids comprising the DNA-binding domain of bHLH/PAS (basic-helix-loop-helix/Per-Arnt-Sim protein Arnt fused to the leucine zipper (LZ dimerization domain from bZIP (basic region-leucine zipper protein C/EBP were designed to bind the E-box DNA site, CACGTG, targeted by bHLHZ (basic-helix-loop-helix-zipper proteins Myc and Max, as well as the Arnt homodimer. The bHLHZ-like structure of ArntbHLH-C/EBP comprises the Arnt bHLH domain fused to the C/EBP LZ: i.e. swap of the 330 aa PAS domain for the 29 aa LZ. In the yeast one-hybrid assay (Y1H, transcriptional activation from the E-box was strong by ArntbHLH-C/EBP, and undetectable for the truncated ArntbHLH (PAS removed, as detected via readout from the HIS3 and lacZ reporters. In contrast, fluorescence anisotropy titrations showed affinities for the E-box with ArntbHLH-C/EBP and ArntbHLH comparable to other transcription factors (K(d 148.9 nM and 40.2 nM, respectively, but only under select conditions that maintained folded protein. Although in vivo yeast results and in vitro spectroscopic studies for ArntbHLH-C/EBP targeting the E-box correlate well, the same does not hold for ArntbHLH. As circular dichroism confirms that ArntbHLH-C/EBP is a much more strongly alpha-helical structure than ArntbHLH, we conclude that the nonfunctional ArntbHLH in the Y1H must be due to misfolding, leading to the false negative that this protein is incapable of targeting the E-box. Many experiments, including protein design and selections from large libraries, depend on protein domains remaining well-behaved in the nonnative experimental environment, especially small motifs like the bHLH (60-70 aa. Interestingly, a short helical LZ can serve as a folding- and/or solubility-enhancing tag, an important device given the focus of current research on exploration of vast networks of biomolecular interactions.

  9. Video Screen Capture Basics (United States)

    Dunbar, Laura


    This article is an introduction to video screen capture. Basic information of two software programs, QuickTime for Mac and BlueBerry Flashback Express for PC, are also discussed. Practical applications for video screen capture are given.

  10. HIV Treatment: The Basics (United States)

    HIV Treatment HIV Treatment: The Basics (Last updated 2/24/2017; last reviewed 2/24/2017) Key Points Antiretroviral therapy (ART) ... reduces the risk of HIV transmission . How do HIV medicines work? HIV attacks and destroys the infection- ...

  11. Kidney Disease Basics (United States)

    ... Links Take the first step Alternate Language URL Kidney Disease Basics Page Content Your kidneys filter extra ... blood pressure are the most common causes of kidney disease. ​These conditions can slowly damage the kidneys ...

  12. Health Literacy Basics (United States)

    ... have the capacity to obtain, process, and understand basic health information and services needed to make appropriate health decisions. 1 Health literacy is dependent on individual and systemic factors: Communication skills of lay persons and professionals Lay and professional ...

  13. Basic Financial Accounting

    DEFF Research Database (Denmark)

    Wiborg, Karsten

    This textbook on Basic Financial Accounting is targeted students in the economics studies at universities and business colleges having an introductory subject in the external dimension of the company's economic reporting, including bookkeeping, etc. The book includes the following subjects...

  14. Basic Concurrency Theory

    DEFF Research Database (Denmark)

    Løvengreen, Hans Henrik


    In this set of notes, we present some of the basic theory underlying the discipline of programming with concurrent processes/threads. The notes are intended to supplement a standard textbook on concurrent programming.......In this set of notes, we present some of the basic theory underlying the discipline of programming with concurrent processes/threads. The notes are intended to supplement a standard textbook on concurrent programming....

  15. Basic Electromagnetism and Materials

    CERN Document Server

    Moliton, André


    Basic Electromagnetism and Materials is the product of many years of teaching basic and applied electromagnetism. This textbook can be used to teach electromagnetism to a wide range of undergraduate science majors in physics, electrical engineering or materials science. However, by making lesser demands on mathematical knowledge than competing texts, and by emphasizing electromagnetic properties of materials and their applications, this textbook is uniquely suited to students of materials science. Many competing texts focus on the study of propagation waves either in the microwave or optical domain, whereas Basic Electromagnetism and Materials covers the entire electromagnetic domain and the physical response of materials to these waves. Professor André Moliton is Director of the Unité de Microélectronique, Optoélectronique et Polymères (Université de Limoges, France), which brings together three groups studying the optoelectronics of molecular and polymer layers, micro-optoelectronic systems for teleco...

  16. Nuclear multifragmentation: Basic concepts

    Indian Academy of Sciences (India)

    G Chaudhuri; S Mallik; S Das Gupta


    We present a brief overview of nuclear multifragmentation reaction. Basic formalism of canonical thermodynamical model based on equilibrium statistical mechanics is described. This model is used to calculate basic observables of nuclear multifragmentation like mass distribution, fragment multiplicity, isotopic distribution and isoscaling. Extension of canonical thermodynamical model to a projectile fragmentation model is outlined. Application of the projectile fragmentation model for calculating average number of intermediate mass fragments and the average size of the largest cluster at different bound, differential charge distribution and cross-section of neutron-rich nuclei of different projectile fragmentation reactions at different energies are described. Application of nuclear multifragmentation reaction in basic research as well as in other domains is outlined.

  17. Decontamination: back to basics. (United States)

    Meredith, Susan J; Sjorgen, Geoff


    My invitation from this Journal's Editor, Felicia Cox, to provide a paper for this themed issue, included the sentence 'I was wondering if you or a colleague would like to contribute a back to basics article on the relevant standards and guidelines for decontamination, including what is compliance?'. The reason it is so interesting to me is that the term 'back to basics' implies reverting to a simpler time in life - when by just sticking to the rules, life became easier. However, with decontamination this is not actually true.

  18. Comprehensive basic mathematics

    CERN Document Server

    Veena, GR


    Salient Features As per II PUC Basic Mathematics syllabus of Karnataka. Provides an introduction to various basic mathematical techniques and the situations where these could be usefully employed. The language is simple and the material is self-explanatory with a large number of illustrations. Assists the reader in gaining proficiency to solve diverse variety of problems. A special capsule containing a gist and list of formulae titled ''REMEMBER! Additional chapterwise arranged question bank and 3 model papers in a separate section---''EXAMINATION CORNER''.

  19. Basic set theory

    CERN Document Server

    Levy, Azriel


    An advanced-level treatment of the basics of set theory, this text offers students a firm foundation, stopping just short of the areas employing model-theoretic methods. Geared toward upper-level undergraduate and graduate students, it consists of two parts: the first covers pure set theory, including the basic motions, order and well-foundedness, cardinal numbers, the ordinals, and the axiom of choice and some of it consequences; the second deals with applications and advanced topics such as point set topology, real spaces, Boolean algebras, and infinite combinatorics and large cardinals. An

  20. Basic research championed (United States)

    Friebele, Elaine

    In April, the Office of National Science and Technology Policy released its biennial report to Congress. Science and Technology: Shaping the Twenty-First Century addresses the President's policy for maintaining U.S. leadership in science and technology, significant developments, and important national issues in science, and opportunities to use science and technology in federal programs and national goals. The administration strongly supports basic research as a sound investment and an inspiration to society. As corporate laboratories increasingly favor applied R&D projects, the federal government is becoming the dominant sponsor of long-term, basic research.

  1. Basic properties of semiconductors

    CERN Document Server

    Landsberg, PT


    Since Volume 1 was published in 1982, the centres of interest in the basic physics of semiconductors have shifted. Volume 1 was called Band Theory and Transport Properties in the first edition, but the subject has broadened to such an extent that Basic Properties is now a more suitable title. Seven chapters have been rewritten by the original authors. However, twelve chapters are essentially new, with the bulk of this work being devoted to important current topics which give this volume an almost encyclopaedic form. The first three chapters discuss various aspects of modern band theory and the

  2. Basic Financial Accounting

    DEFF Research Database (Denmark)

    Wiborg, Karsten

    This textbook on Basic Financial Accounting is targeted students in the economics studies at universities and business colleges having an introductory subject in the external dimension of the company's economic reporting, including bookkeeping, etc. The book includes the following subjects: busin......: business entities, the transformation process, types of businesses, stakeholders, legislation, the annual report, the VAT system, double-entry bookkeeping, inventories, and year-end cast flow analysis.......This textbook on Basic Financial Accounting is targeted students in the economics studies at universities and business colleges having an introductory subject in the external dimension of the company's economic reporting, including bookkeeping, etc. The book includes the following subjects...

  3. Ethanol Basics (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)


    Ethanol is a widely-used, domestically-produced renewable fuel made from corn and other plant materials. More than 96% of gasoline sold in the United States contains ethanol. Learn more about this alternative fuel in the Ethanol Basics Fact Sheet, produced by the U.S. Department of Energy's Clean Cities program.

  4. Korean Basic Course. (United States)

    Defense Language Inst., Washington, DC.

    These 11 volumes of the Korean Basic Course comprise 112 lesson units designed to train native English language speakers to Level 3 proficiency in comprehension and speaking and Level 2 proficiency in reading and writing Korean. (Level 5 on this scale is native-speaker level.) Intended for classroom use in the Defense Language Institute intensive…

  5. Basic physics for all

    CERN Document Server

    Kumar, B N


    This is a simple, concise book for both student and non-physics students, presenting basic facts in straightforward form and conveying fundamental principles and theories of physics. This book will be helpful as a supplement to class teaching and to aid those who have difficulty in mastering concepts and principles.

  6. Vaccine Basics (Smallpox) (United States)

    ... this page: About . Smallpox About Smallpox History of Smallpox Spread and Eradication of Smallpox Transmission Signs and Symptoms Prevention and Treatment Smallpox Vaccine Basics Vaccine Safety Side Effects of Vaccination Who Should Get a Smallpox Vaccination? Bioterrorism The ...

  7. FULA BASIC COURSE. (United States)



  8. Basic Library List. (United States)

    Duren, William L., Jr.

    Reported is an initial attempt to define a minimal college mathematics library. Included is a list of some 300 books, from which approximately 170 are to be chosen to form a basic library in undergraduate mathematics. The areas provided for in this list include Algebra, Analysis, Applied Mathematics, Geometry, Topology, Logic, Foundations and Set…

  9. Lippincott Basic Reading Program. (United States)

    Monterey Peninsula Unified School District, Monterey, CA.

    This program, included in "Effective Reading Programs...," serves 459 students in grades 1-3 at 15 elementary schools. The program employs a diagnostic-prescriptive approach to instruction in a nongraded setting through the use of the Lippincott Basic Reading program. When a child enters the program, he is introduced to a decoding…

  10. Basic Drafting: Book Two. (United States)

    Davis, Ronald; And Others

    The second of a two-book course in drafting, this manual consists of 12 topics in the following units: sketching techniques, geometric constructions, orthographic views, dimensioning procedures, basic tolerancing, auxiliary views, sectional views, inking tools and techniques, axonometrics, oblique, perspective, and computer-aided drafting.…

  11. Health Insurance Basics (United States)

    ... members at a lower cost. The four basic types of managed care plans are: HMO (Health Maintenance Organization). When you join an HMO, you choose a ... may have to pay more. EPO (Exclusive Provider Organization). An EPO is like a PPO, only ... Health Plan (CDHP) This type of plan is fairly new. It lets you ...

  12. Basic bioreactor design.

    NARCIS (Netherlands)

    Riet, van 't K.; Tramper, J.


    Based on a graduate course in biochemical engineering, provides the basic knowledge needed for the efficient design of bioreactors and the relevant principles and data for practical process engineering, with an emphasis on enzyme reactors and aerated reactors for microorganisms. Includes exercises.

  13. Basic Nuclear Physics. (United States)

    Bureau of Naval Personnel, Washington, DC.

    Basic concepts of nuclear structures, radiation, nuclear reactions, and health physics are presented in this text, prepared for naval officers. Applications to the area of nuclear power are described in connection with pressurized water reactors, experimental boiling water reactors, homogeneous reactor experiments, and experimental breeder…

  14. Canadian Adult Basic Education. (United States)

    Brooke, W. Michael, Comp.

    "Trends," a publication of the Canadian Association for Adult Education, is a collection of abstracts on selected subjects affecting adult education; this issue is on adult basic education (ABE). It covers teachers and teacher training, psychological factors relating to the ABE teacher and students, manuals for teachers, instructional…

  15. Basic Microfluidics Theory

    DEFF Research Database (Denmark)

    Svendsen, Winnie Edith


    ,000 m−1, which is a huge difference and has a large impact on flow behavior. In this chapter the basic microfluidic theory will be presented, enabling the reader to gain a comprehensive understanding of how liquids behave at the microscale, enough to be able to engage in design of micro systems...

  16. Basic Tuberculosis Facts

    Centers for Disease Control (CDC) Podcasts


    In this podcast, Dr. Kenneth Castro, Director of the Division of Tuberculosis Elimination, discusses basic TB prevention, testing, and treatment information.  Created: 3/12/2012 by National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention (NCHHSTP).   Date Released: 3/12/2012.

  17. Basic electronic circuits

    CERN Document Server

    Buckley, P M


    In the past, the teaching of electricity and electronics has more often than not been carried out from a theoretical and often highly academic standpoint. Fundamentals and basic concepts have often been presented with no indication of their practical appli­ cations, and all too frequently they have been illustrated by artificially contrived laboratory experiments bearing little relationship to the outside world. The course comes in the form of fourteen fairly open-ended constructional experiments or projects. Each experiment has associated with it a construction exercise and an explanation. The basic idea behind this dual presentation is that the student can embark on each circuit following only the briefest possible instructions and that an open-ended approach is thereby not prejudiced by an initial lengthy encounter with the theory behind the project; this being a sure way to dampen enthusiasm at the outset. As the investigation progresses, questions inevitably arise. Descriptions of the phenomena encounte...

  18. Basics of statistical physics

    CERN Document Server

    Müller-Kirsten, Harald J W


    Statistics links microscopic and macroscopic phenomena, and requires for this reason a large number of microscopic elements like atoms. The results are values of maximum probability or of averaging. This introduction to statistical physics concentrates on the basic principles, and attempts to explain these in simple terms supplemented by numerous examples. These basic principles include the difference between classical and quantum statistics, a priori probabilities as related to degeneracies, the vital aspect of indistinguishability as compared with distinguishability in classical physics, the differences between conserved and non-conserved elements, the different ways of counting arrangements in the three statistics (Maxwell-Boltzmann, Fermi-Dirac, Bose-Einstein), the difference between maximization of the number of arrangements of elements, and averaging in the Darwin-Fowler method. Significant applications to solids, radiation and electrons in metals are treated in separate chapters, as well as Bose-Eins...

  19. Basic linear algebra

    CERN Document Server

    Blyth, T S


    Basic Linear Algebra is a text for first year students leading from concrete examples to abstract theorems, via tutorial-type exercises. More exercises (of the kind a student may expect in examination papers) are grouped at the end of each section. The book covers the most important basics of any first course on linear algebra, explaining the algebra of matrices with applications to analytic geometry, systems of linear equations, difference equations and complex numbers. Linear equations are treated via Hermite normal forms which provides a successful and concrete explanation of the notion of linear independence. Another important highlight is the connection between linear mappings and matrices leading to the change of basis theorem which opens the door to the notion of similarity. This new and revised edition features additional exercises and coverage of Cramer's rule (omitted from the first edition). However, it is the new, extra chapter on computer assistance that will be of particular interest to readers:...

  20. Basic Semiconductor Physics

    CERN Document Server

    Hamaguchi, Chihiro


    This book presents a detailed description of the basic semiconductor physics. The reader is assumed to have a basic command of mathematics and some elementary knowledge of solid state physics. The text covers a wide range of important phenomena in semiconductors, from the simple to the advanced. The reader can understand three different methods of energy band calculations, empirical pseudo-potential, k.p perturbation and tight-binding methods. The effective mass approximation and electron motion in a periodic potential, Boltzmann transport equation and deformation potentials used for full band Monte Carlo simulation are discussed. Experiments and theoretical analysis of cyclotron resonance are discussed in detail because the results are essential to the understanding of semiconductor physics. Optical and transport properties, magneto-transport, two dimensional electron gas transport (HEMT and MOSFET), and quantum transport are reviewed, explaining optical transition, electron phonon interactions, electron mob...

  1. Basics of RF electronics

    CERN Document Server

    Gallo, A


    RF electronics deals with the generation, acquisition and manipulation of high-frequency signals. In particle accelerators signals of this kind are abundant, especially in the RF and beam diagnostics systems. In modern machines the complexity of the electronics assemblies dedicated to RF manipulation, beam diagnostics, and feedbacks is continuously increasing, following the demands for improvement of accelerator performance. However, these systems, and in particular their front-ends and back-ends, still rely on well-established basic hardware components and techniques, while down-converted and acquired signals are digitally processed exploiting the rapidly growing computational capability offered by the available technology. This lecture reviews the operational principles of the basic building blocks used for the treatment of high-frequency signals. Devices such as mixers, phase and amplitude detectors, modulators, filters, switches, directional couplers, oscillators, amplifiers, attenuators, and others are d...

  2. Basic plasma physics

    CERN Document Server

    Ghosh, Basudev


    Basic Plasma Physics is designed to serve as an introductory compact textbook for advanced undergraduate, postgraduate and research students taking plasma physics as one of their subject of study for the first time. It covers the current syllabus of plasma physics offered by the most universities and technical institutions. The book requires no background in plasma physics but only elementary knowledge of basic physics and mathematics. Emphasis has been given on the analytical approach. Topics are developed from first principle so that the students can learn through self-study. One chapter has been devoted to describe some practical aspects of plasma physics. Each chapter contains a good number of solved and unsolved problems and a variety of review questions, mostly taken from recent examination papers. Some classroom experiments described in the book will surely help students as well as instructors.

  3. Emulsion Science Basic Principles

    CERN Document Server

    Leal-Calderon, Fernando; Schmitt, Véronique


    Emulsions are generally made out of two immiscible fluids like oil and water, one being dispersed in the second in the presence of surface-active compounds.They are used as intermediate or end products in a huge range of areas including the food, chemical, cosmetic, pharmaceutical, paint, and coating industries. Besides the broad domain of technological interest, emulsions are raising a variety of fundamental questions at the frontier between physics and chemistry. This book aims to give an overview of the most recent advances in emulsion science. The basic principles, covering aspects of emulsions from their preparation to their destruction, are presented in close relation to both the fundamental physics and the applications of these materials. The book is intended to help scientists and engineers in formulating new materials by giving them the basics of emulsion science.

  4. Menstrual Cycle: Basic Biology



    The basic biology of the menstrual cycle is a complex, coordinated sequence of events involving the hypothalamus, anterior pituitary, ovary, and endometrium. The menstrual cycle with all its complexities can be easily perturbed by environmental factors such as stress, extreme exercise, eating disorders, and obesity. Furthermore, genetic influences such as fragile X premutations (Chapter X), X chromosome abnormalities (Chapter X), and galactose-1-phosphate uridyltransferase (GALT) point mutati...

  5. Risk communication basics

    Energy Technology Data Exchange (ETDEWEB)

    Corrado, P.G. [Lawrence Livermore National Laboratory, CA (United States)


    In low-trust, high-concern situations, 50% of your credibility comes from perceived empathy and caring, demonstrated in the first 30 s you come in contact with someone. There is no second chance for a first impression. These and other principles contained in this paper provide you with a basic level of understanding of risk communication. The principles identified are time-tested caveats and will assist you in effectively communicating technical information.

  6. Visual Basic educational programme


    Pranaitis, Arūnas


    Visual basic educational programme Informational Technologies has become such a popular subject that they are applied in all works of life. However, Informational Technologies are still rarely used in the lessons at school. There are such reasons of the mentioned issue: · Insufficient base of computers, · The old software and its disadvantages, · The lack of computerized educational programmes. The aim of the work was to prove that it is actual to create computerized educat...

  7. Basics of Computer Networking

    CERN Document Server

    Robertazzi, Thomas


    Springer Brief Basics of Computer Networking provides a non-mathematical introduction to the world of networks. This book covers both technology for wired and wireless networks. Coverage includes transmission media, local area networks, wide area networks, and network security. Written in a very accessible style for the interested layman by the author of a widely used textbook with many years of experience explaining concepts to the beginner.

  8. Thermodynamics - basic conception

    Energy Technology Data Exchange (ETDEWEB)

    Wee, Eul Bok


    This book tells of basic conception of thermodynamics, condition and property of matter, work and power, thermal efficiency, the principle of the conservation of energy, relationship between work and heat, enthalpy, Jouel's law, complete gasification, the second low of thermodynamics such as thermal efficiency and quality factor, carnot cycle, and entropy, condensation of gas like press of internal combustion engine, vapor, steam power plant and structure, internal combustion cycle, freeze cycle, flow of fluid, combustion and heat transfer.

  9. Decision support basics

    CERN Document Server

    Power, Daniel J


    This book is targeted to busy managers and MBA students who need to grasp the basics of computerized decision support. Some of the topics covered include: What is a DSS? What do managers need to know about computerized decision support? And how can managers identify opportunities to create innovative DSS? Overall the book addresses 35 fundamental questions that are relevant to understanding computerized decision support.

  10. The basic anaesthesia machine. (United States)

    Gurudatt, Cl


    After WTG Morton's first public demonstration in 1846 of use of ether as an anaesthetic agent, for many years anaesthesiologists did not require a machine to deliver anaesthesia to the patients. After the introduction of oxygen and nitrous oxide in the form of compressed gases in cylinders, there was a necessity for mounting these cylinders on a metal frame. This stimulated many people to attempt to construct the anaesthesia machine. HEG Boyle in the year 1917 modified the Gwathmey's machine and this became popular as Boyle anaesthesia machine. Though a lot of changes have been made for the original Boyle machine still the basic structure remains the same. All the subsequent changes which have been brought are mainly to improve the safety of the patients. Knowing the details of the basic machine will make the trainee to understand the additional improvements. It is also important for every practicing anaesthesiologist to have a thorough knowledge of the basic anaesthesia machine for safe conduct of anaesthesia.

  11. Gq protein mediates UVB-induced cyclooxygenase-2 expression by stimulating HB-EGF secretion from HaCaT human keratinocytes

    Energy Technology Data Exchange (ETDEWEB)

    Seo, MiRan [Department of Biochemistry and Molecular Biology and Cancer Research Institute, Seoul National University College of Medicine, Seoul (Korea, Republic of); Juhnn, Yong-Sung, E-mail: [Department of Biochemistry and Molecular Biology and Cancer Research Institute, Seoul National University College of Medicine, Seoul (Korea, Republic of)


    Ultraviolet (UV) radiation induces cyclooxygenase-2 expression to produce cellular responses including aging and carcinogenesis in skin. We hypothesised that heterotrimeric G proteins mediate UV-induced COX-2 expression by stimulating secretion of soluble HB-EGF (sHB-EGF). In this study, we aimed to elucidate the role and underlying mechanism of the {alpha} subunit of Gq protein (G{alpha}q) in UVB-induced HB-EGF secretion and COX-2 induction. We found that expression of constitutively active G{alpha}q (G{alpha}qQL) augmented UVB-induced HB-EGF secretion, which was abolished by knockdown of G{alpha}q with shRNA in HaCaT human keratinocytes. G{alpha}q was found to mediate the UVB-induced HB-EGF secretion by sequential activation of phospholipase C (PLC), protein kinase C{delta} (PKC{delta}), and matrix metaloprotease-2 (MMP-2). Moreover, G{alpha}qQL mediated UVB-induced COX-2 expression in an HB-EGF-, EGFR-, and p38-dependent manner. From these results, we concluded that G{alpha}q mediates UV-induced COX-2 expression through activation of EGFR by HB-EGF, of which ectodomain shedding was stimulated through sequential activation of PLC, PKC{delta} and MMP-2 in HaCaT cells.

  12. Catalyst in Basic Oleochemicals

    Directory of Open Access Journals (Sweden)

    Eva Suyenty


    Full Text Available Currently Indonesia is the world largest palm oil producer with production volume reaching 16 million tones per annum. The high crude oil and ethylene prices in the last 3 – 4 years contribute to the healthy demand growth for basic oleochemicals: fatty acids and fatty alcohols. Oleochemicals are starting to replace crude oil derived products in various applications. As widely practiced in petrochemical industry, catalyst plays a very important role in the production of basic oleochemicals. Catalytic reactions are abound in the production of oleochemicals: Nickel based catalysts are used in the hydrogenation of unsaturated fatty acids; sodium methylate catalyst in the transesterification of triglycerides; sulfonic based polystyrene resin catalyst in esterification of fatty acids; and copper chromite/copper zinc catalyst in the high pressure hydrogenation of methyl esters or fatty acids to produce fatty alcohols. To maintain long catalyst life, it is crucial to ensure the absence of catalyst poisons and inhibitors in the feed. The preparation methods of nickel and copper chromite catalysts are as follows: precipitation, filtration, drying, and calcinations. Sodium methylate is derived from direct reaction of sodium metal and methanol under inert gas. The sulfonic based polystyrene resin is derived from sulfonation of polystyrene crosslinked with di-vinyl-benzene. © 2007 BCREC UNDIP. All rights reserved.[Presented at Symposium and Congress of MKICS 2007, 18-19 April 2007, Semarang, Indonesia][How to Cite: E. Suyenty, H. Sentosa, M. Agustine, S. Anwar, A. Lie, E. Sutanto. (2007. Catalyst in Basic Oleochemicals. Bulletin of Chemical Reaction Engineering and Catalysis, 2 (2-3: 22-31.  doi:10.9767/bcrec.2.2-3.6.22-31][How to Link/DOI: || or local:

  13. Protective Effect of Electroacupuncture on Neural Myelin Sheaths is Mediated via Promotion of Oligodendrocyte Proliferation and Inhibition of Oligodendrocyte Death After Compressed Spinal Cord Injury. (United States)

    Huang, Siqin; Tang, Chenglin; Sun, Shanquan; Cao, Wenfu; Qi, Wei; Xu, Jin; Huang, Juan; Lu, Weitian; Liu, Qian; Gong, Biao; Zhang, Yi; Jiang, Jin


    Electroacupuncture (EA) has been used worldwide to treat demyelinating diseases, but its therapeutic mechanism is poorly understood. In this study, a custom-designed model of compressed spinal cord injury (CSCI) was used to induce demyelination. Zusanli (ST36) and Taixi (KI3) acupoints of adult rats were stimulated by EA to demonstrate its protective effect. At 14 days after EA, both locomotor skills and ultrastructural features of myelin sheath were significantly improved. Phenotypes of proliferating cells were identified by double immunolabeling of 5-ethynyl-2'-deoxyuridine with antibodies to cell markers: NG2 [oligodendrocyte precursor cell (OPC) marker], 2',3'-cyclic-nucleotide 3'-phosphodiesterase (CNPase) (oligodendrocyte marker), and glial fibrillary acidic protein (GFAP) (astrocyte marker). EA enhanced the proliferation of OPCs and CNPase, as well as the differentiation of OPCs by promoting Olig2 (the basic helix-loop-helix protein) and attenuating Id2 (the inhibitor of DNA binding 2). EA could also improve myelin basic protein (MBP) and protect existing oligodendrocytes from apoptosis by inhibiting caspase-12 (a representative of endoplasmic reticulum stress) and cytochrome c (an apoptotic factor and hallmark of mitochondria). Therefore, our results indicate that the protective effect of EA on neural myelin sheaths is mediated via promotion of oligodendrocyte proliferation and inhibition of oligodendrocyte death after CSCI.

  14. Regulation of the nuclear gene that encodes the alpha-subunit of the mitochondrial F0F1-ATP synthase complex. Activation by upstream stimulatory factor 2. (United States)

    Breen, G A; Jordan, E M


    We have previously identified several positive cis-acting regulatory regions in the promoters of the bovine and human nuclear-encoded mitochondrial F0F1-ATP synthase alpha-subunit genes (ATPA). One of these cis-acting regions contains the sequence 5'-CACGTG-3' (an E-box), to which a number of transcription factors containing a basic helix-loop-helix motif can bind. This E-box element is required for maximum activity of the ATPA promoter in HeLa cells. The present study identifies the human transcription factor, upstream stimulatory factor 2 (USF2), as a nuclear factor that binds to the ATPA E-box and demonstrates that USF2 plays a critical role in the activation of the ATPA gene in vivo. Evidence includes the following. Antiserum directed against USF2 recognized factors present in HeLa nuclear extracts that interact with the ATPA promoter in mobility shift assays. Wild-type USF2 proteins synthesized from expression vectors trans-activated the ATPA promoter through the E-box, whereas truncated USF2 proteins devoid of the amino-terminal activation domains did not. Importantly, expression of a dominant-negative mutant of USF2 lacking the basic DNA binding domain but able to dimerize with endogenous USF proteins significantly reduced the level of activation of the ATPA promoter caused by ectopically coexpressed USF2, demonstrating the importance of endogenous USF2 in activation of the ATPA gene.

  15. Metabolism of hydrophobic carbon sources and regulation of it in n-alkane-assimilating yeast Yarrowia lipolytica. (United States)

    Fukuda, Ryouichi


    A potent ability to assimilate hydrophobic compounds, including n-alkanes and fatty acids as carbon sources, is one of important characteristics of the yeast Yarrowia lipolytica, and has been studied for both basic microbiological interest and biotechnological applications. This review summarizes recent progress on the metabolism of n-alkanes and its transcriptional control in response to n-alkanes and to fatty acids in Y. lipolytica. In the metabolism of n-alkanes, cytochromes P450ALK catalyze their initial hydroxylation to fatty alcohols, which are subsequently converted to fatty acids and utilized. The transcription of ALK1, encoding a predominant cytochrome P450ALK, is regulated in response to n-alkanes by two basic helix-loop-helix transcription activators, Yas1p and Yas2p, and Opi1-family transcription repressor Yas3p. Transcription of the genes involved in fatty acid utilization and peroxisome biogenesis is controlled by Ctf1-family Zn2Cys6 type transcription factor Por1p in response to fatty acids in Y. lipolytica.

  16. Basic heat transfer

    CERN Document Server

    Bacon, D H


    Basic Heat Transfer aims to help readers use a computer to solve heat transfer problems and to promote greater understanding by changing data values and observing the effects, which are necessary in design and optimization calculations.The book is concerned with applications including insulation and heating in buildings and pipes, temperature distributions in solids for steady state and transient conditions, the determination of surface heat transfer coefficients for convection in various situations, radiation heat transfer in grey body problems, the use of finned surfaces, and simple heat exc

  17. Electrical installation calculations basic

    CERN Document Server

    Kitcher, Christopher


    All the essential calculations required for basic electrical installation workThe Electrical Installation Calculations series has proved an invaluable reference for over forty years, for both apprentices and professional electrical installation engineers alike. The book provides a step-by-step guide to the successful application of electrical installation calculations required in day-to-day electrical engineering practice. A step-by-step guide to everyday calculations used on the job An essential aid to the City & Guilds certificates at Levels 2 and 3Fo

  18. Back to basics audio

    CERN Document Server

    Nathan, Julian


    Back to Basics Audio is a thorough, yet approachable handbook on audio electronics theory and equipment. The first part of the book discusses electrical and audio principles. Those principles form a basis for understanding the operation of equipment and systems, covered in the second section. Finally, the author addresses planning and installation of a home audio system.Julian Nathan joined the audio service and manufacturing industry in 1954 and moved into motion picture engineering and production in 1960. He installed and operated recording theaters in Sydney, Austra

  19. Basic genetics for dermatologists

    Directory of Open Access Journals (Sweden)

    Muthu Sendhil Kumaran


    Full Text Available During the past few decades, advances in the field of molecular genetics have enriched us in understanding the pathogenesis of diseases, their identification, and appropriate therapeutic interventions. In the last 20 years, genetic basis of more than 350 monogenic skin diseases have been elucidated and is counting. The widespread use of molecular genetics as a tool in diagnosis is not practiced routinely due to genetic heterogenicity, limited access and low sensitivity. In this review, we have presented the very basics of genetics so as to enable dermatologists to have working understanding of medical genetics.

  20. Machine shop basics

    CERN Document Server

    Miller, Rex


    Use the right tool the right wayHere, fully updated to include new machines and electronic/digital controls, is the ultimate guide to basic machine shop equipment and how to use it. Whether you're a professional machinist, an apprentice, a trade student, or a handy homeowner, this fully illustrated volume helps you define tools and use them properly and safely. It's packed with review questions for students, and loaded with answers you need on the job.Mark Richard Miller is a Professor and Chairman of the Industrial Technology Department at Texas A&M University in Kingsville, T

  1. C# Database Basics

    CERN Document Server

    Schmalz, Michael


    Working with data and databases in C# certainly can be daunting if you're coming from VB6, VBA, or Access. With this hands-on guide, you'll shorten the learning curve considerably as you master accessing, adding, updating, and deleting data with C#-basic skills you need if you intend to program with this language. No previous knowledge of C# is necessary. By following the examples in this book, you'll learn how to tackle several database tasks in C#, such as working with SQL Server, building data entry forms, and using data in a web service. The book's code samples will help you get started

  2. Menstrual Cycle: Basic Biology (United States)

    Hawkins, Shannon M.; Matzuk, Martin M.


    The basic biology of the menstrual cycle is a complex, coordinated sequence of events involving the hypothalamus, anterior pituitary, ovary, and endometrium. The menstrual cycle with all its complexities can be easily perturbed by environmental factors such as stress, extreme exercise, eating disorders, and obesity. Furthermore, genetic influences such as fragile X premutations (Chapter X), X chromosome abnormalities (Chapter X), and galactose-1-phosphate uridyltransferase (GALT) point mutations (galactosemia) also contribute to perturbations of the menstrual cycle. Although not perfect, mouse model have helped to identify and confirm additional components and pathways in menstrual cycle function and dysfunction in humans. PMID:18574203

  3. Basic structural dynamics

    CERN Document Server

    Anderson, James C


    A concise introduction to structural dynamics and earthquake engineering Basic Structural Dynamics serves as a fundamental introduction to the topic of structural dynamics. Covering single and multiple-degree-of-freedom systems while providing an introduction to earthquake engineering, the book keeps the coverage succinct and on topic at a level that is appropriate for undergraduate and graduate students. Through dozens of worked examples based on actual structures, it also introduces readers to MATLAB, a powerful software for solving both simple and complex structural d

  4. Basic and clinical immunology (United States)

    Chinen, Javier; Shearer, William T.


    Progress in immunology continues to grow exponentially every year. New applications of this knowledge are being developed for a broad range of clinical conditions. Conversely, the study of primary and secondary immunodeficiencies is helping to elucidate the intricate mechanisms of the immune system. We have selected a few of the most significant contributions to the fields of basic and clinical immunology published between October 2001 and October 2002. Our choice of topics in basic immunology included the description of T-bet as a determinant factor for T(H)1 differentiation, the role of the activation-induced cytosine deaminase gene in B-cell development, the characterization of CD4(+)CD25(+) regulatory T cells, and the use of dynamic imaging to study MHC class II transport and T-cell and dendritic cell membrane interactions. Articles related to clinical immunology that were selected for review include the description of immunodeficiency caused by caspase 8 deficiency; a case series report on X-linked agammaglobulinemia; the mechanism of action, efficacy, and complications of intravenous immunoglobulin; mechanisms of autoimmunity diseases; and advances in HIV pathogenesis and vaccine development. We also reviewed two articles that explore the possible alterations of the immune system caused by spaceflights, a new field with increasing importance as human space expeditions become a reality in the 21st century.

  5. Basic research projects

    Energy Technology Data Exchange (ETDEWEB)


    The research programs under the cognizance of the Office of Energy Research (OER) are directed toward discovery of natural laws and new knowledge, and to improved understanding of the physical and biological sciences as related to the development, use, and control of energy. The ultimate goal is to develop a scientific underlay for the overall DOE effort and the fundamental principles of natural phenomena so that these phenomena may be understood, and new principles, formulated. The DOE-OER outlay activities include three major programs: High Energy Physics, Nuclear Physics, and Basic Energy Sciences. Taken together, these programs represent some 30 percent of the Nation's Federal support of basic research in the energy sciences. The research activities of OER involve more than 6,000 scientists and engineers working in some 17 major Federal Research Centers and at more than 135 different universities and industrial firms throughout the United States. Contract holders in the areas of high-energy physics, nuclear physics, materials sciences, nuclear science, chemical sciences, engineering, mathematics geosciences, advanced energy projects, and biological energy research are listed. Funding trends for recent years are outlined. (RWR)

  6. Attenuation of G protein-mediated inhibition of N-type calcium currents by expression of caveolins in mammalian NG108–15 cells (United States)

    Toselli, M; Taglietti, V; Parente, V; Flati, S; Pavan, A; Guzzi, F; Parenti, M


    Caveolins are integral proteins of glycolipid/cholesterol-rich plasmalemmal caveolae domains, where, they may function as a plasma membrane scaffold onto which many classes of signalling molecules, including receptors and heterotrimeric G proteins, can assemble. To ascertain whether caveolins influence G protein-mediated signal transduction, we stably expressed caveolin-1 and −3 isoforms in the neuroblastoma × glioma NG108–15 hybrid cell line, lacking endogenous caveolins. Subsequently, using whole-cell voltage clamp methods, we examined whether the modulation of N-type voltage-gated Ca2+ channels by Go protein-coupled, δ-type opioid receptors might be affected by recombinant caveolin expression. In transfected NG108–15 cells, caveolins localized at the plasma membrane and, upon subcellular fractionation on sucrose density gradients, they co-localized in Triton-resistant, low buoyancy fractions, with endogenous Go protein α-subunits. The voltage-dependent inhibition of ω-conotoxin GVIA-sensitive Ba2+ currents following either activation of δ-opioid receptors by the agonist [o-pen2,o-pen5]-enkephalin (DPDPE), or direct stimulation of G proteins with guanosine 5′-O-(thiotriphosphate) (GTPγS) was significantly attenuated in caveolin-expressing cells. The kinetics of Ca2+ channel inhibition were also modified by caveolins. Overall, these results suggest that caveolins may negatively affect G protein-dependent regulation of voltage-gated N-type Ca2+ channels, presumably by causing a reduction of the available pool of activated G proteins. PMID:11600672

  7. Basic real analysis

    CERN Document Server

    Sohrab, Houshang H


    This expanded second edition presents the fundamentals and touchstone results of real analysis in full rigor, but in a style that requires little prior familiarity with proofs or mathematical language. The text is a comprehensive and largely self-contained introduction to the theory of real-valued functions of a real variable. The chapters on Lebesgue measure and integral have been rewritten entirely and greatly improved. They now contain Lebesgue’s differentiation theorem as well as his versions of the Fundamental Theorem(s) of Calculus. With expanded chapters, additional problems, and an expansive solutions manual, Basic Real Analysis, Second Edition, is ideal for senior undergraduates and first-year graduate students, both as a classroom text and a self-study guide. Reviews of first edition: The book is a clear and well-structured introduction to real analysis aimed at senior undergraduate and beginning graduate students. The prerequisites are few, but a certain mathematical sophistication is required. ....

  8. Basics of plasma astrophysics

    CERN Document Server

    Chiuderi, Claudio


    This book is an introduction to contemporary plasma physics that discusses the most relevant recent advances in the field and covers a careful choice of applications to various branches of astrophysics and space science. The purpose of the book is to allow the student to master the basic concepts of plasma physics and to bring him or her up to date in a number of relevant areas of current research. Topics covered include orbit theory, kinetic theory, fluid models, magnetohydrodynamics, MHD turbulence, instabilities, discontinuities, and magnetic reconnection. Some prior knowledge of classical physics is required, in particular fluid mechanics, statistical physics, and electrodynamics. The mathematical developments are self-contained and explicitly detailed in the text. A number of exercises are provided at the end of each chapter, together with suggestions and solutions.

  9. Anisotropic hydrodynamics -- basic concepts

    CERN Document Server

    Florkowski, Wojciech; Ryblewski, Radoslaw; Strickland, Michael


    Due to the rapid longitudinal expansion of the quark-gluon plasma created in relativistic heavy ion collisions, potentially large local rest frame momentum-space anisotropies are generated. The magnitude of these momentum-space anisotropies can be so large as to violate the central assumption of canonical viscous hydrodynamical treatments which linearize around an isotropic background. In order to better describe the early-time dynamics of the quark gluon plasma, one can consider instead expanding around a locally anisotropic background which results in a dynamical framework called anisotropic hydrodynamics. In this proceedings contribution we review the basic concepts of the anisotropic hydrodynamics framework presenting viewpoints from both the phenomenological and microscopic points of view.

  10. Cloud computing basics

    CERN Document Server

    Srinivasan, S


    Cloud Computing Basics covers the main aspects of this fast moving technology so that both practitioners and students will be able to understand cloud computing. The author highlights the key aspects of this technology that a potential user might want to investigate before deciding to adopt this service. This book explains how cloud services can be used to augment existing services such as storage, backup and recovery. Addressing the details on how cloud security works and what the users must be prepared for when they move their data to the cloud. Also this book discusses how businesses could prepare for compliance with the laws as well as industry standards such as the Payment Card Industry.

  11. Atomic Basic Blocks (United States)

    Scheler, Fabian; Mitzlaff, Martin; Schröder-Preikschat, Wolfgang

    Die Entscheidung, einen zeit- bzw. ereignisgesteuerten Ansatz für ein Echtzeitsystem zu verwenden, ist schwierig und sehr weitreichend. Weitreichend vor allem deshalb, weil diese beiden Ansätze mit äußerst unterschiedlichen Kontrollflussabstraktionen verknüpft sind, die eine spätere Migration zum anderen Paradigma sehr schwer oder gar unmöglich machen. Wir schlagen daher die Verwendung einer Zwischendarstellung vor, die unabhängig von der jeweils verwendeten Kontrollflussabstraktion ist. Für diesen Zweck verwenden wir auf Basisblöcken basierende Atomic Basic Blocks (ABB) und bauen darauf ein Werkzeug, den Real-Time Systems Compiler (RTSC) auf, der die Migration zwischen zeit- und ereignisgesteuerten Systemen unterstützt.

  12. Bimolecular fluorescence complementation as a tool to study interactions of regulatory proteins in plant protoplasts. (United States)

    Pattanaik, Sitakanta; Werkman, Joshua R; Yuan, Ling


    Protein-protein interactions are an important aspect of the gene regulation process. The expression of a gene in response to certain stimuli, within a specific cell type or at a particular developmental stage, involves a complex network of interactions between different regulatory proteins and the cis-regulatory elements present in the promoter of the gene. A number of methods have been developed to study protein-protein interactions in vitro and in vivo in plant cells, one of which is bimolecular fluorescence complementation (BiFC). BiFC is a relatively simple technique based upon the reconstitution of a fluorescent protein. The interacting protein complex can be visualized directly in a living plant cell when two non-fluorescent fragments, of an otherwise fluorescent protein, are fused to proteins found within that complex. Interaction of tagged proteins brings the two non-fluorescent fragments into close proximity and reconstitutes the fluorescent protein. In addition, the subcellular location of an interacting protein complex in the cell can be simultaneously determined. Using this approach, we have successfully demonstrated a protein-protein interaction between a R2R3 MYB and a basic helix-loop-helix MYC transcription factor related to flavonoid biosynthetic pathway in tobacco protoplasts.

  13. The DET1-COP1-HY5 Pathway Constitutes a Multipurpose Signaling Module Regulating Plant Photomorphogenesis and Thermomorphogenesis

    Directory of Open Access Journals (Sweden)

    Carolin Delker


    Full Text Available Developmental plasticity enables plants to respond to elevated ambient temperatures by adapting their shoot architecture. On the cellular level, the basic-helix-loop-helix (bHLH transcription factor PHYTOCHROME INTERACTING FACTOR 4 (PIF4 coordinates this response by activating hormonal modules that in turn regulate growth. In addition to an unknown temperature-sensing mechanism, it is currently not understood how temperature regulates PIF4 activity. Using a forward genetic approach in Arabidopsis thaliana, we present extensive genetic evidence demonstrating that the DE-ETIOLATED 1 (DET1-CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1-ELONGATED HYPOCOTYL 5 (HY5-dependent photomorphogenesis pathway transcriptionally regulates PIF4 to coordinate seedling growth in response to elevated temperature. Our findings demonstrate that two of the most prevalent environmental cues, light and temperature, share a much larger set of signaling components than previously assumed. Similar to the toolbox concept in animal embryonic patterning, multipurpose signaling modules might have evolved in plants to translate various environmental stimuli into adaptational growth processes.

  14. Molecular characterisation, evolution and expression of hypoxia-inducible factor in Aurelia sp.1. (United States)

    Wang, Guoshan; Yu, Zhigang; Zhen, Yu; Mi, Tiezhu; Shi, Yan; Wang, Jianyan; Wang, Minxiao; Sun, Song


    The maintenance of physiological oxygen homeostasis is mediated by hypoxia-inducible factor (HIF), a key transcriptional factor of the PHD-HIF system in all metazoans. However, the molecular evolutionary origin of this central physiological regulatory system is not well characterized. As the earliest eumetazoans, Cnidarians can be served as an interesting model for exploring the HIF system from an evolutionary perspective. We identified the complete cDNA sequence of HIF-1α (ASHIF) from the Aurelia sp.1, and the predicted HIF-1α protein (pASHIF) was comprised of 674 amino acids originating from 2,025 bp nucleotides. A Pairwise comparison revealed that pASHIF not only possessed conserved basic helix-loop-helix (bHLH) and Per-Arnt-Sim (PAS) domains but also contained the oxygen dependent degradation (ODD) and the C-terminal transactivation domains (C-TAD), the key domains for hypoxia regulation. As indicated by sequence analysis, the ASHIF gene contains 8 exons interrupted by 7 introns. Western blot analysis indicated that pASHIF that existed in the polyps and medusa of Aurelia. sp.1 was more stable for a hypoxic response than normoxia.

