Glycogen Synthase Kinase-3 regulates IGFBP-1 gene transcription through the Thymine-rich Insulin Response Element

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Marquez Rodolfo

2004-09-01

Full Text Available Abstract Background Hepatic expression of several gene products involved in glucose metabolism, including phosphoenolpyruvate carboxykinase (PEPCK, glucose-6-phosphatase (G6Pase and insulin-like growth factor binding protein-1 (IGFBP-1, is rapidly and completely inhibited by insulin. This inhibition is mediated through the regulation of a DNA element present in each of these gene promoters, that we call the Thymine-rich Insulin Response Element (TIRE. The insulin signalling pathway that results in the inhibition of these gene promoters requires the activation of phosphatidylinositol 3-kinase (PI 3-kinase. However, the molecules that connect PI 3-kinase to these gene promoters are not yet fully defined. Glycogen Synthase Kinase 3 (GSK-3 is inhibited following activation of PI 3-kinase. We have shown previously that inhibitors of GSK-3 reduce the activity of two TIRE-containing gene promoters (PEPCK and G6Pase, whose products are required for gluconeogenesis. Results In this report we demonstrate that in H4IIE-C3 cells, four distinct classes of GSK-3 inhibitor mimic the effect of insulin on a third TIRE-containing gene, IGFBP-1. We identify the TIRE as the minimum requirement for inhibition by these agents, and demonstrate that the target of GSK-3 is unlikely to be the postulated TIRE-binding protein FOXO-1. Importantly, overexpression of GSK-3 in cells reduces the insulin regulation of TIRE activity as well as endogenous IGFBP-1 expression. Conclusions These results implicate GSK-3 as an intermediate in the pathway from the insulin receptor to the TIRE. Indeed, this is the first demonstration of an absolute requirement for GSK-3 inhibition in insulin regulation of gene transcription. These data support the potential use of GSK-3 inhibitors in the treatment of insulin resistant states such as Type 2 diabetes mellitus, but suggest that it will be important to identify all TIRE-containing genes to assess potential side effects of these agents.

The pat1 protein kinase controls transcription of the mating-type genes in fission yeast

DEFF Research Database (Denmark)

Nielsen, O; Egel, R; Nielsen, Olaf

1990-01-01

. This differentiation process is characterized by a transcriptional induction of the mating-type genes. Conjugation can also be induced in pat1-ts mutants by a shift to a semi-permissive temperature. The pat1 gene encodes a protein kinase, which also functions further downstream in the developmental pathway controlling...... of the mating-type genes in the zygote leads to complete loss of pat1 protein kinase activity causing entry into meiosis. Thus, pat1 can promote its own inactivation. We suggest a model according to which a stepwise inactivation of pat1 leads to sequential derepression of the processes of conjugation......The developmental programme of fission yeast brings about a transition from mitotic cell division to the dormant state of ascospores. In response to nitrogen starvation, two cells of opposite mating type conjugate to form a diploid zygote, which then undergoes meiosis and sporulation...

S -Nitrosylation inhibits the kinase activity of tomato phosphoinositide-dependent kinase 1 (PDK1)

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Liu, Jian-Zhong; Duan, Jicheng; Ni, Min; Liu, Zhen; Qiu, Wen-Li; Whitham, Steven A.; Qian, Wei-Jun

2017-09-29

classes of proteins, both in plants and in mammals, have been identified as targets of S-nitrosylation (5-9). In plants, proteins with diverse functions are S-nitrosylated at specific Cys residue(s) and their functions are either inhibited or enhanced by this modification (10-25). 3-Phosphoinositide-dependent protein kinase-1 (PDK1) and its downstream target, protein kinase B (PKB; also known as Akt), are central regulators of mammalian apoptosis (26-28). PKB is a member of the AGC family of protein kinases, which is activated by second messengers such as phospholipids and Ca2+ through PDK1. Mammalian PDK1 phosphorylates PKB to promote its function in suppressing programmed cell death (PCD) (27-30). PKB negatively regulates apoptosis by phosphorylation and inactivation of pro-apoptotic factors such as BAD and activation of anti-apoptotic factors such as CREB and IKK (27-29; and 31). Deficiency of the PDK1 gene(s) in Drosophila (32), mice (33), yeast (34-35) and tomato (36), respectively, results in lethality or severe apoptosis. PKB knockout mice display spontaneous apoptosis in several different tissues (37). In tomato, the PKB/Akt homolog, Adi3 (AvrPto-dependent Pto-interacting protein 3), physically interacts with and is phosphorylated by SlPDK1 (36). Silencing both SlPDK1 and Adi3 or treatment with a PDK1 inhibitor results in MAPKKK -dependent cell death, indicating that Adi3 functions analogously to the mammalian PKB/Akt by negatively regulating cell death via PDK1 phosphorylation (36). Yasukawa et al (38) showed that NO donors induced S-nitrosylation and inactivation of Akt/PKB kinase activity in vitro and in vivo and the mutant Akt1/PKB (C224S) was resistant to S-nitrosylation by NO and its kinase inactivation (38). Although the NO and PDK1-PKB/Akt pathways are both key regulators of cell death, the link between these two pathways has not been firmly established in plants. Here we show that the kinase activity of tomato SlPDK1 was inhibited by GSNO in a conce

Identification of Phosphoglycerate Kinase 1 (PGK1 as a reference gene for quantitative gene expression measurements in human blood RNA

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Unger Elizabeth R

2011-09-01

Full Text Available Abstract Background Blood is a convenient sample and increasingly used for quantitative gene expression measurements with a variety of diseases including chronic fatigue syndrome (CFS. Quantitative gene expression measurements require normalization of target genes to reference genes that are stable and independent from variables being tested in the experiment. Because there are no genes that are useful for all situations, reference gene selection is an essential step to any quantitative reverse transcription-PCR protocol. Many publications have described appropriate genes for a wide variety of tissues and experimental conditions, however, reference genes that may be suitable for the analysis of CFS, or human blood RNA derived from whole blood as well as isolated peripheral blood mononuclear cells (PBMCs, have not been described. Findings Literature review and analyses of our unpublished microarray data were used to narrow down the pool of candidate reference genes to six. We assayed whole blood RNA from Tempus tubes and cell preparation tube (CPT-collected PBMC RNA from 46 subjects, and used the geNorm and NormFinder algorithms to select the most stable reference genes. Phosphoglycerate kinase 1 (PGK1 was one of the optimal normalization genes for both whole blood and PBMC RNA, however, additional genes differed for the two sample types; Ribosomal protein large, P0 (RPLP0 for PBMC RNA and Peptidylprolyl isomerase B (PPIB for whole blood RNA. We also show that the use of a single reference gene is sufficient for normalization when the most stable candidates are used. Conclusions We have identified PGK1 as a stable reference gene for use with whole blood RNA and RNA derived from PBMC. When stable genes are selected it is possible to use a single gene for normalization rather than two or three. Optimal normalization will improve the ability of results from PBMC RNA to be compared with those from whole blood RNA and potentially allows comparison of

Gene disruptions indicate an essential function for the LmmCRK1 cdc2-related kinase of Leishmania mexicana.

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Mottram, J C; McCready, B P; Brown, K G; Grant, K M

1996-11-01

The generation of homozygous null mutants for the crk1 Cdc2-Related Kinase of Leishmania mexicana was attempted using targeted gene disruption. Promastigote mutants heterozygous for crk1 were readily isolated with a hyg-targeting fragment, but attempts to create null mutants by second-round transfections with a bie-targeting fragment yielded two classes of mutant, neither of which was null. First, the transfected fragment formed an episome; second, the cloned transfectants were found to contain wild-type crk1 alleles as well as hyg and ble integrations. DNA-content analysis revealed that these mutants were triploid or tetraploid. Plasticity in chromosome number following targeting has been proposed as a means by which Leishmania avoids deletion of essential genes. These data support this theory and implicate crk1 as an essential gene, validating CRK1 as a potential drug target. L mexicana transfected with a Trypanosoma brucel homologue, tbcrk1, was shown to be viable in an immcrk1 null background, thus showing complementation of function between these trypanosomatid genes. The expression of crk1 was further manipulated by engineering a six-histidine tag at the C-terminus of the kinase, allowing purification of the active complex by affinity selection on Nl(2+)-nitriloacetic acid (NTA) agarose.

Recent Progress on Liver Kinase B1 (LKB1: Expression, Regulation, Downstream Signaling and Cancer Suppressive Function

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Ren-You Gan

2014-09-01

Full Text Available Liver kinase B1 (LKB1, known as a serine/threonine kinase, has been identified as a critical cancer suppressor in many cancer cells. It is a master upstream kinase of 13 AMP-activated protein kinase (AMPK-related protein kinases, and possesses versatile biological functions. LKB1 gene is mutated in many cancers, and its protein can form different protein complexes with different cellular localizations in various cell types. The expression of LKB1 can be regulated through epigenetic modification, transcriptional regulation and post-translational modification. LKB1 dowcnstream pathways mainly include AMPK, microtubule affinity regulating kinase (MARK, salt-inducible kinase (SIK, sucrose non-fermenting protein-related kinase (SNRK and brain selective kinase (BRSK signalings, etc. This review, therefore, mainly discusses recent studies about the expression, regulation, downstream signaling and cancer suppressive function of LKB1, which can be helpful for better understanding of this molecular and its significance in cancers.

Liver kinase B1 inhibits the expression of inflammation-related genes postcontraction in skeletal muscle.