  15. MDL-1, a growth- and tumor-suppressor, slows aging and prevents germline hyperplasia and hypertrophy in C. elegans. (United States)

    Riesen, Michèle; Feyst, Inna; Rattanavirotkul, Nattaphong; Ezcurra, Marina; Tullet, Jennifer M A; Papatheodorou, Irene; Ziehm, Matthias; Au, Catherine; Gilliat, Ann F; Hellberg, Josephine; Thornton, Janet M; Gems, David


    In C. elegans, increased lifespan in daf-2 insulin/IGF-1 receptor mutants is accompanied by up-regulation of the MDL-1 Mad basic helix-loop-helix leucine zipper transcription factor. Here we describe the role of mdl-1 in C. elegans germline proliferation and aging. The deletion allele mdl-1(tm311) shortened lifespan, and did so significantly more so in long-lived daf-2 mutants implying that mdl-1(+) contributes to effects of daf-2 on lifespan. mdl-1 mutant hermaphrodites also lay increased numbers of unfertilized oocytes. During aging, unfertilized oocytes in the uterus develop into tumors, whose development was accelerated by mdl-1(tm311). Opposite phenotypes were seen in daf-2 mutants, i.e. mdl-1 and daf-2 mutant germlines are hyperplastic and hypoplastic, respectively. Thus, MDL-1, like its mammalian orthologs, is an inhibitor of cell proliferation and growth that slows progression of an age-related pathology in C. elegans (uterine tumors). In addition, intestine-limited rescue of mdl-1 increased lifespan but not to wild type levels. Thus, mdl-1 likely acts both in the intestine and the germline to influence age-related mortality.

  16. An ABA-increased interaction of the PYL6 ABA receptor with MYC2 Transcription Factor: A putative link of ABA and JA signaling. (United States)

    Aleman, Fernando; Yazaki, Junshi; Lee, Melissa; Takahashi, Yohei; Kim, Alice Y; Li, Zixing; Kinoshita, Toshinori; Ecker, Joseph R; Schroeder, Julian I


    Abscisic acid (ABA) is a plant hormone that mediates abiotic stress tolerance and regulates growth and development. ABA binds to members of the PYL/RCAR ABA receptor family that initiate signal transduction inhibiting type 2C protein phosphatases. Although crosstalk between ABA and the hormone Jasmonic Acid (JA) has been shown, the molecular entities that mediate this interaction have yet to be fully elucidated. We report a link between ABA and JA signaling through a direct interaction of the ABA receptor PYL6 (RCAR9) with the basic helix-loop-helix transcription factor MYC2. PYL6 and MYC2 interact in yeast two hybrid assays and the interaction is enhanced in the presence of ABA. PYL6 and MYC2 interact in planta based on bimolecular fluorescence complementation and co-immunoprecipitation of the proteins. Furthermore, PYL6 was able to modify transcription driven by MYC2 using JAZ6 and JAZ8 DNA promoter elements in yeast one hybrid assays. Finally, pyl6 T-DNA mutant plants show an increased sensitivity to the addition of JA along with ABA in cotyledon expansion experiments. Overall, the present study identifies a direct mechanism for transcriptional modulation mediated by an ABA receptor different from the core ABA signaling pathway, and a putative mechanistic link connecting ABA and JA signaling pathways.

  17. NeuroD1 mediates nicotine-induced migration and invasion via regulation of the nicotinic acetylcholine receptor subunits in a subset of neural and neuroendocrine carcinomas. (United States)

    Osborne, Jihan K; Guerra, Marcy L; Gonzales, Joshua X; McMillan, Elizabeth A; Minna, John D; Cobb, Melanie H


    Cigarette smoking is a major risk factor for acquisition of small cell lung cancer (SCLC). A role has been demonstrated for the basic helix-loop-helix transcription factor NeuroD1 in the pathogenesis of neural and neuroendocrine lung cancer, including SCLC. In the present study we investigate the possible function of NeuroD1 in established tumors, as well as actions early on in pathogenesis, in response to nicotine. We demonstrate that nicotine up-regulates NeuroD1 in immortalized normal bronchial epithelial cells and a subset of undifferentiated carcinomas. Increased expression of NeuroD1 subsequently leads to regulation of expression and function of the nicotinic acetylcholine receptor subunit cluster of α3, α5, and β4. In addition, we find that coordinated expression of these subunits by NeuroD1 leads to enhanced nicotine-induced migration and invasion, likely through changes in intracellular calcium. These findings suggest that aspects of the pathogenesis of neural and neuroendocrine lung cancers may be affected by a nicotine- and NeuroD1-induced positive feedback loop.

  18. MAGED1 is a novel regulator of a select subset of bHLH PAS transcription factors. (United States)

    Sullivan, Adrienne E; Peet, Daniel J; Whitelaw, Murray L


    Transcription factors of the basic helix-loop-helix (bHLH) PER-ARNT-SIM (PAS) family generally have critical and nonredundant biological roles, but some bHLH PAS proteins compete for common cofactors or recognise similar DNA elements. Identifying factors that regulate function of bHLH PAS proteins, particularly in cells where multiple family members are coexpressed, is important for understanding bHLH PAS factor biology. This study identifies and characterises a novel interaction between melanoma-associated antigen D1 (MAGED1) and select members of the bHLH PAS transcription factor family. MAGED1 binds and positively regulates the transcriptional activity of family members SIM1, SIM2, NPAS4 and ARNT2, but does not interact with AhR, HIF1α and ARNT. This interaction is mediated by PAS repeat regions which also form the interface for bHLH PAS dimerisation, and accordingly MAGED1 is not found in complex with bHLH PAS dimers. We show that MAGED1 does not affect bHLH PAS protein levels and cannot be acting as a coactivator of transcriptionally active heterodimers, but rather appears to interact with nascent bHLH PAS proteins in the cytoplasm to enhance their function prior to nuclear import. As a selective regulator, MAGED1 may play an important role in the biology of these specific factors and in general bHLH PAS protein dynamics.

  19. Antioxidant Functions of the Aryl Hydrocarbon Receptor

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    Cornelia Dietrich


    Full Text Available The aryl hydrocarbon receptor (AhR is a transcription factor belonging to the basic helix-loop-helix/PER-ARNT-SIM family. It is activated by a variety of ligands, such as environmental contaminants like polycyclic aromatic hydrocarbons or dioxins, but also by naturally occurring compounds and endogenous ligands. Binding of the ligand leads to dimerization of the AhR with aryl hydrocarbon receptor nuclear translocator (ARNT and transcriptional activation of several xenobiotic phase I and phase II metabolizing enzymes. It is generally accepted that the toxic responses of polycyclic aromatic hydrocarbons, dioxins, and structurally related compounds are mediated by activation of the AhR. A multitude of studies indicate that the AhR operates beyond xenobiotic metabolism and exerts pleiotropic functions. Increasing evidence points to a protective role of the AhR against carcinogenesis and oxidative stress. Herein, I will highlight data demonstrating a causal role of the AhR in the antioxidant response and present novel findings on potential AhR-mediated antioxidative mechanisms.

  20. Elicitor-induced transcription factors for metabolic reprogramming of secondary metabolism in Medicago truncatula

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    Dixon Richard A


    Full Text Available Abstract Background Exposure of Medicago truncatula cell suspension cultures to pathogen or wound signals leads to accumulation of various classes of flavonoid and/or triterpene defense molecules, orchestrated via a complex signalling network in which transcription factors (TFs are essential components. Results In this study, we analyzed TFs responding to yeast elicitor (YE or methyl jasmonate (MJ. From 502 differentially expressed TFs, WRKY and AP2/EREBP gene families were over-represented among YE-induced genes whereas Basic Helix-Loop-Helix (bHLH family members were more over-represented among the MJ-induced genes. Jasmonate ZIM-domain (JAZ transcriptional regulators were highly induced by MJ treatment. To investigate potential involvement of WRKY TFs in signalling, we expressed four Medicago WRKY genes in tobacco. Levels of soluble and wall bound phenolic compounds and lignin were increased in all cases. WRKY W109669 also induced tobacco endo-1,3-β-glucanase (NtPR2 and enhanced the systemic defense response to tobacco mosaic virus in transgenic tobacco plants. Conclusion These results confirm that Medicago WRKY TFs have broad roles in orchestrating metabolic responses to biotic stress, and that they also represent potentially valuable reagents for engineering metabolic changes that impact pathogen resistance.

  1. RSL Class I Genes Controlled the Development of Epidermal Structures in the Common Ancestor of Land Plants. (United States)

    Proust, Hélène; Honkanen, Suvi; Jones, Victor A S; Morieri, Giulia; Prescott, Helen; Kelly, Steve; Ishizaki, Kimitsune; Kohchi, Takayuki; Dolan, Liam


    The colonization of the land by plants, sometime before 470 million years ago, was accompanied by the evolution tissue systems [1-3]. Specialized structures with diverse functions-from nutrient acquisition to reproduction-derived from single cells in the outermost layer (epidermis) were important sources of morphological innovation at this time [2, 4, 5]. In extant plants, these structures may be unicellular extensions, such as root hairs or rhizoids [6-9], or multicellular structures, such as asexual propagules or secretory hairs (papillae) [10-12]. Here, we show that a ROOTHAIR DEFECTIVE SIX-LIKE (RSL) class I basic helix-loop-helix transcription factor positively regulates the development of the unicellular and multicellular structures that develop from individual cells that expand out of the epidermal plane of the liverwort Marchantia polymorpha; mutants that lack MpRSL1 function do not develop rhizoids, slime papillae, mucilage papillae, or gemmae. Furthermore, we discovered that RSL class I genes are also required for the development of multicellular axillary hairs on the gametophyte of the moss Physcomitrella patens. Because class I RSL proteins also control the development of rhizoids in mosses and root hairs in angiosperms [13, 14], these data demonstrate that the function of RSL class I genes was to control the development of structures derived from single epidermal cells in the common ancestor of the land plants. Class I RSL genes therefore controlled the generation of adaptive morphological diversity as plants colonized the land from the water.

  2. Differential contribution of transcription factors to Arabidopsis thaliana defence against Spodoptera littoralis.

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    Fabian eSchweizer


    Full Text Available In response to insect herbivory, Arabidopsis plants activate the synthesis of the phytohormone jasmonate-isoleucine (JA-Ile, which binds to a complex consisting of the receptor COI1 and JAZ repressors. Upon proteasome-mediated JAZ degradation, basic helix-loop-helix transcription factors (TFs MYC2, MYC3, and MYC4 become activated and this results in the expression of defence genes. Although the jasmonate (JA pathway is known to be essential for the massive transcriptional reprogramming that follows herbivory, there is however little information on other TFs that are required for defence against herbivores and whether they contribute significantly to JA-dependent defence gene expression. By transcriptome profiling, we identified 41 TFs that were induced in response to herbivory by the generalist Spodoptera littoralis. Among them, nine genes, including WRKY18, WRKY40, ANAC019, ANAC055, ZAT10, ZAT12, AZF2, ERF13, and RRTF1, were found to play a significant role in resistance to S. littoralis herbivory. However, compared to the triple mutant myc234 that is as sensitive as coi1-1 to herbivory, knockout lines of these nine TFs were only partially more sensitive to S. littoralis and showed only minor gene expression changes at the whole genome level. Data thus reveal that MYC2, MYC3, and MYC4 are master regulators of Arabidopsis resistance to a generalist herbivore and identify new genes involved in insect defence.

  3. Structure of the leukemia oncogene LMO2: implications for the assembly of a hematopoietic transcription factor complex. (United States)

    El Omari, Kamel; Hoosdally, Sarah J; Tuladhar, Kapil; Karia, Dimple; Vyas, Paresh; Patient, Roger; Porcher, Catherine; Mancini, Erika J


    The LIM only protein 2 (LMO2) is a key regulator of hematopoietic stem cell development whose ectopic expression in T cells leads to the onset of acute lymphoblastic leukemia. Through its LIM domains, LMO2 is thought to function as the scaffold for a DNA-binding transcription regulator complex, including the basic helix-loop-helix proteins SCL/TAL1 and E47, the zinc finger protein GATA-1, and LIM-domain interacting protein LDB1. To understand the role of LMO2 in the formation of this complex and ultimately to dissect its function in normal and aberrant hematopoiesis, we solved the crystal structure of LMO2 in complex with the LID domain of LDB1 at 2.4 Å resolution. We observe a largely unstructured LMO2 kept in register by the LID binding both LIM domains. Comparison of independently determined crystal structures of LMO2 reveals large movements around a conserved hinge between the LIM domains. We demonstrate that such conformational flexibility is necessary for binding of LMO2 to its partner protein SCL/TAL1 in vitro and for the function of this complex in vivo. These results, together with molecular docking and analysis of evolutionarily conserved residues, yield the first structural model of the DNA-binding complex containing LMO2, LDB1, SCL/TAL1, and GATA-1.

  4. Physiological loading of tendons induces scleraxis expression in epitenon fibroblasts. (United States)

    Mendias, Christopher L; Gumucio, Jonathan P; Bakhurin, Konstantin I; Lynch, Evan B; Brooks, Susan V


    Scleraxis is a basic helix-loop-helix transcription factor that plays a central role in promoting fibroblast proliferation and matrix synthesis during the embryonic development of tendons. Mice with a targeted inactivation of scleraxis (Scx(-/-)) fail to properly form limb tendons, but the role that scleraxis has in regulating the growth and adaptation of tendons of adult organisms is unknown. To determine if scleraxis expression changes in response to a physiological growth stimulus to tendons, we subjected adult mice that express green fluorescent protein (GFP) under the control of the scleraxis promoter (ScxGFP) to a 6-week-treadmill training program designed to induce adaptive growth in Achilles tendons. Age matched sedentary ScxGFP mice were used as controls. Scleraxis expression was sparsely observed in the epitenon region of sedentary mice, but in response to treadmill training, scleraxis was robustly expressed in fibroblasts that appeared to be emerging from the epitenon and migrating into the superficial regions of tendon fascicles. Treadmill training also led to an increase in scleraxis, tenomodulin, and type I collagen gene expression as measured by qPCR. These results suggest that in addition to regulating the embryonic formation of limb tendons, scleraxis also appears to play an important role in the adaptation of adult tendons to physiological loading.

  5. Sterol Regulatory Element Binding Protein (Srb1) Is Required for Hypoxic Adaptation and Virulence in the Dimorphic Fungus Histoplasma capsulatum (United States)

    DuBois, Juwen C.; Smulian, A. George


    The Histoplasma capsulatum sterol regulatory element binding protein (SREBP), Srb1 is a member of the basic helix-loop-helix (bHLH), leucine zipper DNA binding protein family of transcription factors that possess a unique tyrosine (Y) residue instead of an arginine (R) residue in the bHLH region. We have determined that Srb1 message levels increase in a time dependent manner during growth under oxygen deprivation (hypoxia). To further understand the role of Srb1 during infection and hypoxia, we silenced the gene encoding Srb1 using RNA interference (RNAi); characterized the resulting phenotype, determined its response to hypoxia, and its ability to cause disease within an infected host. Silencing of Srb1 resulted in a strain of H. capsulatum that is incapable of surviving in vitro hypoxia. We found that without complete Srb1 expression, H. capsulatum is killed by murine macrophages and avirulent in mice given a lethal dose of yeasts. Additionally, silencing Srb1 inhibited the hypoxic upregulation of other known H. capsulatum hypoxia-responsive genes (HRG), and genes that encode ergosterol biosynthetic enzymes. Consistent with these regulatory functions, Srb1 silenced H. capsulatum cells were hypersensitive to the antifungal azole drug itraconazole. These data support the theory that the H. capsulatum SREBP is critical for hypoxic adaptation and is required for H. capsulatum virulence. PMID:27711233

  6. MicroRNA 146 (Mir146) modulates spermatogonial differentiation by retinoic acid in mice. (United States)

    Huszar, Jessica M; Payne, Christopher J


    Impaired biogenesis of microRNAs disrupts spermatogenesis and leads to infertility in male mice. Spermatogonial differentiation is a key step in spermatogenesis, yet the mechanisms that control this event remain poorly defined. In this study, we discovered microRNA 146 (Mir146) to be highly regulated during spermatogonial differentiation, a process dependent on retinoic acid (RA) signaling. Mir146 transcript levels were diminished nearly 180-fold in differentiating spermatogonia when compared with undifferentiated spermatogonia. Luciferase assays revealed the direct binding of Mir146 to the 3' untranslated region of the mediator complex subunit 1 (Med1), a coregulator of retinoid receptors (RARs and RXRs). Overexpression of Mir146 in cultured undifferentiated spermatogonia reduced Med1 transcript levels, as well as those of differentiation marker kit oncogene (Kit). MED1 protein was also diminished. Conversely, inhibition of Mir146 increased the levels of Kit. When undifferentiated spermatogonia were exposed to RA, Mir146 was downregulated along with a marker for undifferentiated germ cells, zinc finger and BTB domain containing 16 (Zbtb16; Plzf); Kit was upregulated. Overexpression of Mir146 in RA-treated spermatogonia inhibited the upregulation of Kit, stimulated by retinoic acid gene 8 (Stra8), and spermatogenesis- and oogenesis-specific basic helix-loop-helix 2 (Sohlh2). Inhibition of Mir146 in RA-treated spermatogonia greatly enhanced the upregulation of these genes. We conclude that Mir146 modulates the effects of RA on spermatogonial differentiation.

  7. MicroRNA 146 (Mir146) Modulates Spermatogonial Differentiation by Retinoic Acid in Mice1 (United States)

    Huszar, Jessica M.; Payne, Christopher J.


    ABSTRACT Impaired biogenesis of microRNAs disrupts spermatogenesis and leads to infertility in male mice. Spermatogonial differentiation is a key step in spermatogenesis, yet the mechanisms that control this event remain poorly defined. In this study, we discovered microRNA 146 (Mir146) to be highly regulated during spermatogonial differentiation, a process dependent on retinoic acid (RA) signaling. Mir146 transcript levels were diminished nearly 180-fold in differentiating spermatogonia when compared with undifferentiated spermatogonia. Luciferase assays revealed the direct binding of Mir146 to the 3′ untranslated region of the mediator complex subunit 1 (Med1), a coregulator of retinoid receptors (RARs and RXRs). Overexpression of Mir146 in cultured undifferentiated spermatogonia reduced Med1 transcript levels, as well as those of differentiation marker kit oncogene (Kit). MED1 protein was also diminished. Conversely, inhibition of Mir146 increased the levels of Kit. When undifferentiated spermatogonia were exposed to RA, Mir146 was downregulated along with a marker for undifferentiated germ cells, zinc finger and BTB domain containing 16 (Zbtb16; Plzf); Kit was upregulated. Overexpression of Mir146 in RA-treated spermatogonia inhibited the upregulation of Kit, stimulated by retinoic acid gene 8 (Stra8), and spermatogenesis- and oogenesis-specific basic helix-loop-helix 2 (Sohlh2). Inhibition of Mir146 in RA-treated spermatogonia greatly enhanced the upregulation of these genes. We conclude that Mir146 modulates the effects of RA on spermatogonial differentiation. PMID:23221399

  8. The effect of carbon monoxide integrating nitric oxide through auxin signal in Arabidopsis to modulate iron deficiency

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    Liming eYang


    Full Text Available Carbon monoxide (CO and nitric oxide (NO are essential modulators that regulate the plant response to iron deficiency (-Fe. Auxin is a phytohormone that plays important roles in plant growth and development. We report here that in Arabidopsis –Fe enhanced heme oxygenase-dependent CO generation and auxin transport through redistribution of PIN1 protein, which subsequently increased NO accumulation; NO signaling regulated the activity of ferric chelate reductase (FCR and the expression of Fe-uptake genes including basic helix-loop-helix transcription factor (FIT and the ferric reduction oxidase 2 (FRO2. Over-expression of HY1 encoding heme oxygenase, or treatment with CO donor enhanced basipetal auxin transport, FCR activity, and the expressions of FIT and FRO2 under –Fe. Such effects were compromised in the mutant aux1-7 impaired in auxin transport or in the mutant noa1 or nia1/nia2 defective in NO biosynthesis. -Fe failed to promote auxin transport and FCR activity in hy1 mutant; such inability was reversed in the double mutant of hy1/yucca1 with elevated auxin production, or in hy1/cue1 mutant with NO over-accumulation. Taken together, our results suggest that CO modulates NO signaling through auxin to cope with Fe deficiency in Arabidopsis.

  9. The Clock gene clone and its circadian rhythms in Pelteobagrus vachelli (United States)

    Qin, Chuanjie; Shao, Ting


    The Clock gene, a key molecule in circadian systems, is widely distributed in the animal kingdom. We isolated a 936-bp partial cDNA sequence of the Clock gene ( Pva-clock) from the darkbarbel catfish Pelteobagrus vachelli that exhibited high identity with Clock genes of other species of fish and animals (65%-88%). The putative domains included a basic helix-loop-helix (bHLH) domain and two period-ARNT-single-minded (PAS) domains, which were also similar to those in other species of fish and animals. Pva-Clock was primarily expressed in the brain, and was detected in all of the peripheral tissues sampled. Additionally, the pattern of Pva-Clock expression over a 24-h period exhibited a circadian rhythm in the brain, liver and intestine, with the acrophase at zeitgeber time 21:35, 23:00, and 23:23, respectively. Our results provide insight into the function of the molecular Clock of P. vachelli.

  10. Regulation of the Drosophila Hypoxia-Inducible Factor α Sima by CRM1-Dependent Nuclear Export ▿ (United States)

    Romero, Nuria M.; Irisarri, Maximiliano; Roth, Peggy; Cauerhff, Ana; Samakovlis, Christos; Wappner, Pablo


    Hypoxia-inducible factor α (HIF-α) proteins are regulated by oxygen levels through several different mechanisms that include protein stability, transcriptional coactivator recruitment, and subcellular localization. It was previously reported that these transcription factors are mainly nuclear in hypoxia and cytoplasmic in normoxia, but so far the molecular basis of this regulation is unclear. We show here that the Drosophila melanogaster HIF-α protein Sima shuttles continuously between the nucleus and the cytoplasm. We identified the relevant nuclear localization signal and two functional nuclear export signals (NESs). These NESs are in the Sima basic helix-loop-helix (bHLH) domain and promote CRM1-dependent nuclear export. Site-directed mutagenesis of either NES provoked Sima nuclear retention and increased transcriptional activity, suggesting that nuclear export contributes to Sima regulation. The identified NESs are conserved and probably functional in the bHLH domains of several bHLH-PAS proteins. We propose that rapid nuclear export of Sima regulates the duration of cellular responses to hypoxia. PMID:18332128

  11. The bHLH142 Transcription Factor Coordinates with TDR1 to Modulate the Expression of EAT1 and Regulate Pollen Development in Rice. (United States)

    Ko, Swee-Suak; Li, Min-Jeng; Sun-Ben Ku, Maurice; Ho, Yi-Cheng; Lin, Yi-Jyun; Chuang, Ming-Hsing; Hsing, Hong-Xian; Lien, Yi-Chen; Yang, Hui-Ting; Chang, Hung-Chia; Chan, Ming-Tsair


    Male sterility plays an important role in F1 hybrid seed production. We identified a male-sterile rice (Oryza sativa) mutant with impaired pollen development and a single T-DNA insertion in the transcription factor gene bHLH142. Knockout mutants of bHLH142 exhibited retarded meiosis and defects in tapetal programmed cell death. RT-PCR and in situ hybridization analyses showed that bHLH142 is specifically expressed in the anther, in the tapetum, and in meiocytes during early meiosis. Three basic helix-loop-helix transcription factors, UDT1 (bHLH164), TDR1 (bHLH5), and EAT1/DTD1 (bHLH141) are known to function in rice pollen development. bHLH142 acts downstream of UDT1 and GAMYB but upstream of TDR1 and EAT1 in pollen development. In vivo and in vitro assays demonstrated that bHLH142 and TDR1 proteins interact. Transient promoter assays demonstrated that regulation of the EAT1 promoter requires bHLH142 and TDR1. Consistent with these results, 3D protein structure modeling predicted that bHLH142 and TDR1 form a heterodimer to bind to the EAT1 promoter. EAT1 positively regulates the expression of AP37 and AP25, which induce tapetal programmed cell death. Thus, in this study, we identified bHLH142 as having a pivotal role in tapetal programmed cell death and pollen development.

  12. Neuronal differentiation of human iPS cells induced by baicalin via regulation of bHLH gene expression. (United States)

    Morita, Akihiro; Soga, Kohei; Nakayama, Hironobu; Ishida, Torao; Kawanishi, Shosuke; Sato, Eisuke F


    Efficient differentiation is important for regenerative medicine based on pluripotent stem cells, including treatment of neurodegenerative disorders and trauma. Baicalin promotes neuronal differentiation of neural stem/progenitor cells of rats and mice. To evaluate the suitability of baicalin for neuronal differentiation of human iPS cells, we investigated whether it promotes neuronal differentiation in human iPS cells and monitored basic helix-loop-helix (bHLH) gene expression during neuronal differentiation. Baicalin promoted neuronal differentiation and inhibited glial differentiation, suggesting that baicalin can influence the neuronal fate decision in human iPS cells. Notch signaling, which is upstream of bHLH proteins, was not involved in baicalin-induced neuronal differentiation. Baicalin treatment did not down-regulate Hes1 gene expression, but it reduced Hes1 protein levels and up-regulated Ascl1 gene expression. Thus, baicalin promoted neuronal differentiation via modulation of bHLH transcriptional factors. Therefore, baicalin has potential to be used as a small-molecule drug for regenerative treatment of neurodegenerative disorders.

  13. The mutational spectrum in Waardenburg syndrome

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    Read, A.P.; Tassabehji, M.; Liu, X.Z. [and others


    101 individuals or families with Waardenburg syndrome (WS) or related abnormalities have been screened for mutations in the PAX3 gene. PAX3 mutations were seen in 19 of 35 individuals or families with features of Type I Waardenburg syndrome. None of the 47 Type 2 WS families showed any PAX3 mutation, nor did any of 19 individuals with other neural crest syndromes or pigmentary disturbances. PAX3 mutations included substitutions of highly conserved amino acids, splice site mutations, nonsense mutations and frameshifting deletions or insertions. One patient (with Type 1 WS, mental retardation and growth retardation) had a chromosomal deletion of 7-8 Mb encompassing the PAX3 gene. Mutations were seen in each of exons 2-6, with a concentration in the 5{prime} part of the paired box (exon 2) and the 3{prime} part of the homeobox (exon 6). There was no evident relation between the molecular change and the clinical manifestations in mutation carriers. We conclude that PAX3 dosage effects very specifically produce dystopia canthorum, the distinguishing feature of Type 1 WS, and variably produce the other features of Type 1 WS depending on genetic background or chance events. Two of the Type 2 families showed linkage to markers from 3p14, the location of the MITF gene. MITF encodes a basic helix-loop-helix-zipper protein which is the homologue of the mouse microphthalmia gene product. It is likely that mutations in MITF cause some but not all Type 2 WS.

  14. Tgfβ-Smad and MAPK signaling mediate scleraxis and proteoglycan expression in heart valves. (United States)

    Barnette, Damien N; Hulin, Alexia; Ahmed, A S Ishtiaq; Colige, Alain C; Azhar, Mohamad; Lincoln, Joy


    Mature heart valves are complex structures consisting of three highly organized extracellular matrix layers primarily composed of collagens, proteoglycans and elastin. Collectively, these diverse matrix components provide all the necessary biomechanical properties for valve function throughout life. In contrast to healthy valves, myxomatous valve disease is the most common cause of mitral valve prolapse in the human population and is characterized by an abnormal abundance of proteoglycans within the valve tri-laminar structure. Despite the clinical significance, the etiology of this phenotype is not known. Scleraxis (Scx) is a basic-helix-loop-helix transcription factor that we previously showed to be required for establishing heart valve structure during remodeling stages of valvulogenesis. In this study, we report that remodeling heart valves from Scx null mice express decreased levels of proteoglycans, particularly chondroitin sulfate proteoglycans (CSPGs), while overexpression in embryonic avian valve precursor cells and adult porcine valve interstitial cells increases CSPGs. Using these systems we further identify that Scx is positively regulated by canonical Tgfβ2 signaling during this process and this is attenuated by MAPK activity. Finally, we show that Scx is increased in myxomatous valves from human patients and mouse models, and overexpression in human mitral valve interstitial cells modestly increases proteoglycan expression consistent with myxomatous mitral valve phenotypes. Together, these studies identify an important role for Scx in regulating proteoglycans in embryonic and mature valve cells and suggest that imbalanced regulation could influence myxomatous pathogenesis.

  15. Characterization of MxFIT, an iron deficiency induced transcriptional factor in Malus xiaojinensis. (United States)

    Yin, Lili; Wang, Yi; Yuan, Mudan; Zhang, Xinzhong; Xu, Xuefeng; Han, Zhenhai


    Iron deficiency often results in nutritional disorder in fruit trees. Transcription factors play an important role in the regulation of iron uptake. In this study, we isolated an iron deficiency response transcription factor gene, MxFIT, from an iron-efficient apple genotype of Malus xiaojinensis. MxFIT encoded a basic helix-loop-helix protein and contained a 966 bp open reading frame. MxFIT protein was targeted to the nucleus in onion epidermal cells and showed strong transcriptional activation in yeast cells. Spatiotemporal expression analysis revealed that MxFIT was up-regulated in roots under iron deficiency at both mRNA and protein levels, while almost no expression was detected in leaves irrespective of iron supply. Ectopic expression of MxFIT resulted in enhanced iron deficiency responses in Arabidopsis under iron deficiency and stronger resistance to iron deficiency. Thus, MxFIT might be involved in iron uptake and plays an important role in iron deficiency response.

  16. [Mutation screening of MITF gene in patients with Waardenburg syndrome type 2]. (United States)

    Chen, Jing; Yang, Shu-Zhi; Liu, Jun; Han, Bing; Wang, Guo-Jian; Zhang, Xin; Kang, Dong-Yang; Dai, Pu; Young, Wie-Yen; Yuan, Hui-Jun


    Warrgenburg syndrome type 2 (WS2) is the most common autosomal dominantly-inherited syndrome with hearing loss. MITF (microphthalmia associated transcription factor)is a basic-helix-loop-helix-luecine zipper (bHLHZip) factor which regulates expression of tyrosinase, and is involved in melanocyte differentiation. Mutations in MITF associated with WS2 have been identified in some but not all affected families. Here, we report a three-generation Chinese family with a point mutation in the MITF gene causing WS2. The proband exhibits congenital severe sensorineural hearing loss, heterochromia iridis and facial freckles. One of family members manifests sensorineural deafness, and the other patients show premature greying or/and freckles. This mutation, heterozygous deletion c.639delA, creates a stop codon in exon 7 and is predicted to result in a truncated protein lacking normal interaction with its target DNA motif. This mutation is a novel mutation and the third case identified in exon 7 of MITF in WS2. Though there is only one base pair distance between this novel mutation and the other two documented cases and similar amino acids change, significant difference is seen in clinical phenotype, which suggests genetic background may play an important role.

  17. The bHLH transcription factor BIS1 controls the iridoid branch of the monoterpenoid indole alkaloid pathway in Catharanthus roseus. (United States)

    Van Moerkercke, Alex; Steensma, Priscille; Schweizer, Fabian; Pollier, Jacob; Gariboldi, Ivo; Payne, Richard; Vanden Bossche, Robin; Miettinen, Karel; Espoz, Javiera; Purnama, Purin Candra; Kellner, Franziska; Seppänen-Laakso, Tuulikki; O'Connor, Sarah E; Rischer, Heiko; Memelink, Johan; Goossens, Alain


    Plants make specialized bioactive metabolites to defend themselves against attackers. The conserved control mechanisms are based on transcriptional activation of the respective plant species-specific biosynthetic pathways by the phytohormone jasmonate. Knowledge of the transcription factors involved, particularly in terpenoid biosynthesis, remains fragmentary. By transcriptome analysis and functional screens in the medicinal plant Catharanthus roseus (Madagascar periwinkle), the unique source of the monoterpenoid indole alkaloid (MIA)-type anticancer drugs vincristine and vinblastine, we identified a jasmonate-regulated basic helix-loop-helix (bHLH) transcription factor from clade IVa inducing the monoterpenoid branch of the MIA pathway. The bHLH iridoid synthesis 1 (BIS1) transcription factor transactivated the expression of all of the genes encoding the enzymes that catalyze the sequential conversion of the ubiquitous terpenoid precursor geranyl diphosphate to the iridoid loganic acid. BIS1 acted in a complementary manner to the previously characterized ethylene response factor Octadecanoid derivative-Responsive Catharanthus APETALA2-domain 3 (ORCA3) that transactivates the expression of several genes encoding the enzymes catalyzing the conversion of loganic acid to the downstream MIAs. In contrast to ORCA3, overexpression of BIS1 was sufficient to boost production of high-value iridoids and MIAs in C. roseus suspension cell cultures. Hence, BIS1 might be a metabolic engineering tool to produce sustainably high-value MIAs in C. roseus plants or cultures.

  18. Multiple post-domestication origins of kabuli chickpea through allelic variation in a diversification-associated transcription factor. (United States)

    Varma Penmetsa, R; Carrasquilla-Garcia, Noelia; Bergmann, Emily M; Vance, Lisa; Castro, Brenna; Kassa, Mulualem T; Sarma, Birinchi K; Datta, Subhojit; Farmer, Andrew D; Baek, Jong-Min; Coyne, Clarice J; Varshney, Rajeev K; von Wettberg, Eric J B; Cook, Douglas R


    Chickpea (Cicer arietinum) is among the founder crops domesticated in the Fertile Crescent. One of two major forms of chickpea, the so-called kabuli type, has white flowers and light-colored seed coats, properties not known to exist in the wild progenitor. The origin of the kabuli form has been enigmatic. We genotyped a collection of wild and cultivated chickpea genotypes with 538 single nucleotide polymorphisms (SNPs) and examined patterns of molecular diversity relative to geographical sources and market types. In addition, we examined sequence and expression variation in candidate anthocyanin biosynthetic pathway genes. A reduction in genetic diversity and extensive genetic admixture distinguish cultivated chickpea from its wild progenitor species. Among germplasm, the kabuli form is polyphyletic. We identified a basic helix-loop-helix (bHLH) transcription factor at chickpea's B locus that conditions flower and seed colors, orthologous to Mendel's A gene of garden pea, whose loss of function is associated invariantly with the kabuli type of chickpea. From the polyphyletic distribution of the kabuli form in germplasm, an absence of nested variation within the bHLH gene and invariant association of loss of function of bHLH among the kabuli type, we conclude that the kabuli form arose multiple times during the phase of phenotypic diversification after initial domestication of cultivated chickpea.

  19. Novel Nuclear Protein ALC-INTERACTING PROTEIN1 is Expressed in Vascular and Mesocarp Cells in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Fang Wang; Dong-Qiao Shi; Jie Liu; Wei-Cai Yang


    Pod shattering is an agronomical trait that is a result of the coordinated action of cell differentiation and separation. In Arabidopsis, pod shattering is controlled by a complex genetic network in which ALCATRAZ (ALC), a member of the basic helix-loop-helix family, is critical for cell separation during fruit dehiscence. Herein, we report the identification of ALC-INTERACTiNG PROTEIN1 (ACI1) via the yeast two-hybrid screen. ACI1 encodes a nuclear protein with a lysine-rich domain and a C-terminal serine-rich domain. ACI1 is mainly expressed in the vascular system throughout the plant and mesocarp of the valve in siliques. Our data showed that ACI1 interacts strongly with the N-terminal portion of ALC in yeast cells and in plant cells in the nucleus as demonstrated by bimolecular fluorescence complementation assay. Both ACl1 and ALC share an overlapping expression pattern, suggesting that they likely function together in planta. However, no detectable phenotype was found in plants with reduced ACI1 expression by RNA interference technology, suggesting that ACI1 may be redundant. Taken together, these data indicate that ALC may interact with ACll and its homologs to control cell separation during fruit dehiscence in Arabidopsis.

  20. Genome-wide identification, classification and functional analyses of the bHLH transcription factor family in the pig, Sus scrofa. (United States)

    Liu, Wuyi


    The basic helix-loop-helix (bHLH) transcription factors are one of the largest families of gene regulatory proteins and play crucial roles in genetic, developmental and physiological processes in eukaryotes. Here, we conducted a survey of the Sus scrofa genome and identified 109 putative bHLH transcription factor members belonging to super-groups A, B, C, D, E, and F, respectively, while four members were orphan genes. We identified 6 most significantly enriched KEGG pathways and 116 most significant GO annotation categories. Further comprehensive surveys in human genome and other 12 medical databases identified 72 significantly enriched biological pathways with these 113 pig bHLH transcription factors. From the functional protein association network analysis 93 hub proteins were identified and 55 hub proteins created a tight network or a functional module within their protein families. Especially, there were 20 hub proteins found highly connected in the functional interaction network. The present study deepens our understanding and provided insights into the evolution and functional aspects of animal bHLH proteins and should serve as a solid foundation for further for analyses of specific bHLH transcription factors in the pig and other mammals.

  1. Regulation of Sterol Biosynthesis in the Human Fungal Pathogen Aspergillus fumigatus: Opportunities for Therapeutic Development (United States)

    Dhingra, Sourabh; Cramer, Robert A.


    Sterols are a major component of eukaryotic cell membranes. For human fungal infections caused by the filamentous fungus Aspergillus fumigatus, antifungal drugs that target sterol biosynthesis and/or function remain the standard of care. Yet, an understanding of A. fumigatus sterol biosynthesis regulatory mechanisms remains an under developed therapeutic target. The critical role of sterol biosynthesis regulation and its interactions with clinically relevant azole drugs is highlighted by the basic helix loop helix (bHLH) class of transcription factors known as Sterol Regulatory Element Binding Proteins (SREBPs). SREBPs regulate transcription of key ergosterol biosynthesis genes in fungi including A. fumigatus. In addition, other emerging regulatory pathways and target genes involved in sterol biosynthesis and drug interactions provide additional opportunities including the unfolded protein response, iron responsive transcriptional networks, and chaperone proteins such as Hsp90. Thus, targeting molecular pathways critical for sterol biosynthesis regulation presents an opportunity to improve therapeutic options for the collection of diseases termed aspergillosis. This mini-review summarizes our current understanding of sterol biosynthesis regulation with a focus on mechanisms of transcriptional regulation by the SREBP family of transcription factors. PMID:28203225

  2. Molecular characterization and expression of As-nurp1 gene from Artemia sinica during development and in response to salinity and temperature stress. (United States)

    Li, Qiuying; Zhang, Qiaozhi; Han, Lulu; Yuan, Zhe; Tan, Jian; Du, Bin; Zou, Xiangyang; Hou, Lin


    Nuclear protein 1 (NURP1) is a stress-related protein and closely related to diapause in the development of Artemia. In the present paper, the full-length 568-bp cDNA sequence of the nurp1 homolog of Artemia sinica (As-nurp1) was isolated by RACE technology for the first time. The putative As-nurp1 protein consists of 66 amino acids with a basic helix-loop-helix (bHLH) motif and a bipartite nuclear localization signal (NLS). Multiple sequence alignments revealed that the putative As-nurp1 protein sequence was relatively conserved across species, especially in the bHLH domain. The expression of As-nurp1 is widely distributed during A. sinica development. This is followed by a dramatic downregulation after diapause and is newly upregulated from the larval nauplius stage. Furthermore, As-nurp1 transcripts are highly upregulated under conditions of high salinity and low temperature. These findings suggest that As-nurp1 is stress-related and may act as a protective factor in embryonic development.

  3. Diversity in the utilization of glucose and lactate in synthetic mammalian myotubes generated by engineered configurations of MyoD and E12 in otherwise non-differentiation growth conditions. (United States)

    Grubišić, Vladimir; Parpura, Vladimir


    We previously used the expression of various combinations and configurations of MyoD and E12, two basic helix-loop-helix transcription factors (TF), to produce populations of myotubes assuming distinct morphology, myofibrillar development and Ca2+ dynamics, from mammalian C2C12 myoblasts in non-differentiation growth conditions. Here, we assessed the synthetically generated myotubes in terms of energetics, otherwise necessary to sustain their mechanical output as bio-actuators. We found that the myotubes exhibit changed expression of key regulators for the uptake and utilization of two major cellular fuels, glucose and lactate. Furthermore, while lactate transport was uniformly slowed in all the populations of myotubes, glucose uptake and utilization were modified by particular TF configuration. Our approach allows the production of a class of biomaterials with predetermined energetics that could be applied in biorobotics, where fuel of choice could be used, and also in reparative medicine where, for example, particular population of myotubes could be additionally employed as glucose sinks to mitigate effects of secondary metabolic syndrome.

  4. Interhelical loops within the bHLH domain are determinant in maintaining TWIST1-DNA complexes. (United States)

    Bouard, Charlotte; Terreux, Raphael; Hope, Jennifer; Chemelle, Julie Anne; Puisieux, Alain; Ansieau, Stéphane; Payen, Léa


    The basic helix-loop-helix (bHLH) transcription factor TWIST1 is essential to embryonic development, and hijacking of its function contributes to the development of numerous cancer types. It forms either a homodimer or a heterodimeric complex with an E2A or HAND partner. These functionally distinct complexes display sometimes antagonistic functions during development, so that alterations in the balance between them lead to pronounced morphological alterations, as observed in mice and in Saethre-Chotzen syndrome patients. We, here, describe the structures of TWIST1 bHLH-DNA complexes produced in silico through molecular dynamics simulations. We highlight the determinant role of the interhelical loops in maintaining the TWIST1-DNA complex structures and provide a structural explanation for the loss of function associated with several TWIST1 mutations/insertions observed in Saethre-Chotzen syndrome patients. An animated interactive 3D complement (I3DC) is available in Proteopedia at

  5. Mutations of the TWIST gene in the Saethre-Chotzen syndrome. (United States)

    el Ghouzzi, V; Le Merrer, M; Perrin-Schmitt, F; Lajeunie, E; Benit, P; Renier, D; Bourgeois, P; Bolcato-Bellemin, A L; Munnich, A; Bonaventure, J


    Saethre-Chotzen syndrome (acrocephalo-syndactyly type III, ACS III) is an autosomal dominant craniosynostosis with brachydactyly, soft tissue syndactyly and facial dysmorphism including ptosis, facial asymmetry and prominent ear crura. ACS III has been mapped to chromosome 7p21-22. Of interest, TWIST, the human counterpart of the murine Twist gene, has been localized on chromosome 7p21 as well. The Twist gene product is a transcription factor containing a basic helix-loop-helix (b-HLH) domain, required in head mesenchyme for cranial neural tube morphogenesis in mice. The co-localisation of ACS III and TWIST prompted us to screen ACS III patients for TWIST gene mutations especially as mice heterozygous for Twist null mutations displayed skull defects and duplication of hind leg digits. Here, we report 21-bp insertions and nonsense mutations of the TWIST gene (S127X, E130X) in seven ACS III probands and describe impairment of head mesenchyme induction by TWIST as a novel pathophysiological mechanism in human craniosynostoses.

  6. Saethre-Chotzen syndrome: a case report. (United States)

    Peña, William A; Slavotinek, Anne; Oberoi, Snehlata


    Saethre-Chotzen syndrome (acrocephalosyndactyly type III) is a craniosynostosis syndrome inherited in an autosomal dominant manner. Although similar to the other craniosynostosis syndromes in its clinical presentation, this syndrome is caused by a mutation in the TWIST1 gene. The TWIST1 gene product is a transcription factor containing a basic helix-loop-helix (bHLH) domain important in the development of the head and limbs. Clinical features of this syndrome include unilateral or bilateral coronal synostosis, ptosis, low-set ears, hearing loss, hypertelorism, maxillary hypoplasia, deviated nasal septum, broad great toes, clinodactyly, and syndactyly. We report a young girl with clinical features of Saethre-Chotzen syndrome who has a previously undescribed sequence variant in the TWIST1 gene, corresponding to p.R191M. The location of the altered amino acid in the Twist-box of TWIST1, the high conservation of this amino acid between different species, and the phenotype of the child all support a pathogenic role for this novel TWIST1 sequence alteration.

  7. Increased bone formation and decreased osteocalcin expression induced by reduced Twist dosage in Saethre-Chotzen syndrome. (United States)

    Yousfi, M; Lasmoles, F; Lomri, A; Delannoy, P; Marie, P J


    The Saethre-Chotzen syndrome is characterized by premature fusion of cranial sutures resulting from mutations in Twist, a basic helix-loop-helix (bHLH) transcription factor. We have identified Twist target genes using human mutant calvaria osteoblastic cells from a child with Saethre-Chotzen syndrome with a Twist mutation that introduces a stop codon upstream of the bHLH domain. We observed that Twist mRNA and protein levels were reduced in mutant cells and that the Twist mutation increased cell growth in mutant osteoblasts compared with control cells. The mutation also caused increased alkaline phosphatase and type I collagen expression independently of cell growth. During in vitro osteogenesis, Twist mutant cells showed increased ability to form alkaline phosphatase-positive bone-like nodular structures associated with increased type I collagen expression. Mutant cells also showed increased collagen synthesis and matrix production when cultured in aggregates, as well as an increased capacity to form a collagenous matrix in vivo when transplanted into nude mice. In contrast, Twist mutant osteoblasts displayed a cell-autonomous reduction of osteocalcin mRNA expression in basal conditions and during osteogenesis. The data show that genetic deletion of Twist causing reduced Twist dosage increases cell growth, collagen expression, and osteogenic capability, but inhibits osteocalcin gene expression. This provides one mechanism that may contribute to the premature cranial ossification induced by deletion of the bHLH Twist domain in Saethre-Chotzen syndrome.

  8. Increased risk for developmental delay in Saethre-Chotzen syndrome is associated with TWIST deletions: an improved strategy for TWIST mutation screening. (United States)

    Cai, Juanliang; Goodman, Barbara K; Patel, Ankita S; Mulliken, John B; Van Maldergem, Lionel; Hoganson, George E; Paznekas, William A; Ben-Neriah, Ziva; Sheffer, Ruth; Cunningham, Michael L; Daentl, Donna L; Jabs, Ethylin Wang


    The majority of patients with Saethre-Chotzen syndrome have mutations in the TWIST gene, which codes for a basic helix-loop-helix transcription factor. Of the genetic alterations identified in TWIST, nonsense mutations, frameshifts secondary to small deletions or insertions, and large deletions implicate haploinsufficiency as the pathogenic mechanism. We identified three novel intragenic mutations and six deletions in our patients by using a new strategy to screen for TWIST mutations. We used polymerase chain reaction (PCR) amplification with subsequent sequencing to identify point mutations and small insertions or deletions in the coding region, and real-time PCR-based gene dosage analysis to identify large deletions encompassing the gene, with confirmation by microsatellite and fluorescence in situ hybridization (FISH) analyses. The size of the deletions can also be analyzed by using the gene dosage assay with "PCR walking" across the critical region. In 55 patients with features of Saethre-Chotzen syndrome, 11% were detected to have deletions by real-time gene dosage analysis. Two patients had a translocation or inversion at least 260 kb 3' of the gene, suggesting they had position-effect mutations. Of the 37 patients with classic features of Saethre-Chotzen syndrome, the overall detection rate for TWIST mutations was 68%. The risk for developmental delay in patients with deletions involving the TWIST gene is approximately 90% or eight times more common than in patients with intragenic mutations.