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Chen, Ting; Moore, Timothy M; Ebbert, Mark T W; McVey, Natalie L; Madsen, Steven R; Hallowell, David M; Harris, Alexander M; Char, Robin E; Mackay, Ryan P; Hancock, Chad R; Hansen, Jason M; Kauwe, John S; Thomson, David M

2016-04-15

Skeletal muscle-specific liver kinase B1 (LKB1) knockout mice (skmLKB1-KO) exhibit elevated mitogen-activated protein kinase (MAPK) signaling after treadmill running. MAPK activation is also associated with inflammation-related signaling in skeletal muscle. Since exercise can induce muscle damage, and inflammation is a response triggered by damaged tissue, we therefore hypothesized that LKB1 plays an important role in dampening the inflammatory response to muscle contraction, and that this may be due in part to increased susceptibility to muscle damage with contractions in LKB1-deficient muscle. Here we studied the inflammatory response and muscle damage with in situ muscle contraction or downhill running. After in situ muscle contractions, the phosphorylation of both NF-κB and STAT3 was increased more in skmLKB1-KO vs. wild-type (WT) muscles. Analysis of gene expression via microarray and RT-PCR shows that expression of many inflammation-related genes increased after contraction only in skmLKB1-KO muscles. This was associated with mild skeletal muscle fiber membrane damage in skmLKB1-KO muscles. Gene markers of oxidative stress were also elevated in skmLKB1-KO muscles after contraction. Using the downhill running model, we observed significantly more muscle damage after running in skmLKB1-KO mice, and this was associated with greater phosphorylation of both Jnk and STAT3 and increased expression of SOCS3 and Fos. In conclusion, we have shown that the lack of LKB1 in skeletal muscle leads to an increased inflammatory state in skeletal muscle that is exacerbated by muscle contraction. Increased susceptibility of the muscle to damage may underlie part of this response. Copyright © 2016 the American Physiological Society.

Direct Regulation of tRNA and 5S rRNA Gene Transcription by Polo-like Kinase 1

NARCIS (Netherlands)

Fairley, Jennifer A.; Mitchell, Louise E.; Berg, Tracy; Kenneth, Niall S.; von Schubert, Conrad; Sillje, Herman H. W.; Medema, Rene H.; Nigg, Erich A.; White, Robert J.

2012-01-01

Polo-like kinase Plk1 controls numerous aspects of cell-cycle progression. We show that it associates with tRNA and 5S rRNA genes and regulates their transcription by RNA polymerase Ill (pol Ill) through direct binding and phosphorylation of transcription factor Brit During interphase, Plk1 promotes

Characterization of Oligomeric and Kinetic Properties of Tomato Thymidine Kinase 1

DEFF Research Database (Denmark)

Mutahir, Zeeshan; Larsen, Nicolai Balle; Andersson, Karl-Magnus

2011-01-01

The gene encoding thymidine kinase 1 from tomato (toTK1) has in combination with azidothymidine (AZT) recently been proposed as a powerful suicide gene for anticancer gene therapy. The toTK1/AZT combination has been demonstrated to have several advantages for the treatment of glioblastomas becaus...

Cytological localization of adenosine kinase, nucleoside phosphorylase-1, and esterase-10 genes on mouse chromosome 14

International Nuclear Information System (INIS)

Samuelson, L.C.; Farber, R.A.

1985-01-01

The authors have determined the regional locations on mouse chromosome 14 of the genes for mouse adenosine kinase (ADK), nucleoside phosphorylase- 1 (NP-1), and esterase-10 (ES-10) by analysis of rearranged mouse chromosomes in gamma-irradiated Chinese hamster X mouse hybrid cell lines. Irradiated clones were screened for expression of the murine forms of these enzymes; segregant clones that expressed only one or two of the three markers were karyotyped. The patterns of enzyme expression in these segregants were correlated with the presence of rearranged chromosomes. The Adk gene was localized to bands A2 to B, Np-1 to bands B to C1, and Es-10 to bands D2 to E2

DYRK1A (Dual-Specificity Tyrosine-Phosphorylated and -Regulated Kinase 1A: A Gene with Dosage Effect During Development and Neurogenesis

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M. Dierssen

2006-01-01

Full Text Available DYRKs (dual-specificity tyrosine-regulated kinases are an emerging family of evolutionarily conserved dual-specificity kinases that play key roles in cell proliferation, survival, and development. The research in the last years suggests a relevant conserved function during neuronal development, related to proliferation and/or differentiation for DYRK1A. It is expressed in neural progenitor cells and has been proposed to participate in the signaling mechanisms that regulate dendrite differentiation. In Drosophila, disruption of the homolog minibrain gene results in flies with reduced neuroblast proliferation, decreased numbers of central brain neurons, and learning/memory deficits. Knockout DYRK1A mice are embryonic lethal, and heterozygotes show decreased viability and region-specific reductions in brain size. In humans, DYRK1A has been proposed to be involved in the neurodevelopmental alterations associated with Down syndrome. The large number of protein interaction and putative substrates described for DYRK1A suggest multiple pathways and functions to be involved in its developmental function. This review focuses on the functional role that DYRK1A plays in brain development.

The long and the short of SAD-1 kinase.

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Kim, Joanne S M; Hung, Wesley; Zhen, Mei

2010-05-01

The Ser/Thr SAD kinases are evolutionarily conserved, critical regulators of neural development. Exciting findings in recent years have significantly advanced our understanding of the mechanism through which SAD kinases regulate neural development. Mammalian SAD-A and SAD-B, activated by a master kinase LKB1, regulate microtubule dynamics and polarize neurons. In C. elegans, the sad-1 gene encodes two isoforms, namely the long and the short, which exhibit overlapping and yet distinct functions in neuronal polarity and synaptic organization. Surprisingly, our most recent findings in C. elegans revealed a SAD-1-independent LKB1 activity in neuronal polarity. We also found that the long SAD-1 isoform directly interacts with a STRADalpha pseudokinase, STRD-1, to regulate neuronal polarity and synaptic organization. We elaborate here a working model of SAD-1 in which the two isoforms dimer/oligomerize to form a functional complex, and STRD-1 clusters and localizes the SAD-1 complex to synapses. While the mechanistic difference between the vertebrate and invertebrate SAD kinases may be puzzling, a recent discovery of the functionally distinct SAD-B isoforms predicts that the difference likely arises from our incomplete understanding of the SAD kinase mechanism and may eventually be reconciled as the revelation continues.

Dinucleotide repeat polymorphism in Fms-like tyrosine kinase-1 (Flt-1 gene is not associated with preeclampsia

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Park So-Yeon

2008-07-01

Full Text Available Abstract Background Preeclampsia is a major cause of maternal and perinatal mortality and morbidity. The etiology of preeclampsia remains unclear. Recently, it was shown that misregulation of fms-like tyrosine kinase-1 (Flt-1 in the peripheral blood mononuclear cells of pregnant women results in over-expression of the soluble splice variant of Flt-1, sFlt-1, producing an additional (extra-placental source of sFlt-1 that can contribute to the etiology of preeclampsia. The aim of this study was to investigate the relationship between preeclampsia and a dinucleotide (threonine-glycine; TGn repeat polymorphism in the 3' non-coding region of the Flt-1 gene. Methods The number of the d(TGn repeats was analyzed in 170 patients with preeclampsia and in 202 normotensive pregnancies. The region containing the dinucleotide repeat polymorphism of the Flt-1 gene was amplified by polymerase chain reaction (PCR from the DNA samples and was analyzed by direct PCR sequencing. Results We found 10 alleles of the dinucleotide repeat polymorphism and designated these as allele*12 (A1 through allele*23 (A12 according to the number of the TG repeats, from 12 to 23. The frequency of the 14-repeat allele (A3 was most abundant (63.82% in preeclampsia and 69.06% in controls, followed by the 21-repeat allele (A10; 28.53% in preeclampsia and 23.76% in controls. There was no significant difference in the allele frequency between patients with preeclampsia and normal controls. The most common genotype in preeclamptic and normotensive pregnancies was heterozygous (TG14/(TG21 (41.76% and homozygous (TG14/(TG14 (45.05%, respectively. However, the genotype frequencies were not significantly different between preeclamptic patients and controls. Conclusion This is the first study to characterize the dinucleotide repeat polymorphism of the Flt-1 gene in patients with preeclampsia. We found no differences in the allele or genotype frequencies between patients with preeclampsia and

Protein kinase D1 (PKD1) influences androgen receptor (AR) function in prostate cancer cells

International Nuclear Information System (INIS)

Mak, Paul; Jaggi, Meena; Syed, Viqar; Chauhan, Subhash C.; Hassan, Sazzad; Biswas, Helal; Balaji, K.C.

2008-01-01

Protein kinase D1 (PKD1), founding member of PKD protein family, is down-regulated in advanced prostate cancer (PCa). We demonstrate that PKD1 and androgen receptor (AR) are present as a protein complex in PCa cells. PKD1 is associated with a transcriptional complex which contains AR and promoter sequence of the Prostate Specific Antigen (PSA) gene. Ectopic expression of wild type PKD1 and the kinase dead mutant PKD1 (K628W) attenuated the ligand-dependent transcriptional activation of AR in prostate cancer cells and yeast cells indicating that PKD1 can affect AR transcription activity, whereas knocking down PKD1 enhanced the ligand-dependent transcriptional activation of AR. Co-expression of kinase dead mutant with AR significantly inhibited androgen-mediated cell proliferation in both LNCaP and DU145 PC cells. Our data demonstrate for the first time that PKD1 can influence AR function in PCa cells

Association of a Network of Interferon-Stimulated Genes with a Locus Encoding a Negative Regulator of Non-conventional IKK Kinases and IFNB1

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Saloua Jeidane

2016-10-01

Full Text Available Functional genomic analysis of gene expression in mice allowed us to identify a quantitative trait locus (QTL linked in trans to the expression of 190 gene transcripts and in cis to the expression of only two genes, one of which was Ypel5. Most of the trans-expression QTL genes were interferon-stimulated genes (ISGs, and their expression in mouse macrophage cell lines was stimulated in an IFNB1-dependent manner by Ypel5 silencing. In human HEK293T cells, YPEL5 silencing enhanced the induction of IFNB1 by pattern recognition receptors and phosphorylation of TBK1/IKBKE kinases, whereas co-immunoprecipitation experiments revealed that YPEL5 interacted physically with IKBKE. We thus found that the Ypel5 gene (contained in a locus linked to a network of ISGs in mice is a negative regulator of IFNB1 production and innate immune responses that interacts functionally and physically with TBK1/IKBKE kinases.

Kinase Associated-1 Domains Drive MARK/PAR1 Kinases to Membrane Targets by Binding Acidic Phospholipids

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Moravcevic, Katarina; Mendrola, Jeannine M.; Schmitz, Karl R.; Wang, Yu-Hsiu; Slochower, David; Janmey, Paul A.; Lemmon, Mark A. (UPENN-MED)

2011-09-28

Phospholipid-binding modules such as PH, C1, and C2 domains play crucial roles in location-dependent regulation of many protein kinases. Here, we identify the KA1 domain (kinase associated-1 domain), found at the C terminus of yeast septin-associated kinases (Kcc4p, Gin4p, and Hsl1p) and human MARK/PAR1 kinases, as a membrane association domain that binds acidic phospholipids. Membrane localization of isolated KA1 domains depends on phosphatidylserine. Using X-ray crystallography, we identified a structurally conserved binding site for anionic phospholipids in KA1 domains from Kcc4p and MARK1. Mutating this site impairs membrane association of both KA1 domains and intact proteins and reveals the importance of phosphatidylserine for bud neck localization of yeast Kcc4p. Our data suggest that KA1 domains contribute to coincidence detection, allowing kinases to bind other regulators (such as septins) only at the membrane surface. These findings have important implications for understanding MARK/PAR1 kinases, which are implicated in Alzheimer's disease, cancer, and autism.

MaHog1, a Hog1-type mitogen-activated protein kinase gene, contributes to stress tolerance and virulence of the entomopathogenic fungus Metarhizium acridum.

Science.gov (United States)

Jin, Kai; Ming, Yue; Xia, Yu Xian

2012-12-01

Fungal biocontrol agents have great potential in integrated pest management. However, poor efficacy and sensitivity to various adverse factors have hampered their wide application. In eukaryotic cells, Hog1 kinase plays a critical role in stress responses. In this study, MaHog1 (GenBank accession no. EFY85878), encoding a member of the Hog1/Sty1/p38 mitogen-activated protein kinase family in Metarhizium (Me.) acridum, was identified. Targeted gene disruption was used to analyse the role of MaHog1 in virulence and tolerance of adverse factors. Mutants with MaHog1 depletion showed increased sensitivity to high osmotic stress, high temperature and oxidative stress, and exhibited remarkable resistance to cell wall-disturbing agents. These results suggest that Hog1 kinase has a conserved function in regulating multistress responses among fungi, and that MaHog1 might influence cell wall biogenesis in Me. acridum. Bioassays conducted with topical inoculation and intrahaemocoel injection revealed that MaHog1 is required for both penetration and postpenetration development of Me. acridum. MaHog1 disruption resulted in a significant reduction in virulence, likely due to the combination of a decrease in conidial germination, a reduction in appressorium formation and a decline in growth rate in insect haemolymph, which might be caused by impairing fungal tolerance of various stresses during infection.

In vitro uptakes of radiolabeled IVDU and IVFRU in herpes simplex virus type-1 thymidine kinase (HSV1-tk) gene transduced morris hepatoma cell line

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Lee, Tae Sup; Choi, Tae Hyun; Ahn, Soon Hyuk; Woo, Kwang Sun; Jeong, Wee Sup; Kwon, Hee Chung; Choi, Chang Woon; Lim, Sang Moo [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Awh, Ok Doo [College of Health Sciences, Yonsei Univ., Wonju (Korea, Republic of)

2004-02-01

The herpes simplex virus type 1 thymidine kinase gene(HSV1-tk) is an attractive candidate as a reporter gene in noninvasive reporter gene monitoring system. The HSV1-tk gene was chosen as a reporter gene, because it has been extensively studied, and there are appropriate reporter probes, substrates of HSV1-tk gene product, to apply for HSV1-tk gene imaging. We used radiolabeled 5-iodovinyl-2'-deoxyuridine (IVDU) and 5-lodovinyl-2'-fluoro-2'-deoxyuridine (IVFRU) as reporter probes for HSV1-tk gene monitoring system. We prepared HSV1-tk gene transduced Morris hepatoma cell line using retroviral vector, MOLTEN containing HSV1-tk gene. And we confirmed the HSV1-tk gene expression by Northern blotting and Western blotting. We compared in vitro uptakes of radioiodinated IVDU and IVFRU to monitor HSV1-tk gene expression in Morris hepatoma cell line (MCA) and HSV1-tk gene tranduced MCA (MAC-tk) cells until 480 minutes. We also performed correlation analysis between percentage of HSV1-tk gene tranduced MCA cell % (MCA-tk%) and uptakes of radiolabeled IVDU or IVFRU. MCA-tk cell expressed HSV1-tk mRNA and HSV1-TK protein. Two compounds showed minimal uptake in MCA, but increased uptake was observed in MCA-tk. IVDU showed 4-fold higher accumulation than IVFRU at 480 min in MCA-tk (p<0.01). Both IVDU and IVFRU uptake were linearly correlated (R{sup 2}>0.96) with increasing MCA-tk%. The rediolabeld IVDU and IVFRU showed higher specific accumulation in retrovirally HSV1-tk gene transfected Morris hepatoma cell line. Both IVDU and IVFRU could be used as good substrates for evaluation of HSV1-tk gene expression.

SlBIR3 Negatively Regulates PAMP Responses and Cell Death in Tomato

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Shuhua Huang

2017-09-01

Full Text Available Bri1-associated kinase 1 (BAK1-interacting receptor-like kinase (BIR proteins have been shown to play important roles in regulating growth and development, pathogen associated molecular pattern (PAMP-triggered immunity (PTI responses, and cell death in the model plant, Arabidopsis thaliana. We identified four BIR family members in tomato (Solanum lycopersicum, including SlBIR3, an ortholog of AtBIR3 from A. thaliana. SlBIR3 is predicted to encode a membrane localized non-arginine-aspartate (non-RD kinase that, based on protein sequence, does not have autophosphorylation activity but that can be phosphorylated in vivo. We established that SlBIR3 interacts with SlBAK1 and AtBAK1 using yeast two-hybrid assays and co-immunoprecipitation and maltose-binding protein pull down assays. We observed that SlBIR3 overexpression in tomato (cv. micro-tom and A. thaliana has weak effect on growth and development through brassinosteroid (BR signaling. SlBIR3 overexpression in A. thaliana suppressed flg22-induced defense responses, but did not affect infection with the bacterial pathogen Pseudomonas syringae (PstDC3000. This result was confirmed using virus-induced gene silencing (VIGS in tomato in conjunction with PstDC3000 infection. Overexpression of SlBIR3 in tomato (cv. micro-tom and A. thaliana resulted in enhanced susceptibility to the necrotrophic fungus Botrytis cinerea. In addition, co-silencing SlBIR3 with SlSERK3A or SlSERK3B using VIGS and the tobacco rattle virus (TRV-RNA2 vector containing fragments of both the SlSERK3 and SlBIR3 genes induced spontaneous cell death, indicating a cooperation between the two proteins in this process. In conclusion, our study revealed that SlBIR3 is the ortholog of AtBIR3 and that it participates in BR, PTI, and cell death signaling pathways.

Methylselenol, a selenium metabolite, induces cell cycle arrest in G1 phase and apoptosis via the extracellular-regulated kinase 1/2 pathway and other cancer signaling genes.

Science.gov (United States)

Zeng, Huawei; Wu, Min; Botnen, James H

2009-09-01

Methylselenol has been hypothesized to be a critical selenium (Se) metabolite for anticancer activity in vivo, and our previous study demonstrated that submicromolar methylselenol generated by incubating methionase with seleno-l-methionine inhibits the migration and invasive potential of HT1080 tumor cells. However, little is known about the association between cancer signal pathways and methylselenol's inhibition of tumor cell invasion. In this study, we demonstrated that methylselenol exposure inhibited cell growth and we used a cancer signal pathway-specific array containing 15 different signal transduction pathways involved in oncogenesis to study the effect of methylselenol on cellular signaling. Using real-time RT-PCR, we confirmed that cellular mRNA levels of cyclin-dependent kinase inhibitor 1C (CDKN1C), heme oxygenase 1, platelet/endothelial cell adhesion molecule, and PPARgamma genes were upregulated to 2.8- to 5.7-fold of the control. BCL2-related protein A1, hedgehog interacting protein, and p53 target zinc finger protein genes were downregulated to 26-52% of the control, because of methylselenol exposure. These genes are directly related to the regulation of cell cycle and apoptosis. Methylselenol increased apoptotic cells up to 3.4-fold of the control and inhibited the extracellular-regulated kinase 1/2 (ERK1/2) signaling and cellular myelocytomatosis oncogene (c-Myc) expression. Taken together, our studies identify 7 novel methylselenol responsive genes and demonstrate that methylselenol inhibits ERK1/2 pathway activation and c-Myc expression. The regulation of these genes is likely to play a key role in G1 cell cycle arrest and apoptosis, which may contribute to the inhibition of tumor cell invasion.

Thy-1 attenuates TNF-alpha-activated gene expression in mouse embryonic fibroblasts via Src family kinase.