  9. Translocation breakpoint maps 5 kb 3' from TWIST in a patient affected with Saethre-Chotzen syndrome. (United States)

    Krebs, I; Weis, I; Hudler, M; Rommens, J M; Roth, H; Scherer, S W; Tsui, L C; Füchtbauer, E M; Grzeschik, K H; Tsuji, K; Kunz, J


    Saethre-Chotzen syndrome, a common autosomal dominant craniosynostosis in humans, is characterized by brachydactyly, soft tissue syndactyly and facial dysmorphism including ptosis, facial asymmetry, and prominent ear crura. Previously, we identified a yeast artificial chromosome that encompassed the breakpoint of an apparently balanced t(6;7) (q16.2;p15.3) translocation associated with a mild form of Saethre-Chotzen syndrome. We now describe, at the DNA sequence level, the region on chromosome 7 affected by this translocation event. The rearrangement occurred approximately 5 kb 3' of the human TWIST locus and deleted 518 bp of chromosome 7. The TWIST gene codes for a transcription factor containing a basic helix-loop-helix (b-HLH) motif and has recently been described as a candidate gene for Saethre-Chotzen syndrome, based on the detection of mutations within the coding region. Potential exon sequences flanking the chromosome 7 translocation breakpoint did not hit known genes in database searches. The chromosome rearrangement downstream of TWIST is compatible with the notion that this is a Saethre-Chotzen syndrome gene and implies loss of function of one allele by a positional effect as a possible mechanism of mutation to evoke the syndrome.

  10. Hes1 is expressed in the second heart field and is required for outflow tract development.

    Directory of Open Access Journals (Sweden)

    Francesca Rochais

    Full Text Available BACKGROUND: Rapid growth of the embryonic heart occurs by addition of progenitor cells of the second heart field to the poles of the elongating heart tube. Failure or perturbation of this process leads to congenital heart defects. In order to provide further insight into second heart field development we characterized the insertion site of a transgene expressed in the second heart field and outflow tract as the result of an integration site position effect. RESULTS: Here we show that the integration site of the A17-Myf5-nlacZ-T55 transgene lies upstream of Hes1, encoding a basic helix-loop-helix containing transcriptional repressor required for the maintenance of diverse progenitor cell populations during embryonic development. Transgene expression in a subset of Hes1 expression sites, including the CNS, pharyngeal epithelia, pericardium, limb bud and lung endoderm suggests that Hes1 is the endogenous target of regulatory elements trapped by the transgene. Hes1 is expressed in pharyngeal endoderm and mesoderm including the second heart field. Analysis of Hes1 mutant hearts at embryonic day 15.5 reveals outflow tract alignment defects including ventricular septal defects and overriding aorta. At earlier developmental stages, Hes1 mutant embryos display defects in second heart field proliferation, a reduction in cardiac neural crest cells and failure to completely extend the outflow tract. CONCLUSIONS: Hes1 is expressed in cardiac progenitor cells in the early embryo and is required for development of the arterial pole of the heart.

  11. Hes1 Is Expressed in the Second Heart Field and Is Required for Outflow Tract Development (United States)

    Mesbah, Karim; Jarry, Thérèse; Mattei, Marie-Geneviève; Kelly, Robert G.


    Background Rapid growth of the embryonic heart occurs by addition of progenitor cells of the second heart field to the poles of the elongating heart tube. Failure or perturbation of this process leads to congenital heart defects. In order to provide further insight into second heart field development we characterized the insertion site of a transgene expressed in the second heart field and outflow tract as the result of an integration site position effect. Results Here we show that the integration site of the A17-Myf5-nlacZ-T55 transgene lies upstream of Hes1, encoding a basic helix-loop-helix containing transcriptional repressor required for the maintenance of diverse progenitor cell populations during embryonic development. Transgene expression in a subset of Hes1 expression sites, including the CNS, pharyngeal epithelia, pericardium, limb bud and lung endoderm suggests that Hes1 is the endogenous target of regulatory elements trapped by the transgene. Hes1 is expressed in pharyngeal endoderm and mesoderm including the second heart field. Analysis of Hes1 mutant hearts at embryonic day 15.5 reveals outflow tract alignment defects including ventricular septal defects and overriding aorta. At earlier developmental stages, Hes1 mutant embryos display defects in second heart field proliferation, a reduction in cardiac neural crest cells and failure to completely extend the outflow tract. Conclusions Hes1 is expressed in cardiac progenitor cells in the early embryo and is required for development of the arterial pole of the heart. PMID:19609448

  12. Hand2 Function in Second Heart Field Progenitors is Essential for Cardiogenesis (United States)

    Tsuchihashi, Takatoshi; Maeda, Jun; Shin, Chong; Ivey, Kathryn N.; Black, Brian; Olson, Eric N.; Yamagishi, Hiroyuki; Srivastava, Deepak


    Cardiogenesis involves the contributions of multiple progenitor pools, including mesoderm-derived cardiac progenitors known as the first and second heart fields. Disruption of genetic pathways regulating individual subsets of cardiac progenitors likely underlies many forms of human cardiac malformations. Hand2 is a member of the basic helix loop helix (bHLH) family of transcription factors and is expressed in numerous cell lineages that contribute to the developing heart. However, the early embryonic lethality of Hand2-null mice has precluded lineage-specific study of its function in myocardial progenitors. Here, we generated and used a floxed allele of Hand2 to ablate its expression in specific cardiac cell populations at defined developmental points. We found that Hand2 expression within the mesoderm-derived second heart field progenitors was required for their survival and deletion in this domain recapitulated the complete Hand2-null phenotype. Loss of Hand2 at later stages of development and in restricted domains of the second heart field revealed a spectrum of cardiac anomalies resembling forms of human congenital heart disease. Molecular analyses of Hand2 mutant cells revealed several genes by which Hand2 may influence expansion of the cardiac progenitors. These findings demonstrate that Hand2 is essential for survival of second heart field progenitors and that the graded loss of Hand2 function in this cardiac progenitor pool can cause a spectrum of congenital heart malformation. PMID:21185281

  13. Arabidopsis HFR1 is a potential nuclear substrate regulated by the Xanthomonas type III effector XopD(Xcc8004). (United States)

    Tan, Choon Meng; Li, Meng-Ying; Yang, Pei-Yun; Chang, Shu Heng; Ho, Yi-Ping; Lin, Hong; Deng, Wen-Ling; Yang, Jun-Yi


    XopDXcc8004, a type III effector of Xanthomonas campestris pv. campestris (Xcc) 8004, is considered a shorter version of the XopD, which lacks the N-terminal domain. To understand the functions of XopDXcc8004, in planta, a transgenic approach combined with inducible promoter to analyze the effects of XopDXcc8004 in Arabidopsis was done. Here, the expression of XopDXcc8004, in Arabidopsis elicited the accumulation of host defense-response genes. These molecular changes were dependent on salicylic acid and correlated with lesion-mimic phenotypes observed in XVE::XopDXcc8004 transgenic plants. Moreover, XopDXcc8004 was able to desumoylate HFR1, a basic helix-loop-helix transcription factor involved in photomorphogenesis, through SUMO protease activity. Interestingly, the hfr1-201 mutant increased the expression of host defense-response genes and displayed a resistance phenotype to Xcc8004. These data suggest that HFR1 is involved in plant innate immunity and is potentially regulated by XopDXcc8004.

  14. Arabidopsis HFR1 Is a Potential Nuclear Substrate Regulated by the Xanthomonas Type III Effector XopDXcc8004 (United States)

    Tan, Choon Meng; Li, Meng-Ying; Yang, Pei-Yun; Chang, Shu Heng; Ho, Yi-Ping; Lin, Hong; Deng, Wen-Ling; Yang, Jun-Yi


    XopDXcc8004, a type III effector of Xanthomonas campestris pv. campestris (Xcc) 8004, is considered a shorter version of the XopD, which lacks the N-terminal domain. To understand the functions of XopDXcc8004, in planta, a transgenic approach combined with inducible promoter to analyze the effects of XopDXcc8004 in Arabidopsis was done. Here, the expression of XopDXcc8004, in Arabidopsis elicited the accumulation of host defense-response genes. These molecular changes were dependent on salicylic acid and correlated with lesion-mimic phenotypes observed in XVE::XopDXcc8004 transgenic plants. Moreover, XopDXcc8004 was able to desumoylate HFR1, a basic helix-loop-helix transcription factor involved in photomorphogenesis, through SUMO protease activity. Interestingly, the hfr1-201 mutant increased the expression of host defense-response genes and displayed a resistance phenotype to Xcc8004. These data suggest that HFR1 is involved in plant innate immunity and is potentially regulated by XopDXcc8004. PMID:25647296

  15. Arabidopsis HFR1 is a potential nuclear substrate regulated by the Xanthomonas type III effector XopD(Xcc8004.

    Directory of Open Access Journals (Sweden)

    Choon Meng Tan

    Full Text Available XopDXcc8004, a type III effector of Xanthomonas campestris pv. campestris (Xcc 8004, is considered a shorter version of the XopD, which lacks the N-terminal domain. To understand the functions of XopDXcc8004, in planta, a transgenic approach combined with inducible promoter to analyze the effects of XopDXcc8004 in Arabidopsis was done. Here, the expression of XopDXcc8004, in Arabidopsis elicited the accumulation of host defense-response genes. These molecular changes were dependent on salicylic acid and correlated with lesion-mimic phenotypes observed in XVE::XopDXcc8004 transgenic plants. Moreover, XopDXcc8004 was able to desumoylate HFR1, a basic helix-loop-helix transcription factor involved in photomorphogenesis, through SUMO protease activity. Interestingly, the hfr1-201 mutant increased the expression of host defense-response genes and displayed a resistance phenotype to Xcc8004. These data suggest that HFR1 is involved in plant innate immunity and is potentially regulated by XopDXcc8004.

  16. Disease-related growth factor and embryonic signaling pathways modulate an enhancer of TCF21 expression at the 6q23.2 coronary heart disease locus.

    Directory of Open Access Journals (Sweden)

    Clint L Miller

    Full Text Available Coronary heart disease (CHD is the leading cause of mortality in both developed and developing countries worldwide. Genome-wide association studies (GWAS have now identified 46 independent susceptibility loci for CHD, however, the biological and disease-relevant mechanisms for these associations remain elusive. The large-scale meta-analysis of GWAS recently identified in Caucasians a CHD-associated locus at chromosome 6q23.2, a region containing the transcription factor TCF21 gene. TCF21 (Capsulin/Pod1/Epicardin is a member of the basic-helix-loop-helix (bHLH transcription factor family, and regulates cell fate decisions and differentiation in the developing coronary vasculature. Herein, we characterize a cis-regulatory mechanism by which the lead polymorphism rs12190287 disrupts an atypical activator protein 1 (AP-1 element, as demonstrated by allele-specific transcriptional regulation, transcription factor binding, and chromatin organization, leading to altered TCF21 expression. Further, this element is shown to mediate signaling through platelet-derived growth factor receptor beta (PDGFR-β and Wilms tumor 1 (WT1 pathways. A second disease allele identified in East Asians also appears to disrupt an AP-1-like element. Thus, both disease-related growth factor and embryonic signaling pathways may regulate CHD risk through two independent alleles at TCF21.

  17. Hes-1, a known transcriptional repressor, acts as a transcriptional activator for the human acid alpha-glucosidase gene in human fibroblast cells. (United States)

    Yan, Bo; Raben, Nina; Plotz, Paul H


    Hes-1, the mammalian homologue 1 of Drosophila hairy and Enhancer of split proteins, belongs to a family of basic helix-loop-helix proteins that are essential to neurogenesis, myogenesis, hematopoiesis, and sex determination. Hes-1 is a transcriptional repressor for a number of known genes including the human acid alpha-glucosidase (GAA) gene as we have previously shown in Hep G2 cells. The human GAA gene encodes the enzyme for glycogen breakdown in lysosomes, deficiency of which results in Glycogen Storage Disease type II (Pompe syndrome). Using constructs containing the DNA element that demonstrates repressive activity in Hep G2 cells and conditions in which the same transcription factors, Hes-1 and YY1, bind, we have shown that this element functions as an enhancer in human fibroblasts. Site-directed mutagenesis and overexpression of Hes-1 showed that Hes-1 functions as a transcriptional activator. The dual function of Hes-1 we have found is likely to contribute to the subtle tissue-specific control of this housekeeping gene.

  18. Conserved Structural Motifs at the C-Terminus of Baculovirus Protein IE0 are Important for its Functions in Transactivation and Supporting hr5-mediated DNA Replication

    Directory of Open Access Journals (Sweden)

    Neta Luria


    Full Text Available IE0 and IE1 are transactivator proteins of the most studied baculovirus, the Autographa californica multiple nucleopolyhedrovirus (AcMNPV. IE0 is a 72.6 kDa protein identical to IE1 with the exception of its 54 N-terminal amino acid residues. To gain some insight about important structural motifs of IE0, we expressed the protein and C‑terminal mutants of it under the control of the Drosophila heat shock promoter and studied the transactivation and replication functions of the transiently expressed proteins. IE0 was able to promote replication of a plasmid bearing the hr5 origin of replication of AcMNPV in transient transfections with a battery of eight plasmids expressing the AcMNPV genes dnapol, helicase, lef-1, lef-2, lef-3, p35, ie-2 and lef-7. IE0 transactivated expression of the baculovirus 39K promoter. Both functions of replication and transactivation were lost after introduction of selected mutations at the basic domain II and helix-loop-helix conserved structural motifs in the C-terminus of the protein. These IE0 mutants were unable to translocate to the cell nucleus. Our results point out the important role of some structural conserved motifs to the proper functioning of IE0.

  19. Expression and function of myc during asexual reproduction of the budding ascidian Polyandrocarpa misakiensis. (United States)

    Fujiwara, Shigeki; Isozaki, Takaomi; Mori, Kyoko; Kawamura, Kazuo


    The budding ascidian Polyandrocarpa misakiensis proliferates asexually by budding. The atrial epithelium is a multipotent but differentiated tissue, which transdifferentiates into various tissues and organs after the bud separates from the parental body. We isolated cDNA clones homologous to the myc proto-oncogene from P. misakiensis. The cDNA, named Pm-myc, encoded a polypeptide of 639 amino acid residues, containing Myc-specific functional motifs, Myc box I and Myc box II, and the basic helix-loop-helix domain. Expression of Pm-myc was observed in the atrial epithelium in the organ-forming region of the developing bud, where the epithelial cells dedifferentiate and re-enter the cell cycle. The expression was also observed in fibroblast-like cells, which are known to participate in the organogenesis together with the epithelial cells. Unexpectedly, the atrial epithelium expressed Pm-myc more than one day before the dedifferentiation. The organogenesis was disturbed by Pm-myc-specific double-stranded RNA. In situ hybridization revealed that Pm-myc-positive fibroblast-like cells disappeared around the organ primordium of the dsRNA-treated bud. The results suggest that the mesenchymal-epithelial transition of fibroblast-like cells is important for the organogenesis in this budding ascidian species.

  20. The aryl hydrocarbon receptor in barrier organ physiology, immunology, and toxicology. (United States)

    Esser, Charlotte; Rannug, Agneta


    The aryl hydrocarbon receptor (AhR) is an evolutionarily old transcription factor belonging to the Per-ARNT-Sim-basic helix-loop-helix protein family. AhR translocates into the nucleus upon binding of various small molecules into the pocket of its single-ligand binding domain. AhR binding to both xenobiotic and endogenous ligands results in highly cell-specific transcriptome changes and in changes in cellular functions. We discuss here the role of AhR for immune cells of the barrier organs: skin, gut, and lung. Both adaptive and innate immune cells require AhR signaling at critical checkpoints. We also discuss the current two prevailing views-namely, 1) AhR as a promiscuous sensor for small chemicals and 2) a role for AhR as a balancing factor for cell differentiation and function, which is controlled by levels of endogenous high-affinity ligands. AhR signaling is considered a promising drug and preventive target, particularly for cancer, inflammatory, and autoimmune diseases. Therefore, understanding its biology is of great importance.

  1. A role for Id2 in regulating photic entrainment of the mammalian circadian system. (United States)

    Duffield, Giles E; Watson, Nathan P; Mantani, Akio; Peirson, Stuart N; Robles-Murguia, Maricela; Loros, Jennifer J; Israel, Mark A; Dunlap, Jay C


    Inhibitor of DNA binding genes (Id1-Id4) encode helix-loop-helix (HLH) transcriptional repressors associated with development and tumorigenesis [1, 2], but little is known concerning the function(s) of these genes in normal adult animals. Id2 was identified in DNA microarray screens for rhythmically expressed genes [3-5], and further analysis revealed a circadian pattern of expression of all four Id genes in multiple tissues including the suprachiasmatic nucleus. To explore an in vivo function, we generated and characterized deletion mutations of Id2 and of Id4. Id2(-/-) mice exhibit abnormally rapid entrainment and an increase in the magnitude of the phase shift of the pacemaker. A significant proportion of mice also exhibit disrupted rhythms when maintained under constant darkness. Conversely, Id4(-/-) mice did not exhibit a noticeable circadian phenotype. In vitro studies using an mPer1 and an AVP promoter reporter revealed the potential for ID1, ID2, and ID3 proteins to interact with the canonical basic HLH clock proteins BMAL1 and CLOCK. These data suggest that the Id genes may be important for entrainment and operation of the mammalian circadian system, potentially acting through BMAL1 and CLOCK targets.

  2. Phosphatidic acid and phosphoinositides facilitate liposome association of Yas3p and potentiate derepression of ARE1 (alkane-responsive element one)-mediated transcription control. (United States)

    Kobayashi, Satoshi; Hirakawa, Kiyoshi; Horiuchi, Hiroyuki; Fukuda, Ryouichi; Ohta, Akinori


    In the n-alkane assimilating yeast Yarrowia lipolytica, the expression of ALK1, encoding a cytochrome P450 that catalyzes terminal mono-oxygenation of n-alkanes, is induced by n-alkanes. The transcription of ALK1 is regulated by a heterocomplex that comprises the basic helix-loop-helix transcription activators, Yas1p and Yas2p, and binds to alkane-responsive element 1 (ARE1) in the ALK1 promoter. An Opi1 family transcription repressor, Yas3p, represses transcription by binding to Yas2p. Yas3p localizes in the nucleus when Y. lipolytica is grown on glucose but localizes to the endoplasmic reticulum (ER) upon the addition of n-alkanes. In this study, we showed that recombinant Yas3p binds to the acidic phospholipids, phosphatidic acid (PA) and phosphoinositides (PIPs), in vitro. The ARE1-mediated transcription was enhanced in vivo in mutants defective in an ortholog of the Saccharomyces cerevisiae gene PAH1, encoding PA phosphatase, and in an ortholog of SAC1, encoding PIP phosphatase in the ER. Truncation mutation analyses for Yas3p revealed two regions that bound to PA and PIPs. These results suggest that the interaction with acidic phospholipids is important for the n-alkane-induced association of Yas3p with the ER membrane.

  3. Specification of jaw identity by the Hand2 transcription factor (United States)

    Funato, Noriko; Kokubo, Hiroki; Nakamura, Masataka; Yanagisawa, Hiromi; Saga, Yumiko


    Acquisition of the lower jaw (mandible) was evolutionarily important for jawed vertebrates. In humans, syndromic craniofacial malformations often accompany jaw anomalies. The basic helix-loop-helix transcription factor Hand2, which is conserved among jawed vertebrates, is expressed in the neural crest in the mandibular process but not in the maxillary process of the first branchial arch. Here, we provide evidence that Hand2 is sufficient for upper jaw (maxilla)-to-mandible transformation by regulating the expression of homeobox transcription factors in mice. Altered Hand2 expression in the neural crest transformed the maxillae into mandibles with duplicated Meckel’s cartilage, which resulted in an absence of the secondary palate. In Hand2-overexpressing mutants, non-Hox homeobox transcription factors were dysregulated. These results suggest that Hand2 regulates mandibular development through downstream genes of Hand2 and is therefore a major determinant of jaw identity. Hand2 may have influenced the evolutionary acquisition of the mandible and secondary palate. PMID:27329940

  4. FHL2 Antagonizes Id1-Promoted Proliferation and Invasive Capacity of Human MCF-7 Breast Cancer Cells

    Institute of Scientific and Technical Information of China (English)

    Wei-dong Han; Zhi-qiang Wu; Ya-li Zhao; Yi-ling Si; Ming-zhou Guo; Xiao-bing Fu


    Objective:FHL2 was previously identified to be a novel interacting factor of Id family proteins.The aim of this study was to investigate,the effects of FHL2 on Id1-mediated transcriptional regulation activity and its oncogenic activity in human breast cancer cells.Methods:Cell transfection was performed by Superfect reagent.Id1 stably overexpressed MCF-7 cells was cloned by G418 screening.The protein level of Id1 was detected by western blot analysis.Dual relative luciferase assays were used to measure the effect of E47-mediated transcriptional activity in MCF-7 human breast cancer cells.MTT assay was used to measure cell proliferation.Transwell assay was used to measure the invasive capacity of MCF-7 cancer cells.Results:The basic helix-loop-helix(bHLH)factor E47-mediated transcription activity was markedly repressed by Id1 in MCF-7 cells.This Id1-mediated repression was effectively antagonized by FHL2 transduction.Overexpression of Id1 markedly promoted the proliferation rate and invasive capacity of MCF-7 cells; however,these effects induced by Id1 were significantly suppressed by overexpression of FHL2 in cells.Conclusion:FHL2 can inhibit the proliferation and invasiveness of human breast cancer cells by repressing the functional activity of Id1.These findings provide the basis for further investigating the functional roles of FHL2-Id1 signaling in the carcinogenesis and development of human breast cancer.

  5. Nato3 integrates with the Shh-Foxa2 transcriptional network regulating the differentiation of midbrain dopaminergic neurons. (United States)

    Nissim-Eliraz, Einat; Zisman, Sophie; Schatz, Omri; Ben-Arie, Nissim


    Mesencephalic dopaminergic (mesDA) neurons originate from the floor plate of the midbrain, a transient embryonic organizing center located at the ventral-most midline. Since the loss of mesDA leads to Parkinson's disease, the molecular mechanisms controlling the genesis and differentiation of dopaminergic progenitors are extensively studied and the identification and characterization of new genes is of interest. Here, we show that the expression of the basic helix-loop-helix transcription factor Nato3 (Ferd3l) increases in parallel to the differentiation of SN4741 dopaminergic cells in vitro. Nato3 transcription is directly regulated by the transcription factor Foxa2, a target and effector of the Sonic hedgehog (Shh) signaling cascade. Moreover, pharmacological inhibition of Shh signaling downregulated the expression of Nato3, thus defining Nato3 as a novel component of one of the major pathways controlling cell patterning and generation of mesDA. Furthermore, we show that Nato3 regulated Shh and Foxa2 through a novel feed-backward loop. Up- and downregulation of Nato3 further affected the transcription of Nurr1, implicated in the genesis of mesDA, but not of TH. Taken together, these data shed new light on the transcriptional networks controlling the generation of mesDA and may be utilized in the efforts to direct stem cells towards a dopaminergic fate.

  6. A Novel Soybean ERF Transcription Factor, GmERF113, Increases Resistance to Phytophthora sojae Infection in Soybean (United States)

    Zhao, Yuanling; Chang, Xin; Qi, Dongyue; Dong, Lidong; Wang, Guangjin; Fan, Sujie; Jiang, Liangyu; Cheng, Qun; Chen, Xi; Han, Dan; Xu, Pengfei; Zhang, Shuzhen


    Phytophthora root and stem rot of soybean caused by the oomycete Phytophthora sojae, is a destructive disease worldwide. Ethylene response factors (ERFs) play important roles in regulating plant biotic and abiotic stress tolerance. In this study, a new ERF gene, GmERF113, was isolated from the highly resistant soybean ‘Suinong 10.’ Sequence analysis suggested that the protein encoded by GmERF113 contained a conserved AP2/ERF domain of 58 amino acid and belonged to the B-4 subgroup of the ERF subfamily. Expression of GmERF113 was significantly induced by P. sojae, ethylene, and methyl jasmonate. GmERF113 protein localized to the nucleus when transiently expressed in Arabidopsis protoplasts, could bind to the GCC-box, and acted as a transcription activator. In addition, a region of the full-length GmERF113, GmERF113-II, interacted with a basic helix-loop-helix transcription factor (GmbHLH) in yeast cells. Full-length GmERF113 also interacted with GmbHLH in planta. GmERF113-overexpressing transgenic plants in susceptible cultivar ‘Dongnong 50’ soybean exhibited increased resistance to P. sojae and positively regulated the expression of the pathogenesis-related genes, PR1 and PR10-1. These results indicate that GmERF113 may play a crucial role in the defense of soybean against P. sojae infection. PMID:28326092

  7. An effective approach for identification of in vivo protein-DNA binding sites from paired-end ChIP-Seq data

    Directory of Open Access Journals (Sweden)

    Wilson Zoe A


    Full Text Available Abstract Background ChIP-Seq, which combines chromatin immunoprecipitation (ChIP with high-throughput massively parallel sequencing, is increasingly being used for identification of protein-DNA interactions in vivo in the genome. However, to maximize the effectiveness of data analysis of such sequences requires the development of new algorithms that are able to accurately predict DNA-protein binding sites. Results Here, we present SIPeS (Site Identification from Paired-end Sequencing, a novel algorithm for precise identification of binding sites from short reads generated by paired-end solexa ChIP-Seq technology. In this paper we used ChIP-Seq data from the Arabidopsis basic helix-loop-helix transcription factor ABORTED MICROSPORES (AMS, which is expressed within the anther during pollen development, the results show that SIPeS has better resolution for binding site identification compared to two existing ChIP-Seq peak detection algorithms, Cisgenome and MACS. Conclusions When compared to Cisgenome and MACS, SIPeS shows better resolution for binding site discovery. Moreover, SIPeS is designed to calculate the mappable genome length accurately with the fragment length based on the paired-end reads. Dynamic baselines are also employed to effectively discriminate closely adjacent binding sites, for effective binding sites discovery, which is of particular value when working with high-density genomes.

  8. Tomato Male sterile 1035 is essential for pollen development and meiosis in anthers. (United States)

    Jeong, Hee-Jin; Kang, Jin-Ho; Zhao, Meiai; Kwon, Jin-Kyung; Choi, Hak-Soon; Bae, Jung Hwan; Lee, Hyun-Ah; Joung, Young-Hee; Choi, Doil; Kang, Byoung-Cheorl


    Male fertility in flowering plants depends on proper cellular differentiation in anthers. Meiosis and tapetum development are particularly important processes in pollen production. In this study, we showed that the tomato male sterile (ms10(35)) mutant of cultivated tomato (Solanum lycopersicum) exhibited dysfunctional meiosis and an abnormal tapetum during anther development, resulting in no pollen production. We demonstrated that Ms10(35) encodes a basic helix-loop-helix transcription factor that is specifically expressed in meiocyte and tapetal tissue from pre-meiotic to tetrad stages. Transgenic expression of the Ms10(35) gene from its native promoter complemented the male sterility of the ms10(35) mutant. In addition, RNA-sequencing-based transcriptome analysis revealed that Ms10(35) regulates 246 genes involved in anther development processes such as meiosis, tapetum development, cell-wall degradation, pollen wall formation, transport, and lipid metabolism. Our results indicate that Ms10(35) plays key roles in regulating both meiosis and programmed cell death of the tapetum during microsporogenesis.

  9. Distinct and shared transcriptomes are regulated by microphthalmia-associated transcription factor isoforms in mast cells. (United States)

    Shahlaee, Amir H; Brandal, Stephanie; Lee, Youl-Nam; Jie, Chunfa; Takemoto, Clifford M


    The Microphthalmia-associated transcription factor (Mitf) is an essential basic helix-loop-helix leucine zipper transcription factor for mast cell development. Mice deficient in Mitf harbor a severe mast cell deficiency, and Mitf-mutant mast cells cultured ex vivo display a number of functional defects. Therefore, an understanding of the genetic program regulated by Mitf may provide important insights into mast cell differentiation. Multiple, distinct isoforms of Mitf have been identified in a variety of cell types; we found that Mitf-a, Mitf-e, and Mitf-mc were the major isoforms expressed in mast cells. To determine the physiologic function of Mitf in mast cells, we restored expression of these isoforms in primary mast cells from Mitf(-/-) mice. We found that these isoforms restored granular morphology and integrin-mediated migration. By microarray analysis, proteases, signaling molecules, cell surface receptor, and transporters comprised the largest groups of genes up-regulated by all isoforms. Furthermore, we found that isoforms also regulated distinct genes sets, suggesting separable biological activities. This work defines the transcriptome regulated by Mitf in mast cells and supports its role as master regulator of mast cell differentiation. Expression of multiple isoforms of this transcription factor may provide for redundancy of biological activities while also allowing diversity of function.

  10. Regulation of cell divisions and differentiation by MALE STERILITY32 is required for anther development in maize. (United States)

    Moon, Jihyun; Skibbe, David; Timofejeva, Ljudmilla; Wang, Chung-Ju Rachel; Kelliher, Timothy; Kremling, Karl; Walbot, Virginia; Cande, William Zacheus


    Male fertility in flowering plants relies on proper division and differentiation of cells in the anther, a process that gives rise to four somatic layers surrounding central germinal cells. The maize gene male sterility32 (ms32) encodes a basic helix-loop-helix (bHLH) transcription factor, which functions as an important regulator of both division and differentiation during anther development. After the four somatic cell layers are generated properly through successive periclinal divisions, in the ms32 mutant, tapetal precursor cells fail to differentiate, and, instead, undergo additional periclinal divisions to form extra layers of cells. These cells become vacuolated and expand, and lead to failure in pollen mother cell development. ms32 expression is specific to the pre-meiotic anthers and is distributed initially broadly in the four lobes, but as the anther develops, its expression becomes restricted to the innermost somatic layer, the tapetum. The ms32-ref mac1-1 double mutant is unable to form tapetal precursors and also exhibits excessive somatic proliferation leading to numerous, disorganized cell layers, suggesting a synergistic interaction between ms32 and mac1. Altogether, our results show that MS32 is a major regulator in maize anther development that promotes tapetum differentiation and inhibits periclinal division once a tapetal cell is specified.

  11. The Prdm13 histone methyltransferase encoding gene is a Ptf1a-Rbpj downstream target that suppresses glutamatergic and promotes GABAergic neuronal fate in the dorsal neural tube

    DEFF Research Database (Denmark)

    Hanotel, Julie; Bessodes, Nathalie; Thélie, Aurore


    The basic helix-loop-helix (bHLH) transcriptional activator Ptf1a determines inhibitory GABAergic over excitatory glutamatergic neuronal cell fate in progenitors of the vertebrate dorsal spinal cord, cerebellum and retina. In an in situ hybridization expression survey of PR domain containing gene...... and glutamatergic neuronal fate in the dorsal and caudal part of the vertebrate neural tube....... and a reduction of the GABAergic neuronal marker Pax2. It also leads to an upregulation of Prdm13 transcription, suggesting an autonegative regulation. Conversely, in animal caps, Prdm13 blocks the ability of the bHLH factor Neurog2 to activate Tlx3. Additional gain of function experiments in the chick neural...... tube confirm that Prdm13 suppresses Tlx3(+)/glutamatergic and induces Pax2(+)/GABAergic neuronal fate. Thus, Prdm13 is a novel crucial component of the Ptf1a regulatory pathway that, by modulating the transcriptional activity of bHLH factors such as Neurog2, controls the balance between GABAergic...

  12. Enhanced generation of myeloid lineages in hematopoietic differentiation from embryonic stem cells by silencing transcriptional repressor Twist-2. (United States)

    Sharabi, Andrew B; Lee, Sung-Hyung; Goodell, Margaret A; Huang, Xue F; Chen, Si-Yi


    The self-renewal and multilineage differentiation of embryonic stem cells (ESC) is largely governed by transcription factors or repressors. Extensive efforts have focused on elucidating critical factors that control the differentiation of specific cell lineages, for instance, myeloid lineages in hematopoietic development. In this study, we found that Twist-2, a basic helix-loop-helix (bHLH) transcription factor, plays a critical role in inhibiting the differentiation of ESC. Murine ES cells, in which Twist-2 expression is silenced by lentivirally delivered shRNA, exhibit an enhanced formation of primary embryoid bodies (EB) and enhanced differentiation into mesodermally derived hematopoietic colonies. Furthermore, Twist-2 silenced (LV-siTwist-2) ESC display significantly increased generation of myeloid lineages (Gr-1(+) and F4/80(+) cells) during in vitro hematopoietic differentiation. Treatment with the Toll-like receptor (TLR) 4 ligand synergistically stimulates the generation of primary EB formation as well as of hematopoietic progenitors differentiated from LV-siTwist-2 ES cells. Thus, this study reveals the critical role of the transcriptional repressor Twist-2 in regulating the development of myeloid lineage in hematopoietic differentiation from ESC. This study also suggests a potential strategy for directional differentiation of ESC by inhibiting a transcriptional repressor.

  13. Verification at the protein level of the PIF4-mediated external coincidence model for the temperature-adaptive photoperiodic control of plant growth in Arabidopsis thaliana. (United States)

    Yamashino, Takafumi; Nomoto, Yuji; Lorrain, Séverine; Miyachi, Miki; Ito, Shogo; Nakamichi, Norihito; Fankhauser, Christian; Mizuno, Takeshi


    Plant circadian clock controls a wide variety of physiological and developmental events, which include the short-days (SDs)-specific promotion of the elongation of hypocotyls during de-etiolation and also the elongation of petioles during vegetative growth. In A. thaliana, the PIF4 gene encoding a phytochrome-interacting basic helix-loop-helix (bHLH) transcription factor plays crucial roles in this photoperiodic control of plant growth. According to the proposed external coincidence model, the PIF4 gene is transcribed precociously at the end of night specifically in SDs, under which conditions the protein product is stably accumulated, while PIF4 is expressed exclusively during the daytime in long days (LDs), under which conditions the protein product is degraded by the light-activated phyB and also the residual proteins are inactivated by the DELLA family of proteins. A number of previous reports provided solid evidence to support this coincidence model mainly at the transcriptional level of the PIF 4 and PIF4-traget genes. Nevertheless, the diurnal oscillation profiles of PIF4 proteins, which were postulated to be dependent on photoperiod and ambient temperature, have not yet been demonstrated. Here we present such crucial evidence on PIF4 protein level to further support the external coincidence model underlying the temperature-adaptive photoperiodic control of plant growth in A. thaliana.

  14. Circadian clock and PIF4-mediated external coincidence mechanism coordinately integrates both of the cues from seasonal changes in photoperiod and temperature to regulate plant growth in Arabidopsis thaliana. (United States)

    Nomoto, Yuji; Kubozono, Saori; Miyachi, Miki; Yamashino, Takafumi; Nakamichi, Norihito; Mizuno, Takeshi


    In Arabidopsis thaliana, the circadian clock regulates the photoperiodic plant growth including the elongation of hypocotyls in a short-days (SDs)-specific manner. The clock-controlled PHYTOCHROME-INTERACTING FACTOR 4 (PIF4) gene encoding a basic helix-loop-helix (bHLH) transcription factor plays crucial roles in this regulation. The SDs-specific elongation of hypocotyls is best explained by accumulation of the active PIF4 proteins at the end of night specifically in SDs due to coincidence between internal (circadian clock) and external (photoperiod) cues. However, this external coincidence model was challenged with the recent finding that the elongation of hypocotyls is markedly promoted at high growth temperature (28˚C) even in long-days (LDs), implying that the model to explain the photoperiodic response of plant architecture appears to be conditional on ambient temperature. With regard to this problem, the results of this and previous studies showed that the model holds under a wide range of ambient temperature conditions (16˚C to 28˚C). We propose that the circadian clock and PIF4-mediated external coincidence mechanism coordinately integrates both of the cues from seasonal changes in photoperiod and temperature to regulate plant growth in natural habitats.

  15. SPATULA links daytime temperature and plant growth rate. (United States)

    Sidaway-Lee, Kate; Josse, Eve-Marie; Brown, Alanna; Gan, Yinbo; Halliday, Karen J; Graham, Ian A; Penfield, Steven


    Plants exhibit a wide variety of growth rates that are known to be determined by genetic and environmental factors, and different plants grow optimally at different temperatures, indicating that this is a genetically determined character. Moderate decreases in ambient temperature inhibit vegetative growth, but the mechanism is poorly understood, although a decrease in gibberellin (GA) levels is known to be required. Here we demonstrate that the basic helix-loop-helix transcription factor SPATULA (SPT), previously known to be a regulator of low temperature-responsive germination, mediates the repression of growth by cool daytime temperatures but has little or no growth-regulating role under warmer conditions. We show that only daytime temperatures affect vegetative growth and that SPT couples morning temperature to growth rate. In seedlings, warm temperatures inhibit the accumulation of the SPT protein, and SPT autoregulates its own transcript abundance in conjunction with diurnal effects. Genetic data show that repression of growth by SPT is independent of GA signaling and phytochrome B, as previously shown for PIF4. Our data suggest that SPT integrates time of day and temperature signaling to control vegetative growth rate.

  16. Transcription factor HAND2 mutations in sporadic Chinese patients with congenital heart disease

    Institute of Scientific and Technical Information of China (English)

    SHEN Lei; LI Xiao-feng; SHEN A-dong; WANG Qiang; LIU Cai-xia; GUO Ya-jie; SONG Zhen-jiang; LI Zhong-zhi


    Background The basic helix-loop-helix transcription factor HAND2 plays an essential role in cardiac morphogenesis.However, the prevalence of HAND2 mutations in congenial heart disease (CHD) and the correlation between the HAND2 genotype and CHD phenotype have not been studied extensively. Methods We amplified the exons and the flanking intron sequences of the HAND2 gene in 131 patients diagnosed with congenital defects of the right ventricle, outflow tract, aortic artery or cardiac cushion and confirmed the mutations by sequencing.Results Seven mutations including three missense mutations (P11R, S36N and V83L), one isonymous mutation (H14H)and three mutations in untranslated region (241 A>G, 604C>T and 3237T>A) were identified in 12 out of the 131 patients.Both nonisonymous mutations are located in the transcriptional activation domain on the N-terminus. Only one mutation (S36N) was identified in 250 normal healthy controls. The distribution of 3637T>A is the unique one which was differentbetween the 2 groups.Conclusions HAND2 may be a potential candidate gene of stenosis of the right ventricle, outflow tract. Further study of those with a family history of HAND2 mutations will help convincingly relate their genotype to the pathogenesis of CHD.

  17. The Role of GH/IGF-I Axis in Muscle Homeostasis During Weightlessness (United States)

    Schwartz, Robert J.


    Exposure to reduced gravity during space travel profoundly alters the loads placed on bone and muscle. Astronauts suffer significant losses of muscle and bone strength during weightlessness. Exercise as a countermeasure is only partially effective in remedying severe muscle atrophy and bone demineralization. Similar wasting of muscles and bones affects people on Earth during prolonged bed rest or immobilization due to injury. In the absence of weight bearing activity, atrophy occurs primarily in the muscles that act in low power, routine movements and in maintaining posture. Hormonal disfunction could contribute in part to the loss of muscle and bone during spaceflight. Reduced levels of human Growth Hormone (hGH) were found in astronauts during space flight, as well as reduced GH secretory activity was observed from the anterior pituitary in 7-day space flight rats. Growth hormone has been shown to be required for maintenance of muscle mass and bone mineralization, in part by mediating the biosynthesis IGF-I, a small polypeptide growth factor. IGF biosynthesis and secretion plays an important role in potentiating muscle cell differentiation and has been shown to drive the expression of myogenin, a myogenic specific basic helix-loop-helix factor. IGF-I has also been shown to have an important role in potentiating muscle regeneration, repair and adult muscle hypertrophy.

  18. A wheat R2R3-MYB protein PURPLE PLANT1 (TaPL1) functions as a positive regulator of anthocyanin biosynthesis. (United States)

    Shin, Dong Ho; Choi, Myoung-Goo; Kang, Chon-Sik; Park, Chul-Soo; Choi, Sang-Bong; Park, Youn-Il


    Transcriptional activation of anthocyanin biosynthesis genes in vegetative tissues of monocotyledonous plants is mediated by cooperative activity of one component from each of the following two transcription factor families: MYB encoded by PURPLE PLANT1/COLORED ALEURONE1 (PL1/C1), and basic helix-loop-helix (bHLH) encoded by RED/BOOSTER (R1/B1). In the present study, putative PL cDNA was cloned from the wheat (Triticum aestivum) cultivar Iksan370, which preferentially expresses anthocyanins in coleoptiles. Phylogenetic tree analysis of deduced amino acid sequences showed that a putative TaPL1 is highly homologous to barley (Hordeum vulgare) HvPL1, but is distinct from wheat TaC1. Transgenic Arabidopsis thaliana stably expressing putative TaPL1 accumulated anthocyanin pigments in leaves and up-regulated structural genes involved in both early and late anthocyanin biosynthesis steps. TaPL1 transcript levels in Iksan370 were more prominent in vegetative tissues such as young coleoptiles than in reproductive tissues such as spikelets. TaPL1 expression was significantly up-regulated by environmental stresses including cold, salt, and light, which are known to induce anthocyanin accumulation. These combined results suggest that TaPL1 is an active positive regulator of anthocyanin biosynthesis in wheat coleoptiles.

  19. CCAR1 is required for Ngn3-mediated endocrine differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Chung-Kuang [Department of Life Science, National Chung Cheng University, Chia-Yi, Taiwan, ROC (China); Lai, Yi-Chyi [Department of Microbiology and Immunology, Chung Shan Medical University, Taichung, Taiwan, ROC (China); Lin, Yung-Fu; Chen, Hau-Ren [Department of Life Science, National Chung Cheng University, Chia-Yi, Taiwan, ROC (China); Chiang, Ming-Ko, E-mail: [Department of Life Science, National Chung Cheng University, Chia-Yi, Taiwan, ROC (China)


    Highlights: Black-Right-Pointing-Pointer We identify CCAR1 to directly interact with Ngn3. Black-Right-Pointing-Pointer CCAR1 is co-localized with Ngn3 in the nucleus. Black-Right-Pointing-Pointer CCAR1 cooperates with Ngn3 in activating NeuroD expression. Black-Right-Pointing-Pointer CCAR1 is required for Ngn3-mediated PANC-1 transdifferentiation. -- Abstract: Neurogenin3 (Ngn3) is a basic helix-loop-helix transcription factor that specifies pancreatic endocrine cell fates during pancreas development. It can also initiate a transdifferentiation program when expressed in pancreatic exocrine and ductal cells. However, how Ngn3 initiates a transcriptional cascade to achieve endocrine differentiation is still poorly understood. Here, we show that cell cycle and apoptosis regulator 1 (CCAR1), which is a transcriptional coactivator for nuclear receptors, also interacts with Ngn3. The association between Ngn3 and CCAR1 was verified by pull-down assays and co-immunoprecipitation analyses. Using gene reporter assays, we found that CCAR1 is essential for Ngn3 to activate the expression of the reporter genes containing the NeuroD promoter. Moreover, down-regulation of endogenous CCAR1 in the PANC-1 pancreatic ductal cell line inhibits the transdifferentiation program initiated by Ngn3. CCAR1 is, therefore, a novel partner of Ngn3 in mediating endocrine differentiation.

  20. Sn, a maize bHLH gene, modulates anthocyanin and condensed tannin pathways in Lotus corniculatus. (United States)

    Robbins, Mark Paske; Paolocci, Francesco; Hughes, John-Wayne; Turchetti, Valentina; Allison, Gordon; Arcioni, Sergio; Morris, Phillip; Damiani, Francesco


    Anthocyanins and condensed tannins are major flavonoid end-products in higher plants. While the transactivation of anthocyanins by basic helix-loop-helix (bHLH) transcription factors is well documented, very little is known about the transregulation of the pathway to condensed tannins. The present study analyses the effect of over-expressing an Sn transgene in Lotus corniculatus, a model legume, with the aim of studying the regulation of anthocyanin and tannin end-products. Contrary to expectation, effects on anthocyanin accumulation were subtle and restricted to the leaf midrib, leaf base and petiole tissues. However, the accumulation of condensed tannin polymers was dramatically enhanced in the leaf blade and this increase was accompanied by a 50-fold increase in the number of tannin-containing cells in this tissue. A detailed analysis of selected lines indicated that this transactivational phenotype correlated with high steady-state transcript levels of the introduced transgene and the introduction of a single copy of the CaMV35S-Sn construct into these clonal genotypes. While the levels of condensed tannins in leaves were increased by up to 1% of the dry weight, other major secondary end-products (flavonols, lignins and inducible phytoalexins) were unaltered in transactivated lines. These results give an initial insight into the developmental and higher-order regulation of polyphenolic metabolism in Lotus and other higher plant species.

  1. Omega-3 Polyunsaturated Fatty Acids Enhance Neuronal Differentiation in Cultured Rat Neural Stem Cells

    Directory of Open Access Journals (Sweden)

    Masanori Katakura


    Full Text Available Polyunsaturated fatty acids (PUFAs can induce neurogenesis and recovery from brain diseases. However, the exact mechanisms of the beneficial effects of PUFAs have not been conclusively described. We recently reported that docosahexaenoic acid (DHA induced neuronal differentiation by decreasing Hes1 expression and increasing p27kip1 expression, which causes cell cycle arrest in neural stem cells (NSCs. In the present study, we examined the effect of eicosapentaenoic acid (EPA and arachidonic acid (AA on differentiation, expression of basic helix-loop-helix transcription factors (Hes1, Hes6, and NeuroD, and the cell cycle of cultured NSCs. EPA also increased mRNA levels of Hes1, an inhibitor of neuronal differentiation, Hes6, an inhibitor of Hes1, NeuroD, and Map2 mRNA and Tuj-1-positive cells (a neuronal marker, indicating that EPA induced neuronal differentiation. EPA increased the mRNA levels of p21cip1 and p27kip1, a cyclin-dependent kinase inhibitor, which indicated that EPA induced cell cycle arrest. Treatment with AA decreased Hes1 mRNA but did not affect NeuroD and Map2 mRNA levels. Furthermore, AA did not affect the number of Tuj-1-positive cells or cell cycle progression. These results indicated that EPA could be involved in neuronal differentiation by mechanisms alternative to those of DHA, whereas AA did not affect neuronal differentiation in NSCs.

  2. The Origin, Development and Molecular Diversity of Rodent Olfactory Bulb Glutamatergic Neurons Distinguished by Expression of Transcription Factor NeuroD1.