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Bin Shan

Full Text Available Heterogeneous surface expression of Thy-1 in fibroblasts modulates inflammation and may thereby modulate injury and repair. As a paradigm, patients with idiopathic pulmonary fibrosis, a disease with pathologic features of chronic inflammation, demonstrate an absence of Thy-1 immunoreactivity within areas of fibrotic activity (fibroblast foci in contrast to the predominant Thy-1 expressing fibroblasts in the normal lung. Likewise, Thy-1 deficient mice display more severe lung fibrosis in response to an inflammatory injury than wildtype littermates. We investigated the role of Thy-1 in the response of fibroblasts to the pro-inflammatory cytokine TNF-alpha. Our study demonstrates distinct profiles of TNF-alpha-activated gene expression in Thy-1 positive (Thy-1+ and negative (Thy-1- subsets of mouse embryonic fibroblasts (MEF. TNF-alpha induced a robust activation of MMP-9, ICAM-1, and the IL-8 promoter driven reporter in Thy-1- MEFs, in contrast to only a modest increase in Thy-1+ counterparts. Consistently, ectopic expression of Thy-1 in Thy-1- MEFs significantly attenuated TNF-alpha-activated gene expression. Mechanistically, TNF-alpha activated Src family kinase (SFK only in Thy-1- MEFs. Blockade of SFK activation abrogated TNF-alpha-activated gene expression in Thy-1- MEFs, whereas restoration of SFK activation rescued the TNF-alpha response in Thy-1+ MEFs. Our findings suggest that Thy-1 down-regulates TNF-alpha-activated gene expression via interfering with SFK- and NF-kappaB-mediated transactivation. The current study provides a novel mechanistic insight to the distinct roles of fibroblast Thy-1 subsets in inflammation.

Novel receptor-like kinases in cacao contain PR-1 extracellular domains.

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Teixeira, Paulo José Pereira Lima; Costa, Gustavo Gilson Lacerda; Fiorin, Gabriel Lorencini; Pereira, Gonçalo Amarante Guimarães; Mondego, Jorge Maurício Costa

2013-08-01

Members of the pathogenesis-related protein 1 (PR-1) family are well-known markers of plant defence responses, forming part of the arsenal of the secreted proteins produced on pathogen recognition. Here, we report the identification of two cacao (Theobroma cacao L.) PR-1s that are fused to transmembrane regions and serine/threonine kinase domains, in a manner characteristic of receptor-like kinases (RLKs). These proteins (TcPR-1f and TcPR-1g) were named PR-1 receptor kinases (PR-1RKs). Phylogenetic analysis of RLKs and PR-1 proteins from cacao indicated that PR-1RKs originated from a fusion between sequences encoding PR-1 and the kinase domain of a LecRLK (Lectin Receptor-Like Kinase). Retrotransposition marks surround TcPR-1f, suggesting that retrotransposition was involved in the origin of PR-1RKs. Genes with a similar domain architecture to cacao PR-1RKs were found in rice (Oryza sativa), barrel medic (Medicago truncatula) and a nonphototrophic bacterium (Herpetosiphon aurantiacus). However, their kinase domains differed from those found in LecRLKs, indicating the occurrence of convergent evolution. TcPR-1g expression was up-regulated in the biotrophic stage of witches' broom disease, suggesting a role for PR-1RKs during cacao defence responses. We hypothesize that PR-1RKs transduce a defence signal by interacting with a PR-1 ligand. © 2013 BSPP AND JOHN WILEY & SONS LTD.

Promoter sequence of 3-phosphoglycerate kinase gene 1 of lactic acid-producing fungus rhizopus oryzae and a method of expressing a gene of interest in fungal species

Energy Technology Data Exchange (ETDEWEB)

Gao, Johnway [Richland, WA; Skeen, Rodney S [Pendleton, OR

2002-10-15

The present invention provides the promoter clone discovery of phosphoglycerate kinase gene 1 of a lactic acid-producing filamentous fungal strain, Rhizopus oryzae. The isolated promoter can constitutively regulate gene expression under various carbohydrate conditions. In addition, the present invention also provides a design of an integration vector for the transformation of a foreign gene in Rhizopus oryzae.

Mechanisms of regulation of SNF1/AMPK/SnRK1 protein kinases

Science.gov (United States)

Crozet, Pierre; Margalha, Leonor; Confraria, Ana; Rodrigues, Américo; Martinho, Cláudia; Adamo, Mattia; Elias, Carlos A.; Baena-González, Elena

2014-01-01

The SNF1 (sucrose non-fermenting 1)-related protein kinases 1 (SnRKs1) are the plant orthologs of the budding yeast SNF1 and mammalian AMPK (AMP-activated protein kinase). These evolutionarily conserved kinases are metabolic sensors that undergo activation in response to declining energy levels. Upon activation, SNF1/AMPK/SnRK1 kinases trigger a vast transcriptional and metabolic reprograming that restores energy homeostasis and promotes tolerance to adverse conditions, partly through an induction of catabolic processes and a general repression of anabolism. These kinases typically function as a heterotrimeric complex composed of two regulatory subunits, β and γ, and an α-catalytic subunit, which requires phosphorylation of a conserved activation loop residue for activity. Additionally, SNF1/AMPK/SnRK1 kinases are controlled by multiple mechanisms that have an impact on kinase activity, stability, and/or subcellular localization. Here we will review current knowledge on the regulation of SNF1/AMPK/SnRK1 by upstream components, post-translational modifications, various metabolites, hormones, and others, in an attempt to highlight both the commonalities of these essential eukaryotic kinases and the divergences that have evolved to cope with the particularities of each one of these systems. PMID:24904600

RNAi-mediated silencing of MAP kinase signalling genes (Fmk1, Hog1, and Pbs2) in Fusarium oxysporum reduces pathogenesis on tomato plants.

Science.gov (United States)

Pareek, Manish; Rajam, Manchikatla Venkat

2017-09-01

Fusarium oxysporum is a soil-borne plant fungal pathogen, and causes colossal losses in several crop plants including tomato. Effective control measures include the use of harmful fungicides and resistant cultivars, but these methods have shown limited success. Conventional methods to validate fungal pathogenic genes are labour intensive. Therefore, an alternative strategy is required to efficiently characterize unknown pathogenic genes. RNA interference (RNAi) has emerged as a potential tool to functionally characterize novel fungal pathogenic genes and also to control fungal diseases. Here, we report an efficient method to produce stable RNAi transformants of F. oxysporum using Agrobacterium-mediated transformation (AMT). We have transformed F. oxysporum spores using RNAi constructs of Fmk1, Hog1, and Pbs2 MAP kinase signalling genes. Fmk1 RNAi fungal transformants showed loss of surface hydrophobicity, reduced invasive growth on tomato fruits and hypo-virulence on tomato seedlings. Hog1 and Pbs2 RNAi transformants showed altered conidial size, and reduced invasive growth and pathogenesis. These results showed that AMT using RNAi constructs is an effective approach for dissecting the role of genes involved in pathogenesis in F. oxysporum and this could be extended for other fungal systems. The obtained knowledge can be easily translated for developing fungal resistant crops by RNAi. Copyright © 2017 British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Congenital Hypopituitarism due to POU1F1 Gene Mutation

Directory of Open Access Journals (Sweden)

Ni-Chung Lee

2011-01-01

Full Text Available POU1F1 (Pit-1; Gene ID 5449 is an anterior pituitary transcriptional factor, and POU1F1 mutation is known to cause anterior pituitary hypoplasia, growth hormone and prolactin deficiency and various degree of hypothyroidism. We report here a patient who presented with growth failure and central hypothyroidism since early infancy. However, treatment with thyroxine gave no effect and he subsequently developed calf muscle pseudohypertrophy (Kocher-Debre-Semelaigne syndrome, elevation of creatinine kinase, dilated cardiomyopathy and pericardial effusion. Final diagnosis was made by combined pituitary function test and sequencing analysis that revealed POU1F1 gene C.698T > C (p.F233S mutation. The rarity of the disease can result in delayed diagnosis and treatment.

Serum-dependent selective expression of EhTMKB1-9, a member of Entamoeba histolytica B1 family of transmembrane kinases.

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Shiteshu Shrimal

Full Text Available Entamoeba histolytica transmembrane kinases (EhTMKs can be grouped into six distinct families on the basis of motifs and sequences. Analysis of the E. histolytica genome revealed the presence of 35 EhTMKB1 members on the basis of sequence identity (>or=95%. Only six homologs were full length containing an extracellular domain, a transmembrane segment and an intracellular kinase domain. Reverse transcription followed by polymerase chain reaction (RT-PCR of the kinase domain was used to generate a library of expressed sequences. Sequencing of randomly picked clones from this library revealed that about 95% of the clones were identical with a single member, EhTMKB1-9, in proliferating cells. On serum starvation, the relative number of EhTMKB1-9 derived sequences decreased with concomitant increase in the sequences derived from another member, EhTMKB1-18. The change in their relative expression was quantified by real time PCR. Northern analysis and RNase protection assay were used to study the temporal nature of EhTMKB1-9 expression after serum replenishment of starved cells. The results showed that the expression of EhTMKB1-9 was sinusoidal. Specific transcriptional induction of EhTMKB1-9 upon serum replenishment was further confirmed by reporter gene (luciferase expression and the upstream sequence responsible for serum responsiveness was identified. EhTMKB1-9 is one of the first examples of an inducible gene in Entamoeba. The protein encoded by this member was functionally characterized. The recombinant kinase domain of EhTMKB1-9 displayed protein kinase activity. It is likely to have dual specificity as judged from its sensitivity to different kinase inhibitors. Immuno-localization showed EhTMKB1-9 to be a surface protein which decreased on serum starvation and got relocalized on serum replenishment. Cell lines expressing either EhTMKB1-9 without kinase domain, or EhTMKB1-9 antisense RNA, showed decreased cellular proliferation and target cell

Fine mapping of a dominantly inherited powdery mildew resistance major-effect QTL, Pm1.1, in cucumber identifies a 41.1 kb region containing two tandemly arrayed cysteine-rich receptor-like protein kinase genes.

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Xu, Xuewen; Yu, Ting; Xu, Ruixue; Shi, Yang; Lin, Xiaojian; Xu, Qiang; Qi, Xiaohua; Weng, Yiqun; Chen, Xuehao

2016-03-01

A dominantly inherited major-effect QTL for powdery mildew resistance in cucumber was fine mapped. Two tandemly arrayed cysteine-rich receptor-like protein kinase genes were identified as the most possible candidates. Powdery mildew (PM) is one of the most severe fungal diseases of cucumber (Cucumis sativus L.) and other cucurbit crops, but the molecular genetic mechanisms of powdery mildew resistance in cucurbits are still poorly understood. In this study, through marker-assisted backcrossing with an elite cucumber inbred line, D8 (PM susceptible), we developed a single-segment substitution line, SSSL0.7, carrying 95 kb fragment from PM resistance donor, Jin5-508, that was defined by two microsatellite markers, SSR16472 and SSR16881. A segregating population with 3600 F2 plants was developed from the SSSL0.7 × D8 mating; segregation analysis confirmed a dominantly inherited major-effect QTL, Pm1.1 in cucumber chromosome 1 underlying PM resistance in SSSL0.7. New molecular markers were developed through exploring the next generation resequenced genomes of Jin5-508 and D8. Linkage analysis and QTL mapping in a subset of the F2 plants delimited the Pm1.1 locus into a 41.1 kb region, in which eight genes were predicted. Comparative gene expression analysis revealed that two concatenated genes, Csa1M064780 and Csa1M064790 encoding the same function of a cysteine-rich receptor-like protein kinase, were the most likely candidate genes. GFP fusion protein-aided subcellular localization indicated that both candidate genes were located in the plasma membrane, but Csa1M064780 was also found in the nucleus. This is the first report of dominantly inherited PM resistance in cucumber. Results of this study will provide new insights into understanding the phenotypic and genetic mechanisms of PM resistance in cucumber. This work should also facilitate marker-assisted selection in cucumber breeding for PM resistance.

p21-activated Kinase1(PAK1) can promote ERK activation in a kinase independent manner

DEFF Research Database (Denmark)

Wang, Zhipeng; Fu, Meng; Wang, Lifeng

2013-01-01

204) although phosphorylation of b-Raf (Ser445) and c-Raf (Ser 338) remained unchanged. Furthermore, increased activation of the PAK1 activator Rac1 induced the formation of a triple complex of Rac1, PAK1 and Mek1, independent of the kinase activity of PAK1. These data suggest that PAK1 can stimulate...... MEK activity in a kinase independent manner, probably by serving as a scaffold to facilitate interaction of c-Raf....

Osabc1k8, an abc1-like kinase gene, mediates abscisic acid sensitivity and dehydration tolerance response in rice seedlings

International Nuclear Information System (INIS)

Liu, Y.; Li, T.; Yang, C.

2015-01-01

The activity of bc1 complex kinase (ABC1K) protein family, which widely exists in prokaryotes and eukaryotes, consists of 15 members in rice, and the role of this family in plants has not yet been studied in details. In this study, a novel function of OsABC1K8 (LOC-Os06g48770), a member of rice ABC1K family, was characterized. The transcript level of OsABC1K8 changes in response to salt, dehydration, cold, PEG, oxidative (H/sub 2/O/sub 2/) stresses, or abscisic acid (ABA) treatment. Overexpression of OsABC1K8 significantly increased sensitivity to dehydration and reduced sensitivity to ABA. In the contrast, RNAi transgenic lines displayed significantly reduced sensitivity to dehydration stress and increased sensitivity to ABA. Furthermore, the transcriptional levels of several ABA/stress-regulated responsive genes were suppressed in OsABC1K8 over-expressing plants under dehydration stress. In conclusion, our results suggested that OsABC1K8 is a negative regulator in response to dehydration stress through an ABA-dependent pathway. (author)

TOR1 and TOR2 are structurally and functionally similar but not identical phosphatidylinositol kinase homologues in yeast

OpenAIRE

Helliwell, S. B.; Wagner, P.; Kunz, J.; Deuter-Reinhard, M.; Henriquez, R.; Hall, M. N.

1994-01-01

The Saccharomyces cerevisiae genes TOR1 and TOR2 were originally identified by mutations that confer resistance to the immunosuppressant rapamycin. TOR2 was previously shown to encode an essential 282-kDa phosphatidylinositol kinase (PI kinase) homologue. The TOR1 gene product is also a large (281 kDa) PI kinase homologue, with 67% identity to TOR2. TOR1 is not essential, but a TOR1 TOR2 double disruption uniquely confers a cell cycle (G1) arrest as does exposure to rapamycin; disruption of T...

ZmCPK1, a calcium-independent kinase member of the Zea mays CDPK gene family, functions as a negative regulator in cold stress signalling.

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Weckwerth, Philipp; Ehlert, Britta; Romeis, Tina

2015-03-01

Calcium-dependent protein kinases (CDPKs) have been shown to play important roles in plant environmental stress signal transduction. We report on the identification of ZmCPK1 as a member of the maize (Zea mays) CDPK gene family involved in the regulation of the maize cold stress response. Based upon in silico analysis of the Z. mays cv. B73 genome, we identified that the maize CDPK gene family consists of 39 members. Two CDPK members were selected whose gene expression was either increased (Zmcpk1) or decreased (Zmcpk25) in response to cold exposure. Biochemical analysis demonstrated that ZmCPK1 displays calcium-independent protein kinase activity. The C-terminal calcium-binding domain of ZmCPK1 was sufficient to mediate calcium independency of a previously calcium-dependent enzyme in chimeric ZmCPK25-CPK1 proteins. Furthermore, co-transfection of maize mesophyll protoplasts with active full-length ZmCPK1 suppressed the expression of a cold-induced marker gene, Zmerf3 (ZmCOI6.21). In accordance, heterologous overexpression of ZmCPK1 in Arabidopsis thaliana yielded plants with altered acclimation-induced frost tolerance. Our results identify ZmCPK1 as a negative regulator of cold stress signalling in maize. © 2014 John Wiley & Sons Ltd.

Congenital hypopituitarism due to POU1F1 gene mutation.

Science.gov (United States)

Lee, Ni-Chung; Tsai, Wen-Yu; Peng, Shinn-Forng; Tung, Yi-Ching; Chien, Yin-Hsiu; Hwu, Wuh-Liang

2011-01-01

POU1F1 (Pit-1; Gene ID 5449) is an anterior pituitary transcriptional factor, and POU1F1 mutation is known to cause anterior pituitary hypoplasia, growth hormone and prolactin deficiency and various degree of hypothyroidism. We report here a patient who presented with growth failure and central hypothyroidism since early infancy. However, treatment with thyroxine gave no effect and he subsequently developed calf muscle pseudohypertrophy (Kocher-Debre-Semelaigne syndrome), elevation of creatinine kinase, dilated cardiomyopathy and pericardial effusion. Final diagnosis was made by combined pituitary function test and sequencing analysis that revealed POU1F1 gene C.698T > C (p.F233S) mutation. The rarity of the disease can result in delayed diagnosis and treatment. Copyright © 2011 Formosan Medical Association & Elsevier. Published by Elsevier B.V. All rights reserved.

Resveratrol upregulates Egr-1 expression and activity involving extracellular signal-regulated protein kinase and ternary complex factors

Energy Technology Data Exchange (ETDEWEB)

Rössler, Oliver G.; Glatzel, Daniel; Thiel, Gerald, E-mail: gerald.thiel@uks.eu

2015-03-01

Many intracellular functions have been attributed to resveratrol, a polyphenolic phytoalexin found in grapes and in other plants. Here, we show that resveratrol induces the expression of the transcription factor Egr-1 in human embryonic kidney cells. Using a chromosomally embedded Egr-1-responsive reporter gene, we show that the Egr-1 activity was significantly elevated in resveratrol-treated cells, indicating that the newly synthesized Egr-1 protein was biologically active. Stimulus-transcription coupling leading to the resveratrol-induced upregulation of Egr-1 expression and activity requires the protein kinases Raf and extracellular signal-regulated protein kinase ERK, while MAP kinase phosphatase-1 functions as a nuclear shut-off device that interrupts the signaling cascade connecting resveratrol stimulation with enhanced Egr-1 expression. On the transcriptional level, Elk-1, a key transcriptional regulator of serum response element-driven gene transcription, connects the intracellular signaling cascade elicited by resveratrol with transcription of the Egr-1 gene. These data were corroborated by the observation that stimulation of the cells with resveratrol increased the transcriptional activation potential of Elk-1. The SRE as well as the GC-rich DNA binding site of Egr-1 function as resveratrol-responsive elements. Thus, resveratrol regulates gene transcription via activation of the stimulus-regulated protein kinases Raf and ERK and the stimulus-responsive transcription factors TCF and Egr-1. - Highlights: • The plant polyphenol resveratrol upregulates Egr-1 expression and activity. • The stimulation of Egr-1 requires the protein kinases ERK and Raf. • Resveratrol treatment upregulates the transcriptional activation potential of Elk-1. • Resveratrol-induced stimulation of Egr-1 requires ternary complex factors. • Two distinct resveratrol-responsive elements were identified.