    Directory of Open Access Journals (Sweden)

    Laurent Roybon

    Full Text Available Production of olfactory bulb neurons occurs continuously in the rodent brain. Little is known, however, about cellular diversity in the glutamatergic neuron subpopulation. In the central nervous system, the basic helix-loop-helix transcription factor NeuroD1 (ND1 is commonly associated with glutamatergic neuron development. In this study, we utilized ND1 to identify the different subpopulations of olfactory bulb glutamategic neurons and their progenitors, both in the embryo and postnatally. Using knock-in mice, transgenic mice and retroviral transgene delivery, we demonstrate the existence of several different populations of glutamatergic olfactory bulb neurons, the progenitors of which are ND1+ and ND1- lineage-restricted, and are temporally and regionally separated. We show that the first olfactory bulb glutamatergic neurons produced - the mitral cells - can be divided into molecularly diverse subpopulations. Our findings illustrate the complexity of neuronal diversity in the olfactory bulb and that seemingly homogenous neuronal populations can consist of multiple subpopulations with unique molecular signatures of transcription factors and expressing neuronal subtype-specific markers.

  3. The execution of the transcriptional axis mutant p53, E2F1 and ID4 promotes tumor neo-angiogenesis. (United States)

    Fontemaggi, Giulia; Dell'Orso, Stefania; Trisciuoglio, Daniela; Shay, Tal; Melucci, Elisa; Fazi, Francesco; Terrenato, Irene; Mottolese, Marcella; Muti, Paola; Domany, Eytan; Del Bufalo, Donatella; Strano, Sabrina; Blandino, Giovanni


    ID4 (inhibitor of DNA binding 4) is a member of a family of proteins that function as dominant-negative regulators of basic helix-loop-helix transcription factors. Growing evidence links ID proteins to cell proliferation, differentiation and tumorigenesis. Here we identify ID4 as a transcriptional target of gain-of-function p53 mutants R175H, R273H and R280K. Depletion of mutant p53 protein severely impairs ID4 expression in proliferating tumor cells. The protein complex mutant p53-E2F1 assembles on specific regions of the ID4 promoter and positively controls ID4 expression. The ID4 protein binds to and stabilizes mRNAs encoding pro-angiogenic factors IL8 and GRO-alpha. This results in the increase of the angiogenic potential of cancer cells expressing mutant p53. These findings highlight the transcriptional axis mutant p53, E2F1 and ID4 as a still undefined molecular mechanism contributing to tumor neo-angiogenesis.

  4. Origin of a Non-Clarke's Column Division of the Dorsal Spinocerebellar Tract and the Role of Caudal Proprioceptive Neurons in Motor Function. (United States)

    Yuengert, Rachel; Hori, Kei; Kibodeaux, Erin E; McClellan, Jacob X; Morales, Justin E; Huang, Teng-Wei P; Neul, Jeffrey L; Lai, Helen C


    Proprioception, the sense of limb and body position, is essential for generating proper movement. Unconscious proprioceptive information travels through cerebellar-projecting neurons in the spinal cord and medulla. The progenitor domain defined by the basic-helix-loop-helix (bHLH) transcription factor, ATOH1, has been implicated in forming these cerebellar-projecting neurons; however, their precise contribution to proprioceptive tracts and motor behavior is unknown. Significantly, we demonstrate that Atoh1-lineage neurons in the spinal cord reside outside Clarke's column (CC), a main contributor of neurons relaying hindlimb proprioception, despite giving rise to the anatomical and functional correlate of CC in the medulla, the external cuneate nucleus (ECu), which mediates forelimb proprioception. Elimination of caudal Atoh1-lineages results in mice with relatively normal locomotion but unable to perform coordinated motor tasks. Altogether, we reveal that proprioceptive nuclei in the spinal cord and medulla develop from more than one progenitor source, suggesting an avenue to uncover distinct proprioceptive functions.

  5. SUMO modification of Stra13 is required for repression of cyclin D1 expression and cellular growth arrest.

    Directory of Open Access Journals (Sweden)

    Yaju Wang

    Full Text Available Stra13, a basic helix-loop-helix (bHLH transcription factor is involved in myriad biological functions including cellular growth arrest, differentiation and senescence. However, the mechanisms by which its transcriptional activity and function are regulated remain unclear. In this study, we provide evidence that post-translational modification of Stra13 by Small Ubiquitin-like Modifier (SUMO dramatically potentiates its ability to transcriptionally repress cyclin D1 and mediate G(1 cell cycle arrest in fibroblast cells. Mutation of SUMO acceptor lysines 159 and 279 located in the C-terminal repression domain has no impact on nuclear localization; however, it abrogates association with the co-repressor histone deacetylase 1 (HDAC1, attenuates repression of cyclin D1, and prevents Stra13-mediated growth suppression. HDAC1, which promotes cellular proliferation and cell cycle progression, antagonizes Stra13 sumoylation-dependent growth arrest. Our results uncover an unidentified regulatory axis between Stra13 and HDAC1 in progression through the G(1/S phase of the cell cycle, and provide new mechanistic insights into regulation of Stra13-mediated transcriptional repression by sumoylation.

  6. Molecular cloning and its expression of trachealess gene (As-trh) during development in brine shrimp, Artemia sinica. (United States)

    Wang, Jia-Qing; Hou, Lin; Yi, Nan; Zhang, Riu-Feng; Zou, Xiang-Yang; Xiao, Qin; Guo, Ran


    Basic helix-loop-helix-PAS (bHLH-PAS) family transcription factors are implicated in multiple developmental and physiological regulatory processes. Herein, a full-length cDNA encoding a bHLH-PAS domain transcription factor trachealess gene (designated as As-trh) was cloned and characterized from brine shrimp (Artemia sinica) for the first time. The full-length cDNA of As-trh was 2,698 bp with a 2,319 bp open reading frame encoding a deduced protein of 772 amino acid polypeptide with a calculated molecular mass of 86.02 kDa and an isoelectric point of 5.87. Sequence alignment revealed that As-trh had high homology with other species trh gene, including the D-trh gene in Drosophila melanogaster and Bm-trh in Bombyx mori. The early and persistent expression of As-trh in the naupliar stages by whole-mount embryonic in situ hybridization and immunohistochemistry suggest that As-trh functions very early in the salt gland and may be required continuously in this tissue. Later in development, expression of As-trh begins to decrease and disappear in salt gland of the older nauplius and appears in the thoracic epipods of the sub-adult Artemia. These results indicated that As-trh might play an important role in osmoregulatiory organ development from the larvae stages through adult stages.

  7. Transcription factor ABF-1 suppresses plasma cell differentiation but facilitates memory B cell formation. (United States)

    Chiu, Yi-Kai; Lin, I-Ying; Su, Shin-Tang; Wang, Kuan-Hsiung; Yang, Shii-Yi; Tsai, Dong-Yan; Hsieh, Yi-Ting; Lin, Kuo-I


    Ag-primed B cells that result from an immune response can form either memory B cells or Ab-secreting plasma cells; however, the molecular machinery that controls this cellular fate is poorly understood. In this study, we show that activated B cell factor-1 (ABF-1), which encodes a basic helix-loop-helix transcriptional repressor, participates in this regulation. ABF-1 was prevalently expressed in purified memory B cells and induced by T follicular helper cell-mediated signals. ABF-1 expression declined by the direct repression of B lymphocyte-induced maturation protein-1 during differentiation. Ectopic expression of ABF-1 reduced the formation of Ab-secreting cells in an in vitro differentiation system of human memory B cells. Accordingly, knockdown of ABF-1 potentiates the formation of Ab-secreting cells. A transgenic mouse that expresses inducible ABF-1 in a B cell-specific manner was generated to demonstrate that the formation of germinal center and memory B cells was augmented by induced ABF-1 in an immune response, whereas the Ag-specific plasma cell response was dampened. This effect was associated with the ability of ABF-1 to limit cell proliferation. Together, our results demonstrate that ABF-1 facilitates formation of memory B cells but prevents plasma cell differentiation.

  8. Achaete-scute complex homolog-1 promotes DNA repair in the lung carcinogenesis through matrix metalloproteinase-7 and O(6-methylguanine-DNA methyltransferase.

    Directory of Open Access Journals (Sweden)

    Xiao-Yang Wang

    Full Text Available Lung cancer is the leading cause of cancer-related deaths in the world. Achaete-scute complex homolog-1 (Ascl1 is a member of the basic helix-loop-helix (bHLH transcription factor family that has multiple functions in the normal and neoplastic lung such as the regulation of neuroendocrine differentiation, prevention of apoptosis and promotion of tumor-initiating cells. We now show that Ascl1 directly regulates matrix metalloproteinase-7 (MMP-7 and O(6-methylguanine-DNA methyltransferase (MGMT. Loss- and gain-of-function experiments in human bronchial epithelial and lung carcinoma cell lines revealed that Ascl1, MMP-7 and MGMT are able to protect cells from the tobacco-specific nitrosamine NNK-induced DNA damage and the alkylating agent cisplatin-induced apoptosis. We also examined the role of Ascl1 in NNK-induced lung tumorigenesis in vivo. Using transgenic mice which constitutively expressed human Ascl1 in airway lining cells, we found that there was a delay in lung tumorigenesis. We conclude that Ascl1 potentially enhances DNA repair through activation of MMP-7 and MGMT which may impact lung carcinogenesis and chemoresistance. The study has uncovered a novel and unexpected function of Ascl1 which will contribute to better understanding of lung carcinogenesis and the broad implications of transcription factors in tobacco-related carcinogenesis.

  9. Regulation of the Mechanism of TWIST1 Transcription by BHLHE40 and BHLHE41 in Cancer Cells. (United States)

    Asanoma, Kazuo; Liu, Ge; Yamane, Takako; Miyanari, Yoko; Takao, Tomoka; Yagi, Hiroshi; Ohgami, Tatsuhiro; Ichinoe, Akimasa; Sonoda, Kenzo; Wake, Norio; Kato, Kiyoko


    BHLHE40 and BHLHE41 (BHLHE40/41) are basic helix-loop-helix type transcription factors that play key roles in multiple cell behaviors. BHLHE40/41 were recently shown to be involved in an epithelial-to-mesenchymal transition (EMT). However, the precise mechanism of EMT control by BHLHE40/41 remains unclear. In the present study, we demonstrated that BHLHE40/41 expression was controlled in a pathological stage-dependent manner in human endometrial cancer (HEC). Our in vitro assays showed that BHLHE40/41 suppressed tumor cell invasion. BHLHE40/41 also suppressed the transcription of the EMT effectors SNAI1, SNAI2, and TWIST1. We identified the critical promoter regions of TWIST1 for its basal transcriptional activity. We elucidated that the transcription factor SP1 was involved in the basal transcriptional activity of TWIST1 and that BHLHE40/41 competed with SP1 for DNA binding to regulate gene transcription. This study is the first to report the detailed functions of BHLHE40 and BHLHE41 in the suppression of EMT effectors in vitro. Our results suggest that BHLHE40/41 suppress tumor cell invasion by inhibiting EMT in tumor cells. We propose that BHLHE40/41 are promising markers to predict the aggressiveness of each HEC case and that molecular targeting strategies involving BHLHE40/41 and SP1 may effectively regulate HEC progression.

  10. Tissue-Specific Regulation of Gibberellin Signaling Fine-Tunes Arabidopsis Iron-Deficiency Responses. (United States)

    Wild, Michael; Davière, Jean-Michel; Regnault, Thomas; Sakvarelidze-Achard, Lali; Carrera, Esther; Lopez Diaz, Isabel; Cayrel, Anne; Dubeaux, Guillaume; Vert, Grégory; Achard, Patrick


    Iron is an essential element for most living organisms. Plants acquire iron from the rhizosphere and have evolved different biochemical and developmental responses to adapt to a low-iron environment. In Arabidopsis, FIT encodes a basic helix-loop-helix transcription factor that activates the expression of iron-uptake genes in root epidermis upon iron deficiency. Here, we report that the gibberellin (GA)-signaling DELLA repressors contribute substantially in the adaptive responses to iron-deficient conditions. When iron availability decreases, DELLAs accumulate in the root meristem, thereby restraining root growth, while being progressively excluded from epidermal cells in the root differentiation zone. Such DELLA exclusion from the site of iron acquisition relieves FIT from DELLA-dependent inhibition and therefore promotes iron uptake. Consistent with this mechanism, expression of a non-GA-degradable DELLA mutant protein in root epidermis interferes with iron acquisition. Hence, spatial distribution of DELLAs in roots is essential to fine-tune the adaptive responses to iron availability.

  11. Molecular characterization and expression patterns of myogenin in compensatory growth of Megalobrama amblycephala. (United States)

    Zhu, Kecheng; Chen, Liping; Zhao, Jinkun; Wang, Huijuan; Wang, Weimin; Li, Zhong; Wang, Huanling


    Myogenin (myog) is a muscle-specific basic helix-loop-helix (bHLH) transcription factor that plays an essential role in regulating skeletal muscle development and growth. To investigate molecular characterization of myog and the effect of starvation/refeeding on the gene expression, we isolated the myog cDNA sequence and analyzed the expression patterns using quantitative real-time polymerase chain reaction in Megalobrama amblycephala. Sequence analysis indicated that M. amblycephala myog shared an analogous structure with the highly conserved His/Cys-rich, bHLH and C-terminal helix III domains with other vertebrates. Sequence alignment and phylogenetic tree showed that M. amblycephala myog had the highest identity with the homologues of Ctenopharyngodon idella and Cyprinus carpio. Spatio-temporal expression patterns revealed that myog mRNA levels at the segmentation period and 12 h post-hatching (hph) were significantly higher than at other development stages (Pgrowth possibly occurred in M. amblycephala; meanwhile, the relative somatic growth rate after refeeding was also dramatically higher than the control group. In addition, the myog expression decreased during 21days of starvation and then exhibited a strong rebound effect after 7days of refeeding and subsequently declined gradually to the control level by 21days of refeeding.

  12. A proteomic study showing differential regulation of stress, redox regulation and peroxidase proteins by iron supply and the transcription factor FER. (United States)

    Brumbarova, Tzvetina; Matros, Andrea; Mock, Hans-Peter; Bauer, Petra


    Plants need to mobilize iron in the soil, and the basic helix-loop-helix transcription factor FER is a central regulator of iron acquisition in tomato roots. FER activity is controlled by iron supply. To analyse to what extent FER influences Fe-regulated protein expression, we investigated the root proteome of wild-type tomato, the fer mutant and a transgenic FER overexpression line under low-iron conditions versus sufficient and generous iron supply. The root proteomes were analysed by two-dimensional gel electrophoresis with three technical and three biological replicates. Statistical analysis identified 39 protein spots that were differentially regulated in selected pairwise comparisons of experimental conditions. Of these, 24 were correlated with expression clusters revealed by principal component analysis. The 39 protein spots were analysed by MALDI-TOF and nanoLC-MS/MS to deduce their possible functions. We investigated the functional representation in the identified expression clusters, and found that loss of FER function in iron-cultured plants mimicked an iron-deficiency status. The largest identified protein expression cluster was upregulated by iron deficiency and in the fer mutant. Two iron-regulated proteins required FER activity for induction by iron deficiency. Few proteins were suppressed by iron deficiency. The differentially expressed proteins belonged predominantly to the functional categories 'stress', 'redox regulation' and 'miscellaneous peroxidases'. Hence, we were able to identify distinct expression clusters of proteins with distinct functions.

  13. TAL-1/SCL and its partners E47 and LMO2 up-regulate VE-cadherin expression in endothelial cells. (United States)

    Deleuze, Virginie; Chalhoub, Elias; El-Hajj, Rawan; Dohet, Christiane; Le Clech, Mikaël; Couraud, Pierre-Olivier; Huber, Philippe; Mathieu, Danièle


    The basic helix-loop-helix TAL-1/SCL essential for hematopoietic development is also required during vascular development for embryonic angiogenesis. We reported that TAL-1 acts positively on postnatal angiogenesis by stimulating endothelial morphogenesis. Here, we investigated the functional consequences of TAL-1 silencing in human primary endothelial cells. We found that TAL-1 knockdown caused the inhibition of in vitro tubulomorphogenesis, which was associated with a dramatic reduction in vascular endothelial cadherin (VE-cadherin) at intercellular junctions. Consistently, silencing of TAL-1 as well as of its cofactors E47 and LMO2 down-regulated VE-cadherin at both the mRNA and the protein level. Endogenous VE-cadherin transcription could be activated in nonendothelial HEK-293 cells by the sole concomitant ectopic expression of TAL-1, E47, and LMO2. Transient transfections in human primary endothelial cells derived from umbilical vein (HUVECs) demonstrated that VE-cadherin promoter activity was dependent on the integrity of a specialized E-box associated with a GATA motif and was maximal with the coexpression of the different components of the TAL-1 complex. Finally, chromatin immunoprecipitation assays showed that TAL-1 and its cofactors occupied the VE-cadherin promoter in HUVECs. Together, these data identify VE-cadherin as a bona fide target gene of the TAL-1 complex in the endothelial lineage, providing a first clue to TAL-1 function in angiogenesis.

  14. BARREN STALK FASTIGIATE1 is an AT-hook protein required for the formation of maize ears. (United States)

    Gallavotti, Andrea; Malcomber, Simon; Gaines, Craig; Stanfield, Sharon; Whipple, Clinton; Kellogg, Elizabeth; Schmidt, Robert J


    Ears are the seed-bearing inflorescences of maize (Zea mays) plants and represent a crucial component of maize yield. The first step in the formation of ears is the initiation of axillary meristems in the axils of developing leaves. In the classic maize mutant barren stalk fastigiate1 (baf1), first discovered in the 1950s, ears either do not form or, if they do, are partially fused to the main stalk. We positionally cloned Baf1 and found that it encodes a transcriptional regulator containing an AT-hook DNA binding motif. Single coorthologs of Baf1 are found in syntenic regions of brachypodium (Brachypodium distachyon), rice (Oryza sativa), and sorghum (Sorghum bicolor), suggesting that the gene is likely present in all cereal species. Protein-protein interaction assays suggest that BAF1 is capable of forming homodimers and heterodimers with other members of the AT-hook family. Another transcriptional regulator required for ear initiation is the basic helix-loop-helix protein BARREN STALK1 (BA1). Genetic and expression analyses suggest that Baf1 is required to reach a threshold level of Ba1 expression for the initiation of maize ears. We propose that Baf1 functions in the demarcation of a boundary region essential for the specification of a stem cell niche.

  15. Auxin signaling modules regulate maize inflorescence architecture. (United States)

    Galli, Mary; Liu, Qiujie; Moss, Britney L; Malcomber, Simon; Li, Wei; Gaines, Craig; Federici, Silvia; Roshkovan, Jessica; Meeley, Robert; Nemhauser, Jennifer L; Gallavotti, Andrea


    In plants, small groups of pluripotent stem cells called axillary meristems are required for the formation of the branches and flowers that eventually establish shoot architecture and drive reproductive success. To ensure the proper formation of new axillary meristems, the specification of boundary regions is required for coordinating their development. We have identified two maize genes, BARREN INFLORESCENCE1 and BARREN INFLORESCENCE4 (BIF1 and BIF4), that regulate the early steps required for inflorescence formation. BIF1 and BIF4 encode AUXIN/INDOLE-3-ACETIC ACID (Aux/IAA) proteins, which are key components of the auxin hormone signaling pathway that is essential for organogenesis. Here we show that BIF1 and BIF4 are integral to auxin signaling modules that dynamically regulate the expression of BARREN STALK1 (BA1), a basic helix-loop-helix (bHLH) transcriptional regulator necessary for axillary meristem formation that shows a striking boundary expression pattern. These findings suggest that auxin signaling directly controls boundary domains during axillary meristem formation and define a fundamental mechanism that regulates inflorescence architecture in one of the most widely grown crop species.

  16. BARREN STALK FASTIGIATE1 Is an AT-Hook Protein Required for the Formation of Maize Ears[W][OA (United States)

    Gallavotti, Andrea; Malcomber, Simon; Gaines, Craig; Stanfield, Sharon; Whipple, Clinton; Kellogg, Elizabeth; Schmidt, Robert J.


    Ears are the seed-bearing inflorescences of maize (Zea mays) plants and represent a crucial component of maize yield. The first step in the formation of ears is the initiation of axillary meristems in the axils of developing leaves. In the classic maize mutant barren stalk fastigiate1 (baf1), first discovered in the 1950s, ears either do not form or, if they do, are partially fused to the main stalk. We positionally cloned Baf1 and found that it encodes a transcriptional regulator containing an AT-hook DNA binding motif. Single coorthologs of Baf1 are found in syntenic regions of brachypodium (Brachypodium distachyon), rice (Oryza sativa), and sorghum (Sorghum bicolor), suggesting that the gene is likely present in all cereal species. Protein–protein interaction assays suggest that BAF1 is capable of forming homodimers and heterodimers with other members of the AT-hook family. Another transcriptional regulator required for ear initiation is the basic helix-loop-helix protein BARREN STALK1 (BA1). Genetic and expression analyses suggest that Baf1 is required to reach a threshold level of Ba1 expression for the initiation of maize ears. We propose that Baf1 functions in the demarcation of a boundary region essential for the specification of a stem cell niche. PMID:21540434

  17. The role of barren stalk1 in the architecture of maize. (United States)

    Gallavotti, Andrea; Zhao, Qiong; Kyozuka, Junko; Meeley, Robert B; Ritter, Matthew K; Doebley, John F; Pè, M Enrico; Schmidt, Robert J


    The architecture of higher plants is established through the activity of lateral meristems--small groups of stem cells formed during vegetative and reproductive development. Lateral meristems generate branches and inflorescence structures, which define the overall form of a plant, and are largely responsible for the evolution of different plant architectures. Here, we report the isolation of the barren stalk1 gene, which encodes a non-canonical basic helix-loop-helix protein required for the initiation of all aerial lateral meristems in maize. barren stalk1 represents one of the earliest genes involved in the patterning of maize inflorescences, and, together with the teosinte branched1 gene, it regulates vegetative lateral meristem development. The architecture of maize has been a major target of selection for early agriculturalists and modern farmers, because it influences harvesting, breeding strategies and mechanization. By sampling nucleotide diversity in the barren stalk1 region, we show that two haplotypes entered the maize gene pool from its wild progenitor, teosinte, and that only one was incorporated throughout modern inbreds, suggesting that barren stalk1 was selected for agronomic purposes.

  18. Failure to Target RANKL Signaling Through p38-MAPK Results in Defective Osteoclastogenesis in the Microphthalmia Cloudy-Eyed Mutant. (United States)

    Carey, Heather A; Bronisz, Agnieszka; Cabrera, Jennifer; Hildreth, Blake E; Cuitiño, Maria; Fu, Qi; Ahmad, Asrar; Toribio, Ramiro E; Ostrowski, Michael C; Sharma, Sudarshana M


    The Microphthalmia-associated transcription factor (MITF) is a basic helix-loop-helix leucine zipper family factor that is essential for terminal osteoclast differentiation. Previous work demonstrates that phosphorylation of MITF by p38 MAPK downstream of Receptor Activator of NFkB Ligand (RANKL) signaling is necessary for MITF activation in osteoclasts. The spontaneous Mitf cloudy eyed (ce) allele results in production of a truncated MITF protein that lacks the leucine zipper and C-terminal end. Here we show that the Mitf(ce) allele leads to a dense bone phenotype in neonatal mice due to defective osteoclast differentiation. In response to RANKL stimulation, in vitro osteoclast differentiation was impaired in myeloid precursors derived from neonatal or adult Mitf(ce/ce) mice. The loss of the leucine zipper domain in Mitf(ce/ce) mice does not interfere with the recruitment of MITF/PU.1 complexes to target promoters. Further, we have mapped the p38 MAPK docking site within the region deleted in Mitf(ce). This interaction is necessary for the phosphorylation of MITF by p38 MAPK. Site-directed mutations in the docking site interfered with the interaction between MITF and its co-factors FUS and BRG1. MITF-ce fails to recruit FUS and BRG1 to target genes, resulting in decreased expression of target genes and impaired osteoclast function. These results highlight the crucial role of signaling dependent MITF/p38 MAPK interactions in osteoclast differentiation.

  19. Molecular markers of neuronal progenitors in the embryonic cerebellar anlage. (United States)

    Morales, Daniver; Hatten, Mary E


    The cerebellum, like the cerebrum, includes a nuclear structure and an overlying cortical structure. Experiments in the past decade have expanded knowledge beyond the traditional function of the cerebellum to include critical roles in motor learning and memory and sensory discrimination. The initial steps in cerebellar development depend on inductive signaling involving FGF and Wnt proteins produced at the mesencephalic/metencephalic boundary. To address the issue of how individual cerebellar cell fates within the cerebellar territory are specified, we examined the expression of transcription factors, including mammalian homologues of LIM homeodomain-containing proteins, basic helix-loop-helix proteins, and three amino acid loop-containing proteins. The results of these studies show that combinatorial codes of transcription factors define precursors of the cerebellar nuclei, and both Purkinje cells and granule neurons of the cerebellar cortex. Examination of gene expression patterns in several hundred lines of Egfp-BAC (bacterial artificial chromosome) transgenic mice in the GENSAT Project revealed numerous genes with restricted expression in cerebellar progenitor populations, including genes specific for cerebellar nuclear precursors and Purkinje cell precursors. In addition, we identified patterns of gene expression that link granule and Purkinje cells to their precerebellar nuclei. These results identify molecular pathways that offer new insights on the development of the nuclear and cortical structures of the cerebellum, as well as components of the cerebellar circuitry.

  20. Conserved sequence motifs in the small subunit of human general transcription factor TFIIE. (United States)

    Sumimoto, H; Ohkuma, Y; Sinn, E; Kato, H; Shimasaki, S; Horikoshi, M; Roeder, R G


    A general initiation factor, TFIIE, is essential for transcription initiation by RNA polymerase II in conjunction with other general factors. TFIIE is a heterotetramer containing two subunits of relative molecular mass 57,000 (TFIIE-alpha) and two of 34,000 (TFIIE-beta). TFIIE-beta is required in conjunction with TFIIE-alpha for transcription initiation. Here we report the cloning and expression of a complementary DNA encoding a functional human TFIIE-beta. Recombinant TFIIE-beta could replace the natural TFIIE-beta for transcription in conjunction with TFIIE-alpha. Amino-acid sequence comparisons reveal regions with sequence similarities to: subregion 3 of bacterial sigma factors; a region of RAP30 (the small subunit of TFIIF) with sequence similarity to a sigma-factor subregion implicated in binding to RNA polymerase; and a portion of the basic region-helix-loop-helix motif found in several enhancer-binding proteins. These potential homologies have implications for the role of TFIIE in preinitiation complex assembly and function.

  1. Synergistic interactions of lipids and myelin basic protein (United States)

    Hu, Yufang; Doudevski, Ivo; Wood, Denise; Moscarello, Mario; Husted, Cynthia; Genain, Claude; Zasadzinski, Joseph A.; Israelachvili, Jacob


    This report describes force measurements and atomic force microscope imaging of lipid-protein interactions that determine the structure of a model membrane system that closely mimics the myelin sheath. Our results suggest that noncovalent, mainly electrostatic and hydrophobic, interactions are responsible for the multilamellar structure and stability of myelin. We find that myelin basic protein acts as a lipid coupler between two apposed bilayers and as a lipid "hole-filler," effectively preventing defect holes from developing. From our protein-mediated-adhesion and force-distance measurements, we develop a simple quantitative model that gives a reasonably accurate picture of the molecular mechanism and adhesion of bilayer-bridging proteins by means of noncovalent interactions. The results and model indicate that optimum myelin adhesion and stability depend on the difference between, rather than the product of, the opposite charges on the lipid bilayers and myelin basic protein, as well as on the repulsive forces associated with membrane fluidity, and that small changes in any of these parameters away from the synergistically optimum values can lead to large changes in the adhesion or even its total elimination. Our results also show that the often-asked question of which membrane species, the lipids or the proteins, are the "important ones" may be misplaced. Both components work synergistically to provide the adhesion and overall structure. A better appreciation of the mechanism of this synergy may allow for a better understanding of stacked and especially myelin membrane structures and may lead to better treatments for demyelinating diseases such as multiple sclerosis. lipid-protein interactions | myelin membrane structure | membrane adhesion | membrane regeneration/healing | demyelinating diseases

  2. Basics of aerothermodynamics

    CERN Document Server

    Hirschel, Ernst Heinrich


    This successful book gives an introduction to the basics of aerothermodynamics, as applied in particular to winged re-entry vehicles and airbreathing hypersonic cruise and acceleration vehicles. The book gives a review of the issues of transport of momentum, energy and mass, real-gas effects as well as inviscid and viscous flow phenomena. In this second, revised edition the chapters with the classical topics of aerothermodynamics more or less were left untouched. The access to some single topics of practical interest was improved. Auxiliary chapters were put into an appendix. The recent successful flights of the X-43A and the X-51A indicate that the dawn of sustained airbreathing hypersonic flight now has arrived. This proves that the original approach of the book to put emphasis on viscous effects and the aerothermodynamics of radiation-cooled vehicle surfaces was timely. This second, revised edition even more accentuates these topics. A new, additional chapter treats examples of viscous thermal surface eff...

  3. [Basic research in pulmonology]. (United States)

    Gea, Joaquim


    This is a review of the articles dealing with basic science published in recent issues of Archivos de Bronconeumología. Of particular interest with regard to chronic obstructive pulmonary disease were an article on extrapulmonary inflammation and oxidative stress and another on bronchial remodeling. The articles relating to asthma included a review on the use of drugs that block free immunoglobulin-E and an article about the contribution of experimental models to our knowledge of this disease. Two of the most interesting articles on the topic of lung cancer dealt with gene therapy and resistance to chemotherapy. Also notable were 2 studies that investigated ischemia-reperfusion injury. One evaluated tissue resistance to injury while the other analyzed the role played by interleukin-8 in this process. On the topic of pulmonary fibrosis, an article focused on potential biomarkers of progression and prognosis; others dealt with the contribution of experimental models to our understanding of this disorder and the fibrogenic role of transforming growth factor b. In the context of both sleep apnea syndrome and pulmonary infection, studies investigating the role of oxidative stress were published. Finally, 2 studies analyzed the diagnosis and treatment of tuberculosis and other pulmonary infections.

  4. Gastric cancer: basic aspects. (United States)

    Resende, Carlos; Thiel, Alexandra; Machado, José C; Ristimäki, Ari


    Gastric cancer (GC) is a world health burden, ranging as the second cause of cancer death worldwide. Etiologically, GC arises not only from the combined effects of environmental factors and susceptible genetic variants but also from the accumulation of genetic and epigenetic alterations. In the last years, molecular oncobiology studies brought to light a number of genes that are implicated in gastric carcinogenesis. This review is intended to focus on the recently described basic aspects that play key roles in the process of gastric carcinogenesis. Genetic variants of the genes IL-10, IL-17, MUC1, MUC6, DNMT3B, SMAD4, and SERPINE1 have been reported to modify the risk of developing GC. Several genes have been newly associated with gastric carcinogenesis, both through oncogenic activation (GSK3β, CD133, DSC2, P-Cadherin, CDH17, CD168, CD44, metalloproteinases MMP7 and MMP11, and a subset of miRNAs) and through tumor suppressor gene inactivation mechanisms (TFF1, PDX1, BCL2L10, XRCC, psiTPTE-HERV, HAI-2, GRIK2, and RUNX3). It also addressed the role of the inflammatory mediator cyclooxygenase-2 (COX-2) in the process of gastric carcinogenesis and its importance as a potential molecular target for therapy.

  5. Nanodesign: some basic questions

    CERN Document Server

    Schommers, Wolfram


    There is no doubt that nanoscience will be the dominant direction for technology in this century, and that this science will influence our lives to a large extent as well as open completely new perspectives on all scientific and technological disciplines. To be able to produce optimal nanosystems with tailor-made properties, it is necessary to analyze and construct such systems in advance by adequate theoretical and computational methods. Since we work in nanoscience and nanotechnology at the ultimate level, we have to apply the basic laws of physics. What methods and tools are relevant here? The book gives an answer to this question. The background of the theoretical methods and tools is critically discussed, and also the world view on which these physical laws are based. Such a debate is not only of academic interest but is of highly general concern, and this is because we constantly move in nanoscience and nanotechnology between two extreme poles, between infinite life and total destruction . On the one ...

  6. Basic operator theory

    CERN Document Server

    Gohberg, Israel


    rii application of linear operators on a Hilbert space. We begin with a chapter on the geometry of Hilbert space and then proceed to the spectral theory of compact self adjoint operators; operational calculus is next presented as a nat­ ural outgrowth of the spectral theory. The second part of the text concentrates on Banach spaces and linear operators acting on these spaces. It includes, for example, the three 'basic principles of linear analysis and the Riesz­ Fredholm theory of compact operators. Both parts contain plenty of applications. All chapters deal exclusively with linear problems, except for the last chapter which is an introduction to the theory of nonlinear operators. In addition to the standard topics in functional anal­ ysis, we have presented relatively recent results which appear, for example, in Chapter VII. In general, in writ­ ing this book, the authors were strongly influenced by re­ cent developments in operator theory which affected the choice of topics, proofs and exercises. One ...

  7. Basic Social Processes

    Directory of Open Access Journals (Sweden)

    Barney G. Glaser, PhD, Hon. PhD


    Full Text Available The goal of grounded theory is to generate a theory that accounts for a pattern of behavior that is relevant and problematic for those involved. The goal is not voluminous description, nor clever verification. As with all grounded theory, the generation of a basic social process (BSP theory occurs around a core category. While a core category is always present in a grounded research study, a BSP may not be.BSPs are ideally suited to generation by grounded theory from qualitative research because qualitative research can pick up process through fieldwork that continues over a period of time. BSPs are a delight to discover and formulate since they give so much movement and scope to the analyst’s perception of the data. BSPs such as cultivating, defaulting, centering, highlighting or becoming, give the feeling of process, change and movement over time. They also have clear, amazing general implications; so much so, that it is hard to contain them within the confines of a single substantive study. The tendency is to refer to them as a formal theory without the necessary comparative development of formal theory. They are labeled by a “gerund”(“ing” which both stimulates their generation and the tendency to over-generalize them.

  8. Basic science of osteoarthritis. (United States)

    Cucchiarini, Magali; de Girolamo, Laura; Filardo, Giuseppe; Oliveira, J Miguel; Orth, Patrick; Pape, Dietrich; Reboul, Pascal


    Osteoarthritis (OA) is a prevalent, disabling disorder of the joints that affects a large population worldwide and for which there is no definitive cure. This review provides critical insights into the basic knowledge on OA that may lead to innovative end efficient new therapeutic regimens. While degradation of the articular cartilage is the hallmark of OA, with altered interactions between chondrocytes and compounds of the extracellular matrix, the subchondral bone has been also described as a key component of the disease, involving specific pathomechanisms controlling its initiation and progression. The identification of such events (and thus of possible targets for therapy) has been made possible by the availability of a number of animal models that aim at reproducing the human pathology, in particular large models of high tibial osteotomy (HTO). From a therapeutic point of view, mesenchymal stem cells (MSCs) represent a promising option for the treatment of OA and may be used concomitantly with functional substitutes integrating scaffolds and drugs/growth factors in tissue engineering setups. Altogether, these advances in the fundamental and experimental knowledge on OA may allow for the generation of improved, adapted therapeutic regimens to treat human OA.

  9. Basic Data on Biogas

    Energy Technology Data Exchange (ETDEWEB)



    Renewable gases such as biogas and biomethane are considered as key energy carrier when the society is replacing fossil fuels with renewable alternatives. In Sweden, almost 80 % of the fossil fuels are used in the transport sector. Therefore, the focus in Sweden has been to use the produced biogas in this sector as vehicle gas. Basic Data on Biogas contains an overview of production, utilisation, climate effects etc. of biogas from a Swedish perspective. The purpose is to give an easy overview of the current situation in Sweden for politicians, decision makers and interested public. 1.4 TWh of biogas is produced annually in Sweden at approximately 230 facilities. The 135 wastewater treatment plants that produce biogas contribute with around half of the production. In order to reduce the sludge volume, biogas has been produced at wastewater treatment plants for decades. New biogas plants are mainly co-digestion plants and farm plants. The land filling of organic waste has been banned since 2005, thus the biogas produced in landfills is decreasing.

  10. Visual Basic 2012 programmer's reference

    CERN Document Server

    Stephens, Rod


    The comprehensive guide to Visual Basic 2012 Microsoft Visual Basic (VB) is the most popular programming language in the world, with millions of lines of code used in businesses and applications of all types and sizes. In this edition of the bestselling Wrox guide, Visual Basic expert Rod Stephens offers novice and experienced developers a comprehensive tutorial and reference to Visual Basic 2012. This latest edition introduces major changes to the Visual Studio development platform, including support for developing mobile applications that can take advantage of the Windows 8 operating system

  11. Basic Learning Processes in Childhood. (United States)

    Reese, Hayne W.

    This book is an introduction to the psychological study of basic learning processes in children. Written for students who are not majors in psychology and who do not have much familiarity with the technical vocabulary of psychology, it has two themes: even the most basic kinds of learning are included by cognitive processes or mental activities;…

  12. Basics for Handling Food Safely (United States)

    ... 888-MPHotline (1-888-674-6854) Basics for Safe Food Handling dishes in bowls of ice or use ... 9 months Do not freeze 2 Basics for Safe Food Handling Product Refrigerator Freezer (40 °F) (0 °F) ...

  13. Japanese Basic Course: Exercise Book. (United States)

    Defense Language Inst., Washington, DC.

    This exercise book, prepared for use after Lesson 121 of the Defense Language Institute Basic Course in Japanese, provides for instruction in the use of Kanji dictionaries, familiarizes students with useful phrases and expressions that are not included in the Basic Course, and allows for greater variety in the classroom. The ten lessons, in the…

  14. Basic principles of concrete structures

    CERN Document Server

    Gu, Xianglin; Zhou, Yong


    Based on the latest version of designing codes both for buildings and bridges (GB50010-2010 and JTG D62-2004), this book starts from steel and concrete materials, whose properties are very important to the mechanical behavior of concrete structural members. Step by step, analysis of reinforced and prestressed concrete members under basic loading types (tension, compression, flexure, shearing and torsion) and environmental actions are introduced. The characteristic of the book that distinguishes it from other textbooks on concrete structures is that more emphasis has been laid on the basic theories of reinforced concrete and the application of the basic theories in design of new structures and analysis of existing structures. Examples and problems in each chapter are carefully designed to cover every important knowledge point. As a basic course for undergraduates majoring in civil engineering, this course is different from either the previously learnt mechanics courses or the design courses to be learnt. Compa...

  15. Basic properties of Fedosov supermanifolds

    CERN Document Server

    Geyer, B


    Basic properties of even (odd) supermanifolds endowed with a connection respecting a given symplectic structure are studied. Such supermanifolds can be considered as generalization of Fedosov manifolds to the supersymmetric case.

  16. Complementary Basic Education in Tanzania


    大津, 和子


    This paper discusses current development in the Complementary Basic Education program (COBET), which aims to contribute to the provision of alternative learning opportunities for out-of-school children, particularly girls in a non-formal setting. The Ministry of Education and Culture started the program as part of the Basic Education Master Plan (BEMP) in 1999. Unlike traditional primary schools, the COBET centers have no school fees, no uniforms, no corporal punishment and no child labou...

  17. Experiment list: SRX190262 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available omains. USF also contains a leucine repeat that is required for efficient DNA binding. USF was originally of regulatory factors containing helix-loop-helix domains. USF also contains a leucine repeat that is required for efficient

  18. Experiment list: SRX190292 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ix domains. USF also contains a leucine repeat that is required for efficient DNA binding. USF was of regulatory factors containing helix-loop-helix domains. USF also contains a leucine repeat that is required for efficient

  19. Experiment list: SRX100502 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available contains a leucine repeat that is required for efficient DNA binding. USF was originally identified as an helix-loop-helix domains. USF also contains a leucine repeat that is required for efficient DNA binding.

  20. Experiment list: SRX190284 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ns. USF also contains a leucine repeat that is required for efficient DNA binding. USF was originally identi...y factors containing helix-loop-helix domains. USF also contains a leucine repeat that is required for efficient

  1. Experiment list: SRX100486 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available lix domains. USF also contains a leucine repeat that is required for efficient DNA binding. USF was original...containing helix-loop-helix domains. USF also contains a leucine repeat that is required for efficient DNA b

  2. Experiment list: SRX100471 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ontains a leucine repeat that is required for efficient DNA binding. USF was originally identified as an up-...gulatory factors containing helix-loop-helix domains. USF also contains a leucine repeat that is required for efficient

  3. Experiment list: SRX190342 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available s. USF also contains a leucine repeat that is required for efficient DNA binding. USF was originally identif...ory factors containing helix-loop-helix domains. USF also contains a leucine repeat that is required for efficient

  4. Structure and Interactions of a Dimeric Variant of sHIP, a Novel Virulence Determinant of Streptococcus pyogenes

    DEFF Research Database (Denmark)

    Diehl, Carl; Wisniewska, Magdalena; Frick, Inga-Maria;


    tetramers both in the crystal and in solution. The tetramers are composed of four helix-loop-helix motifs with the loop regions connecting the helices displaying a high degree of flexibility. Owing to interactions at the tetramer interface, the observed tetramer can be described as a dimer of dimers. We...

  5. Sequence Classification: 785813 [

    Lifescience Database Archive (English)

    Full Text Available -1, mammalian HIF (hypoxia inducible factor) homolog, Helix Loop Helix containing protein (79.9 kD) (hif-1) || ... ...Non-TMB Non-TMH Non-TMB Non-TMB Non-TMB Non-TMB >gi|25153882|ref|NP_508008.2| hypoxia Inducible Factor HIF


    Abstract Inhibitor of DNA binding (Id2) is a member of the helix-loop-helix (HLH) transcription factor family whose members play important roles in cell differentiation and proliferation. Id2 has been linked to the development of cardiovascular diseases since thiazolidinediones,...

  7. E-Basics: Online Basic Training in Program Evaluation (United States)

    Silliman, Ben


    E-Basics is an online training in program evaluation concepts and skills designed for youth development professionals, especially those working in nonformal science education. Ten hours of online training in seven modules is designed to prepare participants for mentoring and applied practice, mastery, and/or team leadership in program evaluation.…

  8. Basic Operational Robotics Instructional System (United States)

    Todd, Brian Keith; Fischer, James; Falgout, Jane; Schweers, John


    The Basic Operational Robotics Instructional System (BORIS) is a six-degree-of-freedom rotational robotic manipulator system simulation used for training of fundamental robotics concepts, with in-line shoulder, offset elbow, and offset wrist. BORIS is used to provide generic robotics training to aerospace professionals including flight crews, flight controllers, and robotics instructors. It uses forward kinematic and inverse kinematic algorithms to simulate joint and end-effector motion, combined with a multibody dynamics model, moving-object contact model, and X-Windows based graphical user interfaces, coordinated in the Trick Simulation modeling environment. The motivation for development of BORIS was the need for a generic system for basic robotics training. Before BORIS, introductory robotics training was done with either the SRMS (Shuttle Remote Manipulator System) or SSRMS (Space Station Remote Manipulator System) simulations. The unique construction of each of these systems required some specialized training that distracted students from the ideas and goals of the basic robotics instruction.

  9. Basic research for environmental restoration

    Energy Technology Data Exchange (ETDEWEB)


    The Department of Energy (DOE) is in the midst of a major environmental restoration effort to reduce the health and environmental risks resulting from past waste management and disposal practices at DOE sites. This report describes research needs in environmental restoration and complements a previously published document, DOE/ER-0419, Evaluation of Mid-to-Long Term Basic Research for Environmental Restoration. Basic research needs have been grouped into five major categories patterned after those identified in DOE/ER-0419: (1) environmental transport and transformations; (2) advanced sampling, characterization, and monitoring methods; (3) new remediation technologies; (4) performance assessment; and (5) health and environmental effects. In addition to basic research, this document deals with education and training needs for environmental restoration. 2 figs., 6 tabs.

  10. Electronic imaging fundamentals: basic theory. (United States)

    Vizy, K N


    Introduction of the computer into the field of medical imaging, as typified by the extensive use of digital subtraction angiography (DSA), created an important need for a basic understanding of the principles of digital imaging. This paper reviews these fundamental principles, starting with the definition of images and the interaction of these images with television display systems, then continuing with a detailed description of the way in which imaging systems are specified. This work defines the basic terms and concepts that will be used throughout the contents of this issue.

  11. Stereochemistry basic concepts and applications

    CERN Document Server

    Nógrádi, M


    Stereochemistry: Basic Concepts and Applications is a three-chapter text that introduces the basic principles and concepts of stereochemistry, as well as its application to organic chemistry application.Chapter 1 describes first the stereochemistry of the ground state, specifically the configuration and conformation of organic compounds, as well as the most important methods for its investigation. This chapter also deals with the kinetics of conformational changes and provides an overview of the so-called ""applied stereochemistry"". Chapter 2 focuses on the analysis of the internal motions of

  12. Basic linear partial differential equations

    CERN Document Server

    Treves, Francois


    Focusing on the archetypes of linear partial differential equations, this text for upper-level undergraduates and graduate students features most of the basic classical results. The methods, however, are decidedly nontraditional: in practically every instance, they tend toward a high level of abstraction. This approach recalls classical material to contemporary analysts in a language they can understand, as well as exploiting the field's wealth of examples as an introduction to modern theories.The four-part treatment covers the basic examples of linear partial differential equations and their

  13. The chemisorptive bond basic concepts

    CERN Document Server

    Clark, Alfred


    The Chemisorptive Bond: Basic Concepts describes the basic concepts of the chemisorptive bond on solid surfaces from the simple analogies with ordinary chemical bonds to the quantum-mechanical approaches.This book is composed of 10 chapters and begins with discussions of simple formulas for correlating measurable quantities in chemisorptions and catalysis. The succeeding chapters deal with theories based on quantum-mechanical principles that describe the mutual interactions of atoms of the solid and foreign atoms on the surface. The remaining chapters consider the possible arrangements

  14. Predicting Grades in Basic Algebra. (United States)

    Newman, Elise


    Data from (n=470) students at Owens Technical College in Fall 1991 showed that high school GPA was the best predictor of grades in Basic Algebra, followed by high school rank, college GPA, ACT natural sciences, ASSET numerical skills, and ASSET elementary algebra scores. (11 references) (SW)

  15. Dental Health: The Basic Facts (United States)

    ... difficult to manage. The basic fact is healthy teeth and gums are essential for: n Preventing infections which may cause MS symptoms to increase n ... person clenches his or her jaws or “grinds” teeth, usually during the night n ... and periodontitis are infections, each of which can be made worse by ...