Resveratrol upregulates Egr-1 expression and activity involving extracellular signal-regulated protein kinase and ternary complex factors

International Nuclear Information System (INIS)

Rössler, Oliver G.; Glatzel, Daniel; Thiel, Gerald

2015-01-01

Many intracellular functions have been attributed to resveratrol, a polyphenolic phytoalexin found in grapes and in other plants. Here, we show that resveratrol induces the expression of the transcription factor Egr-1 in human embryonic kidney cells. Using a chromosomally embedded Egr-1-responsive reporter gene, we show that the Egr-1 activity was significantly elevated in resveratrol-treated cells, indicating that the newly synthesized Egr-1 protein was biologically active. Stimulus-transcription coupling leading to the resveratrol-induced upregulation of Egr-1 expression and activity requires the protein kinases Raf and extracellular signal-regulated protein kinase ERK, while MAP kinase phosphatase-1 functions as a nuclear shut-off device that interrupts the signaling cascade connecting resveratrol stimulation with enhanced Egr-1 expression. On the transcriptional level, Elk-1, a key transcriptional regulator of serum response element-driven gene transcription, connects the intracellular signaling cascade elicited by resveratrol with transcription of the Egr-1 gene. These data were corroborated by the observation that stimulation of the cells with resveratrol increased the transcriptional activation potential of Elk-1. The SRE as well as the GC-rich DNA binding site of Egr-1 function as resveratrol-responsive elements. Thus, resveratrol regulates gene transcription via activation of the stimulus-regulated protein kinases Raf and ERK and the stimulus-responsive transcription factors TCF and Egr-1. - Highlights: • The plant polyphenol resveratrol upregulates Egr-1 expression and activity. • The stimulation of Egr-1 requires the protein kinases ERK and Raf. • Resveratrol treatment upregulates the transcriptional activation potential of Elk-1. • Resveratrol-induced stimulation of Egr-1 requires ternary complex factors. • Two distinct resveratrol-responsive elements were identified

Myeloproliferative disorder FOP-FGFR1 fusion kinase recruits phosphoinositide-3 kinase and phospholipase Cγ at the centrosome

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Tassin Anne-Marie

2008-04-01

Full Text Available Abstract Background The t(6;8 translocation found in rare and agressive myeloproliferative disorders results in a chimeric gene encoding the FOP-FGFR1 fusion protein. This protein comprises the N-terminal region of the centrosomal protein FOP and the tyrosine kinase of the FGFR1 receptor. FOP-FGFR1 is localized at the centrosome where it exerts a constitutive kinase activity. Results We show that FOP-FGFR1 interacts with the large centrosomal protein CAP350 and that CAP350 is necessary for FOP-FGFR1 localisation at centrosome. FOP-FGFR1 activates the phosphoinositide-3 kinase (PI3K pathway. We show that p85 interacts with tyrosine 475 of FOP-FGFR1, which is located in a YXXM consensus binding sequence for an SH2 domain of p85. This interaction is in part responsible for PI3K activation. Ba/F3 cells that express FOP-FGFR1 mutated at tyrosine 475 have reduced proliferative ability. Treatment with PI3K pathway inhibitors induces death of FOP-FGFR1 expressing cells. FOP-FGFR1 also recruits phospholipase Cγ1 (PLCγ1 at the centrosome. We show that this enzyme is recruited by FOP-FGFR1 at the centrosome during interphase. Conclusion These results delineate a particular type of oncogenic mechanism by which an ectopic kinase recruits its substrates at the centrosome whence unappropriate signaling induces continuous cell growth and MPD.

Kinase impact assessment in the landscape of fusion genes that retain kinase domains: a pan-cancer study

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Kim, Pora; Jia, Peilin; Zhao, Zhongming

2018-01-01

Abstract Assessing the impact of kinase in gene fusion is essential for both identifying driver fusion genes (FGs) and developing molecular targeted therapies. Kinase domain retention is a crucial factor in kinase fusion genes (KFGs), but such a systematic investigation has not been done yet. To this end, we analyzed kinase domain retention (KDR) status in chimeric protein sequences of 914 KFGs covering 312 kinases across 13 major cancer types. Based on 171 kinase domain-retained KFGs including 101 kinases, we studied their recurrence, kinase groups, fusion partners, exon-based expression depth, short DNA motifs around the break points and networks. Our results, such as more KDR than 5′-kinase fusion genes, combinatorial effects between 3′-KDR kinases and their 5′-partners and a signal transduction-specific DNA sequence motif in the break point intronic sequences, supported positive selection on 3′-kinase fusion genes in cancer. We introduced a degree-of-frequency (DoF) score to measure the possible number of KFGs of a kinase. Interestingly, kinases with high DoF scores tended to undergo strong gene expression alteration at the break points. Furthermore, our KDR gene fusion network analysis revealed six of the seven kinases with the highest DoF scores (ALK, BRAF, MET, NTRK1, NTRK3 and RET) were all observed in thyroid carcinoma. Finally, we summarized common features of ‘effective’ (highly recurrent) kinases in gene fusions such as expression alteration at break point, redundant usage in multiple cancer types and 3′-location tendency. Collectively, our findings are useful for prioritizing driver kinases and FGs and provided insights into KFGs’ clinical implications. PMID:28013235

Differential expression of poplar sucrose nonfermenting1-related protein kinase 2 genes in response to abiotic stress and abscisic acid.

Science.gov (United States)

Yu, Xiang; Takebayashi, Arika; Demura, Taku; Ohtani, Misato

2017-09-01

Knowledge on the responses of woody plants to abiotic stress can inform strategies to breed improved tree varieties and to manage tree species for environmental conservation and the production of lignocellulosic biomass. In this study, we examined the expression patterns of poplar (Populus trichocarpa) genes encoding members of the sucrose nonfermenting1-related protein kinase 2 (SnRK2) family, which are core components of the abiotic stress response. The P. trichocarpa genome contains twelve SnRK2 genes (PtSnRK2.1- PtSnRK2.12) that can be divided into three subclasses (I-III) based on the structures of their encoded kinase domains. We found that PtSnRK2s are differentially expressed in various organs. In MS medium-grown plants, all of the PtSnRK2 genes were significantly upregulated in response to abscisic acid (ABA) treatment, whereas osmotic and salt stress treatments induced only some (four and seven, respectively) of the PtSnRK2 genes. By contrast, soil-grown plants showed increased expression of most PtSnRK2 genes under drought and salt treatments, but not under ABA treatment. In soil-grown plants, drought stress induced SnRK2 subclass II genes in all tested organs (leaves, stems, and roots), whereas subclass III genes tended to be upregulated in leaves only. These results suggest that the PtSnRK2 genes are involved in abiotic stress responses, are at least partially activated by ABA, and show organ-specific responses.

The Link between Protein Kinase CK2 and Atypical Kinase Rio1

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Konrad Kubiński

2017-02-01

Full Text Available The atypical kinase Rio1 is widespread in many organisms, ranging from Archaebacteria to humans, and is an essential factor in ribosome biogenesis. Little is known about the protein substrates of the enzyme and small-molecule inhibitors of the kinase. Protein kinase CK2 was the first interaction partner of Rio1, identified in yeast cells. The enzyme from various sources undergoes CK2-mediated phosphorylation at several sites and this modification regulates the activity of Rio1. The aim of this review is to present studies of the relationship between the two different kinases, with respect to CK2-mediated phosphorylation of Rio1, regulation of Rio1 activity, and similar susceptibility of the kinases to benzimidazole inhibitors.

Transcription factor Reb1p regulates DGK1-encoded diacylglycerol kinase and lipid metabolism in Saccharomyces cerevisiae.

Science.gov (United States)

Qiu, Yixuan; Fakas, Stylianos; Han, Gil-Soo; Barbosa, Antonio Daniel; Siniossoglou, Symeon; Carman, George M

2013-10-04

In the yeast Saccharomyces cerevisiae, the DGK1-encoded diacylglycerol kinase catalyzes the CTP-dependent phosphorylation of diacylglycerol to form phosphatidate. This enzyme, in conjunction with PAH1-encoded phosphatidate phosphatase, controls the levels of phosphatidate and diacylglycerol for phospholipid synthesis, membrane growth, and lipid droplet formation. In this work, we showed that a functional level of diacylglycerol kinase is regulated by the Reb1p transcription factor. In the electrophoretic mobility shift assay, purified recombinant Reb1p was shown to specifically bind its consensus recognition sequence (CGGGTAA, -166 to -160) in the DGK1 promoter. Analysis of cells expressing the PDGK1-lacZ reporter gene showed that mutations (GT→TG) in the Reb1p-binding sequence caused an 8.6-fold reduction in β-galactosidase activity. The expression of DGK1(reb1), a DGK1 allele containing the Reb1p-binding site mutation, was greatly lower than that of the wild type allele, as indicated by analyses of DGK1 mRNA, Dgk1p, and diacylglycerol kinase activity. In the presence of cerulenin, an inhibitor of de novo fatty acid synthesis, the dgk1Δ mutant expressing DGK1(reb1) exhibited a significant defect in growth as well as in the synthesis of phospholipids from triacylglycerol mobilization. Unlike DGK1, the DGK1(reb1) expressed in the dgk1Δ pah1Δ mutant did not result in the nuclear/endoplasmic reticulum membrane expansion, which occurs in cells lacking phosphatidate phosphatase activity. Taken together, these results indicate that the Reb1p-mediated regulation of diacylglycerol kinase plays a major role in its in vivo functions in lipid metabolism.

Gene program-specific regulation of PGC-1{alpha} activity

DEFF Research Database (Denmark)

Schmidt, Søren F; Mandrup, Susanne

2011-01-01

Peroxisome proliferator-activated receptor γ (PPARγ) coactivator 1 α (PGC-1α) activation coordinates induction of the hepatic fasting response through coactivation of numerous transcription factors and gene programs. In the June 15, 2011, issue of Genes & Development, Lustig and colleagues (pp....... 1232-1244) demonstrated that phosphorylation of PGC-1α by the p70 ribosomal protein S6 kinase 1 (S6K1) specifically interfered with the interaction between PGC-1α and HNF4α in liver and blocked the coactivation of the gluconeogenic target genes. This demonstrates how independent fine-tuning of gene...

Cloning of the rat Waf1/Cip1 gene

International Nuclear Information System (INIS)

Belinsky, S.A.; Middleton, S.K.

1994-01-01

The progression of eukaryotic cells through the cell cycle involves the sequential expression of specific genes. This process is regulated by both external and internal stimuli that prevent the cell from prematurely entering the next phase before all macromolecular events have been completed. The activation and subsequent inactivation of cyclin dependent kinases (Cdks) represent one internal stimuli required to regulate the transit of cells from one stage of the cell cycle to the next. Another member of this regulatory cascade is the p53 tumor suppressor gene, which controls a G 1 checkpoint at which the cell cycle can be arrested prior to the initiation of DNA synthesis. Following DNA damage, p53 protein levels rise, and entry into S phase is delayed, presumably to allow time for repair of the lesions. When p53 function is lost, cells containing damaged DNA template enter S phase leading to fixation and propagation of genetic alterations. Recently, evidence linking the growth-suppressing activity of p53 and inactivation of Cdks has been provided by the cloning of the Waf1/Cip1 gene. Waf1/Cip1 encodes a protein of M r 21,000 (p21), which inhibits Cdks in vitro. The overexpression of Waf1/Cip1 in cells inhibits cell growth, suggesting that p21 is a downstream mediator of p53 function. Loss of Waf1/Cip1 gene function could lead to deregulation of the cell cycle and contribute to the development of the neoplastic phenotype in tumors that do not contain mutations in the p53 gene. The purpose of the present investigation was to clone the rat Waf1/Cip1 gene,then determine the frequency for alteration of this gene in lung tumors induced by X-rays

A comprehensive protein-protein interactome for yeast PAS kinase 1 reveals direct inhibition of respiration through the phosphorylation of Cbf1.

Science.gov (United States)

DeMille, Desiree; Bikman, Benjamin T; Mathis, Andrew D; Prince, John T; Mackay, Jordan T; Sowa, Steven W; Hall, Tacie D; Grose, Julianne H

2014-07-15

Per-Arnt-Sim (PAS) kinase is a sensory protein kinase required for glucose homeostasis in yeast, mice, and humans, yet little is known about the molecular mechanisms of its function. Using both yeast two-hybrid and copurification approaches, we identified the protein-protein interactome for yeast PAS kinase 1 (Psk1), revealing 93 novel putative protein binding partners. Several of the Psk1 binding partners expand the role of PAS kinase in glucose homeostasis, including new pathways involved in mitochondrial metabolism. In addition, the interactome suggests novel roles for PAS kinase in cell growth (gene/protein expression, replication/cell division, and protein modification and degradation), vacuole function, and stress tolerance. In vitro kinase studies using a subset of 25 of these binding partners identified Mot3, Zds1, Utr1, and Cbf1 as substrates. Further evidence is provided for the in vivo phosphorylation of Cbf1 at T211/T212 and for the subsequent inhibition of respiration. This respiratory role of PAS kinase is consistent with the reported hypermetabolism of PAS kinase-deficient mice, identifying a possible molecular mechanism and solidifying the evolutionary importance of PAS kinase in the regulation of glucose homeostasis. © 2014 DeMille et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Transcription Factor Reb1p Regulates DGK1-encoded Diacylglycerol Kinase and Lipid Metabolism in Saccharomyces cerevisiae*

Science.gov (United States)

Qiu, Yixuan; Fakas, Stylianos; Han, Gil-Soo; Barbosa, Antonio Daniel; Siniossoglou, Symeon; Carman, George M.

2013-01-01

In the yeast Saccharomyces cerevisiae, the DGK1-encoded diacylglycerol kinase catalyzes the CTP-dependent phosphorylation of diacylglycerol to form phosphatidate. This enzyme, in conjunction with PAH1-encoded phosphatidate phosphatase, controls the levels of phosphatidate and diacylglycerol for phospholipid synthesis, membrane growth, and lipid droplet formation. In this work, we showed that a functional level of diacylglycerol kinase is regulated by the Reb1p transcription factor. In the electrophoretic mobility shift assay, purified recombinant Reb1p was shown to specifically bind its consensus recognition sequence (CGGGTAA, −166 to −160) in the DGK1 promoter. Analysis of cells expressing the PDGK1-lacZ reporter gene showed that mutations (GT→TG) in the Reb1p-binding sequence caused an 8.6-fold reduction in β-galactosidase activity. The expression of DGK1(reb1), a DGK1 allele containing the Reb1p-binding site mutation, was greatly lower than that of the wild type allele, as indicated by analyses of DGK1 mRNA, Dgk1p, and diacylglycerol kinase activity. In the presence of cerulenin, an inhibitor of de novo fatty acid synthesis, the dgk1Δ mutant expressing DGK1(reb1) exhibited a significant defect in growth as well as in the synthesis of phospholipids from triacylglycerol mobilization. Unlike DGK1, the DGK1(reb1) expressed in the dgk1Δ pah1Δ mutant did not result in the nuclear/endoplasmic reticulum membrane expansion, which occurs in cells lacking phosphatidate phosphatase activity. Taken together, these results indicate that the Reb1p-mediated regulation of diacylglycerol kinase plays a major role in its in vivo functions in lipid metabolism. PMID:23970552

The OXI1 kinase pathway mediates Piriformospora indica-induced growth promotion in Arabidopsis.

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Iris Camehl

2011-05-01

Full Text Available Piriformospora indica is an endophytic fungus that colonizes roots of many plant species and promotes growth and resistance to certain plant pathogens. Despite its potential use in agriculture, little is known on the molecular basis of this beneficial plant-fungal interaction. In a genetic screen for plants, which do not show a P. indica- induced growth response, we isolated an Arabidopsis mutant in the OXI1 (Oxidative Signal Inducible1 gene. OXI1 has been characterized as a protein kinase which plays a role in pathogen response and is regulated by H₂O₂ and PDK1 (3-PHOSPHOINOSITIDE-DEPENDENT PROTEIN KINASE1. A genetic analysis showed that double mutants of the two closely related PDK1.1 and PDK1.2 genes are defective in the growth response to P. indica. While OXI1 and PDK1 gene expression is upregulated in P. indica-colonized roots, defense genes are downregulated, indicating that the fungus suppresses plant defense reactions. PDK1 is activated by phosphatidic acid (PA and P. indica triggers PA synthesis in Arabidopsis plants. Under beneficial co-cultivation conditions, H₂O₂ formation is even reduced by the fungus. Importantly, phospholipase D (PLDα1 or PLDδ mutants, which are impaired in PA synthesis do not show growth promotion in response to fungal infection. These data establish that the P. indica-stimulated growth response is mediated by a pathway consisting of the PLD-PDK1-OXI1 cascade.

Sphingosine kinase-1 is a hypoxia-regulated gene that stimulates migration of human endothelial cells

International Nuclear Information System (INIS)

Schwalm, Stephanie; Doell, Frauke; Roemer, Isolde; Bubnova, Svetlana; Pfeilschifter, Josef; Huwiler, Andrea

2008-01-01

Sphingosine kinases (SK) catalyze the production of sphingosine-1-phosphate which in turn regulates cell responses such as proliferation and migration. Here, we show that exposure of the human endothelial cell line EA.hy 926 to hypoxia stimulates a increased SK-1, but not SK-2, mRNA, protein expression, and activity. This effect was due to stimulated SK-1 promoter activity which contains two putative hypoxia-inducible factor-responsive-elements (HRE). By deletion of one of the two HREs, hypoxia-induced promoter activation was abrogated. Furthermore, hypoxia upregulated the expression of HIF-1α and HIF-2α, and both contributed to SK-1 gene transcription as shown by selective depletion of HIF-1α or HIF-2α by siRNA. The hypoxia-stimulated SK-1 upregulation was functionally coupled to increased migration since the selective depletion of SK-1, but not of SK-2, by siRNAs abolished the migratory response. In summary, these data show that hypoxia upregulates SK-1 activity and results in an accelerated migratory capacity of endothelial cells. SK-1 may thus serve as an attractive therapeutic target to treat diseases associated with increased endothelial migration and angiogenesis such as cancer growth and progression

Regulation of the interaction between protein kinase C-related protein kinase 2 (PRK2) and its upstream kinase, 3-phosphoinositide-dependent protein kinase 1 (PDK1)

DEFF Research Database (Denmark)

Dettori, Rosalia; Sonzogni, Silvina; Meyer, Lucas

2009-01-01

of numerous AGC kinases, including the protein kinase C-related protein kinases (PRKs). Here we studied the docking interaction between PDK1 and PRK2 and analyzed the mechanisms that regulate this interaction. In vivo labeling of recombinant PRK2 by (32)P(i) revealed phosphorylation at two sites......, the activation loop and the Z/TM in the C-terminal extension. We provide evidence that phosphorylation of the Z/TM site of PRK2 inhibits its interaction with PDK1. Our studies further provide a mechanistic model to explain different steps in the docking interaction and regulation. Interestingly, we found...... that the mechanism that negatively regulates the docking interaction of PRK2 to the upstream kinase PDK1 is directly linked to the activation mechanism of PRK2 itself. Finally, our results indicate that the mechanisms underlying the regulation of the interaction between PRK2 and PDK1 are specific for PRK2 and do...

Phosphorylation sites of Arabidopsis MAP Kinase Substrate 1 (MKS1)

DEFF Research Database (Denmark)

Caspersen, M.B.; Qiu, J.-L.; Zhang, X.