  16. Basic DTU Wind Energy controller

    DEFF Research Database (Denmark)

    Hansen, Morten Hartvig; Henriksen, Lars Christian

    This report contains a description and documentation, including source code, of the basic DTU Wind Energy controller applicable for pitch-regulated, variable speed wind turbines. The controller features both partial and full load operation capabilities as well as switching mechanisms ensuring...

  17. Unions: Bread, Butter & Basic Skills. (United States)

    BCEL Newsletter for the Business Community, 1987


    Unions are natural providers of basic skills instruction. They are in daily workplace contact with their membership, are trusted to work on members' behalf, and speak the language of the worker. Unions are trying to address the needs of illiterate workers through collective bargaining arrangements in which employers contribute a percentage of…

  18. Basic HIV/AIDS Statistics (United States)

    ... Abroad Treatment Basic Statistics Get Tested Find an HIV testing site near you. Enter ZIP code or city Follow HIV/AIDS CDC HIV CDC HIV/AIDS See RSS | ... Statistics Center . How many people are diagnosed with HIV each year in the United States? In 2015, ...

  19. Guarani Basic Course, Part II. (United States)

    Blair, Robert W.; And Others

    This volume of the basic course in Guarani (the indigenous language of Paraguay) contains the core stage, or class-instructional phase, of the ten units presented in Volume One. These units contain explanations, exercises, dialogues, various types of pattern drills, suggestions for games and communication activities, and various types of…

  20. Guarani Basic Course, Part I. (United States)

    Blair, Robert W.; And Others

    This is the first in a two-volume basic course in Guarani, the indigenous language of Paraguay. The volume consists of an introduction to the Guarani language, some general principles for adult language-learning, and ten instructional units. Because the goal of the course is to encourage and lead the learner to communicate in Guarani in class and…

  1. The Measurement of Basic Stuff. (United States)

    Disch, James G., Ed.; And Others


    Seven articles contain information about measurement and evaluation in physical education and sport and complement the "Basic Stuff" series. They focus on (1) student self-assessment for exercise physiology; (2) monitoring motor development; (3) biomechanical analysis; and (4) measurements of aesthetic qualities, psychosocial…

  2. Emergency medicine: beyond the basics. (United States)

    Malamed, S F


    Medical emergencies can arise in the dental office. Preparedness for these emergencies is predicated on an ability to rapidly recognize a problem and to effectively institute prompt and proper management. In all emergency situations, management is based on implementation of basic life support, as needed. The author describes the appropriate management of two common emergency situations: allergy and chest pain.

  3. Basic research in kidney cancer

    NARCIS (Netherlands)

    Oosterwijk, E.; Rathmell, W.K.; Junker, K.; Brannon, A.R.; Pouliot, F.; Finley, D.S.; Mulders, P.F.A.; Kirkali, Z.; Uemura, H.; Belldegrun, A.


    CONTEXT: Advances in basic research will enhance prognosis, diagnosis, and treatment of renal cancer patients. OBJECTIVE: To discuss advances in our understanding of the molecular basis of renal cancer, targeted therapies, renal cancer and immunity, and genetic factors and renal cell carcinoma (RCC)

  4. Thermionics basic principles of electronics

    CERN Document Server

    Jenkins, J; Ashhurst, W


    Basic Principles of Electronics, Volume I : Thermionics serves as a textbook for students in physics. It focuses on thermionic devices. The book covers topics on electron dynamics, electron emission, and the themionic vacuum diode and triode. Power amplifiers, oscillators, and electronic measuring equipment are studied as well. The text will be of great use to physics and electronics students, and inventors.

  5. Women in Adult Basic Education (United States)

    Park, Rosemarie J.


    A survey of adult basic education (ABE) program directors in five states revealed that most ABE teachers are women and work part-time without benefits while most ABE administrators are men who are employed full-time. Concludes that women employed in ABE are victims of discrimination. (EM)

  6. Welding. Performance Objectives. Basic Course. (United States)

    Vincent, Kenneth

    Several intermediate performance objectives and corresponding criterion measures are listed for each of eight terminal objectives for a basic welding course. The materials were developed for a 36-week (2 hours daily) course developed to teach the fundamentals of welding shop work, to become familiar with the operation of the welding shop…

  7. Basic Income on the Agenda

    NARCIS (Netherlands)

    Groot, Loek; Veen, van der Robert-Jan


    Persisting unemployment, poverty and social exclusion, labour market flexibility, job insecurity and higher wage inequality, changing patterns of work and family life are among the factors that exert pressure on welfare states in Europe. This book explores the potential of an unconditional basic inc

  8. Basic types of plant layout


    Salas Bacalla, Julio; Docente FII-UNMSM


    Basic formats plant layout shown, considering the criteria to be taken into account in each of the formats.  Se muestra los formatos básicos de la distribución de planta, considerando los criterios que se deben tomar en cuenta en cada uno de los formatos.

  9. Basic concepts in computational physics

    CERN Document Server

    Stickler, Benjamin A


    This new edition is a concise introduction to the basic methods of computational physics. Readers will discover the benefits of numerical methods for solving complex mathematical problems and for the direct simulation of physical processes. The book is divided into two main parts: Deterministic methods and stochastic methods in computational physics. Based on concrete problems, the first part discusses numerical differentiation and integration, as well as the treatment of ordinary differential equations. This is extended by a brief introduction to the numerics of partial differential equations. The second part deals with the generation of random numbers, summarizes the basics of stochastics, and subsequently introduces Monte-Carlo (MC) methods. Specific emphasis is on MARKOV chain MC algorithms. The final two chapters discuss data analysis and stochastic optimization. All this is again motivated and augmented by applications from physics. In addition, the book offers a number of appendices to provide the read...

  10. Health insurance basic actuarial models

    CERN Document Server

    Pitacco, Ermanno


    Health Insurance aims at filling a gap in actuarial literature, attempting to solve the frequent misunderstanding in regards to both the purpose and the contents of health insurance products (and ‘protection products’, more generally) on the one hand, and the relevant actuarial structures on the other. In order to cover the basic principles regarding health insurance techniques, the first few chapters in this book are mainly devoted to the need for health insurance and a description of insurance products in this area (sickness insurance, accident insurance, critical illness covers, income protection, long-term care insurance, health-related benefits as riders to life insurance policies). An introduction to general actuarial and risk-management issues follows. Basic actuarial models are presented for sickness insurance and income protection (i.e. disability annuities). Several numerical examples help the reader understand the main features of pricing and reserving in the health insurance area. A short int...

  11. Magnetic resonance imaging the basics

    CERN Document Server

    Constantinides, Christakis


    Magnetic resonance imaging (MRI) is a rapidly developing field in basic applied science and clinical practice. Research efforts in this area have already been recognized with five Nobel prizes awarded to seven Nobel laureates in the past 70 years. Based on courses taught at The Johns Hopkins University, Magnetic Resonance Imaging: The Basics provides a solid introduction to this powerful technology. The book begins with a general description of the phenomenon of magnetic resonance and a brief summary of Fourier transformations in two dimensions. It examines the fundamental principles of physics for nuclear magnetic resonance (NMR) signal formation and image construction and provides a detailed explanation of the mathematical formulation of MRI. Numerous image quantitative indices are discussed, including (among others) signal, noise, signal-to-noise, contrast, and resolution. The second part of the book examines the hardware and electronics of an MRI scanner and the typical measurements and simulations of m...

  12. Nuclear medicine physics the basics

    CERN Document Server

    Chandra, Ramesh


    For decades this classic reference has been the book to review to master the complexities of nuclear-medicine physics. Part of the renowned The Basics series of medical physics books, Nuclear Medicine Physics has become an essential resource for radiology residents and practitioners, nuclear cardiologists, medical physicists, and radiologic technologists. This thoroughly revised Seventh Edition retains all the features that have made The Basics series a reliable and trusted partner for board review and reference. This handy manual contains key points at the end of each chapter that help to underscore principal concepts. You'll also find review questions at the end of each chapter—with detailed answers at the end of the book—to help you master the material. This edition includes useful appendices that elaborate on specific topics, such as physical characteristics of radionuclides and CGS and SI Units.

  13. Basics of modern mathematical statistics

    CERN Document Server

    Spokoiny, Vladimir


    This textbook provides a unified and self-contained presentation of the main approaches to and ideas of mathematical statistics. It collects the basic mathematical ideas and tools needed as a basis for more serious studies or even independent research in statistics. The majority of existing textbooks in mathematical statistics follow the classical asymptotic framework. Yet, as modern statistics has changed rapidly in recent years, new methods and approaches have appeared. The emphasis is on finite sample behavior, large parameter dimensions, and model misspecifications. The present book provides a fully self-contained introduction to the world of modern mathematical statistics, collecting the basic knowledge, concepts and findings needed for doing further research in the modern theoretical and applied statistics. This textbook is primarily intended for graduate and postdoc students and young researchers who are interested in modern statistical methods.

  14. Positron emission tomography basic sciences

    CERN Document Server

    Townsend, D W; Valk, P E; Maisey, M N


    Essential for students, science and medical graduates who want to understand the basic science of Positron Emission Tomography (PET), this book describes the physics, chemistry, technology and overview of the clinical uses behind the science of PET and the imaging techniques it uses. In recent years, PET has moved from high-end research imaging tool used by the highly specialized to an essential component of clinical evaluation in the clinic, especially in cancer management. Previously being the realm of scientists, this book explains PET instrumentation, radiochemistry, PET data acquisition and image formation, integration of structural and functional images, radiation dosimetry and protection, and applications in dedicated areas such as drug development, oncology, and gene expression imaging. The technologist, the science, engineering or chemistry graduate seeking further detailed information about PET, or the medical advanced trainee wishing to gain insight into the basic science of PET will find this book...

  15. Basic statistics in cell biology. (United States)

    Vaux, David L


    The physicist Ernest Rutherford said, "If your experiment needs statistics, you ought to have done a better experiment." Although this aphorism remains true for much of today's research in cell biology, a basic understanding of statistics can be useful to cell biologists to help in monitoring the conduct of their experiments, in interpreting the results, in presenting them in publications, and when critically evaluating research by others. However, training in statistics is often focused on the sophisticated needs of clinical researchers, psychologists, and epidemiologists, whose conclusions depend wholly on statistics, rather than the practical needs of cell biologists, whose experiments often provide evidence that is not statistical in nature. This review describes some of the basic statistical principles that may be of use to experimental biologists, but it does not cover the sophisticated statistics needed for papers that contain evidence of no other kind.

  16. Generalized Stieltjes transforms: basic aspects

    CERN Document Server

    Karp, Dmitry


    The paper surveys the basic properties of generalized Stieltjes functions including some new ones. We introduce the notion of exact Stieltjes order and give a criterion of exactness, simple sufficient conditions and some prototypical examples. The paper includes an appendix, where we define the left sided Riemann-Liouville and the right sided Kober-Erdelyi fractional integrals of measures supported on half axis and give inversion formulas for them.

  17. Basic emotions - self-awareness


    Correia, Ana Almeida; Veiga-Branco, Augusta


    We start from basic emotions using Paul Ekman’s model (1999): joy, sadness, anger, surprise, disgust, fear and contempt, to study the concepts of Self- Awareness - Knowing our own emotions - (Goleman, 1995), and Emotional Awareness - Ability to become aware of one's own emotions - (Bisquerra, 2001). Objectives: To understand the levels of Emotional Self-awareness/ Emotional awareness of a group of preschool, primary and lower secondary school teachers through the identifi...

  18. Basic statistics for social research

    CERN Document Server

    Hanneman, Robert A; Riddle, Mark D


    A core statistics text that emphasizes logical inquiry, notmath Basic Statistics for Social Research teaches core generalstatistical concepts and methods that all social science majorsmust master to understand (and do) social research. Its use ofmathematics and theory are deliberately limited, as the authorsfocus on the use of concepts and tools of statistics in theanalysis of social science data, rather than on the mathematicaland computational aspects. Research questions and applications aretaken from a wide variety of subfields in sociology, and eachchapter is organized arou

  19. HMPT: Basic Radioactive Material Transportation

    Energy Technology Data Exchange (ETDEWEB)

    Hypes, Philip A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)


    Hazardous Materials and Packaging and Transportation (HMPT): Basic Radioactive Material Transportation Live (#30462, suggested one time) and Test (#30463, required initially and every 36 months) address the Department of Transportation’s (DOT’s) function-specific [required for hazardous material (HAZMAT) handlers, packagers, and shippers] training requirements of the HMPT Los Alamos National Laboratory (LANL) Labwide training. This course meets the requirements of 49 CFR 172, Subpart H, Section 172.704(a)(ii), Function-Specific Training.

  20. Basic principles of electronics thermionics

    CERN Document Server

    Jenkins, J


    Basic Principles of Electronics, Volume I: Thermionics covers topics related to thermionic devices. The book starts by providing a physical background about electronics, including structure of matter, ionic, chemical and covalent combination, crystalline structure, conductors and insulators, and thermionic emission. The text then discusses electron dynamics; the characteristics and properties of electrons in solids; electron emission; and thermionic emission in a vacuum diode or triode. The development of the vacuum triode; gas-filled valves; and power amplifiers are also considered. The book

  1. Basic Studies in Plasma Physics (United States)


    close to a Maxwellian parametrized by a temperature T and mean velocity u which satisfy certain non -linear equations, which are the macroscopic equations...Simulations with Particle-to-Grid Methods 17 E. Microscopic-Shock Profiles: Exact Solution of a Non -Equilibrium System 18 IV. List of Publications...Investigator ABSTRACT An improved understanding of equilibrium and non -equilibrium properties of plasmas is central to many areas of basic science as

  2. RF Basics I and II

    CERN Document Server

    Gerigk, Frank


    Maxwell's equations are introduced in their general form, together with a basic set of mathematical operations needed to work with them. After simplifying and adapting the equations for application to radio frequency problems, we derive the most important formulae and characteristic quantities for cavities and waveguides. Several practical examples are given to demonstrate the use of the derived equations and to explain the importance of the most common figures of merit.

  3. Basic sciences agonize in Turkey! (United States)

    Akdemir, Fatma; Araz, Asli; Akman, Ferdi; Durak, Rıdvan


    In this study, changes from past to present in the departments of physics, chemistry, biology and mathematics, which are considered as the basic sciences in Turkey, are shown. The importance of basic science for the country emphasized and the status of our country was discussed with a critical perspective. The number of academic staff, the number of students, opened quotas according to years for these four departments at universities were calculated and analysis of the resulting changes were made. In examined graphics changes to these four departments were similar. Especially a significant change was observed in the physics department. Lack of jobs employing young people who have graduated from basic science is also an issue that must be discussed. There are also qualitative results of this study that we have discussed as quantitative. Psychological problems caused by unemployment have become a disease among young people. This study was focused on more quantitative results. We have tried to explain the causes of obtained results and propose solutions.


    Krogh, F. T.


    The Basic Linear Algebra Subprogram (BLAS) library is a collection of FORTRAN callable routines for employing standard techniques in performing the basic operations of numerical linear algebra. The BLAS library was developed to provide a portable and efficient source of basic operations for designers of programs involving linear algebraic computations. The subprograms available in the library cover the operations of dot product, multiplication of a scalar and a vector, vector plus a scalar times a vector, Givens transformation, modified Givens transformation, copy, swap, Euclidean norm, sum of magnitudes, and location of the largest magnitude element. Since these subprograms are to be used in an ANSI FORTRAN context, the cases of single precision, double precision, and complex data are provided for. All of the subprograms have been thoroughly tested and produce consistent results even when transported from machine to machine. BLAS contains Assembler versions and FORTRAN test code for any of the following compilers: Lahey F77L, Microsoft FORTRAN, or IBM Professional FORTRAN. It requires the Microsoft Macro Assembler and a math co-processor. The PC implementation allows individual arrays of over 64K. The BLAS library was developed in 1979. The PC version was made available in 1986 and updated in 1988.

  5. Basic Color Terms in Estonian Sign Language (United States)

    Hollman, Liivi; Sutrop, Urmas


    The article is written in the tradition of Brent Berlin and Paul Kay's theory of basic color terms. According to this theory there is a universal inventory of eleven basic color categories from which the basic color terms of any given language are always drawn. The number of basic color terms varies from 2 to 11 and in a language having a fully…

  6. The Basics of Basic Education: Reflections on the Review and Updating of Basic Education Curriculum

    Directory of Open Access Journals (Sweden)

    César Coll


    Full Text Available This lecture presents a reflection on the fundamental content of the basic education curriculum. The arguments set forth within the Spanish educational context may be divided into three main categories. The first refers to the contradictions in the decision making processes regarding what should be taught and what should be learned in basic education, and in which the requirement to attend to the needs of new social, economic and technological scenarios call for the incorporation of new content in the curriculum, but the accumulation of curricular contents makes it practically impossible for them to be taught and learned. Secondly, the author ponders some aspects or dimensions that acquire a special relevance in the new perspective of the basic education curriculum and in which concepts of content such as “indispensable basic” and “desirable basic” are discussed as criteria for decision making. Finally, in the third category, a succinct diagram is presented as an example based on the concepts of literacy, competency and knowledge associated with the acquisition and development of the capacities that illustrate this new perspective.

  7. [Basic science and applied science]. (United States)

    Pérez-Tamayo, R


    A lecture was presented by the author at the Democratic Opinion Forum on Health Teaching and Research, organized by Mexico's National Health Institutes Coordinating Office, at National Cardiology Institute "Ignacio Chavez", where he presented a critical review of the conventional classification of basic and applied science, as well as his personal view on health science teaching and research. According to the author, "well-conducted science" is that "generating reality-checked knowledge" and "mis-conducted science" is that "unproductive or producing 'just lies' and 'non-fundable'. To support his views, the author reviews utilitarian and pejorative definitions of science, as well as those of committed and pure science, useful and useless science, and practical and esoterical science, as synonyms of applied and basic science. He also asserts that, in Mexico, "this classification has been used in the past to justify federal funding cutbacks to basic science, allegedly because it is not targeted at solving 'national problems' or because it was not relevant to priorities set in a given six-year political administration period". Regarding health education and research, the author asserts that the current academic programs are inefficient and ineffective; his proposal to tackle these problems is to carry out a solid scientific study, conducted by a multidisciplinary team of experts, "to design the scientific researcher curricula from recruitment of intelligent young people to retirement or death". Performance assessment of researchers would not be restricted to publication of papers, since "the quality of scientific work and contribution to the development of science is not reflected by the number of published papers". The English version of this paper is available at:

  8. Basic Radar Altimetry Toolbox & Tutorial (United States)

    Rosmorduc, Vinca; Benveniste, Jerome; Breebaart, Leo; Bronner, Emilie; Dinardo, Salvatore; Earith, Didier; Lucas, Bruno Manuel; Niejmeier, Sander; Picot, Nicolas


    The Basic Radar Altimetry Toolbox is an "all-altimeter" collection of tools, tutorials and documents designed to facilitate the use of radar altimetry data, including the last mission launched, CryoSat. It has been available from April 2007, and had been demonstrated during training courses and scientific meetings. Nearly 1200 people downloaded it (as of end of June 2010), with many "newcomers" to altimetry among them. Users' feedbacks, developments in altimetry, and practice, showed that new interesting features could be added. Some have been added and/or improved in version 2. Others are ongoing, some are in discussion. The Basic Radar Altimetry Toolbox is able: - to read most distributed radar altimetry data, from ERS-1 & 2, Topex/Poseidon, Geosat Follow-on, Jason- 1, Envisat, Jason- 2, CryoSat and also the future Saral and Sentinel 3 missions, - to perform some processing, data editing and statistic, - and to visualize the results. It can be used at several levels/several ways: - as a data reading tool, with APIs for C, Fortran, Matlab and IDL - as processing/extraction routines, through the on-line command mode - as an educational and a quick-look tool both, with the graphical user interface As part of the Toolbox, a Radar Altimetry Tutorial gives general information about altimetry, the technique involved and its applications, as well as an overview of past, present and future missions, including information on how to access data, additional software and documentation. It also presents a series of data use cases, covering all uses of altimetry over ocean, cryosphere and land, showing the basic methods for some of the most frequent manners of using altimetry data. BRAT is developed under contract with ESA and CNES. It is available at and

  9. Basic Concepts of Positional Astronomy (United States)

    Ruggles, Clive L. N.

    This article describes and defines a number of basic concepts that are commonly used in archaeoastronomy and ethnoastronomy, sometimes in particular ways, and attempts to clarify some of the issues of confusion that frequently arise. It is aimed primarily at archaeologists and ethnographers entering or exploring the field and emphasizes the broad principles that are generally of importance to them, while trying to avoid unnecessary complications as well as technical details. It is not aimed at those studying historical sources from antiquity onward, who need a more sophisticated knowledge of positional astronomy, mathematically formulated. Further detail can be found in a variety of sources, including a number aimed specifically at archaeoastronomers.

  10. Sound Symbolism in Basic Vocabulary

    Directory of Open Access Journals (Sweden)

    Søren Wichmann


    Full Text Available The relationship between meanings of words and their sound shapes is to a large extent arbitrary, but it is well known that languages exhibit sound symbolism effects violating arbitrariness. Evidence for sound symbolism is typically anecdotal, however. Here we present a systematic approach. Using a selection of basic vocabulary in nearly one half of the world’s languages we find commonalities among sound shapes for words referring to same concepts. These are interpreted as due to sound symbolism. Studying the effects of sound symbolism cross-linguistically is of key importance for the understanding of language evolution.

  11. Basic developments in fluid dynamics

    CERN Document Server

    Holt, Maurice


    Basic Developments in Fluid Dynamics, Volume 2 focuses on the developments, approaches, methodologies, reactions, and processes involved in fluid dynamics, including sea motion, wave interactions, and motion of spheres in a viscous fluid.The selection first offers information on inviscid cavity and wake flows and weak-interaction theory of ocean waves. Discussions focus on steady and unsteady cavity flows, radiation balance, theory of weak interactions in random fields, interactions between gravity waves and the atmosphere, and interactions within the ocean. The text then examines low Reynolds

  12. Basic radiotherapy physics and biology

    CERN Document Server

    Chang, David S; Das, Indra J; Mendonca, Marc S; Dynlacht, Joseph R


    This book is a concise and well-illustrated review of the physics and biology of radiation therapy intended for radiation oncology residents, radiation therapists, dosimetrists, and physicists. It presents topics that are included on the Radiation Therapy Physics and Biology examinations and is designed with the intent of presenting information in an easily digestible format with maximum retention in mind. The inclusion of mnemonics, rules of thumb, and reader-friendly illustrations throughout the book help to make difficult concepts easier to grasp. Basic Radiotherapy Physics and Biology is a

  13. Security basics for computer architects

    CERN Document Server

    Lee, Ruby B


    Design for security is an essential aspect of the design of future computers. However, security is not well understood by the computer architecture community. Many important security aspects have evolved over the last several decades in the cryptography, operating systems, and networking communities. This book attempts to introduce the computer architecture student, researcher, or practitioner to the basic concepts of security and threat-based design. Past work in different security communities can inform our thinking and provide a rich set of technologies for building architectural support fo

  14. Basic Elements of Knowledge Management

    Directory of Open Access Journals (Sweden)

    Marcin W. Staniewski


    Full Text Available The article is a review of basic knowledge management terminology. It presents such a description as: knowledge resources levels (data, information, knowledge, and wisdom, knowledge sources (internal, external, and knowledge typology (implicit, tacit or individual, social. Moreover the article characterizes knowledge management process, knowledge management system and main knowledge management strategies (codification, personalization. At the end of the article there is mentioned the knowledge creating process (the concept of knowledge creation spiral and the role of Intelligence Technology (IT and organizational culture as main elements supporting knowledge management implementation in organizations.

  15. Basic entwinements: unassuming analogue inserts in basic digital modeling (courses)

    DEFF Research Database (Denmark)

    Wiesner, Thomas


    to diverse inter-active discussions and a more conscious re-plays of material transcending the dichotomies of digital/analogue. Keywords Simple didactics, analogue sketching, cognitive space awareness, digital modelling, bachelor first year, morphology of body and space, pataphysics...... between the various intentions and the student’s actual grasp of the many basic architectural element’s interplays of form and space can become apparent. To alleviate, calibrate and cognitively fine-tune the potential for more acute and lasting cognitive understandings of (scaled) body and space...... of options for speedily produced material for various attuned and conscious, supplementary oblique architectural assessments. The simple procedure(s) advance a certain amount of beneficial cognitive complementarities: Beneficial interplay-changes between right and left brain concentrations; Change...

  16. 78 FR 59121 - Basic Health Program: State Administration of Basic Health Programs; Eligibility and Enrollment... (United States)


    ... 42 CFR Part 600 Office of the Secretary 45 CFR Part 144 Basic Health Program: State Administration of... Standard Health Plans; Performance Standards for Basic Health Programs; Premium and Cost Sharing for Basic... CFR Part 144 RIN 0938-AR93 Basic Health Program: State Administration of Basic Health...

  17. Further Analysis of the Function of AtBHLH29 in Regulating the Iron Uptake Process in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    Juan Zhang; Hui-Fen Zhu; Hui Liang; Kun-Fan Liu; Ai-Min Zhang; Hong-Qing Ling; Dao-Wen Wang


    Using T-DNA insertion and chemical mutants, two recent studies have shown that AtBHLH29, encoding a putative basic helix-loop-helix (BHLH) protein, is involved in regulating the iron uptake process in Arabidopsis thaliana. Herein, we report that RNA interference (RNAi) mutants can be used to reveal more accurately the genetic function of AtBHLH29. We compared the iron deficiency responses of seven RNAi strains that contained decreasing amounts of AtBHLH29transcripts. Under high iron conditions (50 μmol/L iron), only in the most severe RNAi strains (R101, R111, and R119) was plant growth significantly retarded. However, these mutants could still survive and produce seeds. This suggests that the function of AtBHLH29 is beneficial, but not absolutely essential, to plant growth when iron supply is not limiting. Under low iron conditions (less than 10 μmol/L iron), the R111 and R119 strains died prematurely, demonstrating that AtBHLH29 is absolutely necessary for plant survival when iron supply is restricted. The transcription of AtBHLH29 was essential for the expression of AtFRO2 (encoding the ferric chelate reductase). In contrast, the expression of AtlRT1(encoding the high-affinity iron transporter) was not so strongly dependent upon the transcription of AtBHLH29.By transient expression, we found that the AtBHLH29-GUS fusion protein was targeted specifically to the nucleus in plant cells. Interestingly, the nuclear localization of AtBHLH29-GUS was abolished when the four consecutive arginine residues located in the basic region of the putative AtBHLH29 protein were replaced by alanine residues by mutagenesis. The implications of our findings on further studies of the mechanism underlying the function of AtBHLH29 are discussed.

  18. Characterization and expression analysis of AH receptors in aquatic mammals and birds

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun-Young [Ehime Prefectural Institute of Public Health and Environmental Science, Matsuyama (Japan); Yasui, Tomoko; Hisato, Iwata; Shinsuke, Tanabe [Ehime Univ., Matsuyama (Japan)


    The magnitude of the risk that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and related planar halogenated aromatic hydrocarbons (PHAHs) pose to the health of aquatic birds and mammals is uncertain, because of the lack of direct information on the sensitivity and toxicity to these chemicals. Exposure to PHAHs is speculated to produce toxicity through changes in the expression of genes involved in the control of cell growth and differentiation. These changes are initiated by the binding to the aryl hydrocarbon receptor (AHR), a ligand-dependent transcription factor. The AHR and its dimerization partner ARNT belong to the basic-helix-loop-helix/Per-ARNT-Sim (bHLH-PAS) family of transcriptional regulation proteins. The bHLH domain was involved in protein-DNA and protein-protein interactions, and the PAS domain forms a secondary dimerization surface for heteromeric interactions between AHR and ARNT. Although the presence and basic function of AHR are known to be conserved in most vertebrates, only a limited number of studies on the structure and functional diversity of AHR in aquatic mammals and birds have been reported, in spite of their high exposure to dioxins and other related chemicals. To understand the molecular mechanism of susceptibility to dioxin exposure and toxic effects that PHAHs pose in wild animals, we investigated the molecular and functional characterization of AHRs from aquatic mammals and birds. Initially, the AHR cDNAs from the livers of Baikal seal (Pusa sibirica), black-footed albatross (Diomedea nigripes) and common cormorant (Phalacrocorax carbo) were cloned and sequenced. We also clarified the tissue-specific expression pattern of AHR mRNA and the relationships among PHAHs, AHR and CYP expression levels in the liver of Baikal seals and common cormorants.

  19. Comprehensive Analysis of Expressed Sequence Tags from the Pulp of the Red Mutant 'Cara Cara' Navel Orange(Citrus sinensis Osbeck)

    Institute of Scientific and Technical Information of China (English)

    Jun-Li Ye; An-Dan Zhu; Neng-Guo Tao; Qiang Xu; Juan Xu; Xiu-Xin Deng


    Expressed sequence tag(EST)analysis of the pulp of the red-fleshed mutant 'Cara Cara' navel orange provided a starting point for gene discovery and transcriptome survey during citrus fruit maturation. Interpretation of the EST datasets revealed that the mutant pulp transcriptome held a high section of stress responses related genes,such as the type Ⅲ metallothionein-like gene(6.0%),heat shock protein(2.8%),Cu/Zn superoxide dismutase(0.8%),late embryogenesis abundant protein 5(0.8%),etc. 133transcripts were detected to be differentially expressed between the red mutant and its orange-color wild genotype 'Washington' via digital expression analysis. Among them,genes involved in metabolism,defense/stress and signal transduction were statistical overrepresented. Fifteen transcription factors,composed of NAM,ATAF,and CUC transcription factor(NAC); myeloblastosis(MYB); myelocytomatosis(MYC); basic helix-loop-helix(bHLH); basic leucine zipper(bZIP)domain members,were also included. The data reflected the distinct expression profile and the unique regulatory module associated with these two genotypes. Eight differently expressed genes analyzed in digital were validated by quantitative realtime polymerase chain reaction. For structural polymorphism,both simple sequence repeats and single nucleotide polymorphisms(SNP)loci were surveyed; dinucleotide presentation revealed a bias toward AG/GA/TC/CT repeats(52.5%),against GC/CG repeats(0%). SNPs analysis found that transitions(73%)outnumbered transversions(27%). Seventeen potential cultivar-specific and 387 heterozygous SNP loci were detected from 'Cara Cara' and 'Washington' EST pool.

  20. Regulatory Role of a Receptor-Like Kinase in Specifying Anther Cell Identity1[OPEN (United States)

    Yang, Li; Qian, Xiaoling; Chen, Mingjiao


    In flowering plants, sequential formation of anther cell types is a highly ordered process that is essential for successful meiosis and sexual reproduction. Differentiation of meristematic cells and cell-cell communication are proposed to coordinate anther development. Among the proposed mechanisms of cell fate specification are cell surface-localized Leu-rich repeat receptor-like kinases (LRR-RLKs) and their putative ligands. Here, we present the genetic and biochemical evidence that a rice (Oryza sativa) LRR-RLK, MSP1 (MULTIPLE SPOROCYTE1), interacts with its ligand OsTDL1A (TPD1-like 1A), specifying the cell identity of anther wall layers and microsporocytes. An in vitro assay indicates that the 21-amino acid peptide of OsTDL1A has a physical interaction with the LRR domain of MSP1. The ostdl1a msp1 double mutant showed the defect in lacking middle layers and tapetal cells and having an increased number of microsporocytes similar to the ostdl1a or msp1 single mutant, indicating the same pathway of OsTDL1A-MSP1 in regulating anther development. Genome-wide expression profiles showed the altered expression of genes encoding transcription factors, particularly basic helix-loop-helix and basic leucine zipper domain transcription factors in ostdl1a and msp1. Among these reduced expressed genes, one putatively encodes a TGA (TGACGTCA cis-element-binding protein) factor OsTGA10, and another one encodes a plant-specific CC-type glutaredoxin OsGrx_I1. OsTGA10 was shown to interact with OsGrx_I1, suggesting that OsTDL1A-MSP1 signaling specifies anther cell fate directly or indirectly affecting redox status. Collectively, these data point to a central role of the OsTDL1A-MSP1 signaling pathway in specifying somatic cell identity and suppressing overproliferation of archesporial cells in rice. PMID:27208278

  1. Delayed onset of experimental autoimmune encephalomyelitis in Olig1 deficient mice.

    Directory of Open Access Journals (Sweden)

    Xiaoli Guo

    Full Text Available BACKGROUND: Olig1 is a basic helix-loop-helix (bHLH transcription factor that is essential for oligodendrogenesis and efficient remyelination. However, its role in neurodegenerative disorders has not been well-elucidated. METHODOLOGY/PRINCIPAL FINDINGS: Here we investigated the effects of Olig1 deficiency on experimental autoimmune encephalomyelitis (EAE, an animal model of multiple sclerosis (MS. We show that the mean disease onset of myelin oligodendrocyte glycoprotein (MOG-induced EAE in Olig1(-/- mice is significantly slower than wide-type (WT mice (19.8 ± 2.2 in Olig1(-/- mice and 9.5 ± 0.3 days in WT mice. In addition, 10% of Olig1(-/- mice did not develop EAE by the end of the observation periods (60 days. The severity of EAE, the extent of demyelination, and the activation of microglial cells and astrocytes in spinal cords, were significantly milder in Olig1(-/- mice compared with WT mice in the early stage. Moreover, the visual function, as assessed by the second-kernel of multifocal electroretinograms, was better preserved, and the number of degenerating axons in the optic nerve was significantly reduced in Olig1(-/- mice. Interestingly, Olig1 deficiency had no effect on T cell response capability, however, it reduced the expression of myelin proteins such as MOG, myelin basic protein (MBP and myelin-associated glycoprotein (MAG. The expression of Olig2 remained unchanged in the optic nerve and brain, and it was reduced in the spinal cord of Olig1(-/- mice. CONCLUSIONS/SIGNIFICANCE: Our results suggest that the Olig1 signaling pathways may be involved in the incidence rate and the severity of neurological symptoms in MS.

  2. Basic Information about BCI Systems

    Directory of Open Access Journals (Sweden)

    S. Noshadi


    Full Text Available Brain Computer Interface (BCI systems establish a one way communication link between man and computer. The main goal of this technology is to provide a link between the brain and the physical world without any physical contact. Indeed these systems interlink thought to action. As the result, the user would be able to control the environment via brain signals. Electro-Encephalogram Signals (EEG is input signals for these systems that include two main stages for processing of those signals, feature extraction and classification. Almost researches in this field are done to find what feature extracting methods and classifier are suitable. As regard spread of the existing information in this field, in this study, we first introduce a BCI system and then try to collect and organize the most needed information for processing EEG signals in BCIs. This study with having sufficient references presents the basic information for researchers who want to start their studying in this field.

  3. PC Basic Linear Algebra Subroutines

    Energy Technology Data Exchange (ETDEWEB)


    PC-BLAS is a highly optimized version of the Basic Linear Algebra Subprograms (BLAS), a standardized set of thirty-eight routines that perform low-level operations on vectors of numbers in single and double-precision real and complex arithmetic. Routines are included to find the index of the largest component of a vector, apply a Givens or modified Givens rotation, multiply a vector by a constant, determine the Euclidean length, perform a dot product, swap and copy vectors, and find the norm of a vector. The BLAS have been carefully written to minimize numerical problems such as loss of precision and underflow and are designed so that the computation is independent of the interface with the calling program. This independence is achieved through judicious use of Assembly language macros. Interfaces are provided for Lahey Fortran 77, Microsoft Fortran 77, and Ryan-McFarland IBM Professional Fortran.

  4. Economic analysis: A basic primer

    Directory of Open Access Journals (Sweden)

    Doig G


    Full Text Available Medical knowledge is advancing at an incredible rate. This rapid increase in the fundamental understanding of disease states has led to some important breakthroughs in care over the past ten years and will undoubtedly lead to untold more. At the same time that we are being presented with more options for diagnosis and treatment, governments around the world are fighting to reduce deficit spending and inflation. As a direct result of this combination of reduced spending and increased options for care, medical professionals are being asked to provide more effective care more efficiently. The randomized control trial may be the best way to determine the effectiveness of different options, however, only a full economic analysis can help decide which option is more efficient. This paper is intended to provide the reader with a basic understanding of the methods used to perform a full economic analysis.

  5. Basic sciences of nuclear medicine

    Energy Technology Data Exchange (ETDEWEB)

    Khalil, Magdy M. (ed.) [Imperial College London (United Kingdom). Biological Imaging Centre


    Nuclear medicine has become an ever-changing and expanding diagnostic and therapeutic medical profession. The day-to-day innovations seen in the field are, in great part, due to the integration of many scientific bases with complex technologic advances. The aim of this reference book, Basic Sciences of Nuclear Medicine, is to provide the reader with a comprehensive and detailed discussion of the scientific bases of nuclear medicine, covering the different topics and concepts that underlie many of the investigations and procedures performed in the field. Topics include radiation and nuclear physics, Tc-99m chemistry, single-photon radiopharmaceuticals and PET chemistry, radiobiology and radiation dosimetry, image processing, image reconstruction, quantitative SPECT imaging, quantitative cardiac SPECT, small animal imaging (including multimodality hybrid imaging, e.g., PET/CT, SPECT/CT, and PET/MRI), compartmental modeling, and tracer kinetics. (orig.)

  6. Basic Concepts of String Theory

    CERN Document Server

    Blumenhagen, Ralph; Theisen, Stefan


    The purpose of this book is to thoroughly prepare the reader for research in string theory. It is intended as a textbook in the sense that, starting from the basics, the material is presented in a pedagogical and self-contained fashion. The emphasis is on the world-sheet perspective of closed strings and of open strings ending on D-branes, where two-dimensional conformal field theory is the main tool. Compactifications of string theory, with and without fluxes, and string dualities are also discussed from the space-time point of view, i.e. in geometric language. End-of-chapter references have been added to guide the reader intending to pursue further studies or to start research in the topics covered by this book.

  7. Basic algebraic geometry, v.2

    CERN Document Server

    Shafarevich, Igor Rostislavovich


    Shafarevich Basic Algebraic Geometry 2 The second edition of Shafarevich's introduction to algebraic geometry is in two volumes. The second volume covers schemes and complex manifolds, generalisations in two different directions of the affine and projective varieties that form the material of the first volume. Two notable additions in this second edition are the section on moduli spaces and representable functors, motivated by a discussion of the Hilbert scheme, and the section on Kähler geometry. The book ends with a historical sketch discussing the origins of algebraic geometry. From the Zentralblatt review of this volume: "... one can only respectfully repeat what has been said about the first part of the book (...): a great textbook, written by one of the leading algebraic geometers and teachers himself, has been reworked and updated. As a result the author's standard textbook on algebraic geometry has become even more important and valuable. Students, teachers, and active researchers using methods of al...

  8. Basic concepts of string theory

    Energy Technology Data Exchange (ETDEWEB)

    Blumenhagen, Ralph [Max-Planck-Institut fuer Physik, Muenchen (Germany). Werner-Heisenberg-Institut; Luest, Dieter [Muenchen Univ. (Germany). Arnold-Sommerfeld Zentrum fuer Theoretische Physik; Theisen, Stefan [Albert-Einstein-Institut (Max-Planck Institut fuer Gravitationsphysik), Golm (Germany)


    The purpose of this book is to thoroughly prepare the reader for research in string theory. It is intended as a textbook in the sense that, starting from the basics, the material is presented in a pedagogical and self-contained fashion. The emphasis is on the world-sheet perspective of closed strings and of open strings ending on D-branes, where two-dimensional conformal field theory is the main tool. Compactifications of string theory, with and without fluxes, and string dualities are also discussed from the space-time point of view, i.e. in geometric language. End-of-chapter references have been added to guide the reader intending to pursue further studies or to start research in the topics covered by this book.

  9. Basic results on braid groups

    CERN Document Server

    Gonzalez-Meneses, Juan


    These are Lecture Notes of a course given by the author at the French-Spanish School "Tresses in Pau", held in Pau (France) in October 2009. It is basically an introduction to distinct approaches and techniques that can be used to show results in braid groups. Using these techniques we provide several proofs of well known results in braid groups, namely the correctness of Artin's presentation, that the braid group is torsion free, or that its center is generated by the full twist. We also recall some solutions of the word and conjugacy problems, and that roots of a braid are always conjugate. We also describe the centralizer of a given braid. Most proofs are classical ones, using modern terminology. I have chosen those which I find simpler or more beautiful.

  10. Heat Transfer Basics and Practice

    CERN Document Server

    Böckh, Peter


    The book provides an easy way to understand the fundamentals of heat transfer. The reader will acquire the ability to design and analyze heat exchangers. Without extensive derivation of the fundamentals, the latest correlations for heat transfer coefficients and their application are discussed. The following topics are presented - Steady state and transient heat conduction - Free and forced convection - Finned surfaces - Condensation and boiling - Radiation - Heat exchanger design - Problem-solving After introducing the basic terminology, the reader is made familiar with the different mechanisms of heat transfer. Their practical application is demonstrated in examples, which are available in the Internet as MathCad files for further use. Tables of material properties and formulas for their use in programs are included in the appendix. This book will serve as a valuable resource for both students and engineers in the industry. The author’s experience indicates that students, after 40 lectures and exercises ...

  11. Digital storytelling teaching robotics basics

    Directory of Open Access Journals (Sweden)

    Michele Scandola


    Full Text Available Digital Storytelling (DST is a powerful tool for teaching complex concepts. DSTs are typically used in the humanities but several papers have shown that they are also a wonderful tool for the sciences because they are more involving, contextualized and can easily lead to deeper understanding. In the classical use of DST the story is thecontent, while the digital medium is the way of telling it. Our approach is slightly different: the story is not the content but a glue for the main contents, while the digital medium remains the way to tell the story. We propose the use of DST as a means to teach surgeons the basics of robotic surgery, by using a story that should be involving forthem, i.e. a surgical operation, within which we will illustrate specific concepts onrobotics in surgery.

  12. [Basic concepts about paternity testing]. (United States)

    Lagos, Marcela; Poggi, Helena; Mellado, Cecilia


    Nowadays, the analysis of genetic markers is a very important and validated tool for the identification of individuals, and for paternity testing. To do so, highly variable regions of the human genome are analyzed, making it possible to obtain the genetic profile of an individual, and to distinguish between different individuals. The methodology used is basically the same all over the world, consisting in the analysis of 13 to 15 markers. To assign biological paternity the child must have inherited the characteristics from the alleged father in each of the genetic markers analyzed. This analysis achieves a certainty higher than with any other test, which is expressed as the probability of paternity. This probability has to be at least 99.9%, but greater probabilities are usually obtained, especially if the mother is included in the analysis. If the characteristics of two or more genetic markers from the alleged father are absent in the child, biological paternity is excluded.

  13. Basic symptoms in schizophrenic and affective psychoses. (United States)

    Ebel, H; Gross, G; Klosterkötter, J; Huber, G


    The study compares schizophrenic and affective psychoses with regard to basic symptoms. 30 patients in schizophrenic pre-, intra-, and postpsychotic basic stages and 30 patients in endogenous-depressive phases were examined according to the Bonn Scale for the Assessment of Basic Symptoms. The most important result is that certain cognitive basic symptoms and cenesthesias which are decisive for the development of florid productive-psychotic phenomena are found more frequently in the group of schizophrenias.

  14. Helicobacter pylori neutrophil-activating protein induces release of histamine and interleukin-6 through G protein-mediated MAPKs and PI3K/Akt pathways in HMC-1 cells. (United States)

    Tsai, Chung-Che; Kuo, Ting-Yu; Hong, Zhi-Wei; Yeh, Ying-Chieh; Shih, Kuo-Shun; Du, Shin-Yi; Fu, Hua-Wen


    Helicobacter pylori neutrophil-activating protein (HP-NAP) activates several innate leukocytes including neutrophils, monocytes, and mast cells. It has been reported that HP-NAP induces degranulation and interleukin-6 (IL-6) secretion of rat peritoneal mast cells. However, the molecular mechanism is not very clear. Here, we show that HP-NAP activates human mast cell line-1 (HMC-1) cells to secrete histamine and IL-6. The secretion depends on pertussis toxin (PTX)-sensitive heterotrimeric G proteins but not on Toll-like receptor 2. Moreover, HP-NAP induces PTX-sensitive G protein-mediated activation of extracellular signal-regulated kinase 1/2 (ERK1/2), p38-mitogen-activated protein kinase (p38 MAPK), and Akt in HMC-1 cells. Inhibition of ERK1/2, p38 MAPK, or phosphatidylinositol 3-kinase (PI3K) suppresses HP-NAP-induced release of histamine and IL-6 from HMC-1 cells. Thus, the activation of HMC-1 cells by HP-NAP is through Gi-linked G protein-coupled receptor-mediated MAPKs and PI3K/Akt pathways.

  15. Basic concepts in social sciences III

    NARCIS (Netherlands)

    Hoede, C.


    In this paper the set of concepts considered to be basic to the fields of Economics, Organization Theory, Political Science, Psychology and Sociology is completed. The set of 55 basic concepts in the first two papers on basic concepts was mainly determined by considering concepts in relation to soci

  16. Measuring Student Teachers' Basic Psychological Needs (United States)

    Vermeulen, Marjan; Castelijns, Jos; Kools, Quinta; Koster, Bob


    In Self-Determination Theory, basic psychological needs for relatedness, autonomy and competence are distinguished. Basic psychological need-fulfilment is considered to be critical for human development and intrinsic motivation. In the Netherlands, the concept of basic psychological need-fulfilment is introduced in the curricula of many teacher…

  17. Measuring student teachers' basic psychological needs

    NARCIS (Netherlands)

    Vermeulen, Marjan; Castelijns, Jos; Kools, Quinta; Koster, Bob


    In the Self-Determination Theory (SDT) basic psychological needs for relatedness, autonomy and competence are distinguished. Basic psychological need fulfilment is considered to be critical for human development and intrinsic motivation. In the Netherlands, the concept of basic psychological need fu

  18. Reinventing Biostatistics Education for Basic Scientists. (United States)

    Weissgerber, Tracey L; Garovic, Vesna D; Milin-Lazovic, Jelena S; Winham, Stacey J; Obradovic, Zoran; Trzeciakowski, Jerome P; Milic, Natasa M


    Numerous studies demonstrating that statistical errors are common in basic science publications have led to calls to improve statistical training for basic scientists. In this article, we sought to evaluate statistical requirements for PhD training and to identify opportunities for improving biostatistics education in the basic sciences. We provide recommendations for improving statistics training for basic biomedical scientists, including: 1. Encouraging departments to require statistics training, 2. Tailoring coursework to the students' fields of research, and 3. Developing tools and strategies to promote education and dissemination of statistical knowledge. We also provide a list of statistical considerations that should be addressed in statistics education for basic scientists.

  19. Basic Energy Sciences Program Update

    Energy Technology Data Exchange (ETDEWEB)

    None, None


    The U.S. Department of Energy’s (DOE) Office of Basic Energy Sciences (BES) supports fundamental research to understand, predict, and ultimately control matter and energy at the electronic, atomic, and molecular levels to provide the foundations for new energy technologies and to support DOE missions in energy, environment, and national security. The research disciplines covered by BES—condensed matter and materials physics, chemistry, geosciences, and aspects of physical biosciences— are those that discover new materials and design new chemical processes. These disciplines touch virtually every aspect of energy resources, production, conversion, transmission, storage, efficiency, and waste mitigation. BES also plans, constructs, and operates world-class scientific user facilities that provide outstanding capabilities for imaging and spectroscopy, characterizing materials of all kinds ranging from hard metals to fragile biological samples, and studying the chemical transformation of matter. These facilities are used to correlate the microscopic structure of materials with their macroscopic properties and to study chemical processes. Such experiments provide critical insights to electronic, atomic, and molecular configurations, often at ultrasmall length and ultrafast time scales.

  20. Diagnostic validity of basic symptoms. (United States)

    Klosterkötter, J; Ebel, H; Schultze-Lutter, F; Steinmeyer, E M


    Although the Bonn Scale for the Assessment of Basic Symptoms (BSABS) [13] has come into use in several European countries, its diagnostic validity has not yet been sufficiently examined. That is why we have assessed BSABS items on a sample of 243 consecutive admissions to the Department of Psychiatry at the RWTH University, Aachen, and 79 psychologically healthy persons. Then, a cluster analysis was calculated to identify the empirical item-grouping. Five well-interpretable BSABS subsyndromes were found. In addition, uni- and multivariate analyses were computed to evaluate the diagnostic validity of these subsyndromes. We were able to show that every BSABS subsyndrome separates at least schizophrenic, organic mental and affective disorders from personality, neurotic and substance-induced disorders, as well as from psychological health. Furthermore, the subsyndrome "information processing disturbances" differentiates between schizophrenic and organic mental disorders, on the one hand, and affective disorders, on the other, and additionally, the subsyndrome "interpersonal irritation" between schizophrenics and all other persons examined.

  1. R Basics with Tabular Data

    Directory of Open Access Journals (Sweden)

    Taryn Dewar


    Full Text Available As more and more historical records are digitized, having a way to quickly analyze large volumes of tabular data makes research faster and more effective. R is a programming language with strengths in statistical analyses. As such, it can be used to complete quantitative analysis on historical sources, including but not limited to statistical tests. Because you can repeatedly re-run the same code on the same sources, R lets you analyze data quickly and produces repeatable results. Because you can save your code, R lets you re-purpose or revise functions for future projects, making it a flexible part of your toolkit. This tutorial presumes no prior knowledge of R. It will go through some of the basic functions of R and serves as an introduction to the language. It will take you through the installation process, explain some of the tools that you can use in R, as well as explain how to work with data sets while doing research. The tutorial will do so by going through a series of mini-lessons that will show the kinds of sources R works well with and examples of how to do calculations to find information that could be relevant to historical research. The lesson will also cover different input methods for R such as matrices and using CSV files.

  2. Basic DTU Wind Energy controller

    Energy Technology Data Exchange (ETDEWEB)

    Hartvig Hansen, M.; Henriksen, Lars Christian


    This report contains a description and documentation, including source code, of the basic DTU Wind Energy controller applicable for pitch-regulated, variable speed wind turbines. The controller features both partial and full load operation capabilities as well as switching mechanisms ensuring smooth switching between the two modes of operation. The partial and full load controllers are both based on classical proportional-integral control theory as well as additional filters such as an optional drive train damper and a notch filter mitigating the influence of rotor speed dependent variations in the feedback. The controller relies on generator speed as the primary feedback sensor. Additionally, the reference generator power is used as a feedback term to smoothen the switching between partial and full load operation. Optionally, a low-pass filtered wind speed measurement can be used for wind speed dependent minimum blade pitch in partial load operation. The controller uses the collective blade pitch angle and electromagnetic generator torque to control the wind turbine. In full load operation a feedback term from the collective blade pitch angle is used to schedule the gains of the proportional-integral controller to counter the effects of changing dynamics of the wind turbine for different wind speeds. Blade pitch servo and generator models are not included in this controller and should be modeled separately, if they are to be included in the simulations. (Author)

  3. The Arabidopsis SET-domain protein ASHR3 is involved in stamen development and interacts with the bHLH transcription factor ABORTED MICROSPORES (AMS). (United States)

    Thorstensen, Tage; Grini, Paul E; Mercy, Inderjit S; Alm, Vibeke; Erdal, Sigrid; Aasland, Rein; Aalen, Reidunn B


    The Arabidopsis thaliana genome contains more than 30 genes encoding SET-domain proteins that are thought to be epigenetic regulators of gene expression and chromatin structure. SET-domain proteins can be divided into subgroups, and members of the Polycomb group (PcG) and trithorax group (trxG) have been shown to be important regulators of development. Both in animals and plants some of these proteins are components of multimeric protein complexes. Here, we have analyzed the Arabidopsis trxG protein ASHR3 which has a SET domain and pre- and post-SET domains similar to that of Ash1 in Drosophila. In addition to the SET domain, a divergent PHD finger is found in the N-terminus of the ASHR3 protein. As expected from SET-domain proteins involved in transcriptional activation, ASHR3 (coupled to GFP) localizes to euchromatin. A yeast two-hybrid screening revealed that the ASHR3 protein interacts with the putative basic helix-loop-helix (bHLH) transcription factor ABORTED MICROSPORES (AMS), which is involved in anther and stamen development in Arabidopsis. Deletion mapping indicated that both the PHD finger and the SET domain mediate the interaction between the two proteins. Overexpression of ASHR3 led in general to growth arrest, and specifically to degenerated anthers and male sterility. Expression analyses demonstrated that ASHR3 like AMS is expressed in the anther and in stamen filaments. We therefore propose that AMS can target ASHR3 to chromatin and regulate genes involved in stamen development and function.

  4. Differential gene expression and mitotic cell analysis of the drought tolerant soybean (Glycine max L. Merrill Fabales, Fabaceae cultivar MG/BR46 (Conquista under two water deficit induction systems

    Directory of Open Access Journals (Sweden)

    Polyana K. Martins


    Full Text Available Drought cause serious yield losses in soybean (Glycine max, roots being the first plant organ to detect the water-stress signals triggering defense mechanisms. We used two drought induction systems to identify genes differentially expressed in the roots of the drought-tolerant soybean cultivar MG/BR46 (Conquista and characterize their expression levels during water deficit. Soybean plants grown in nutrient solution hydroponically and in sand-pots were submitted to water stress and gene expression analysis was conducted using the differential display (DD and real time polymerase chain reaction (PCR techniques. Three differentially expressed mRNA transcripts showed homology to the Antirrhinum majus basic helix-loop-helix transcription factor bHLH, the Arabidopsis thaliana phosphatidylinositol transfer protein PITP and the auxin-independent growth regulator 1 (axi 1. The hydroponic experiments showed that after 100 min outside the nutrient solution photosynthesis completely stopped, stomata closed and leaf temperature rose. Both stress induction treatments produced significant decrease in the mitotic indices of root cells. Axi 1, PITP and bHLH were not only differentially expressed during dehydration in the hydroponics experiments but also during induced drought in the pot experiments. Although, there were differences between the two sets of experiments in the time at which up or down regulation occurred, the expression pattern of all three transcripts was related. Similar gene expression and cytological analysis results occurred in both systems, suggesting that hydroponics could be used to simulate drought detection by roots growing in soil and thus facilitate rapid and easy root sampling.

  5. Tobacco Transcription Factors NtMYC2a and NtMYC2b Form Nuclear Complexes with the NtJAZ1 Repressor and Regulate Multiple Jasmonate-Inducible Steps in Nicotine Biosynthesis

    Institute of Scientific and Technical Information of China (English)

    Hong-Bo Zhang; Marta T. Bokowiec; Paul J. Rushton; Sheng-Cheng Han; Michael P. Timko


    Biotic and abiotic stress lead to elevated levels of jasmonic acid (JA) and its derivatives and activation of the biosynthesis of nicotine and related pyridine alkaloids in cultivated tobacco (Nicotiana tabacum L.).Among the JAresponsive genes is NtPMT1a,encoding putrescine N-methyl transferase,a key regulatory enzyme in nicotine formation.We have characterized three genes (NtMYC2a,b,c) encoding basic helix-loop-helix (bH LH) transcription factors (TFs) whose expression is rapidly induced by JA and that specifically activate JA-inducible NtPMT1a expression by binding a G-box motif within the NtPMT1a promoter in in vivo and in vitro assays.Using split-YFP assays,we further show that,in the absence of JA,NtMYC2a and NtMYC2b are present as nuclear complexes with the NtJAZ1 repressor.RNA interference (RNAi)-mediated knockdown of NtMYC2a and NtMYC2b expression results in significant decreases in JA-inducible NtPMT1a transcript levels,as well as reduced levels of transcripts encoding other enzymes involved in nicotine and minor alkaloid biosynthesis,including an 80-90% reduction in the level of transcripts encoding the putative nicotine synthase gene NtA662.In contrast,ectopic overexpression of NtMYC2a and NtMYC2b had no effect on NtPMT1a expression in the presence or absence of exogenously added JA.These data suggest that NtMYC2a,b,c are required components of JA-inducible expression of multiple genes in the nicotine biosynthetic pathway and may act additively in the activation of JA responses.

  6. Folic acid supplementation changes the fate of neural progenitors in mouse embryos of hyperglycemic and diabetic pregnancy. (United States)

    Yuan, Qiuhuan; Zhao, Shidou; Liu, Shangming; Zhang, Yanmin; Fu, Jie; Wang, Fuwu; Liu, Qian; Ling, Eng-Ang; Hao, Aijun


    Folic acid has been shown to decrease the incidence of neural tube defects (NTDs) in normal and hyperglycemic conditions, but the influence of folic acid on the development of central nervous system is not fully understood. Here, we aimed to explore the effects of folic acid, especially high dose of folic acid, on the characteristics of neural progenitors in embryos of hyperglycemic and diabetic mouse. Hyperglycemic and diabetic pregnant mice were given 3 mg/kg or 15 mg/kg folic acid from embryonic day 0.5 (E0.5) and were euthanased on E11.5, E13.5 or E18.5. The incidence of NTDs at E13.5 was counted. The proliferation, apoptosis and differentiation of neural progenitors and neuronal migration were determined using BrdU incorporation assay, TUNEL assay, immunofluorescence, Western blot and real-time reverse transcriptase polymerase chain reaction. Both normal and high doses of folic acid decreased the incidence of NTDs, promoted proliferation and reduced apoptosis of neuroepithelial cells in embryos of hyperglycemic and diabetic mice. Importantly, folic acid, especially at high dose, might affect the premature differentiation of neural progenitors in embryos of hyperglycemic and diabetic pregnancy. This may be attributed to changes of messenger RNA expression levels of some basic-helix-loop-helix transcription factors. In addition, folic acid might be involved in regulating neuronal migration in embryos of hyperglycemic and diabetic pregnancy. These findings suggest that periconceptional supplementation of folic acid, especially at high dose, may be a double-edged sword because it may result in undesirable outcomes affecting both the neuronal and glial differentiation in hyperglycemic and diabetic pregnancy.

  7. Analyses of loss-of-function mutations of the MITF gene suggest that haploinsufficiency is a cause of Waardenburg syndrome type 2A

    Energy Technology Data Exchange (ETDEWEB)

    Nobukuni, Yoshitaka; Watanabe, A.; Takeda, Kazushisa; Skarka, Hana; Tachibana, Masayoshi [National Inst. of Health, Bethesda, MD (United States)


    Waardenburg syndrome type 2 (WS2) is a dominantly inherited disorder characterized by a pigmentation anomaly and hearing impairment due to lack of melanocyte. Previous work has linked a subset of families with WS2 (WS2A) to the MITF gene that encodes a transcription factor with a basic-helix-loop-helix-leucine zipper (bHLH-Zip) motif and that is involved in melanocyte differentiation. Several splice-site and missense mutations have been reported in individuals affected with WS2A. In this report, we have identified two novel point mutations in the MITF gene in affected individuals from two different families with WS2A. The two mutations (C760{r_arrow}T and C895{r_arrow}T) create stop codons in exons 7 and 8, respectively. Corresponding mutant alleles predict the truncated proteins lacking HLH-Zip or Zip structure. To understand how these mutations cause WS2 in heterozygotes, we generated mutant MITF cDNAs and used them for DNA-binding and luciferase reporter assays. The mutated MITF proteins lose the DNA-binding activity and fail to transactivate the promoter of tyrosinase, a melanocyte-specific enzyme. However, these mutated proteins do not appear to interfere with the activity of wild-type MITF protein in these assays, indicating that they do not show a dominant-negative effect. These findings suggest that the phenotypes of the two families with WS2A in the present study are caused by loss-of-function mutations in one of the two alleles of the MITF gene, resulting in haploinsufficiency of the MITF protein, the protein necessary for normal development of melanocytes. 37 refs., 4 figs.

  8. A role for PacMYBA in ABA-regulated anthocyanin biosynthesis in red-colored sweet cherry cv. Hong Deng (Prunus avium L.). (United States)

    Shen, Xinjie; Zhao, Kai; Liu, Linlin; Zhang, Kaichun; Yuan, Huazhao; Liao, Xiong; Wang, Qi; Guo, Xinwei; Li, Fang; Li, Tianhong


    The MYB transcription factors and plant hormone ABA have been suggested to play a role in fruit anthocyanin biosynthesis, but supporting genetic evidence has been lacking in sweet cherry. The present study describes the first functional characterization of an R2R3-MYB transcription factor, PacMYBA, from red-colored sweet cherry cv. Hong Deng (Prunus avium L.). Transient promoter assays demonstrated that PacMYBA physically interacted with several anthocyanin-related basic helix-loop-helix (bHLH) transcription factors to activate the promoters of PacDFR, PacANS and PacUFGT, which are thought to be involved in anthocyanin biosynthesis. Furthermore, the immature seeds of transgenic Arabidopsis plants overexpressing PacMYBA exhibited ectopic pigmentation. Silencing of PacMYBA, using a Tobacco rattle virus (TRV)-induced gene silencing technique, resulted in sweet cherry fruit that lacked red pigment. ABA treatment significantly induced anthocyanin accumulation, while treatment with the ABA biosynthesis inhibitor nordihydroguaiaretic acid (NDGA) blocked anthocyanin production. PacMYBA expression peaked after 2 h of pre-incubation in ABA and was 15.2-fold higher than that of sweet cherries treated with NDGA. The colorless phenotype was also observed in the fruits silenced in PacNCED1, which encodes a key enzyme in the ABA biosynthesis pathway. The endogenous ABA content as well as the transcript levels of six structural genes and PacMYBA in PacNCED1-RNAi (RNA interference) fruit were significantly lower than in the TRV vector control fruit. These results suggest that PacMYBA plays an important role in ABA-regulated anthocyanin biosynthesis and ABA is a signal molecule that promotes red-colored sweet cherry fruit accumulating anthocyanin.

  9. Maintaining cholesterol homeostasis:Sterol regulatory element-binding proteins

    Institute of Scientific and Technical Information of China (English)

    Lutz W. Weber; Meinrad Boll; Andreas Stampfl


    The molecular mechanism of how hepatocytes maintain cholesterol homeostasis has become much more transparent with the discovery of sterol regulatory element binding proteins (SREBPs) in recent years. These membrane proteins are members of the basic helix-loop-helix-leucine zipper (bHLHZip) family of transcription factors. They activate the expression of at least 30 genes involved in the synthesis of cholesterol and lipids. SREBPs are synthesized as precursor proteins in the endoplasmic reticulum (ER), where they form a complex with another protein, SREBP cleavage activating protein (SCAP).The SCAP molecule contains a sterol sensory domain. In the presence of high cellular sterol concentrations SCAP confines SREBP to the ER. With low cellular concentrations, SCAP escorts SREBP to activation in the Golgi. There, SREBP undergoes two proteolytic cleavage steps to release the mature, biologically active transcription factor, nuclear SREBP (nSREBP). nSREBP translocates to the nucleus and binds to sterol response elements (SRE) in the promoter/enhancer regions of target genes. Additional transcription factors are required to activate transcription of these genes. Three different SREBPs are known, SREBPs-1a, -1c and -2. SREBP-1a and -1c are isoforms produced from a single gene by alternate splicing. SREBP-2is encoded by a different gene and does not display any isoforms. It appears that SREBPs alone, in the sequence described above, can exert complete control over cholesterol synthesis, whereas many additional factors (hormones,cytokines, etc.) are required for complete control of lipid metabolism. Medicinal manipulation of the SREBP/SCAP system is expected to prove highly beneficial in the management of cholesterol-related disease.

  10. Down-regulation of AP-4 inhibits proliferation, induces cell cycle arrest and promotes apoptosis in human gastric cancer cells.

    Directory of Open Access Journals (Sweden)

    Xinghua Liu

    Full Text Available BACKGROUND: AP-4 belongs to the basic helix-loop-helix leucine-zipper subgroup; it controls target gene expression, regulates growth, development and cell apoptosis and has been implicated in tumorigenesis. Our previous studies indicated that AP-4 was frequently overexpressed in gastric cancers and may be associated with the poor prognosis. The purpose of this study is to examine whether silencing of AP-4 can alter biological characteristics of gastric cancer cells. METHODS: Two specific siRNAs targeting AP-4 were designed, synthesized, and transfected into gastric cancer cell lines and human normal mucosa cells. AP-4 expression was measured with real-time quantitative PCR and Western blot. Cell proliferation and chemo-sensitivity were detected by CCK-8 assay. Cell cycle assay and apoptosis assay were performed by flow cytometer, and relative expression of cell cycle regulators were detected by real-time quantitative PCR and Western blot, expression of the factors involved in the apoptosis pathway were examined in mRNA and protein level. RESULTS: The expression of AP-4 was silenced by the siRNAs transfection and the effects of AP-4 knockdown lasted 24 to 96 hrs. The siRNA-mediated silencing of AP-4 suppressed the cellular proliferation, induced apoptosis and sensitized cancer cells to anticancer drugs. In addition, the expression level of p21, p53 and Caspase-9 were increased when AP-4 was knockdown, but the expression of cyclin D1, Bcl-2 and Bcl-x(L was inhibited. It didn't induce cell cycle arrest when AP-4 was knockdown in p53 defect gastric cancer cell line Kato-III. CONCLUSIONS: These results illustrated that gene silencing of AP-4 can efficiently inhibited cell proliferation, triggered apoptosis and sensitized cancer cells to anticancer drugs in vitro, suggesting that AP-4 siRNAs mediated silencing has a potential value in the treatment of human gastric cancer.

  11. The Small C-terminal Domain Phosphatase 1 Inhibits Cancer Cell Migration and Invasion by Dephosphorylating Ser(P)68-Twist1 to Accelerate Twist1 Protein Degradation. (United States)

    Sun, Tong; Fu, Junjiang; Shen, Tao; Lin, Xia; Liao, Lan; Feng, Xin-Hua; Xu, Jianming


    Twist1 is a basic helix-loop-helix transcription factor that strongly promotes epithelial-to-mesenchymal transition, migration, invasion, and metastasis of cancer cells. The MAPK-phosphorylated Twist1 on its serine 68 (Ser(P)(68)-Twist1) has a significantly enhanced stability and function to drive cancer cell invasion and metastasis. However, the phosphatase that dephosphorylates Ser(P)(68)-Twist1 and destabilizes Twist1 has not been identified and characterized. In this study, we screened a serine/threonine phosphatase cDNA expression library in HEK293T cells with ectopically coexpressed Twist1. We found that the small C-terminal domain phosphatase 1 (SCP1) specifically dephosphorylates Ser(P)(68)-Twist1 in both cell-free reactions and living cells. SCP1 uses its amino acid residues 43-63 to interact with the N terminus of Twist1. Increased SCP1 expression in cells decreased Ser(P)(68)-Twist1 and total Twist1 proteins, whereas knockdown of SCP1 increased Ser(P)(68)-Twist1 and total Twist1 proteins. Furthermore, the levels of SCP1 are negatively correlated with Twist1 protein levels in several cancer cell lines. SCP1-dephosphorylated Twist1 undergoes fast degradation via the ubiquitin-proteasome pathway. Importantly, an increase in SCP1 expression in breast cancer cells with either endogenous or ectopically expressed Twist1 largely inhibits the Twist1-induced epithelial-to-mesenchymal transition phenotype and the migration and invasion capabilities of these cells. These results indicate that SCP1 is the phosphatase that counterregulates the MAPK-mediated phosphorylation of Ser(68)-Twist1. Thus, an increase in SCP1 expression and activity may be a useful strategy for eliminating the detrimental roles of Twist1 in cancer cells.

  12. Evolving gene regulatory networks into cellular networks guiding adaptive behavior: an outline how single cells could have evolved into a centralized neurosensory system. (United States)

    Fritzsch, Bernd; Jahan, Israt; Pan, Ning; Elliott, Karen L


    Understanding the evolution of the neurosensory system of man, able to reflect on its own origin, is one of the major goals of comparative neurobiology. Details of the origin of neurosensory cells, their aggregation into central nervous systems and associated sensory organs and their localized patterning leading to remarkably different cell types aggregated into variably sized parts of the central nervous system have begun to emerge. Insights at the cellular and molecular level have begun to shed some light on the evolution of neurosensory cells, partially covered in this review. Molecular evidence suggests that high mobility group (HMG) proteins of pre-metazoans evolved into the definitive Sox [SRY (sex determining region Y)-box] genes used for neurosensory precursor specification in metazoans. Likewise, pre-metazoan basic helix-loop-helix (bHLH) genes evolved in metazoans into the group A bHLH genes dedicated to neurosensory differentiation in bilaterians. Available evidence suggests that the Sox and bHLH genes evolved a cross-regulatory network able to synchronize expansion of precursor populations and their subsequent differentiation into novel parts of the brain or sensory organs. Molecular evidence suggests metazoans evolved patterning gene networks early, which were not dedicated to neuronal development. Only later in evolution were these patterning gene networks tied into the increasing complexity of diffusible factors, many of which were already present in pre-metazoans, to drive local patterning events. It appears that the evolving molecular basis of neurosensory cell development may have led, in interaction with differentially expressed patterning genes, to local network modifications guiding unique specializations of neurosensory cells into sensory organs and various areas of the central nervous system.

  13. The neuronal differentiation factor NeuroD1 downregulates the neuronal repellent factor Slit2 expression and promotes cell motility and tumor formation of neuroblastoma. (United States)

    Huang, Peng; Kishida, Satoshi; Cao, Dongliang; Murakami-Tonami, Yuko; Mu, Ping; Nakaguro, Masato; Koide, Naoshi; Takeuchi, Ichiro; Onishi, Akira; Kadomatsu, Kenji


    The basic helix-loop-helix transcription factor NeuroD1 has been implicated in the neurogenesis and early differentiation of pancreatic endocrine cells. However, its function in relation to cancer has been poorly examined. In this study, we found that NeuroD1 is involved in the tumorigenesis of neuroblastoma. NeuroD1 was strongly expressed in a hyperplastic region comprising neuroblasts in the celiac sympathetic ganglion of 2-week-old MYCN transgenic (Tg) mice and was consistently expressed in the subsequently generated neuroblastoma tissue. NeuroD1 knockdown by short hairpin RNA (shRNA) resulted in motility inhibition of the human neuroblastoma cell lines, and this effect was reversed by shRNA-resistant NeuroD1. The motility inhibition by NeuroD1 knockdown was associated with induction of Slit2 expression, and knockdown of Slit2 could restore cell motility. Consistent with this finding, shRNA-resistant NeuroD1 suppressed Slit2 expression. NeuroD1 directly bound to the first and second E-box of the Slit2 promoter region. Moreover, we found that the growth of tumor spheres, established from neuroblastoma cell lines in MYCN Tg mice, was suppressed by NeuroD1 suppression. The functions identified for NeuroD1 in cell motility and tumor sphere growth may suggest a link between NeuroD1 and the tumorigenesis of neuroblastoma. Indeed, tumor formation of tumor sphere-derived cells was significantly suppressed by NeuroD1 knockdown. These data are relevant to the clinical features of human neuroblastoma: high NeuroD1 expression was closely associated with poor prognosis. Our findings establish the critical role of the neuronal differentiation factor NeuroD1 in neuroblastoma as well as its functional relationship with the neuronal repellent factor Slit2.

  14. A novel Zea mays ssp. mexicana L. MYC-type ICE-like transcription factor gene ZmmICE1, enhances freezing tolerance in transgenic Arabidopsis thaliana. (United States)

    Lu, Xiang; Yang, Lei; Yu, Mengyuan; Lai, Jianbin; Wang, Chao; McNeil, David; Zhou, Meixue; Yang, Chengwei


    The annual Zea mays ssp. mexicana L., a member of the teosinte group, is a close wild relative of maize and thus can be effectively used in maize improvement. In this study, an ICE-like gene, ZmmICE1, was isolated from a cDNA library of RNA-Seq from cold-treated seedling tissues of Zea mays ssp. mexicana L. The deduced protein of ZmmICE1 contains a highly conserved basic helix-loop-helix (bHLH) domain and C-terminal region of ICE-like proteins. The ZmmICE1 protein localizes to the nucleus and shows sumoylation when expressed in an Escherichia coli reconstitution system. In addition, yeast one hybrid assays indicated that ZmmICE1 has transactivation activities. Moreover, ectopic expression of ZmmICE1 in the Arabidopsis ice1-2 mutant increased freezing tolerance. The ZmmICE1 overexpressed plants showed lower electrolyte leakage (EL), reduced contents of malondialdehyde (MDA). The expression of downstream cold related genes of Arabidopsis C-repeat-binding factors (AtCBF1, AtCBF2 and AtCBF3), cold-responsive genes (AtCOR15A and AtCOR47), kinesin-1 member gene (AtKIN1) and responsive to desiccation gene (AtRD29A) was significantly induced when compared with wild type under low temperature treatment. Taken together, these results indicated that ZmmICE1 is the homolog of Arabidopsis inducer of CBF expression genes (AtICE1/2) and plays an important role in the regulation of freezing stress response.

  15. Hippocalcin Is Required for Astrocytic Differentiation through Activation of Stat3 in Hippocampal Neural Precursor Cells.

    Directory of Open Access Journals (Sweden)

    Min-Jeong Kang


    Full Text Available Hippocalcin (Hpca is a neuronal calcium sensor protein expressed in the mammalian brain. However, its function in neural stem/precursor cells has not yet been studied. Here, we clarify the function of Hpca in astrocytic differentiation in hippocampal neural precursor cells (HNPCs. When we overexpressed Hpca in HNPCs in the presence or absence of bFGF, expression levels of nerve-growth factors such as neurotrophin-3 (NT-3, neurotrophin-4/5 (NT-4/5 and brain-derived neurotrophic factor (BDNF, together with the proneural basic helix loop helix (bHLH transcription factors neuroD and neurogenin 1 (ngn1, increased significantly. In addition, there was an increase in the number of cells expressing glial fibrillary acidic protein (GFAP, an astrocyte marker, and in dendrite outgrowth, indicating astrocytic differentiation of the HNPCs. Downregulation of Hpca by transfection with Hpca siRNA reduced expression of NT-3, NT-4/5, BDNF, neuroD and ngn1 as well as levels of GFAP protein. Furthermore, overexpression of Hpca increased the phosphorylation of STAT3 (Ser727, and this effect was abolished by treatment with a STAT3 inhibitor (S3I-201, suggesting that STAT3 (Ser727 activation is involved in Hpca-mediated astrocytic differentiation. As expected, treatment with Stat3 siRNA or STAT3 inhibitor caused a complete inhibition of astrogliogenesis induced by Hpca overexpression. Taken together, this is the first report to show that Hpca, acting through Stat3, has an important role in the expression of neurotrophins and proneural bHLH transcription factors, and that it is an essential regulator of astrocytic differentiation and dendrite outgrowth in HNPCs.

  16. Expression and cellular localization of the transcription factor NeuroD1 in the developing and adult rat pineal gland. (United States)

    Castro, Analía E; Benitez, Sergio G; Farias Altamirano, Luz E; Savastano, Luis E; Patterson, Sean I; Muñoz, Estela M


    Circadian rhythms govern many aspects of mammalian physiology. The daily pattern of melatonin synthesis and secretion is one of the classic examples of circadian oscillations. It is mediated by a class of neuroendocrine cells known as pinealocytes which are not yet fully defined. An established method to evaluate functional and cytological characters is through the expression of lineage-specific transcriptional regulators. NeuroD1 is a basic helix-loop-helix transcription factor involved in the specification and maintenance of both endocrine and neuronal phenotypes. We have previously described developmental and adult regulation of NeuroD1 mRNA in the rodent pineal gland. However, the transcript levels were not influenced by the elimination of sympathetic input, suggesting that any rhythmicity of NeuroD1 might be found downstream of transcription. Here, we describe NeuroD1 protein expression and cellular localization in the rat pineal gland during development and the daily cycle. In embryonic and perinatal stages, protein expression follows the mRNA pattern and is predominantly nuclear. Thereafter, NeuroD1 is mostly found in pinealocyte nuclei in the early part of the night and in cytoplasm during the day, a rhythm maintained into adulthood. Additionally, nocturnal nuclear NeuroD1 levels are reduced after sympathetic disruption, an effect mimicked by the in vivo administration of α- and β-adrenoceptor blockers. NeuroD1 phosphorylation at two sites, Ser(274) and Ser(336) , associates with nuclear localization in pinealocytes. These data suggest that NeuroD1 influences pineal phenotype both during development and adulthood, in an autonomic and phosphorylation-dependent manner.

  17. The C. elegans NeuroD homolog cnd-1 functions in multiple aspects of motor neuron fate specification. (United States)

    Hallam, S; Singer, E; Waring, D; Jin, Y


    The basic helix-loop-helix transcription factor NeuroD (Neurod1) has been implicated in neuronal fate determination, differentiation and survival. Here we report the expression and functional analysis of cnd-1, a C. elegans NeuroD homolog. cnd-1 expression was first detected in neuroblasts of the AB lineage in 14 cell embryos and maintained in many neuronal descendants of the AB lineage during embryogenesis, diminishing in most terminally differentiated neurons prior to hatching. Specifically, cnd-1 reporter genes were expressed in the precursors of the embryonic ventral cord motor neurons and their progeny. A loss-of-function mutant, cnd-1(ju29), exhibited multiple defects in the ventral cord motor neurons. First, the number of motor neurons was reduced, possibly caused by the premature withdrawal of the precursors from mitotic cycles. Second, the strict correlation between the fate of a motor neuron with respect to its lineage and position in the ventral cord was disrupted, as manifested by the variable expression pattern of motor neuron fate specific markers. Third, motor neurons also exhibited defects in terminal differentiation characteristics including axonal morphology and synaptic connectivity. Finally, the expression patterns of three neuronal type-specific transcription factors, unc-3, unc-4 and unc-30, were altered. Our data suggest that cnd-1 may specify the identity of ventral cord motor neurons both by maintaining the mitotic competence of their precursors and by modulating the expression of neuronal type-specific determination factors. cnd-1 appears to have combined the functions of several vertebrate neurogenic bHLH proteins and may represent an ancestral form of this protein family.

  18. SREBP-2 negatively regulates FXR-dependent transcription of FGF19 in human intestinal cells. (United States)

    Miyata, Masaaki; Hata, Tatsuya; Yamazoe, Yasushi; Yoshinari, Kouichi


    Sterol regulatory element-binding protein-2 (SREBP-2) is a basic helix-loop-helix-leucine zipper transcription factor that positively regulates transcription of target genes involved in cholesterol metabolism. In the present study, we have investigated a possible involvement of SREBP-2 in human intestinal expression of fibroblast growth factor (FGF)19, which is an endocrine hormone involved in the regulation of lipid and glucose metabolism. Overexpression of constitutively active SREBP-2 decreased FGF19 mRNA levels in human colon-derived LS174T cells. In reporter assays, active SREBP-2 overexpression suppressed GW4064/FXR-mediated increase in reporter activities in regions containing the IR-1 motif (+848 to +5200) in the FGF19 gene. The suppressive effect disappeared in reporter activities in the region containing the IR-1 motif when the mutation was introduced into the IR-1 motif. In electrophoretic mobility shift assays, binding of the FXR/retinoid X receptor α heterodimer to the IR-1 motif was attenuated by adding active SREBP-2, but SREBP-2 binding to the IR-1 motif was not observed. In chromatin immunoprecipitation assays, specific binding of FXR to the IR-1-containing region of the FGF19 gene (+3214 to +3404) was increased in LS174T cells by treatment with cholesterol and 25-hydroxycholesterol. Specific binding of SREBP-2 to FXR was observed in glutathione-S-transferase (GST) pull-down assays. These results suggest that SREBP-2 negatively regulates the FXR-mediated transcriptional activation of the FGF19 gene in human intestinal cells.

  19. Hey2 functions in parallel with Hes1 and Hes5 for mammalian auditory sensory organ development

    Directory of Open Access Journals (Sweden)

    Chin Michael T


    Full Text Available Abstract Background During mouse development, the precursor cells that give rise to the auditory sensory organ, the organ of Corti, are specified prior to embryonic day 14.5 (E14.5. Subsequently, the sensory domain is patterned precisely into one row of inner and three rows of outer sensory hair cells interdigitated with supporting cells. Both the restriction of the sensory domain and the patterning of the sensory mosaic of the organ of Corti involve Notch-mediated lateral inhibition and cellular rearrangement characteristic of convergent extension. This study explores the expression and function of a putative Notch target gene. Results We report that a putative Notch target gene, hairy-related basic helix-loop-helix (bHLH transcriptional factor Hey2, is expressed in the cochlear epithelium prior to terminal differentiation. Its expression is subsequently restricted to supporting cells, overlapping with the expression domains of two known Notch target genes, Hairy and enhancer of split homolog genes Hes1 and Hes5. In combination with the loss of Hes1 or Hes5, genetic inactivation of Hey2 leads to increased numbers of mis-patterned inner or outer hair cells, respectively. Surprisingly, the ectopic hair cells in Hey2 mutants are accompanied by ectopic supporting cells. Furthermore, Hey2-/-;Hes1-/- and Hey2-/-;Hes1+/- mutants show a complete penetrance of early embryonic lethality. Conclusion Our results indicate that Hey2 functions in parallel with Hes1 and Hes5 in patterning the organ of Corti, and interacts genetically with Hes1 for early embryonic development and survival. Our data implicates expansion of the progenitor pool and/or the boundaries of the developing sensory organ to account for patterning defects observed in Hey2 mutants.

  20. I-mfa domain proteins interact with Axin and affect its regulation of the Wnt and c-Jun N-terminal kinase signaling pathways. (United States)

    Kusano, Shuichi; Raab-Traub, Nancy


    I-mfa has been identified as an inhibitor of myogenic basic helix-loop-helix transcription factors, and a related human I-mfa domain-containing protein (HIC) also has been identified as a protein that regulates Tat- and Tax-mediated expression of viral promoters. HIC and I-mfa represent a family of proteins that share a highly conserved cysteine-rich domain, termed the I-mfa domain. We show here that both I-mfa domain proteins, HIC and I-mfa, interacted in vivo with the Axin complex through their C-terminal I-mfa domains. This interaction inhibited Axin-mediated downregulation of free levels of cytosolic beta-catenin. I-mfa and HIC also both directly interacted with lymphocyte enhancer factor (LEF); however, I-mfa but not HIC significantly inhibited reporter constructs regulated by beta-catenin. The overexpression of HIC but not I-mfa decreased the inhibitory effects of Axin on beta-catenin-regulated reporter constructs, while both HIC and I-mfa decreased Axin-mediated c-Jun N-terminal kinase (JNK) activation. These data reveal for the first time that I-mfa domain proteins interact with the Axin complex and affect Axin regulation of both the Wnt and the JNK activation pathways. Interestingly, HIC differs from I-mfa in that I-mfa affects both Axin function and T-cell factor- or LEF-regulated transcription in the Wnt signaling pathway while HIC affects primarily Axin function.

  1. Molecular cloning of a novel human I-mfa domain-containing protein that differently regulates human T-cell leukemia virus type I and HIV-1 expression. (United States)

    Thébault, S; Gachon, F; Lemasson, I; Devaux, C; Mesnard, J M


    Regulation of viral genome expression is the result of complex cooperation between viral proteins and host cell factors. We report here the characterization of a novel cellular factor sharing homology with the specific cysteine-rich C-terminal domain of the basic helix-loop-helix repressor protein I-mfa. The synthesis of this new factor, called HIC for Human I-mfa domain-Containing protein, is controlled at the translational level by two different codons, an ATG and an upstream non-ATG translational initiator, allowing the production of two protein isoforms, p32 and p40, respectively. We show that the HIC protein isoforms present different subcellular localizations, p32 being mainly distributed throughout the cytoplasm, whereas p40 is targeted to the nucleolus. Moreover, in trying to understand the function of HIC, we have found that both isoforms stimulate in T-cells the expression of a luciferase reporter gene driven by the human T-cell leukemia virus type I-long terminal repeat in the presence of the viral transactivator Tax. We demonstrate by mutagenesis that the I-mfa-like domain of HIC is involved in this regulation. Finally, we also show that HIC is able to down-regulate the luciferase expression from the human immunodeficiency virus type 1-long terminal repeat induced by the viral transactivator Tat. From these results, we propose that HIC and I-mfa represent two members of a new family of proteins regulating gene expression and characterized by a particular cysteine-rich C-terminal domain.

  2. The bHLH transcription factor bHLH104 interacts with IAA-LEUCINE RESISTANT3 and modulates iron homeostasis in Arabidopsis. (United States)

    Zhang, Jie; Liu, Bing; Li, Mengshu; Feng, Dongru; Jin, Honglei; Wang, Peng; Liu, Jun; Xiong, Feng; Wang, Jinfa; Wang, Hong-Bin


    Iron (Fe) is an indispensable micronutrient for plant growth and development. The regulation of Fe homeostasis in plants is complex and involves a number of transcription factors. Here, we demonstrate that a basic helix-loop-helix (bHLH) transcription factor, bHLH104, belonging to the IVc subgroup of bHLH family, acts as a key component positively regulating Fe deficiency responses. Knockout of bHLH104 in Arabidopsis thaliana greatly reduced tolerance to Fe deficiency, whereas overexpression of bHLH104 had the opposite effect and led to accumulation of excess Fe in soil-grown conditions. The activation of Fe deficiency-inducible genes was substantially suppressed by loss of bHLH104. Further investigation showed that bHLH104 interacted with another IVc subgroup bHLH protein, IAA-LEUCINE RESISTANT3 (ILR3), which also plays an important role in Fe homeostasis. Moreover, bHLH104 and ILR3 could bind directly to the promoters of Ib subgroup bHLH genes and POPEYE (PYE) functioning in the regulation of Fe deficiency responses. Interestingly, genetic analysis showed that loss of bHLH104 could decrease the tolerance to Fe deficiency conferred by the lesion of BRUTUS, which encodes an E3 ligase and interacts with bHLH104. Collectively, our data support that bHLH104 and ILR3 play pivotal roles in the regulation of Fe deficiency responses via targeting Ib subgroup bHLH genes and PYE expression.

  3. Twist-1 Up-Regulation in Carcinoma Correlates to Poor Survival

    Directory of Open Access Journals (Sweden)

    Alimujiang Wushou


    Full Text Available Epithelial-to-mesenchymal transition (EMT facilitates tumor metastasis. Twist is a basic helix-loop-helix protein that modulates many target genes through E-box-responsive elements. There are two twist-like proteins, Twist-1 and Twist-2, sharing high structural homology in mammals. Twist-1 was found to be a key factor in the promotion of metastasis of cancer cells, and is known to induce EMT. Twist-1 participation in carcinoma progression and metastasis has been reported in a variety of tumors. However, controversy exists concerning the correlation between Twist-1 and prognostic value with respect to carcinoma. A systematic review and meta-analysis were performed to determine whether the expression of Twist-1 was associated with the prognosis of carcinoma patients. This analysis included 17 studies: four studies evaluated lung cancer, three evaluated head and neck cancer, two evaluated breast cancer, two evaluated esophageal cancer, two evaluated liver cancer and one each evaluated osteosarcoma, bladder, cervical and ovarian cancer. A total of 2006 patients were enrolled in these studies, and the median trial sample size was 118 patients. Twist-1 expression was associated with worse overall survival (OS at both 3 years (hazard ratio “HR” for death = 2.13, 95% CI = 1.86 to 2.45, p < 0.001 and 5 years (HR for death = 2.01, 95% CI = 1.76 to 2.29, p < 0.001. Expression of Twist-1 is associated with worse survival in carcinoma.

  4. Adenosine Triphosphate (ATP Is a Candidate Signaling Molecule in the Mitochondria-to-Nucleus Retrograde Response Pathway

    Directory of Open Access Journals (Sweden)

    Zhengchang Liu


    Full Text Available Intracellular communication from the mitochondria to the nucleus is achieved via the retrograde response. In budding yeast, the retrograde response, also known as the RTG pathway, is regulated positively by Rtg1, Rtg2, Rtg3 and Grr1 and negatively by Mks1, Lst8 and two 14-3-3 proteins, Bmh1/2. Activation of retrograde signaling leads to activation of Rtg1/3, two basic helix-loop-helix leucine zipper transcription factors. Rtg1/3 activation requires Rtg2, a cytoplasmic protein with an N-terminal adenosine triphosphate (ATP binding domain belonging to the actin/Hsp70/sugar kinase superfamily. The critical regulatory step of the retrograde response is the interaction between Rtg2 and Mks1. Rtg2 binds to and inactivates Mks1, allowing for activation of Rtg1/3 and the RTG pathway. When the pathway is inactive, Mks1 has dissociated from Rtg2 and bound to Bmh1/2, preventing activation of Rtg1/3. What signals association or disassociation of Mks1 and Rtg2 is unknown. Here, we show that ATP at physiological concentrations dissociates Mks1 from Rtg2 in a highly cooperative fashion. We report that ATP-mediated dissociation of Mks1 from Rtg2 is conserved in two other fungal species, K. lactis and K. waltii. Activation of Rtg1/3 upregulates expression of genes encoding enzymes catalyzing the first three reactions of the Krebs cycle, which is coupled to ATP synthesis through oxidative phosphorylation. Therefore, we propose that the retrograde response is an ATP homeostasis pathway coupling ATP production with ATP-mediated repression of the retrograde response by releasing Mks1 from Rtg2.

  5. Recurrence of Chromosome Rearrangements and Reuse of DNA Breakpoints in the Evolution of the Triticeae Genomes

    Directory of Open Access Journals (Sweden)

    Wanlong Li


    Full Text Available Chromosomal rearrangements (CRs play important roles in karyotype diversity and speciation. While many CR breakpoints have been characterized at the sequence level in yeast, insects, and primates, little is known about the structure of evolutionary CR breakpoints in plant genomes, which are much more dynamic in genome size and sequence organization. Here, we report identification of breakpoints of a translocation between chromosome arms 4L and 5L of Triticeae, which is fixed in several species, including diploid wheat and rye, by comparative mapping and analysis of the draft genome and chromosome survey sequences of the Triticeae species. The wheat translocation joined the ends of breakpoints downstream of a WD40 gene on 4AL and a gene of the PMEI family on 5AL. A basic helix-loop-helix transcription factor gene in 5AL junction was significantly restructured. Rye and wheat share the same position for the 4L breakpoint, but the 5L breakpoint positions are not identical, although very close in these two species, indicating the recurrence of 4L/5L translocations in the Triticeae. Although barley does not carry the translocation, collinearity across the breakpoints was violated by putative inversions and/or transpositions. Alignment with model grass genomes indicated that the translocation breakpoints coincided with ancient inversion junctions in the Triticeae ancestor. Our results show that the 4L/5L translocation breakpoints represent two CR hotspots reused during Triticeae evolution, and support breakpoint reuse as a widespread mechanism in all eukaryotes. The mechanisms of the recurrent translocation and its role in Triticeae evolution are also discussed.

  6. Early genetic responses in rat vascular tissue after simulated diving. (United States)

    Eftedal, Ingrid; Jørgensen, Arve; Røsbjørgen, Ragnhild; Flatberg, Arnar; Brubakk, Alf O


    Diving causes a transient reduction of vascular function, but the mechanisms behind this are largely unknown. The aim of this study was therefore to analyze genetic reactions that may be involved in acute changes of vascular function in divers. Rats were exposed to 709 kPa of hyperbaric air (149 kPa Po(2)) for 50 min followed by postdive monitoring of vascular bubble formation and full genome microarray analysis of the aorta from diving rats (n = 8) and unexposed controls (n = 9). Upregulation of 23 genes was observed 1 h after simulated diving. The differential gene expression was characteristic of cellular responses to oxidative stress, with functions of upregulated genes including activation and fine-tuning of stress-responsive transcription, cytokine/cytokine receptor signaling, molecular chaperoning, and coagulation. By qRT-PCR, we verified increased transcription of neuron-derived orphan receptor-1 (Nr4a3), plasminogen activator inhibitor 1 (Serpine1), cytokine TWEAK receptor FN14 (Tnfrsf12a), transcription factor class E basic helix-loop-helix protein 40 (Bhlhe40), and adrenomedullin (Adm). Hypoxia-inducible transcription factor HIF1 subunit HIF1-α was stabilized in the aorta 1 h after diving, and after 4 h there was a fivefold increase in total protein levels of the procoagulant plasminogen activator inhibitor 1 (PAI1) in blood plasma from diving rats. The study did not have sufficient power for individual assessment of effects of hyperoxia and decompression-induced bubbles on postdive gene expression. However, differential gene expression in rats without venous bubbles was similar to that of all the diving rats, indicating that elevated Po(2) instigated the observed genetic reactions.

  7. The Prdm13 histone methyltransferase encoding gene is a Ptf1a-Rbpj downstream target that suppresses glutamatergic and promotes GABAergic neuronal fate in the dorsal neural tube. (United States)

    Hanotel, Julie; Bessodes, Nathalie; Thélie, Aurore; Hedderich, Marie; Parain, Karine; Van Driessche, Benoit; Brandão, Karina De Oliveira; Kricha, Sadia; Jorgensen, Mette C; Grapin-Botton, Anne; Serup, Palle; Van Lint, Carine; Perron, Muriel; Pieler, Tomas; Henningfeld, Kristine A; Bellefroid, Eric J


    The basic helix-loop-helix (bHLH) transcriptional activator Ptf1a determines inhibitory GABAergic over excitatory glutamatergic neuronal cell fate in progenitors of the vertebrate dorsal spinal cord, cerebellum and retina. In an in situ hybridization expression survey of PR domain containing genes encoding putative chromatin-remodeling zinc finger transcription factors in Xenopus embryos, we identified Prdm13 as a histone methyltransferase belonging to the Ptf1a synexpression group. Gain and loss of Ptf1a function analyses in both frog and mice indicates that Prdm13 is positively regulated by Ptf1a and likely constitutes a direct transcriptional target. We also showed that this regulation requires the formation of the Ptf1a-Rbp-j complex. Prdm13 knockdown in Xenopus embryos and in Ptf1a overexpressing ectodermal explants lead to an upregulation of Tlx3/Hox11L2, which specifies a glutamatergic lineage and a reduction of the GABAergic neuronal marker Pax2. It also leads to an upregulation of Prdm13 transcription, suggesting an autonegative regulation. Conversely, in animal caps, Prdm13 blocks the ability of the bHLH factor Neurog2 to activate Tlx3. Additional gain of function experiments in the chick neural tube confirm that Prdm13 suppresses Tlx3(+)/glutamatergic and induces Pax2(+)/GABAergic neuronal fate. Thus, Prdm13 is a novel crucial component of the Ptf1a regulatory pathway that, by modulating the transcriptional activity of bHLH factors such as Neurog2, controls the balance between GABAergic and glutamatergic neuronal fate in the dorsal and caudal part of the vertebrate neural tube.

  8. The molecular mechanisms of phytochrome interacting factors (PIFs) in phy-tohormone signaling transduction%光敏色素作用因子PIFs参与植物激素信号转导的分子机制

    Institute of Scientific and Technical Information of China (English)

    任小芸; 吴美琴; 陈建民; 张冬平; 高勇


    Phytochrome interacting factors (PIFs) belonging to basic helix-loop-helix (bHLH) transcription fac-tors family, play an important role in plant growth and development. As the hubs of signal network in plant, PIFs integrate multiple plant hormone signals to regulate the transcriptional network. Existing research shows that PIFs can not only affect the synthesis of GA, ABA and IAA, but also regulate signal transmission of GA, BR, JA, IAA, ABA and ethylene. This review summarizes the research progress of function of PIFs in plant homone, and provides help for the further study of PIFs.%光敏色素作用因子(PIFs)属于bHLH 转录因子家族,在植物的生长发育中起到重要调节作用。作为一个关键的胞内信号调控组分, PIFs扮演着整合不同激素信号通路“枢纽”的角色。现有研究表明, PIFs能影响GA、ABA、IAA等激素的合成,调控GA、BR、JA、IAA、ABA、乙烯等激素的信号传递。本文重点阐述PIFs在植物激素信号中调控功能的研究进展,以期为进一步探索PIFs的功能及机制提供帮助。

  9. Targeting the bHLH transcriptional networks by mutated E proteins in experimental glioma. (United States)

    Beyeler, Sarah; Joly, Sandrine; Fries, Michel; Obermair, Franz-Josef; Burn, Felice; Mehmood, Rashid; Tabatabai, Ghazaleh; Raineteau, Olivier


    Glioblastomas (GB) are aggressive primary brain tumors. Helix-loop-helix (HLH, ID proteins) and basic HLH (bHLH, e.g., Olig2) proteins are transcription factors that regulate stem cell proliferation and differentiation throughout development and into adulthood. Their convergence on many oncogenic signaling pathways combined with the observation that their overexpression in GB correlates with poor clinical outcome identifies these transcription factors as promising therapeutic targets. Important dimerization partners of HLH/bHLH proteins are E proteins that are necessary for nuclear translocation and DNA binding. Here, we overexpressed a wild type or a dominant negative form of E47 (dnE47) that lacks its nuclear localization signal thus preventing nuclear translocation of bHLH proteins in long-term glioma cell lines and in glioma-initiating cell lines and analyzed the effects in vitro and in vivo. While overexpression of E47 was sufficient to induce apoptosis in absence of bHLH proteins, dnE47 was necessary to prevent nuclear translocation of Olig2 and to achieve similar proapoptotic responses. Transcriptional analyses revealed downregulation of the antiapoptotic gene BCL2L1 and the proproliferative gene CDC25A as underlying mechanisms. Overexpression of dnE47 in glioma-initiating cell lines with high HLH and bHLH protein levels reduced sphere formation capacities and expression levels of Nestin, BCL2L1, and CDC25A. Finally, the in vivo induction of dnE47 expression in established xenografts prolonged survival. In conclusion, our data introduce a novel approach to jointly neutralize HLH and bHLH transcriptional networks activities, and identify these transcription factors as potential targets in glioma.

  10. Regulation of Phytochrome Interacting Factors (PIFs) on Plant Growth and Development%光敏色素互作因子(PIFs)对植物生长发育的调控

    Institute of Scientific and Technical Information of China (English)

    潘教文; 赵术珍; 张烨; 李长生; 王玉红; 王兴军


    Phytochrome interacting factors ( PIFs ) belonging to Arabidopsis basic helix -loop -helix ( bHLH) transcription factors subgroup 15 are key regulators in light signal transduction .Light -activated phytochromes regulate plant growth and development by promoting the degradation of PIFs and directly or indi -rectly inhibiting their DNA binding activity .Studies showed that PIFs played important roles in the regulation of seed germination, seedling morphogenesis , shade avoidance , circadian clock, phytohormone biosynthesis and signal transduction .PIFs have broader roles than previously expected and work as a cellular signaling hub that integrates multiple signals to orchestrate the transcriptional network of plants .%光敏色素相互作用因子( PIFs)属于拟南芥bHLH转录因子家族的第15亚族,是光信号响应过程中的关键负调控因子。光激活的光敏色素通过促进PIFs蛋白降解,直接或间接抑制它们与DNA的结合,从而实现光对植物生长发育的调控。研究发现PIFs在调控种子萌发、幼苗形态建成、避荫反应、昼夜节律以及各种植物激素响应过程中起着重要作用。此外,PIFs作为细胞信号传导的“枢纽”具有更为广泛的作用,能够整合不同信号,精细调控整个转录网络。

  11. Overexpression of GmERF5, a new member of the soybean EAR motif-containing ERF transcription factor, enhances resistance to Phytophthora sojae in soybean. (United States)

    Dong, Lidong; Cheng, Yingxin; Wu, Junjiang; Cheng, Qun; Li, Wenbin; Fan, Sujie; Jiang, Liangyu; Xu, Zhaolong; Kong, Fanjiang; Zhang, Dayong; Xu, Pengfei; Zhang, Shuzhen


    Phytophthora root and stem rot of soybean [Glycine max (L.) Merr.], caused by Phytophthora sojae Kaufmann and Gerdemann, is a destructive disease throughout the soybean planting regions in the world. Here, we report insights into the function and underlying mechanisms of a novel ethylene response factor (ERF) in soybean, namely GmERF5, in host responses to P. sojae. GmERF5-overexpressing transgenic soybean exhibited significantly enhanced resistance to P. sojae and positively regulated the expression of the PR10, PR1-1, and PR10-1 genes. Sequence analysis suggested that GmERF5 contains an AP2/ERF domain of 58 aa and a conserved ERF-associated amphiphilic repression (EAR) motif in its C-terminal region. Following stress treatments, GmERF5 was significantly induced by P. sojae, ethylene (ET), abscisic acid (ABA), and salicylic acid (SA). The activity of the GmERF5 promoter (GmERF5P) was upregulated in tobacco leaves with ET, ABA, Phytophthora nicotianae, salt, and drought treatments, suggesting that GmERF5 could be involved not only in the induced defence response but also in the ABA-mediated pathway of salt and drought tolerance. GmERF5 could bind to the GCC-box element and act as a repressor of gene transcription. It was targeted to the nucleus when transiently expressed in Arabidopsis protoplasts. GmERF5 interacted with a basic helix-loop-helix transcription factor (GmbHLH) and eukaryotic translation initiation factor (GmEIF) both in yeast cells and in planta. To the best of our knowledge, GmERF5 is the first soybean EAR motif-containing ERF transcription factor demonstrated to be involved in the response to pathogen infection.

  12. Genetic analysis of strawberry fruit aroma and identification of O-methyltransferase FaOMT as the locus controlling natural variation in mesifurane content. (United States)

    Zorrilla-Fontanesi, Yasmín; Rambla, José-Luis; Cabeza, Amalia; Medina, Juan J; Sánchez-Sevilla, José F; Valpuesta, Victoriano; Botella, Miguel A; Granell, Antonio; Amaya, Iraida


    Improvement of strawberry (Fragaria × ananassa) fruit flavor is an important goal in breeding programs. To investigate genetic factors controlling this complex trait, a strawberry mapping population derived from genotype '1392', selected for its superior flavor, and '232' was profiled for volatile compounds over 4 years by headspace solid phase microextraction coupled to gas chromatography and mass spectrometry. More than 300 volatile compounds were detected, of which 87 were identified by comparison of mass spectrum and retention time to those of pure standards. Parental line '1392' displayed higher volatile levels than '232', and these and many other compounds with similar levels in both parents segregated in the progeny. Cluster analysis grouped the volatiles into distinct chemically related families and revealed a complex metabolic network underlying volatile production in strawberry fruit. Quantitative trait loci (QTL) detection was carried out over 3 years based on a double pseudo-testcross strategy. Seventy QTLs covering 48 different volatiles were detected, with several of them being stable over time and mapped as major QTLs. Loci controlling γ-decalactone and mesifurane content were mapped as qualitative traits. Using a candidate gene approach we have assigned genes that are likely responsible for several of the QTLs. As a proof of concept we show that one homoeolog of the O-methyltransferase gene (FaOMT) is the locus responsible for the natural variation of mesifurane content. Sequence analysis identified 30 bp in the promoter of this FaOMT homoeolog containing putative binding sites for basic/helix-loop-helix, MYB, and BZIP transcription factors. This polymorphism fully cosegregates with both the presence of mesifurane and the high expression of FaOMT during ripening.

  13. Reprogramming amacrine and photoreceptor progenitors into retinal ganglion cells by replacing Neurod1 with Atoh7. (United States)

    Mao, Chai-An; Cho, Jang-Hyeon; Wang, Jing; Gao, Zhiguang; Pan, Ping; Tsai, Wen-Wei; Frishman, Laura J; Klein, William H


    The specification of the seven retinal cell types from a common pool of retina progenitor cells (RPCs) involves complex interactions between the intrinsic program and the environment. The proneural basic helix-loop-helix (bHLH) transcriptional regulators are key components for the intrinsic programming of RPCs and are essential for the formation of the diverse retinal cell types. However, the extent to which an RPC can re-adjust its inherent program and the mechanisms through which the expression of a particular bHLH factor influences RPC fate is unclear. Previously, we have shown that Neurod1 inserted into the Atoh7 locus activates the retinal ganglion cell (RGC) program in Atoh7-expressing RPCs but not in Neurod1-expressing RPCs, suggesting that Atoh7-expressing RPCs are not able to adopt the cell fate determined by Neurod1, but rather are pre-programmed to produce RGCs. Here, we show that Neurod1-expressing RPCs, which are destined to produce amacrine and photoreceptor cells, can be re-programmed into RGCs when Atoh7 is inserted into the Neurod1 locus. These results suggest that Atoh7 acts dominantly to convert a RPC subpopulation not destined for an RGC fate to adopt that fate. Thus, Atoh7-expressing and Neurod1-expressing RPCs are intrinsically different in their behavior. Additionally, ChIP-Seq analysis identified an Atoh7-dependent enhancer within the intronic region of Nrxn3. The enhancer recognized and used Atoh7 in the developing retina to regulate expression of Nrxn3, but could be forced to use Neurod1 when placed in a different regulatory context. The results indicate that Atoh7 and Neurod1 activate distinct sets of genes in vivo, despite their common DNA-binding element.

  14. In vitro differentiation profile of osteoblasts derived from patients with Saethre-Chotzen syndrome. (United States)

    Ratisoontorn, Chootima; Seto, Marianne L; Broughton, Kristen M; Cunningham, Michael L


    Seathre-Chotzen syndrome (SCS) is an autosomal dominant craniosynostosis syndrome, associated with loss-of-function mutations in the basic helix-loop-helix transcription factor, TWIST1. The biologic activity of TWIST1 has been implicated in the inhibition of differentiation of multiple cell lineages. Therefore, premature fusion of cranial sutures (craniosynostosis) in SCS may be mediated by altered differentiation of calvarial osteoblasts. In this study, we evaluated osteoblasts derived from calvarial bone of three patients with SCS and three unaffected individuals as controls to investigate the principle stages of osteoblast differentiation: (1) proliferation, (2) matrix maturation, and (3) mineralization. Using a BrdU-Hoechst flow cytometry assay, we found that the percent of proliferating cells was significantly reduced in cells derived from patients with SCS compared with those derived from controls (P < or = 0.05). In the matrix maturation stage, alkaline phosphatase (ALP) enzyme activity and the expression of extracellular matrix genes, collagen I alpha 2 (COL1A2), osteopontin (OPN), osteocalcin (OC), and the runt-related transcription factor RUNX2 were examined by enzymatic assay and real-time quantitative RT-PCR, respectively. We identified no significant differences in the expression of matrix related transcripts. However, we found significant reductions in ALP activity on days 3 and 7 and in RUNX2 expression on days 14 and 21 (P < or = 0.05). Quantitative alizarin red S mineralization assays showed a trend toward increased mineralization in osteoblasts derived from patients with SCS at days 21 and 28, although not statistically significant. Our results demonstrated that loss-of-function mutations of TWIST1 led to reduced proliferation regardless of the functional domain affected. We did not find any conclusive differences in matrix maturation or mineralization in these primary osteoblasts. It is plausible that mutations in different functional domains of

  15. Women with Saethre-Chotzen syndrome are at increased risk of breast cancer. (United States)

    Sahlin, Pelle; Windh, Per; Lauritzen, Claes; Emanuelsson, Monica; Grönberg, Henrik; Stenman, Göran


    The Saethre-Chotzen syndrome is an autosomal, dominantly inherited craniosynostosis caused by mutations in the basic helix-loop-helix transcription factor gene TWIST1. This syndrome has hitherto not been associated with an increased risk of cancer. However, recent studies, using a murine breast tumor model, have shown that Twist may act as a key regulator of metastasis and that the gene is overexpressed in subsets of sporadic human breast cancers. Here, we report a novel association between the Saethre-Chotzen syndrome and breast cancer. In 15 Swedish Saethre-Chotzen families, 15 of 29 (52%) women carriers over the age of 25 had developed breast cancer. At least four patients developed breast cancer before 40 years of age, and five between 40 and 50 years of age. The observed cases with breast cancer (n = 15) are significantly higher than expected (n = 0.89), which gives a standardized incidence ratio (SIR) of 16.80 (95% CI 1.54-32.06). Our finding of a high frequency of breast cancer in women with the Saethre-Chotzen syndrome identifies breast cancer as an important and previously unrecognized symptom characteristic of this syndrome. The results strongly suggest that women carriers of this syndrome would benefit from genetic counseling and enrolment in surveillance programs including yearly mammography. Our results also indicate that the TWIST1 gene may be a novel breast cancer susceptibility gene. Additional studies are, however, necessary to reveal the mechanism by which TWIST1 may predispose to early onset breast cancer in Saethre-Chotzen patients.

  16. Identification and comparative analysis of differential gene expression in soybean leaf tissue under drought and flooding stress revealed by RNA-Seq

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    Wei Chen


    Full Text Available Drought and flooding are two major causes of severe yield loss in soybean worldwide. A lack of knowledge of the molecular mechanisms involved in drought and flood stress has been a limiting factor for the effective management of soybeans; therefore, it is imperative to assess the expression of genes involved in response to flood and drought stress. In this study, differentially expressed genes under drought and flooding conditions were investigated using Illumina RNA-Seq transcriptome profiling. A total of 2,724 and 3,498 differentially expressed genes (DEGs were identified under drought and flooding treatments, respectively. These genes comprise 289 Transcription Factors (TFs representing Basic Helix-loop Helix (bHLH, Ethylene Response Factors (ERFs, myeloblastosis (MYB, No apical meristem (NAC, and WRKY amino acid motif (WRKY type major families known to be involved in the mechanism of stress tolerance. The expression of photosynthesis and chlorophyll synthesis related genes were significantly reduced under both types of stresses, which limit the metabolic processes and thus help prolong survival under extreme conditions. However, cell wall synthesis related genes were up-regulated under drought stress and down-regulated under flooding stress. Transcript profiles involved in the starch and sugar metabolism pathways were also affected under both stress conditions. The changes in expression of genes involved in regulating the flux of cell wall precursors and starch/sugar content can serve as an adaptive mechanism for soybean survival under stress conditions. This study has revealed the involvement of TFs, transporters, and photosynthetic genes, and has also given a glimpse of hormonal cross talk under the extreme water regimes, which will aid as an important resource for soybean crop improvement.

  17. Angiopoietin-2 is a direct transcriptional target of TAL1, LYL1 and LMO2 in endothelial cells. (United States)

    Deleuze, Virginie; El-Hajj, Rawan; Chalhoub, Elias; Dohet, Christiane; Pinet, Valérie; Couttet, Philippe; Mathieu, Danièle


    The two related basic helix-loop-helix, TAL1 and LYL1, and their cofactor LIM-only-2 protein (LMO2) are present in blood and endothelial cells. While their crucial role in early hematopoiesis is well established, their function in endothelial cells and especially in angiogenesis is less understood. Here, we identified ANGIOPOIETIN-2 (ANG-2), which encodes a major regulator of angiogenesis, as a direct transcriptional target of TAL1, LYL1 and LMO2. Knockdown of any of the three transcription factors in human blood and lymphatic endothelial cells caused ANG-2 mRNA and protein down-regulation. Transient transfections showed that the full activity of the ANG-2 promoter required the integrity of a highly conserved Ebox-GATA composite element. Accordingly, chromatin immunoprecipitation assays demonstrated that TAL1, LYL1, LMO2 and GATA2 occupied this region of ANG-2 promoter in human endothelial cells. Furthermore, we showed that LMO2 played a central role in assembling TAL1-E47, LYL1-LYL1 or/and LYL1-TAL1 dimers with GATA2. The resulting complexes were able to activate endogenous ANG-2 expression in endothelial cells as well as in non-endothelial cells. Finally, we showed that ANG-2 gene activation during angiogenesis concurred with the up-regulation of TAL1 and LMO2. Altogether, we identified ANG-2 as a bona fide target gene of LMO2-complexes with TAL1 and/or LYL1, highlighting a new function of the three hematopoietic factors in the endothelial lineage.

  18. Biochemical and molecular analysis of pink tomatoes: deregulated expression of the gene encoding transcription factor SlMYB12 leads to pink tomato fruit color. (United States)

    Ballester, Ana-Rosa; Molthoff, Jos; de Vos, Ric; Hekkert, Bas te Lintel; Orzaez, Diego; Fernández-Moreno, Josefina-Patricia; Tripodi, Pasquale; Grandillo, Silvana; Martin, Cathie; Heldens, Jos; Ykema, Marieke; Granell, Antonio; Bovy, Arnaud


    The color of tomato fruit is mainly determined by carotenoids and flavonoids. Phenotypic analysis of an introgression line (IL) population derived from a cross between Solanum lycopersicum 'Moneyberg' and the wild species Solanum chmielewskii revealed three ILs with a pink fruit color. These lines had a homozygous S. chmielewskii introgression on the short arm of chromosome 1, consistent with the position of the y (yellow) mutation known to result in colorless epidermis, and hence pink-colored fruit, when combined with a red flesh. Metabolic analysis showed that pink fruit lack the ripening-dependent accumulation of the yellow-colored flavonoid naringenin chalcone in the fruit peel, while carotenoid levels are not affected. The expression of all genes encoding biosynthetic enzymes involved in the production of the flavonol rutin from naringenin chalcone was down-regulated in pink fruit, suggesting that the candidate gene underlying the pink phenotype encodes a regulatory protein such as a transcription factor rather than a biosynthetic enzyme. Of 26 MYB and basic helix-loop-helix transcription factors putatively involved in regulating transcription of genes in the phenylpropanoid and/or flavonoid pathway, only the expression level of the MYB12 gene correlated well with the decrease in the expression of structural flavonoid genes in peel samples of pink- and red-fruited genotypes during ripening. Genetic mapping and segregation analysis showed that MYB12 is located on chromosome 1 and segregates perfectly with the characteristic pink fruit color. Virus-induced gene silencing of SlMYB12 resulted in a decrease in the accumulation of naringenin chalcone, a phenotype consistent with the pink-colored tomato fruit of IL1b. In conclusion, biochemical and molecular data, gene mapping, segregation analysis, and virus-induced gene silencing experiments demonstrate that the MYB12 transcription factor plays an important role in regulating the flavonoid pathway in tomato fruit

  19. Smad mediated regulation of inhibitor of DNA binding 2 and its role in phenotypic maintenance of human renal proximal tubule epithelial cells.

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    Mangalakumar Veerasamy

    Full Text Available The basic-Helix-Loop-Helix family (bHLH of transcriptional factors plays a major role in regulating cellular proliferation, differentiation and phenotype maintenance. The downregulation of one of the members of bHLH family protein, inhibitor of DNA binding 2 (Id2 has been shown to induce de-differentiation of epithelial cells. Opposing regulators of epithelial/mesenchymal phenotype in renal proximal tubule epithelial cells (PTEC, TGFβ1 and BMP7 also have counter-regulatory effects in models of renal fibrosis. We investigated the regulation of Id2 by these growth factors in human PTECs and its implication in the expression of markers of epithelial versus myofibroblastic phenotype. Cellular Id2 levels were reduced by TGFβ1 treatment; this was prevented by co-incubation with BMP7. BMP7 alone increased cellular levels of Id2. TGFβ1 and BMP7 regulated Id2 through Smad2/3 and Smad1/5 dependent mechanisms respectively. TGFβ1 mediated Id2 suppression was essential for α-SMA induction in PTECs. Although Id2 over-expression prevented α-SMA induction, it did not prevent E-cadherin loss under the influence of TGFβ1. This suggests that the loss of gate keeper function of E-cadherin alone may not necessarily result in complete EMT and further transcriptional re-programming is essential to attain mesenchymal phenotype. Although BMP7 abolished TGFβ1 mediated α-SMA expression by restoring Id2 levels, the loss of Id2 was not sufficient to induce α-SMA expression even in the context of reduced E-cadherin expression. Hence, a reduction in Id2 is critical for TGFβ1-induced α-SMA expression in this model of human PTECs but is not sufficient in it self to induce α-SMA even in the context of reduced E-cadherin.

  20. Interaction of MTG family proteins with NEUROG2 and ASCL1 in the developing nervous system. (United States)

    Aaker, Joshua D; Patineau, Andrea L; Yang, Hyun-Jin; Ewart, David T; Nakagawa, Yasushi; McLoon, Steven C; Koyano-Nakagawa, Naoko


    During neural development, members of MTG family of transcriptional repressors are induced by proneural basic helix-loop-helix (bHLH) transcription factors and in turn inhibit the activity of the bHLH proteins, forming a negative feedback loop that regulates the normal progression of neurogenesis. Three MTG genes, MTG8, MTG16 and MTGR1, are expressed in distinct patterns in the developing nervous system. Various bHLH proteins are also expressed in distinct patterns. We asked whether there is a functional relationship between specific MTG and bHLH proteins in developing chick spinal cord. First, we examined if each MTG gene is induced by specific bHLH proteins. Although expression of NEUROG2, ASCL1 and MTG genes overlapped, the boundaries of gene expression did not match. Ectopic expression analysis showed that MTGR1 and NEUROD4, which show similar expression patterns, are regulated differently by NEUROG2 and ASCL1. Thus, our results show that expression of MTG genes is not regulated by a single upstream bHLH protein, but represents an integration of the activity of multiple regulators. Next, we asked if each MTG protein inhibits specific bHLH proteins. Transcription assay showed that NEUROG2 and ASCL1 are inhibited by MTGR1 and MTG16, and less efficiently by MTG8. Deletion mapping of MTGR1 showed that MTGR1 binds NEUROG2 and ASCL1 using multiple interaction surfaces, and all conserved domains are required for its repressor activity. These results support the model that MTG proteins form a higher-order repressor complex and modulate transcriptional activity of bHLH proteins during neurogenesis.

  1. Characterization of progenitor domains in the developing mouse thalamus. (United States)

    Vue, Tou Yia; Aaker, Joshua; Taniguchi, Aya; Kazemzadeh, Christina; Skidmore, Jennifer M; Martin, Donna M; Martin, James F; Treier, Mathias; Nakagawa, Yasushi


    To understand the molecular basis of the specification of thalamic nuclei, we analyzed the expression patterns of various transcription factors and defined progenitor cell populations in the embryonic mouse thalamus. We show that the basic helix-loop-helix (bHLH) transcription factor Olig3 is expressed in the entire thalamic ventricular zone and the zona limitans intrathalamica (ZLI). Next, we define two distinct progenitor domains within the thalamus, which we name pTH-R and pTH-C, located caudal to the ZLI. pTH-R is immediately caudal to the ZLI and expresses Nkx2.2, Mash1, and Olig3. pTH-C is caudal to pTH-R and expresses Ngn1, Ngn2, and Olig3. Short-term lineage analysis of Olig3-, Mash1-, Ngn1-, and Ngn2-expressing progenitor cells as well as tracing the Pitx2 cell lineage suggests that pTH-C is the only major source of thalamic nuclei containing neurons that project to the cerebral cortex, whereas pTH-R and ZLI are likely to produce distinct postmitotic populations outside of the cortex-projecting part of the thalamus. To determine if pTH-C is composed of subdomains, we characterized expression of the homeodomain protein Dbx1 and the bHLH protein Olig2. We show that Dbx1 is expressed in caudodorsal-high to rostroventral-low gradient within pTH-C. Analysis of heterozygous Dbx1(nlslacZ) knockin mice demonstrated that Dbx1-expressing progenitors preferentially give rise to caudodorsal thalamic nuclei. Olig2 is expressed in an opposite gradient within pTH-C to that of Dbx1. These results establish the molecular heterogeneity within the progenitor cells of the thalamus, and suggest that such heterogeneity contributes to the specification of thalamic nuclei.

  2. Cellular and developmental adaptations to hypoxia: a Drosophila perspective. (United States)

    Romero, Nuria Magdalena; Dekanty, Andrés; Wappner, Pablo


    The fruit fly Drosophila melanogaster, a widely utilized genetic model, is highly resistant to oxygen starvation and is beginning to be used for studying physiological, developmental, and cellular adaptations to hypoxia. The Drosophila respiratory (tracheal) system has features in common with the mammalian circulatory system so that an angiogenesis-like response occurs upon exposure of Drosophila larvae to hypoxia. A hypoxia-responsive system homologous to mammalian hypoxia-inducible factor (HIF) has been described in the fruit fly, where Fatiga is a Drosophila oxygen-dependent HIF prolyl hydroxylase, and the basic helix-loop-helix Per/ARNT/Sim (bHLH-PAS) proteins Sima and Tango are, respectively, the Drosophila homologues of mammalian HIF-alpha (alpha) and HIF-beta (beta). Tango is constitutively expressed regardless of oxygen tension and, like in mammalian cells, Sima is controlled at the level of protein degradation and subcellular localization. Sima is critically required for development in hypoxia, but, unlike mammalian model systems, it is dispensable for development in normoxia. In contrast, fatiga mutant alleles are all lethal; however, strikingly, viability to adulthood is restored in fatiga sima double mutants, although these double mutants are not entirely normal, suggesting that Fatiga has Sima-independent functions in fly development. Studies in cell culture and in vivo have revealed that Sima is activated by the insulin receptor (InR) and target-of-rapamycin (TOR) pathways. Paradoxically, Sima is a negative regulator of growth. This suggests that Sima is engaged in a negative feedback loop that limits growth upon stimulation of InR/TOR pathways.

  3. CtBP and associated LSD1 are required for transcriptional activation by NeuroD1 in gastrointestinal endocrine cells. (United States)

    Ray, Subir K; Li, H Joyce; Metzger, Eric; Schüle, Roland; Leiter, Andrew B


    Gene expression programs required for differentiation depend on both DNA-bound transcription factors and surrounding histone modifications. Expression of the basic helix-loop-helix (bHLH) protein NeuroD1 is restricted to endocrine cells in the gastrointestinal (GI) tract, where it is important for endocrine differentiation. RREB1 (RAS-responsive element binding protein 1), identified as a component of the CtBP corepressor complex, binds to nearby DNA elements to associate with NeuroD and potentiate transcription of a NeuroD1 target gene. Transcriptional activation by RREB1 depends on recruitment of CtBP with its associated proteins, including LSD1, through its PXDLS motifs. The mechanism of transcriptional activation by CtBP has not been previously characterized. Here we found that activation was dependent on the histone H3 lysine 9 (H3K9) demethylase activity of LSD1, which removes repressive methyl marks from dimethylated H3K9 (H3K9Me2), to facilitate subsequent H3K9 acetylation by the NeuroD1-associated histone acetyltransferase, P300/CBP-associated factor (PCAF). The secretin, β-glucokinase, insulin I, and insulin II genes, four known direct targets of NeuroD1 in intestinal and pancreatic endocrine cells, all show similar promoter occupancy by CtBP-associated proteins and PCAF, with acetylation of H3K9. This work may indicate a mechanism for selective regulation of transcription by CtBP and LSD1 involving their association with specific transcription factors and cofactors to drive tissue-specific transcription.

  4. An overview of the gene regulatory network controlling trichome development in the model plant, Arabidopsis

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    Sitakanta ePattanaik


    Full Text Available Trichomes are specialized epidermal cells located on aerial parts of plants and are associated with a wide array of biological processes. Trichomes protect plants from adverse conditions including UV light and herbivore attack and are also an important source of a number of phytochemicals. The simple unicellular trichomes of Arabidopsis serve as an excellent model to study molecular mechanism of cell differentiation and pattern formation in plants. The emerging picture suggests that the developmental process is controlled by a transcriptional network involving three major groups of transcription factors: the R2R3 MYB, basic helix-loop-helix (bHLH and WD40 repeat (WDR protein. These regulatory proteins form a trimeric activator complex that positively regulates trichome development. The single repeat R3 MYBs act as negative regulators of trichome development. They compete with the R2R3 MYBs to bind the bHLH factor and form a repressor complex. In addition to activator-repressor mechanism, a depletion mechanism may operate in parallel during trichome development. In this mechanism, the bHLH factor traps the WDR protein which results in depletion of WDR protein in neighboring cells. Consequently, the cells with high levels of bHLH and WDR proteins are developed into trichomes. A group of C2H2 zinc finger TFs has also been implicated in trichome development. Phytohormones, including gibberellins and jasmonic acid, play significant roles in this developmental process. Recently, microRNAs have been shown to be involved in trichome development. Furthermore, it has been demonstrated that the activities of the key regulatory proteins involved in trichome development are controlled by the 26S/ubiquitin proteasome system (UPS, highlighting the complexity of the regulatory network controlling this developmental process. To complement several excellent recent relevant reviews, this review focuses on the transcriptional network and hormonal interplay

  5. Normal and disease-related biological functions of Twist1 and underlying molecular mechanisms

    Institute of Scientific and Technical Information of China (English)

    Qian Qin; Young Xu; Tao He; Chunlin Qin; Jianming Xu


    This article reviews the molecular structure,expression pattern,physiological function,pathological roles and molecular mechanisms of Twist1 in development,genetic disease and cancer.Twist1 is a basic helix-loop-helix domaincontaining transcription factor.It forms homo- or hetero-dimers in order to bind the Nde1 E-box element and activate or repress its target genes.During development,Twistl is essential for mesoderm specification and differentiation.Heterozygous loss-of-function mutations of the human Twist1 gene cause several diseases including the SaethreChotzen syndrome.The Twist1-null mouse embryos die with unclosed cranial neural tubes and defective head mesenchyme,somites and limb buds.Twist1 is expressed in breast,liver,prostate,gastric and other types of cancers,and its expression is usually associated with invasive and metastatic cancer phenotypes.In cancer cells,Twistl is upregulated by multiple factors including SRC-1,STAT3,MSX2,HIF-1α,integrin-linked kinase and NF-κB.Twist1 significantly enhances epithelial-mesenchymal transition (EMT) and cancer cell migration and invasion,hence promoting cancer metastasis.Twistl promotes EMT in part by directly repressing E-cadherin expression by recruiting the nucleosome remodeling and deacetylase complex for gene repression and by upregulating Bmil,AKT2,YB-1,etc.Emerging evidence also suggests that Twist1 plays a role in expansion and chemotherapeutic resistance of cancer stem cells.Further understanding of the mechanisms by which Twist1 promotes metastasis and identification of Twist1 functional modulators may hold promise for developing new strategies to inhibit EMT and cancer metastasis.

  6. Twist1 activity thresholds define multiple functions in limb development. (United States)

    Krawchuk, Dayana; Weiner, Shoshana J; Chen, You-Tzung; Lu, Benson C; Costantini, Frank; Behringer, Richard R; Laufer, Ed


    The basic helix-loop-helix transcription factor Twist1 is essential for normal limb development. Twist1(-/-) embryos die at midgestation. However, studies on early limb buds found that Twist1(-/-) mutant limb mesenchyme has an impaired response to FGF signaling from the apical ectodermal ridge, which disrupts the feedback loop between the mesenchyme and AER, and reduces and shifts anteriorly Shh expression in the zone of polarizing activity. We have combined Twist1 null, hypomorph and conditional alleles to generate a Twist1 allelic series that survives to birth. As Twist1 activity is reduced, limb skeletal defects progress from preaxial polydactyly to girdle reduction combined with hypoplasia, aplasia or mirror symmetry of all limb segments. With reduced Twist1 activity there is striking and progressive upregulation of ectopic Shh expression in the anterior of the limb, combined with an anterior shift in the posterior Shh domain, which is expressed at normal intensity, and loss of the posterior AER. Consequently limb outgrowth is initially impaired, before an ectopic anterior Shh domain expands the AER, promoting additional growth and repatterning. Reducing the dosage of FGF targets of the Etv gene family, which are known repressors of Shh expression in anterior limb mesenchyme, strongly enhances the anterior skeletal phenotype. Conversely this and other phenotypes are suppressed by reducing the dosage of the Twist1 antagonist Hand2. Our data support a model whereby multiple Twist1 activity thresholds contribute to early limb bud patterning, and suggest how particular combinations of skeletal defects result from differing amounts of Twist1 activity.

  7. Introducing Pitt-Hopkins syndrome-associated mutations of TCF4 to Drosophila daughterless

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    Laura Tamberg


    Full Text Available Pitt-Hopkins syndrome (PTHS is caused by haploinsufficiency of Transcription factor 4 (TCF4, one of the three human class I basic helix-loop-helix transcription factors called E-proteins. Drosophila has a single E-protein, Daughterless (Da, homologous to all three mammalian counterparts. Here we show that human TCF4 can rescue Da deficiency during fruit fly nervous system development. Overexpression of Da or TCF4 specifically in adult flies significantly decreases their survival rates, indicating that these factors are crucial even after development has been completed. We generated da transgenic fruit fly strains with corresponding missense mutations R578H, R580W, R582P and A614V found in TCF4 of PTHS patients and studied the impact of these mutations in vivo. Overexpression of wild type Da as well as human TCF4 in progenitor tissues induced ectopic sensory bristles and the rough eye phenotype. By contrast, overexpression of DaR580W and DaR582P that disrupt DNA binding reduced the number of bristles and induced the rough eye phenotype with partial lack of pigmentation, indicating that these act dominant negatively. Compared to the wild type, DaR578H and DaA614V were less potent in induction of ectopic bristles and the rough eye phenotype, respectively, suggesting that these are hypomorphic. All studied PTHS-associated mutations that we introduced into Da led to similar effects in vivo as the same mutations in TCF4 in vitro. Consequently, our Drosophila models of PTHS are applicable for further studies aiming to unravel the molecular mechanisms of this disorder.

  8. Molecular genetics of blood-fleshed peach reveals activation of anthocyanin biosynthesis by NAC transcription factors. (United States)

    Zhou, Hui; Lin-Wang, Kui; Wang, Huiliang; Gu, Chao; Dare, Andrew P; Espley, Richard V; He, Huaping; Allan, Andrew C; Han, Yuepeng


    Anthocyanin pigmentation is an important consumer trait in peach (Prunus persica). In this study, the genetic basis of the blood-flesh trait was investigated using the cultivar Dahongpao, which shows high levels of cyanidin-3-glucoside in the mesocarp. Elevation of anthocyanin levels in the flesh was correlated with the expression of an R2R3 MYB transcription factor, PpMYB10.1. However, PpMYB10.1 did not co-segregate with the blood-flesh trait. The blood-flesh trait was mapped to a 200-kb interval on peach linkage group (LG) 5. Within this interval, a gene encoding a NAC domain transcription factor (TF) was found to be highly up-regulated in blood-fleshed peaches when compared with non-red-fleshed peaches. This NAC TF, designated blood (BL), acts as a heterodimer with PpNAC1 which shows high levels of expression in fruit at late developmental stages. We show that the heterodimer of BL and PpNAC1 can activate the transcription of PpMYB10.1, resulting in anthocyanin pigmentation in tobacco. Furthermore, silencing the BL gene reduces anthocyanin pigmentation in blood-fleshed peaches. The transactivation activity of the BL-PpNAC1 heterodimer is repressed by a SQUAMOSA promoter-binding protein-like TF, PpSPL1. Low levels of PpMYB10.1 expression in fruit at early developmental stages is probably attributable to lower levels of expression of PpNAC1 plus the presence of high levels of repressors such as PpSPL1. We present a mechanism whereby BL is the key gene for the blood-flesh trait in peach via its activation of PpMYB10.1 in maturing fruit. Partner TFs such as basic helix-loop-helix proteins and NAC1 are required, as is the removal of transcriptional repressors.

  9. Notch signaling induces rapid degradation of achaete-scute homolog 1. (United States)

    Sriuranpong, Virote; Borges, Michael W; Strock, Christopher L; Nakakura, Eric K; Watkins, D Neil; Blaumueller, Christine M; Nelkin, Barry D; Ball, Douglas W


    In neural development, Notch signaling plays a key role in restricting neuronal differentiation, promoting the maintenance of progenitor cells. Classically, Notch signaling causes transactivation of Hairy-enhancer of Split (HES) genes which leads to transcriptional repression of neural determination and differentiation genes. We now report that in addition to its known transcriptional mechanism, Notch signaling also leads to rapid degradation of the basic helix-loop-helix (bHLH) transcription factor human achaete-scute homolog 1 (hASH1). Using recombinant adenoviruses expressing active Notch1 in small-cell lung cancer cells, we showed that the initial appearance of Notch1 coincided with the loss of hASH1 protein, preceding the full decay of hASH1 mRNA. Overexpression of HES1 alone was capable of down-regulating hASH1 mRNA but could not replicate the acute reduction of hASH1 protein induced by Notch1. When adenoviral hASH1 was coinfected with Notch1, we still observed a dramatic and abrupt loss of the exogenous hASH1 protein, despite high levels of ongoing hASH1 RNA expression. Notch1 treatment decreased the apparent half-life of the adenoviral hASH1 protein and increased the fraction of hASH1 which was polyubiquitinylated. The proteasome inhibitor MG132 reversed the Notch1-induced degradation. The Notch RAM domain was dispensable but a lack of the OPA and PEST domains inactivated this Notch1 action. Overexpression of the hASH1-dimerizing partner E12 could protect hASH1 from degradation. This novel function of activated Notch to rapidly degrade a class II bHLH protein may prove to be important in many contexts in development and in cancer.

  10. Identification of interacting proteins with aryl hydrocarbon receptor in scallop Chlamys farreri by yeast two hybrid screening. (United States)

    Cai, Yuefeng; Pan, Luqing; Miao, Jingjing; Liu, Tong


    The aryl hydrocarbon receptor (AhR) belongs to the basic-helix-loop helix (bHLH) Per-Arnt-Sim (PAS) family of transcription factors. AhR has been known primarily for its role in the regulation of several drug and xenobiotic metabolizing enzymes, as well as the mediation of the toxicity of certain xenobiotics, including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Although the AhR is well-studied as a mediator of the toxicity of certain xenobiotics in marine bivalves, the normal physiological function remains unknown. In order to explore the function of the AhR, the bait protein expression plasmid pGBKT7-CfAhR and the cDNA library of gill from Chlamys farreri were constructed. By yeast two hybrid system, after multiple screening with the high screening rate medium, rotary verification, sequencing and bioinformatics analysis, the interactions of the CfAhR with receptor for activated protein kinase C 1 (RACK1), thyroid peroxidase-like protein (TPO), Toll-like receptor 4(TLR 4), androglobin-like, store-operated Ca(2+) entry (SocE), ADP/ATP carrier protein, cytochrome b, thioesterase, actin, ferritin subunit 1, poly-ubiquitin, short-chain collagen C4-like and one hypothetical protein in gill cells were identified. This study suggests that the CfAhR played fundamental roles in immune system homeostasis, oxidative stress response, and in grow and development of C. farreri. The elucidation of these protein interactions is of much importance both in understanding the normal physiological function of AhR, and as potential targets for further research on protein function in AhR interactions.

  11. bHLH106 Integrates Functions of Multiple Genes through Their G-Box to Confer Salt Tolerance on Arabidopsis.

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    Aftab Ahmad

    Full Text Available An activation-tagging methodology was applied to dedifferentiated calli of Arabidopsis to identify new genes involved in salt tolerance. This identified salt tolerant callus 8 (stc8 as a gene encoding the basic helix-loop-helix transcription factor bHLH106. bHLH106-knockout (KO lines were more sensitive to NaCl, KCl, LiCl, ABA, and low temperatures than the wild-type. Back-transformation of the KO line rescued its phenotype, and over-expression (OX of bHLH106 in differentiated plants exhibited tolerance to NaCl. Green fluorescent protein (GFP fused with bHLH106 revealed that it was localized to the nucleus. Prepared bHLH106 protein was subjected to electrophoresis mobility shift assays against E-box sequences (5'-CANNTG-3'. The G-box sequence 5'-CACGTG-3' had the strongest interaction with bHLH106. bHLH106-OX lines were transcriptomically analyzed, and resultant up- and down-regulated genes selected on the criterion of presence of a G-box sequence. There were 198 genes positively regulated by bHLH106 and 36 genes negatively regulated; these genes possessed one or more G-box sequences in their promoter regions. Many of these genes are known to be involved in abiotic stress response. It is concluded that bHLH106 locates at a branching point in the abiotic stress response network by interacting directly to the G-box in genes conferring salt tolerance on plants.

  12. Evolution of the bHLH genes involved in stomatal development: implications for the expansion of developmental complexity of stomata in land plants.

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    Jin-Hua Ran

    Full Text Available Stomata play significant roles in plant evolution. A trio of closely related basic Helix-Loop-Helix (bHLH subgroup Ia genes, SPCH, MUTE and FAMA, mediate sequential steps of stomatal development, and their functions may be conserved in land plants. However, the evolutionary history of the putative SPCH/MUTE/FAMA genes is still greatly controversial, especially the phylogenetic positions of the bHLH Ia members from basal land plants. To better understand the evolutionary pattern and functional diversity of the bHLH genes involved in stomatal development, we made a comprehensive evolutionary analysis of the homologous genes from 54 species representing the major lineages of green plants. The phylogenetic analysis indicated: (1 All bHLH Ia genes from the two basal land plants Physcomitrella and Selaginella were closely related to the FAMA genes of seed plants; and (2 the gymnosperm 'SPCH' genes were sister to a clade comprising the angiosperm SPCH and MUTE genes, while the FAMA genes of gymnosperms and angiosperms had a sister relationship. The revealed phylogenetic relationships are also supported by the distribution of gene structures and previous functional studies. Therefore, we deduce that the function of FAMA might be ancestral in the bHLH Ia subgroup. In addition, the gymnosperm "SPCH" genes may represent an ancestral state and have a dual function of SPCH and MUTE, two genes that could have originated from a duplication event in the common ancestor of angiosperms. Moreover, in angiosperms, SPCHs have experienced more duplications and harbor more copies than MUTEs and FAMAs, which, together with variation of the stomatal development in the entry division, implies that SPCH might have contributed greatly to the diversity of stomatal development. Based on the above, we proposed a model for the correlation between the evolution of stomatal development and the genes involved in this developmental process in land plants.

  13. Identification of anthocyanin biosynthesis related microRNAs in a distinctive Chinese radish (Raphanus sativus L.) by high-throughput sequencing. (United States)

    Sun, Yuyan; Qiu, Yang; Duan, Mengmeng; Wang, Jinglei; Zhang, Xiaohui; Wang, Haiping; Song, Jiangping; Li, Xixiang


    Anthocyanins are widely distributed water-soluble phytochemical pigments belonging to the flavonoid group. To date, limited knowledge is available about the regulatory roles of miRNAs in anthocyanin biosynthesis in plants. To identify the miRNAs associated with anthocyanin biosynthesis in radish, five small RNA (sRNA) libraries constructed from 'Xinlimei' radish roots at 11, 21, 44, 56 and 73 days (d) were examined using high-throughput sequencing technology. A total of 102.02 million (M) clean reads were generated, from which 483 known and 1415 novel miRNAs were identified. Combined with target prediction and annotation, 72 differentially expressed miRNAs (52 known and 20 novel miRNAs) were more likely to participate in anthocyanin biosynthesis. Several target genes for these miRNAs encode a few transcription factors, including Myb domain (MYB), basic helix-loop-helix (bHLH), WD40 repeat, squamosa promoter binding protein like (SPL), auxin response factor (ARF), ethylene insensitive 3 (EIN3), WRKY and MADS-box proteins. Furthermore, the expression patterns of some anthocyanin biosynthesis related miRNAs and their corresponding targets were validated by RT-qPCR. Based on the characterization of anthocyanin biosynthesis related miRNAs and their target genes, a putative miRNA-target module regulating anthocyanin biosynthesis was proposed. This study represents the first genome-wide identification of miRNAs associated with anthocyanin biosynthesis in radish, and provides insights into the molecular mechanisms underlying regulation of anthocyanin biosynthesis in radish and other crops.

  14. The Arabidopsis bHLH25 and bHLH27 transcription factors contribute to susceptibility to the cyst nematode Heterodera schachtii. (United States)

    Jin, Jing; Hewezi, Tarek; Baum, Thomas J


    Successful cyst nematode parasitism depends on the formation and maintenance of feeding sites (syncytia) in host roots, and these processes are highly regulated by the interaction between the cyst nematode and the host. Using an integrated research approach and the Arabidopsis-Beta vulgaris (sugar beet) cyst nematode (Heterodera schachtii) pathosystem, we have determined that the two Arabidopsis basic helix-loop-helix transcription factors bHLH25 and bHLH27 positively influence cyst nematode parasitism. Promoter studies indicated that as early as 1 day post-inoculation, both transcription factor genes were upregulated in developing syncytia, whereas in non-infected plants, these two promoters were not found to be active in the same cells. By using yeast two-hybrid analyses and bimolecular fluorescence complementation assays, we documented that the two bHLH transcription factors can dimerize in planta. Transgenic Arabidopsis plants overexpressing either one or both of the bHLH genes exhibited altered morphology of roots and shoots, as well as an increased susceptibility to H. schachtii. bhlh25 or bhlh27 single mutants were without strong phenotypes, presumably because of functional redundancies in this gene family. However, the bhlh25 bhlh27 double mutant was less susceptible to H. schachtii, confirming an important conducive role of the co-expression of both transcription factor genes for cyst nematode parasitism. Our results document an example of pathogen-induced ectopic co-expression of two regulatory genes to enhance pathogen success, although these transcription factors apparently do not function in concert in non-infected plants. This is an intriguing biological phenomenon that highlights the complexity of obligate biotrophic plant-pathogen interactions, like those of cyst nematodes.

  15. Regulation of anthocyanin and proanthocyanidin biosynthesis by Medicago truncatula bHLH transcription factor MtTT8. (United States)

    Li, Penghui; Chen, Beibei; Zhang, Gaoyang; Chen, Longxiang; Dong, Qiang; Wen, Jiangqi; Mysore, Kirankumar S; Zhao, Jian


    The MYB- basic helix-loop-helix (bHLH)-WD40 complexes regulating anthocyanin and proanthocyanidin (PA) biosynthesis in plants are not fully understood. Here Medicago truncatula bHLH MtTT8 was characterized as a central component of these ternary complexes that control anthocyanin and PA biosynthesis. Mttt8 mutant seeds have a transparent testa phenotype with reduced PAs and anthocyanins. MtTT8 restores PA and anthocyanin productions in Arabidopsis tt8 mutant. Ectopic expression of MtTT8 restores anthocyanins and PAs in mttt8 plant and hairy roots and further enhances both productions in wild-type hairy roots. Transcriptomic analyses and metabolite profiling of mttt8 mutant seeds and M. truncatula hairy roots (mttt8 mutant, mttt8 mutant complemented with MtTT8, or MtTT8 overexpression lines) indicate that MtTT8 regulates a subset of genes involved in PA and anthocyanin biosynthesis. MtTT8 is genetically regulated by MtLAP1, MtPAR and MtWD40-1. Combinations of MtPAR, MtLAP1, MtTT8 and MtWD40-1 activate MtTT8 promoter in yeast assay. MtTT8 interacts with these transcription factors to form regulatory complexes. MtTT8, MtWD40-1 and an MYB factor, MtPAR or MtLAP1, interacted and activated promoters of anthocyanidin reductase and anthocyanidin synthase to regulate PA and anthocyanin biosynthesis, respectively. Our results provide new insights into the complex regulation of PA and anthocyanin biosynthesis in M. truncatula.

  16. Effects of hypoxia-inducible factor 1 on ischemic cerebrovascular disease

    Institute of Scientific and Technical Information of China (English)

    Yongjie Luo; Xiaoping Wang; Hongbin Sun


    Hypoxia-inducible factor I, a nuclear transcription factor, is induced by hypoxia. Hypoxia-inducible factor I, a heterodimeric DNA-binding protein, is composed of hypoxia-inducible factor 1α and hypoxia-inducible factor 1 β subunits, which are family members of the basic helix-loop-helix-PER, ARNT, SIM (PAS) protein. O2 concentration regulates hypoxia-inducible factor 1 activity via this subunit. Hypoxia-inducible factor 1α plays a major role in response to hypoxia and transcriptional activation, as well as in the target gene specificity of the DNA enhancer. Hypoxia-inducible factor 1β cannot be induced by hypoxia. This effect may be due to hypoxia-inducible factor 1 stability and activated conformation due to dimerization. Previous studies have shown that hypoxia-inducible factor 1 mRNA expression increases in the penumbra following ischemia/hypoxia. Hypoxia-inducible factor 1 plays an important role in brain tissue injury alter ischemia by affecting a series of target genes, elevating tolerance to hypoxia, and ensuring survival of neural cells. This article summarizes the structure, function, expression, regulatory mechanisms, biological effects, and significance of hypoxia-inducible factor 1 in patients with ischemic cerebrovascular disease. As a transcriptional activator, hypoxia- inducible factor 1 plays a key role in hypoxic responses by stabilizing the internal environment. It also has been shown to regulate the expression of several genes. The regulatory effects of hypoxia-inducible factor 1 in patients with ischemic cerebrovascular disease have been described. The present review re-examined the concept of brain protection at the level of gene regulation.

  17. A large insertion in bHLH transcription factor BrTT8 resulting in yellow seed coat in Brassica rapa.

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    Xia Li

    Full Text Available Yellow seed is a desirable quality trait of the Brassica oilseed species. Previously, several seed coat color genes have been mapped in the Brassica species, but the molecular mechanism is still unknown. In the present investigation, map-based cloning method was used to identify a seed coat color gene, located on A9 in B. rapa. Blast analysis with the Arabidopsis genome showed that there were 22 Arabidopsis genes in this region including at4g09820 to at4g10620. Functional complementation test exhibited a phenotype reversion in the Arabidopsis thaliana tt8-1 mutant and yellow-seeded plant. These results suggested that the candidate gene was a homolog of TRANSPARENT TESTA8 (TT8 locus. BrTT8 regulated the accumulation of proanthocyanidins (PAs in the seed coat. Sequence analysis of two alleles revealed a large insertion of a new class of transposable elements, Helitron in yellow sarson. In addition, no mRNA expression of BrTT8 was detected in the yellow-seeded line. It indicated that the natural transposon might have caused the loss in function of BrTT8. BrTT8 encodes a basic/helix-loop-helix (bHLH protein that shares a high degree of similarity with other bHLH proteins in the Brassica. Further expression analysis also revealed that BrTT8 was involved in controlling the late biosynthetic genes (LBGs of the flavonoid pathway. Our present findings provided with further studies could assist in understanding the molecular mechanism involved in seed coat color formation in Brassica species, which is an important oil yielding quality trait.

  18. Metabolic Profiling of Retrograde Pathway Transcription Factors Rtg1 and Rtg3 Knockout Yeast

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    Zanariah Hashim


    Full Text Available Rtg1 and Rtg3 are two basic helix-loop-helix (bHLH transcription factors found in yeast Saccharomyces cerevisiae that are involved in the regulation of the mitochondrial retrograde (RTG pathway. Under RTG response, anaplerotic synthesis of citrate is activated, consequently maintaining the supply of important precursors necessary for amino acid and nucleotide synthesis. Although the roles of Rtg1 and Rtg3 in TCA and glyoxylate cycles have been extensively reported, the investigation of other metabolic pathways has been lacking. Characteristic dimer formation in bHLH proteins, which allows for combinatorial gene expression, and the link between RTG and other regulatory pathways suggest more complex metabolic signaling involved in Rtg1/Rtg3 regulation. In this study, using a metabolomics approach, we examined metabolic alteration following RTG1 and RTG3 deletion. We found that apart from TCA and glyoxylate cycles, which have been previously reported, polyamine biosynthesis and other amino acid metabolism were significantly altered in RTG-deficient strains. We revealed that metabolic alterations occurred at various metabolic sites and that these changes relate to different growth phases, but the difference can be detected even at the mid-exponential phase, when mitochondrial function is repressed. Moreover, the effect of metabolic rearrangements can be seen through the chronological lifespan (CLS measurement, where we confirmed the role of the RTG pathway in extending the yeast lifespan. Through a comprehensive metabolic profiling, we were able to explore metabolic phenotypes previously unidentified by other means and illustrate the possible correlations of Rtg1 and Rtg3 in different pathways.

  19. Transcription factors, sucrose, and sucrose metabolic genes interact to regulate potato phenylpropanoid metabolism. (United States)

    Payyavula, Raja S; Singh, Rajesh K; Navarre, Duroy A


    Much remains unknown about how transcription factors and sugars regulate phenylpropanoid metabolism in tuber crops like potato (Solanum tuberosum). Based on phylogeny and protein similarity to known regulators of phenylpropanoid metabolism, 15 transcription factors were selected and their expression was compared in white, yellow, red, and purple genotypes with contrasting phenolic and anthocyanin profiles. Red and purple genotypes had increased phenylalanine ammonia lyase (PAL) enzyme activity, markedly higher levels of phenylpropanoids, and elevated expression of most phenylpropanoid structural genes, including a novel anthocyanin O-methyltransferase. The transcription factors Anthocyanin1 (StAN1), basic Helix Loop Helix1 (StbHLH1), and StWD40 were more strongly expressed in red and purple potatoes. Expression of 12 other transcription factors was not associated with phenylpropanoid content, except for StMYB12B, which showed a negative relationship. Increased expression of AN1, bHLH1, and WD40 was also associated with environmentally mediated increases in tuber phenylpropanoids. Treatment of potato plantlets with sucrose induced hydroxycinnamic acids, flavonols, anthocyanins, structural genes, AN1, bHLH1, WD40, and genes encoding the sucrose-hydrolysing enzymes SUSY1, SUSY4, and INV2. Transient expression of StAN1 in tobacco leaves induced bHLH1, structural genes, SUSY1, SUSY4, and INV1, and increased phenylpropanoid amounts. StAN1 infiltration into tobacco leaves decreased sucrose and glucose concentrations. In silico promoter analysis revealed the presence of MYB and bHLH regulatory elements on sucrolytic gene promoters and sucrose-responsive elements on the AN1 promoter. These findings reveal an interesting dynamic between AN1, sucrose, and sucrose metabolic genes in modulating potato phenylpropanoids.

  20. Insulin gene: organisation, expression and regulation. (United States)

    Dumonteil, E; Philippe, J


    Insulin, a major hormone of the endocrine pancreas, plays a key role in the control of glucose homeostasis. This review discusses the mechanisms of cell-specific expression and regulation of the insulin gene. Whereas expression is restricted to islet beta-cells in adults, the insulin gene is more widely expressed at several embryonic stages, although the role of extrapancreatic expression is still unclear. beta-cell-specific expression relies on the interactions of 5'-flanking sequence motifs of the promoter with a number of ubiquitous and islet-specific transcription factors. IEF1 and IPF-1, by their binding to the E and A boxes, respectively, of the insulin gene promoter, appear to be the major determinants of beta-cell-specific expression. IEF1 is a heterodimer of the basic helix-loop-helix family of transcription factors, whereas IPF-1 belongs to the homeodomain-containing family. beta-cell specific determinants are conserved throughout evolution, although the human insulin gene 5'-flanking sequence also contains a polymorphic minisatellite which is unique to primates and may play a role in insulin gene regulation. Glucose modulates insulin gene transcription, with multiple elements of the promoter involved in glucose responsiveness. Remarkably, IPF-1 and IEF1 are involved in both beta-cell-specific expression and glucose regulation of the insulin gene. cAMP also regulates insulin gene transcription through a CRE, in response to various hormonal stimuli. On the whole, recent studies have provided a better understanding of beta-cell differentiation and function.

  1. Cloning and functional characterisation of avian transcription factor E2A

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    Meyer Kerstin B


    Full Text Available Abstract Background During B lymphocyte development the E2A gene is a critical regulator of cell proliferation and differentiation. With regards to the immunoglobulin genes the E2A proteins contribute to the regulation of gene rearrangement, expression and class switch recombination. We are now using the chicken cell line DT40 as a model system to further analyse the function of E2A. Results Here we report the cloning and functional analysis of the transcription factor E2A from chicken. Using RACE PCR on the chicken lymphoma cell line DT40 we have isolated full-length clones for the two E2A splice variants E12 and E47. Sequence conservation between the human and chicken proteins is extensive: the basic-helix-loop-helix DNA binding domain of human and chicken E47 and E12 are 93% and 92% identical, respectively. In addition high levels of conservation are seen in activation domain I, the potential NLS and the ubiquitin ligase interaction domain. E2A is expressed in a variety of tissues in chicken, with higher levels of expression in organs rich in immune cells. We demonstrate that chicken E12 and E47 proteins are strong transcriptional activators whose function depends on the presence of activation domain I. As in mammals, the dominant negative proteins Id1 and Id3 can inhibit the function of chicken E47. Conclusions The potential for homologous recombination in DT40 allows the genetic dissection of biochemical pathways in somatic cells. With the cloning of avian E2A and the recent description of an in vitro somatic hypermutation assay in this cell line, it should now be possible to dissect the potential role of E2A in the regulation of somatic hypermutation and gene conversion.

  2. Multiple phosphorylation events control mitotic degradation of the muscle transcription factor Myf5

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    Lorca Thierry


    Full Text Available Abstract Background The two myogenic regulatory factors Myf5 and MyoD are basic helix-loop-helix muscle transcription factors undergoing differential cell cycle dependent proteolysis in proliferating myoblasts. This regulated degradation results in the striking expression of these two factors at distinct phases of the cell cycle, and suggests that their precise and alternated disappearance is an important feature of myoblasts, maybe connected to the maintenance of the proliferative status and/or commitment to the myogenic lineage of these cells. One way to understand the biological function(s of the cyclic expression of these proteins is to specifically alter their degradation, and to analyze the effects of their stabilization on cells. To this aim, we undertook the biochemical analysis of the mechanisms governing Myf5 mitotic degradation, using heterologous systems. Results We show here that mitotic degradation of Myf5 is conserved in non-myogenic cells, and is thus strictly under the control of the cell cycle apparatus. Using Xenopus egg extracts as an in vitro system to dissect the main steps of Myf5 mitotic proteolysis, we show that (1 Myf5 stability is regulated by a complex interplay of phosphorylation/dephosphorylation, probably involving various kinases and phosphatases, (2 Myf5 is ubiquitylated in mitotic extracts, and this is a prerequisite to its degradation by the proteasome and (3 at least in the Xenopus system, the E3 responsible for its mitotic degradation is not the APC/C (the major E3 during mitosis. Conclusion Altogether, our data strongly suggest that the mitotic degradation of Myf5 by the ubiquitin-proteasome system is precisely controlled by multiple phosphorylation of the protein, and that the APC/C is not involved in this process.

  3. Decoding c-Myc networks of cell cycle and apoptosis regulated genes in a transgenic mouse model of papillary lung adenocarcinomas. (United States)

    Ciribilli, Yari; Singh, Prashant; Spanel, Reinhard; Inga, Alberto; Borlak, Jürgen


    The c-Myc gene codes for a basic-helix-loop-helix-leucine zipper transcription factor protein and is reported to be frequently over-expressed in human cancers. Given that c-Myc plays an essential role in neoplastic transformation we wished to define its activity in lung cancer and therefore studied its targeted expression to respiratory epithelium in a transgenic mouse disease model. Using histological well-defined tumors, transcriptome analysis identified novel c-Myc responsive cell cycle and apoptosis genes that were validated as direct c-Myc targets using EMSA, Western blotting, gene reporter and ChIP assays.Through computational analyses c-Myc cooperating transcription factors emerged for repressed and up-regulated genes in cancer samples, namely Klf7, Gata3, Sox18, p53 and Elf5 and Cebpα, respectively. Conversely, at promoters of genes regulated in transgenic but non-carcinomatous lung tissue enriched binding sites for c-Myc, Hbp1, Hif1 were observed. Bioinformatic analysis of tumor transcriptomic data revealed regulatory gene networks and highlighted mortalin and moesin as master regulators while gene reporter and ChIP assays in the H1299 lung cancer cell line as well as cross-examination of published ChIP-sequence data of 7 human and 2 mouse cell lines provided strong evidence for the identified genes to be c-Myc targets. The clinical significance of findings was established by evaluating expression of orthologous proteins in human lung cancer. Taken collectively, a molecular circuit for c-Myc-dependent cellular transformation was identified and the network analysis broadened the perspective for molecularly targeted therapies.

  4. ChIP-seq and in vivo transcriptome analyses of the Aspergillus fumigatus SREBP SrbA reveals a new regulator of the fungal hypoxia response and virulence.

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    Dawoon Chung


    Full Text Available The Aspergillus fumigatus sterol regulatory element binding protein (SREBP SrbA belongs to the basic Helix-Loop-Helix (bHLH family of transcription factors and is crucial for antifungal drug resistance and virulence. The latter phenotype is especially striking, as loss of SrbA results in complete loss of virulence in murine models of invasive pulmonary aspergillosis (IPA. How fungal SREBPs mediate fungal virulence is unknown, though it has been suggested that lack of growth in hypoxic conditions accounts for the attenuated virulence. To further understand the role of SrbA in fungal infection site pathobiology, chromatin immunoprecipitation followed by massively parallel DNA sequencing (ChIP-seq was used to identify genes under direct SrbA transcriptional regulation in hypoxia. These results confirmed the direct regulation of ergosterol biosynthesis and iron uptake by SrbA in hypoxia and revealed new roles for SrbA in nitrate assimilation and heme biosynthesis. Moreover, functional characterization of an SrbA target gene with sequence similarity to SrbA identified a new transcriptional regulator of the fungal hypoxia response and virulence, SrbB. SrbB co-regulates genes involved in heme biosynthesis and demethylation of C4-sterols with SrbA in hypoxic conditions. However, SrbB also has regulatory functions independent of SrbA including regulation of carbohydrate metabolism. Loss of SrbB markedly attenuates A. fumigatus virulence, and loss of both SREBPs further reduces in vivo fungal growth. These data suggest that both A. fumigatus SREBPs are critical for hypoxia adaptation and virulence and reveal new insights into SREBPs' complex role in infection site adaptation and fungal virulence.

  5. ZINC FINGER OF ARABIDOPSIS THALIANA12 (ZAT12) Interacts with FER-LIKE IRON DEFICIENCY-INDUCED TRANSCRIPTION FACTOR (FIT) Linking Iron Deficiency and Oxidative Stress Responses. (United States)

    Le, Cham Thi Tuyet; Brumbarova, Tzvetina; Ivanov, Rumen; Stoof, Claudia; Weber, Eva; Mohrbacher, Julia; Fink-Straube, Claudia; Bauer, Petra


    Plants grown under iron (Fe)-deficient conditions induce a set of genes that enhance the efficiency of Fe uptake by the roots. In Arabidopsis (Arabidopsis thaliana), the central regulator of this response is the basic helix-loop-helix transcription factor FER-LIKE IRON DEFICIENCY-INDUCED TRANSCRIPTION FACTOR (FIT). FIT activity is regulated by protein-protein interactions, which also serve to integrate external signals that stimulate and possibly inhibit Fe uptake. In the search of signaling components regulating FIT function, we identified ZINC FINGER OF ARABIDOPSIS THALIANA12 (ZAT12), an abiotic stress-induced transcription factor. ZAT12 interacted with FIT, dependent on the presence of the ethylene-responsive element-binding factor-associated amphiphilic repression motif. ZAT12 protein was found expressed in the root early differentiation zone, where its abundance was modulated in a root layer-specific manner. In the absence of ZAT12, FIT expression was upregulated, suggesting a negative effect of ZAT12 on Fe uptake. Consistently, zat12 loss-of-function mutants had higher Fe content than the wild type at sufficient Fe. We found that under Fe deficiency, hydrogen peroxide (H2O2) levels were enhanced in a FIT-dependent manner. FIT protein, in turn, was stabilized by H2O2 but only in the presence of ZAT12, showing that H2O2 serves as a signal for Fe deficiency responses. We propose that oxidative stress-induced ZAT12 functions as a negative regulator of Fe acquisition. A model where H2O2 mediates the negative regulation of plant responses to prolonged stress might be applicable to a variety of stress conditions.

  6. OsIRO2 is responsible for iron utilization in rice and improves growth and yield in calcareous soil. (United States)

    Ogo, Yuko; Itai, Reiko N; Kobayashi, Takanori; Aung, May Sann; Nakanishi, Hiromi; Nishizawa, Naoko K


    Iron (Fe) deficiency, a worldwide agricultural problem on calcareous soil with low Fe availability, is also a major human nutritional deficit. Plants induce Fe acquisition systems under conditions of low Fe availability. Previously, we reported that an Fe-deficiency-inducible basic helix-loop-helix (bHLH) transcription factor, OsIRO2, is responsible for regulation of the genes involved in Fe homeostasis in rice. Using promoter-GUS transformants, we showed that OsIRO2 is expressed throughout a plant's lifetime in a spatially and temporally similar manner to the genes OsNAS1, OsNAS2 and TOM1, which is involved in Fe absorption and translocation. During germination, OsIRO2 expression was detected in embryos. OsIRO2 expression in vegetative tissues was restricted almost exclusively to vascular bundles of roots and leaves, and to the root exodermis under Fe-sufficient conditions, and expanded to all tissues of roots and leaves in response to Fe deficiency. OsIRO2 expression was also detected in flowers and developing seeds. Plants overexpressing OsIRO2 grew better, and OsIRO2-repressed plants showed poor growth compared to non-transformant rice after germination. OsIRO2 overexpression also resulted in improved tolerance to low Fe availability in calcareous soil. In addition to increased Fe content in shoots, the overexpression plants accumulated higher amounts of Fe in seeds than non-transformants when grown on calcareous soil. These results suggest that OsIRO2 is synchronously expressed with genes involved in Fe homeostasis, and performs a crucial function in regulation not only of Fe uptake from soil but also Fe transport during germination and Fe translocation to grain during seed maturation.

  7. Transcriptional coordination between leaf cell differentiation and chloroplast development established by TCP20 and the subgroup Ib bHLH transcription factors. (United States)

    Andriankaja, Megan E; Danisman, Selahattin; Mignolet-Spruyt, Lorin F; Claeys, Hannes; Kochanke, Irina; Vermeersch, Mattias; De Milde, Liesbeth; De Bodt, Stefanie; Storme, Veronique; Skirycz, Aleksandra; Maurer, Felix; Bauer, Petra; Mühlenbock, Per; Van Breusegem, Frank; Angenent, Gerco C; Immink, Richard G H; Inzé, Dirk


    The establishment of the photosynthetic apparatus during chloroplast development creates a high demand for iron as a redox metal. However, iron in too high quantities becomes toxic to the plant, thus plants have evolved a complex network of iron uptake and regulation mechanisms. Here, we examined whether four of the subgroup Ib basic helix-loop-helix transcription factors (bHLH38, bHLH39, bHLH100, bHLH101), previously implicated in iron homeostasis in roots, also play a role in regulating iron metabolism in developing leaves. These transcription factor genes were strongly up-regulated during the transition from cell proliferation to expansion, and thus sink-source transition, in young developing leaves of Arabidopsis thaliana. The four subgroup Ib bHLH genes also showed reduced expression levels in developing leaves of plants treated with norflurazon, indicating their expression was tightly linked to the onset of photosynthetic activity in young leaves. In addition, we provide evidence for a mechanism whereby the transcriptional regulators SAC51 and TCP20 antagonistically regulate the expression of these four subgroup Ib bHLH genes. A loss-of-function mutant analysis also revealed that single mutants of bHLH38, bHLH39, bHLH100, and bHLH101 developed smaller rosettes than wild-type plants in soil. When grown in agar plates with reduced iron concentration, triple bhlh39 bhlh100 bhlh101 mutant plants were smaller than wild-type plants. However, measurements of the iron content in single and multiple subgroup Ib bHLH genes, as well as transcript profiling of iron response genes during early leaf development, do not support a role for bHLH38, bHLH39, bHLH100, and bHLH101 in iron homeostasis during early leaf development.

  8. Molecular characterization of hypoxia and hypoxia-inducible factor 1 alpha (HIF-1α) from Taiwan voles (Microtus kikuchii). (United States)

    Jiang, Yi-Fan; Chou, Chung-Hsi; Lin, En-Chung; Chiu, Chih-Hsien


    Hypoxia-inducible factor 1 (HIF-1) is a transcription factor that senses and adapts cells to hypoxic environmental conditions. HIF-1 is composed of an oxygen-regulated α subunit (HIF-1α) and a constitutively expressed β subunit (HIF-1β). Taiwan voles (Microtus kikuchii) are an endemic species in Taiwan, found only in mountainous areas greater than 2000m above sea level. In this study, the full-length HIF-1α cDNA was cloned and sequenced from liver tissues of Taiwan voles. We found that HIF-1α of Taiwan voles had high sequence similarity to HIF-1α of other species. Sequence alignment of HIF-1α functional domains indicated basic helix-loop-helix (bHLH), PER-ARNT-SIM (PAS) and C-terminal transactivation (TAD-C) domains were conserved among species, but sequence variations were found between the oxygen-dependent degradation domains (ODDD). To measure Taiwan vole HIF-1α responses to hypoxia, animals were challenged with cobalt chloride, and HIF-1α mRNA and protein expression in brain, lung, heart, liver, kidney, and muscle was assessed by quantitative RT-PCR and Western blot analysis. Upon induction of hypoxic stress with cobalt chloride, an increase in HIF-1α mRNA levels was detected in lung, heart, kidney, and muscle tissue. In contrast, protein expression levels showed greater variation between individual animals. These results suggest that the regulation of HIF-1α may be important to the Taiwan vole under cobalt chloride treatments. But more details regarding the evolutionary effect of environmental pressure on HIF-1α primary sequence, HIF-1α function and regulation in Taiwan voles remain to be identified.

  9. Genome-wide and phase-specific DNA-binding rhythms of BMAL1 control circadian output functions in mouse liver.

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    Guillaume Rey


    Full Text Available The mammalian circadian clock uses interlocked negative feedback loops in which the heterodimeric basic helix-loop-helix transcription factor BMAL1/CLOCK is a master regulator. While there is prominent control of liver functions by the circadian clock, the detailed links between circadian regulators and downstream targets are poorly known. Using chromatin immunoprecipitation combined with deep sequencing we obtained a time-resolved and genome-wide map of BMAL1 binding in mouse liver, which allowed us to identify over 2,000 binding sites, with peak binding narrowly centered around Zeitgeber time 6. Annotation of BMAL1 targets confirms carbohydrate and lipid metabolism as the major output of the circadian clock in mouse liver. Moreover, transcription regulators are largely overrepresented, several of which also exhibit circadian activity. Genes of the core circadian oscillator stand out as strongly bound, often at promoter and distal sites. Genomic sequence analysis of the sites identified E-boxes and tandem E1-E2 consensus elements. Electromobility shift assays showed that E1-E2 sites are bound by a dimer of BMAL1/CLOCK heterodimers with a spacing-dependent cooperative interaction, a finding that was further validated in transactivation assays. BMAL1 target genes showed cyclic mRNA expression profiles with a phase distribution centered at Zeitgeber time 10. Importantly, sites with E1-E2 elements showed tighter phases both in binding and mRNA accumulation. Finally, analyzing the temporal profiles of BMAL1 binding, precursor mRNA and mature mRNA levels showed how transcriptional and post-transcriptional regulation contribute differentially to circadian expression phase. Together, our analysis of a dynamic protein-DNA interactome uncovered how genes of the core circadian oscillator crosstalk and drive phase-specific circadian output programs in a complex tissue.

  10. Embryonic and Postnatal Expression of Aryl Hydrocarbon Receptor mRNA in Mouse Brain (United States)

    Kimura, Eiki; Tohyama, Chiharu


    Aryl hydrocarbon receptor (AhR), a member of the basic helix-loop-helix-Per-Arnt-Sim transcription factor family, plays a critical role in the developing nervous system of invertebrates and vertebrates. Dioxin, a ubiquitous environmental pollutant, avidly binds to this receptor, and maternal exposure to dioxin has been shown to impair higher brain functions and dendritic morphogenesis, possibly via an AhR-dependent mechanism. However, there is little information on AhR expression in the developing mammalian brain. To address this issue, the present study analyzed AhR mRNA expression in the brains of embryonic, juvenile, and adult mice by reverse transcription (RT)-PCR and in situ hybridization. In early brain development (embryonic day 12.5), AhR transcript was detected in the innermost cortical layer. The mRNA was also expressed in the hippocampus, cerebral cortex, cerebellum, olfactory bulb, and rostral migratory stream on embryonic day 18.5, postnatal days 3, 7, and 14, and in 12-week-old (adult) mice. Hippocampal expression was abundant in the CA1 and CA3 pyramidal and dentate gyrus granule cell layers, where expression level of AhR mRNA in 12-week old is higher than that in 7-day old. These results reveal temporal and spatial patterns of AhR mRNA expression in the mouse brain, providing the information that may contribute to the elucidation of the physiologic and toxicologic significance of AhR in the developing brain. PMID:28223923

  11. Expression of epithelial-mesenchymal transition regulators SNAI2 and TWIST1 in thyroid carcinomas. (United States)

    Buehler, Darya; Hardin, Heather; Shan, Weihua; Montemayor-Garcia, Celina; Rush, Patrick S; Asioli, Sofia; Chen, Herbert; Lloyd, Ricardo V


    Epithelial-mesenchymal transition is an important mechanism of epithelial tumor progression, local invasion and metastasis. The E-cadherin (CDH1) repressor SLUG (SNAI2) and the basic helix-loop-helix transcription factor TWIST1 inhibit CDH1 expression in poorly differentiated malignancies as inducers of epithelial-mesenchymal transition. Epithelial-mesenchymal transition has been implicated in progression from well to poorly differentiated/anaplastic thyroid carcinoma but the expression of SNAI2 and TWIST1 proteins and their phenotypic association in human thyroid cancers has not been extensively studied. We examined the expression of SNAI2, TWIST1 and CDH1 by immunohistochemistry in a panel of well-differentiated and anaplastic thyroid cancers and by qRT-PCR in thyroid cell lines. Ten normal thyroids, 33 follicular adenomas, 56 papillary thyroid carcinomas including 28 follicular variants, 27 follicular carcinomas and 10 anaplastic thyroid carcinomas were assembled on a tissue microarray and immunostained for SNAI2, TWIST1 and CDH1. Most (8/10) anaplastic thyroid carcinomas demonstrated strong nuclear immunoreactivity for SNAI2 with associated absence of CDH1 in 6/8 cases (75%). TWIST1 was expressed in 5/10 anaplastic thyroid carcinomas with absence of CDH1 in 3/5 (60%) cases. These findings were confirmed in whole sections of all anaplastic thyroid carcinomas and in a separate validation set of 10 additional anaplastic thyroid carcinomas. All normal thyroids, follicular adenomas, papillary and follicular thyroid carcinomas were negative for SNAI2 and TWIST1 (Pcarcinoma and two anaplastic thyroid carcinoma cell lines tested, but the highest levels of CDH1 mRNA were detected in the normal thyroid cell line while the anaplastic thyroid carcinoma cell line demonstrated the highest levels of SNAI2 and TWIST1 mRNA. Our findings support the role of epithelial-mesenchymal transition in the development of anaplastic thyroid carcinoma.

  12. Characterization of the promoter region of biosynthetic enzyme genes involved in berberine biosynthesis in Coptis japonica

    Directory of Open Access Journals (Sweden)

    Yasuyuki Yamada


    Full Text Available The presence of alkaloids is rather specific to certain plant species. However, berberine, an isoquinoline alkaloid, is relatively broadly distributed in the plant kingdom. Thus, berberine biosynthesis has been intensively investigated, especially using Coptis japonica cell cultures. Almost all biosynthetic enzyme genes have already been characterized at the molecular level. Particularly, two transcription factors (TFs, a plant-specific WRKY-type transcription factor, CjWRKY1, and a basic helix-loop-helix (bHLH transcription factor, CjbHLH1, were shown to comprehensively regulate berberine biosynthesis in C. japonica cells. In this study, we characterized the promoter region of some biosynthetic enzyme genes and associated cis-acting elements involved in the transcriptional regulation via two TFs. The promoter regions of three berberine biosynthetic enzyme genes (CYP80B2, 4’OMT and CYP719A1 were isolated, and their promoter activities were dissected by a transient assay involving the sequentially truncated promoter::luciferase (LUC reporter constructs. Furthermore, transactivation activities of CjWRKY1 were determined using the truncated promoter::LUC reporter constructs or constructs with mutated cis-elements. These results suggest the involvement of a putative W-box in the regulation of biosynthetic enzyme genes. Direct binding of CjWRKY1 to the W-box DNA sequence was also confirmed by an electrophoresis mobility shift assay (EMSA and by a chromatin immunoprecipitation (ChIP assay. In addition, CjbHLH1 also activated transcription from truncated 4’OMT and CYP719A1 promoters independently of CjWRKY1, suggesting the involvement of a putative E-box. Unexpected transcriptional activation of biosynthetic enzyme genes via a non-W-box sequence and by CjWRKY1 as well as the possible involvement of a GCC-box in berberine biosynthesis in C. japonica are discussed.

  13. Protein-mediated synthesis of gold nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Ravindra, Pratibha [Department of Life Sciences, University of Mumbai, Kalina, Santacruz (E) 400098, Mumbai (India)], E-mail:


    Our current approach is to synthesize gold nanoparticles utilizing Serrapeptase that serves as both a reducing and stabilizing agent. The investigations further reveal that certain amino acid groups like lysine are involved in reduction and stabilization of these particles. The particles are characterized with UV-vis spectroscopy, Transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, Proton Nuclear Magnetic Resonance (H NMR) Spectroscopy studies and Sodium dodecyl sulphate-polyacrylamide gel electrophoresis for Serrapeptidase and Au-Serrapeptidase isolation. Transmission electron microscopy studies show particles ranging from 20 nm to 200 nm that are spherical, hexagonal and polygonal in nature. UV-vis spectroscopy shows surface plasmon band at 536 nm that indicates formation of spherical particles whereas, results further add that gold particles are formed inside the nanosphere that is stabilized by interaction of amino acid groups like {gamma}-lysine of peptase. Fourier transform infrared spectroscopy studies reveal that few carboxyl groups are involved during the synthesis process followed by stretching of -CH bonds which has been seen in the case of lysine of Serrapeptase. Current studies therefore show that the method utilized for the synthesis of Au-nanoparticles is a biofriendly method and the nanogold formed can be a useful attribute for various applications.

  14. Domesticated DNA transposon proteins mediate retrotransposon control

    Institute of Scientific and Technical Information of China (English)

    Kathryn A O'Donnell; Jef D Boeke


    @@ The Schizosaccharomyces pontbe genome, like those of many eukaryotes, contains a number of retrotransposable repeat sequences. The pombe elements, termed Tfl (transposon of fission yeast 1) and Tf2 possess long terminal repeats (LTRs) and belong to the gypsy family of retrotransposons [1].

  15. Orm family proteins mediate sphingolipid homeostasis

    DEFF Research Database (Denmark)

    Breslow, David K; Collins, Sean R; Bodenmiller, Bernd;


    in humans)-a conserved gene family that includes ORMDL3, which has recently been identified as a potential risk factor for childhood asthma. Starting from an unbiased functional genomic approach in Saccharomyces cerevisiae, we identify Orm proteins as negative regulators of sphingolipid synthesis that form...... a conserved complex with serine palmitoyltransferase, the first and rate-limiting enzyme in sphingolipid production. We also define a regulatory pathway in which phosphorylation of Orm proteins relieves their inhibitory activity when sphingolipid production is disrupted. Changes in ORM gene expression...

  16. Basic research in solar physics (United States)

    Linsky, Jeffrey L.


    heated at a 'basal' rate that is also found in the centers of solar supergranules, and using the Doppler-imaging technique to measure the position, size, and brightness of stellar active regions. We are computing multi-component models for solar and stellar atmospheres, and models for coronal loops and for the transition-region down flows. The study of solar and stellar flares permits us to assess the role of turbulent energy transport, to pinpoint the mechanism behind Type I radio bursts, to determine whether plasma radiation or cyclotron maser is responsible for microwave flares on M dwarfs, and to extend our knowledge of the basic physics pertinent to cyclotron-maser processes operating on the Sun.

  17. Basic needs: a survey of the literature. (United States)

    Afxentiou, P C


    Poverty is widespread and significant in developing countries. As world poverty expands and the gap between rich and poor widens, advocates increasingly support development policies designed to help the poor meet basic needs. Policies generally followed since the second World War have contributed to GNP growth but fail to reduce income inequalities and noticeably improve life for the poor. This paper discusses the evolution of basic needs as a concept and policy goal, the conflict between basic needs and growth, the impact of basic needs on population and popular participation, and results of empirical studies. Basic needs policies may be humanitarian, but evidence supports neither their ability to promote growth, control population, nor encourage popular participation. Basic needs policies are nonetheless noble and challenge us to face poverty as a universal problem.

  18. Basic concepts in social sciences III


    Hoede, C.


    In this paper the set of concepts considered to be basic to the fields of Economics, Organization Theory, Political Science, Psychology and Sociology is completed. The set of 55 basic concepts in the first two papers on basic concepts was mainly determined by considering concepts in relation to social atoms. The concepts that play a role in n-networks form the majority of the concepts added in this paper.

  19. Electronics Technology. Performance Objectives. Basic Course. (United States)

    Campbell, Guy

    Several intermediate performance objectives and corresponding criterion measures are listed for each of 20 terminal objectives for a basic electronics technology course. The materials were developed for a two-semester course (2 hours daily) designed to include instruction in basic electricity and electronic fundamentals, and to develop skills and…

  20. Basic Functional Analysis Puzzles of Spectral Flow

    DEFF Research Database (Denmark)

    Booss-Bavnbek, Bernhelm


    We explain an array of basic functional analysis puzzles on the way to general spectral flow formulae and indicate a direction of future topological research for dealing with these puzzles.......We explain an array of basic functional analysis puzzles on the way to general spectral flow formulae and indicate a direction of future topological research for dealing with these puzzles....

  1. 32 CFR 37.1240 - Basic research. (United States)


    ... 32 National Defense 1 2010-07-01 2010-07-01 false Basic research. 37.1240 Section 37.1240 National... TECHNOLOGY INVESTMENT AGREEMENTS Definitions of Terms Used in This Part § 37.1240 Basic research. Efforts... practical application of that knowledge and understanding. It typically is funded within...

  2. Teaching Basic Writers: The Personality Factor. (United States)

    Reigstad, Tom


    Reviews research on the Myers-Briggs Type Indicator's (MBTI's) use in personalizing the basic writing curriculum. Describes an MBTI-based study of personality and writing performance in a basic writing class. Identifies ways MBTI results can inform teacher feedback and the use of prewriting, small groups, computers, and essay tests. (DMM)

  3. Basic concepts in social sciences II


    Hoede, C.


    In this paper an extension is given of the set of concepts considered to be basic to the fields of Economics, Organization Theory, Political Science, Psychology and Sociology. The modeling is in terms of automata and automata networks. In the first paper on basic concepts the simplest unit, the social atom, stood central. In this second paper social structures and processes are focused upon.

  4. Basic concepts in social sciences II

    NARCIS (Netherlands)

    Hoede, C.


    In this paper an extension is given of the set of concepts considered to be basic to the fields of Economics, Organization Theory, Political Science, Psychology and Sociology. The modeling is in terms of automata and automata networks. In the first paper on basic concepts the simplest unit, the soci

  5. 32 CFR 806b.2 - Basic guidelines. (United States)


    ... 32 National Defense 6 2010-07-01 2010-07-01 false Basic guidelines. 806b.2 Section 806b.2 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE ADMINISTRATION PRIVACY ACT PROGRAM Overview of the Privacy Act Program § 806b.2 Basic guidelines. This part implements the Privacy Act of...

  6. Essentials of Basic Writing Pedagogy for Librarians (United States)

    King, Reabeka


    There is an ongoing paradigm shift in librarianship that prompts the application of pedagogy throughout our professional practice. In light of the special attention to basic writing development in community college curricula, this article provides an overview of basic writing pedagogy. It discusses the overall college-level writing and research…

  7. Basic Chemistry for the Cement Industry. (United States)

    Turner, Mason

    This combined student workbook and instructor's guide contains nine units for inplant classes on basic chemistry for employees in the cement industry. The nine units cover the following topics: chemical basics; measurement; history of cement; atoms; bonding and chemical formulas; solids, liquids, and gases; chemistry of Portland cement…

  8. Visual Basic Applications to Physics Teaching (United States)

    Chitu, Catalin; Inpuscatu, Razvan Constantin; Viziru, Marilena


    Derived from basic language, VB (Visual Basic) is a programming language focused on the video interface component. With graphics and functional components implemented, the programmer is able to bring and use their components to achieve the desired application in a relatively short time. Language VB is a useful tool in physics teaching by creating…

  9. Basics of Solar Heating & Hot Water Systems. (United States)

    American Inst. of Architects, Washington, DC.

    In presenting the basics of solar heating and hot water systems, this publication is organized from the general to the specific. It begins by presenting functional and operational descriptions of solar heating and domestic hot water systems, outlining the basic concepts and terminology. This is followed by a description of solar energy utilization…

  10. 5 CFR 551.401 - Basic principles. (United States)


    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Basic principles. 551.401 Section 551.401 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY ADMINISTRATION UNDER THE FAIR LABOR STANDARDS ACT Hours of Work General Provisions § 551.401 Basic principles. (a) All...

  11. Basic sciences curriculum in medical education

    Directory of Open Access Journals (Sweden)



    Full Text Available Introduction: Traditional methods are generally used for teaching basic science courses at Shiraz Medical School. Such courses are taught during the first and second years of a seven-year medical program. The goal of this study was to analyze teachers and students’ perceptions of basic science teaching in medical education. Methods: A descriptive cross-sectional study was conducted at the college of medicine of Shiraz University of Medical Sciences. Results: Regarding the students’ viewpoints, 71.4% reported that curriculum content in basic sciences was enough and had good relevance. 59.2% of students believed the objectives of basic sciences curriculum were clear. Conclusion: The burden of teaching basic sciences ranges from sustaining interest to clinical relevance. It is expected that medical schools will continuously monitor what works and what does not work with their curricula and make the necessary adaptations as required.

  12. Basic design in architectural education in Turkey

    Directory of Open Access Journals (Sweden)

    Makaklı Elif Süyük


    Full Text Available Creative activity is one of the most significant parts of architectural education. In the architectural curriculum organisation ‘design studio’ is the unique and preeminent subject. Freshman students encounter ‘design’ first in basic design course, before they know what designing incorporates. The Basic Design is the starting point of initiating creativity in architecture education. It helps each student to understand architecture as a creative and innovative practice in the first year of education. This study analyzes the characteristics of basic design course, the topics of the course contents and its significance in the architectural curriculum in Turkey as well.

  13. Basic Research Needs for Countering Terrorism

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, W.; Michalske, T.; Trewhella, J.; Makowski, L.; Swanson, B.; Colson, S.; Hazen, T.; Roberto, F.; Franz, D.; Resnick, G.; Jacobson, S.; Valdez, J.; Gourley, P.; Tadros, M.; Sigman, M.; Sailor, M.; Ramsey, M.; Smith, B.; Shea, K.; Hrbek, J.; Rodacy, P.; Tevault, D.; Edelstein, N.; Beitz, J.; Burns, C.; Choppin, G.; Clark, S.; Dietz, M.; Rogers, R.; Traina, S.; Baldwin, D.; Thurnauer, M.; Hall, G.; Newman, L.; Miller, D.; Kung, H.; Parkin, D.; Shuh, D.; Shaw, H.; Terminello, L.; Meisel, D.; Blake, D.; Buchanan, M.; Roberto, J.; Colson, S.; Carling, R.; Samara, G.; Sasaki, D.; Pianetta, P.; Faison, B.; Thomassen, D.; Fryberger, T.; Kiernan, G.; Kreisler, M.; Morgan, L.; Hicks, J.; Dehmer, J.; Kerr, L.; Smith, B.; Mays, J.; Clark, S.


    To identify connections between technology needs for countering terrorism and underlying science issues and to recommend investment strategies to increase the impact of basic research on efforts to counter terrorism.

  14. Elliptic Polylogarithms and Basic Hypergeometric Functions

    CERN Document Server

    Passarino, Giampiero


    Multiple elliptic polylogarithms can be written as (multiple) integrals of products of basic hypergeometric functions. The latter are computable, to arbitrary precision, using a q-difference equation and q-contiguous relations.

  15. Basic Research in the United States. (United States)

    Handler, Philip


    Presents a discussion of the development of basic research in the U.S. since World War II. Topics include the creation of the federal agencies, physics and astronomy, chemistry, earth science, life science, the environment, and social science. (BB)

  16. Basic Stand Alone Medicare Hospice Beneficiary PUF (United States)

    U.S. Department of Health & Human Services — This release contains the Basic Stand Alone (BSA) Hospice Beneficiary Public Use Files (PUF) with information from Medicare hospice claims. The CMS BSA Hospice...

  17. Basic Stand Alone Medicare Inpatient Claims PUF (United States)

    U.S. Department of Health & Human Services — This release contains the Basic Stand Alone (BSA) Inpatient Public Use Files (PUF) named CMS 2008 BSA Inpatient Claims PUF with information from 2008 Medicare...

  18. Basic Stand Alone Medicare Outpatient Procedures PUF (United States)

    U.S. Department of Health & Human Services — This release contains the Basic Stand Alone (BSA) Outpatient Procedures Public Use Files (PUF) with information from Medicare outpatient claims. The CMS BSA...

  19. Basic Stand Alone Carrier Line Items PUF (United States)

    U.S. Department of Health & Human Services — This release contains the Basic Stand Alone (BSA) Carrier Line Items Public Use Files (PUF) with information from Medicare Carrier claims. The CMS BSA Carrier Line...

  20. Benchmarking polish basic metal manufacturing companies

    Directory of Open Access Journals (Sweden)

    P. Pomykalski


    Full Text Available Basic metal manufacturing companies are undergoing substantial strategic changes resulting from global changes in demand. During such periods managers should closely monitor and benchmark the financial results of companies operating in their section. Proper and timely identification of the consequences of changes in these areas may be crucial as managers seek to exploit opportunities and avoid threats. The paper examines changes in financial ratios of basic metal manufacturing companies operating in Poland in the period 2006-2011.