2007-01-01

The Arabidopsis MAP kinase 4 (MPK4) substrate MKS1 was expressed in Escherichia coli and purified, full-length, 6x histidine (His)-tagged MKS1 was phosphorylated in vitro by hemagglutinin (HA)-tagged MPK4 immuno-precipitated from plants. MKS1 phosphorylation was initially verified by electrophore......The Arabidopsis MAP kinase 4 (MPK4) substrate MKS1 was expressed in Escherichia coli and purified, full-length, 6x histidine (His)-tagged MKS1 was phosphorylated in vitro by hemagglutinin (HA)-tagged MPK4 immuno-precipitated from plants. MKS1 phosphorylation was initially verified...... phosphopeptide detection. As MAP kinases generally phosphorylate serine or threonine followed by proline (Ser/Thr-Pro), theoretical masses of potentially phosphorylated peptides were calculated and mass spectrometric peaks matching these masses were fragmented and searched for a neutral-loss signal...... at approximately 98 Da indicative of phosphorylation. Additionally, mass spectrometric peaks present in the MPK4-treated MKS1, but not in the control peptide map of untreated MKS1, were fragmented. Fragmentation spectra were subjected to a MASCOT database search which identified three of the twelve Ser-Pro serine...

Akt1/protein kinase Bα is critical for ischemic and VEGF-mediated angiogenesis

OpenAIRE

Ackah, Eric; Yu, Jun; Zoellner, Stefan; Iwakiri, Yasuko; Skurk, Carsten; Shibata, Rei; Ouchi, Noriyuki; Easton, Rachael M.; Galasso, Gennaro; Birnbaum, Morris J.; Walsh, Kenneth; Sessa, William C.

2005-01-01

Akt, or protein kinase B, is a multifunctional serine-threonine protein kinase implicated in a diverse range of cellular functions including cell metabolism, survival, migration, and gene expression. However, the in vivo roles and effectors of individual Akt isoforms in signaling are not explicitly clear. Here we show that the genetic loss of Akt1, but not Akt2, in mice results in defective ischemia and VEGF-induced angiogenesis as well as severe peripheral vascular disease. Akt1 knockout (Ak...

The wheat AGC kinase TaAGC1 is a positive contributor to host resistance to the necrotrophic pathogen Rhizoctonia cerealis.

Science.gov (United States)

Zhu, Xiuliang; Yang, Kun; Wei, Xuening; Zhang, Qiaofeng; Rong, Wei; Du, Lipu; Ye, Xingguo; Qi, Lin; Zhang, Zengyan

2015-11-01

Considerable progress has been made in understanding the roles of AGC kinases in mammalian systems. However, very little is known about the roles of AGC kinases in wheat (Triticum aestivum). The necrotrophic fungus Rhizoctonia cerealis is the major pathogen of the destructive disease sharp eyespot of wheat. In this study, the wheat AGC kinase gene TaAGC1, responding to R. cerealis infection, was isolated, and its properties and role in wheat defence were characterized. R. cerealis-resistant wheat lines expressed TaAGC1 at higher levels than susceptible wheat lines. Sequence and phylogenetic analyses showed that the TaAGC1 protein is a serine/threonine kinase belonging to the NDR (nuclear Dbf2-related) subgroup of AGC kinases. Kinase activity assays proved that TaAGC1 is a functional kinase and the Asp-239 residue located in the conserved serine/threonine kinase domain of TaAGC1 is required for the kinase activity. Subcellular localization assays indicated that TaAGC1 localized in the cytoplasm and nucleus. Virus-induced TaAGC1 silencing revealed that the down-regulation of TaAGC1 transcripts significantly impaired wheat resistance to R. cerealis. The molecular characterization and responses of TaAGC1 overexpressing transgenic wheat plants indicated that TaAGC1 overexpression significantly enhanced resistance to sharp eyespot and reduced the accumulation of reactive oxygen species (ROS) in wheat plants challenged with R. cerealis. Furthermore, ROS-scavenging and certain defence-associated genes were up-regulated in resistant plants overexpressing TaAGC1 but down-regulated in susceptible knock-down plants. These results suggested that the kinase TaAGC1 positively contributes to wheat immunity to R. cerealis through regulating expression of ROS-related and defence-associated genes. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

IDC1, a pezizomycotina-specific gene that belongs to the PaMpk1 MAP kinase transduction cascade of the filamentous fungus Podospora anserina.

Science.gov (United States)

Jamet-Vierny, Corinne; Debuchy, Robert; Prigent, Magali; Silar, Philippe

2007-12-01

Components involved in the activation of the MAPK cascades in filamentous fungi are not well known. Here, we provide evidence that IDC1, a pezizomycotina-specific gene is involved along with the PaNox1 NADPH oxidase in the nuclear localization of the PaMpk1 MAP kinase, a prerequisite for MAPK activity. Mutants of IDC1 display the same phenotypes as mutants in PaNox1 and PaMpk1, i.e., lack of pigment and of aerial hyphae, female sterility, impairment in hyphal interference and inability to develop Crippled Growth cell degeneration. As observed for the PaNox1 mutant, IDC1 mutants are hypostatic to PaMpk1 mutants. IDC1 seems to play a key role in sexual reproduction. Indeed, fertility is diminished in strains with lower level of IDC1. In strains over-expressing IDC1, protoperithecia reach a later stage of development towards perithecia without fertilization; however, upon fertilization maturation of fertile perithecia is diminished and delayed. In addition, heterokaryon construction shows that IDC1 is necessary together with PaNox1 in the perithecial envelope but not in the dikaryon resulting from fertilization.

HIV-1 incorporates and proteolytically processes human NDR1 and NDR2 serine-threonine kinases

International Nuclear Information System (INIS)

Devroe, Eric; Silver, Pamela A.; Engelman, Alan

2005-01-01

Mammalian genomes encode two related serine-threonine kinases, nuclear Dbf2 related (NDR)1 and NDR2, which are homologous to the Saccharomyces cerevisiae Dbf2 kinase. Recently, a yeast genetic screen implicated the Dbf2 kinase in Ty1 retrotransposition. Since several virion-incorporated kinases regulate the infectivity of human immunodeficiency virus type 1 (HIV-1), we speculated that the human NDR1 and NDR2 kinases might play a role in the HIV-1 life cycle. Here we show that the NDR1 and NDR2 kinases were incorporated into HIV-1 particles. Furthermore, NDR1 and NDR2 were cleaved by the HIV-1 protease (PR), both within virions and within producer cells. Truncation at the PR cleavage site altered NDR2 subcellular localization and inhibited NDR1 and NDR2 enzymatic activity. These studies identify two new virion-associated host cell enzymes and suggest a novel mechanism by which HIV-1 alters the intracellular environment of human cells

Sphingosine Kinase 1 and Sphingosine-1-Phosphate Signaling in Colorectal Cancer

Directory of Open Access Journals (Sweden)

Yonghua Bao

2017-10-01

Full Text Available Sphingosine kinase 1 (Sphk1 is a highly conserved lipid kinase that phosphorylates sphingosine to form sphingosine-1-phosphate (S1P. Growing studies have demonstrated that Sphk1 is overexpressed in various types of solid cancers and can be induced by growth factors, cytokines, and carcinogens, leading to the increase of S1P production. Subsequently, the increased Sphk1/S1P facilitates cancer cell proliferation, mobility, angiogenesis, invasion, and metastasis. Therefore, Sphk1/S1P signaling plays oncogenic roles. This review summarizes the features of Sphk1/S1P signaling and their functions in colorectal cancer cell growth, tumorigenesis, and metastasis, as well as the possible underlying mechanisms.

GIT1/βPIX signaling proteins and PAK1 kinase regulate microtubule nucleation.

Science.gov (United States)

Černohorská, Markéta; Sulimenko, Vadym; Hájková, Zuzana; Sulimenko, Tetyana; Sládková, Vladimíra; Vinopal, Stanislav; Dráberová, Eduarda; Dráber, Pavel

2016-06-01

Microtubule nucleation from γ-tubulin complexes, located at the centrosome, is an essential step in the formation of the microtubule cytoskeleton. However, the signaling mechanisms that regulate microtubule nucleation in interphase cells are largely unknown. In this study, we report that γ-tubulin is in complexes containing G protein-coupled receptor kinase-interacting protein 1 (GIT1), p21-activated kinase interacting exchange factor (βPIX), and p21 protein (Cdc42/Rac)-activated kinase 1 (PAK1) in various cell lines. Immunofluorescence microscopy revealed association of GIT1, βPIX and activated PAK1 with centrosomes. Microtubule regrowth experiments showed that depletion of βPIX stimulated microtubule nucleation, while depletion of GIT1 or PAK1 resulted in decreased nucleation in the interphase cells. These data were confirmed for GIT1 and βPIX by phenotypic rescue experiments, and counting of new microtubules emanating from centrosomes during the microtubule regrowth. The importance of PAK1 for microtubule nucleation was corroborated by the inhibition of its kinase activity with IPA-3 inhibitor. GIT1 with PAK1 thus represent positive regulators, and βPIX is a negative regulator of microtubule nucleation from the interphase centrosomes. The regulatory roles of GIT1, βPIX and PAK1 in microtubule nucleation correlated with recruitment of γ-tubulin to the centrosome. Furthermore, in vitro kinase assays showed that GIT1 and βPIX, but not γ-tubulin, serve as substrates for PAK1. Finally, direct interaction of γ-tubulin with the C-terminal domain of βPIX and the N-terminal domain of GIT1, which targets this protein to the centrosome, was determined by pull-down experiments. We propose that GIT1/βPIX signaling proteins with PAK1 kinase represent a novel regulatory mechanism of microtubule nucleation in interphase cells. Copyright © 2016 Elsevier B.V. All rights reserved.

CK1δ in lymphoma: gene expression and mutation analyses and validation of CK1δ kinase activity for therapeutic application

Directory of Open Access Journals (Sweden)

Brigitte Sophia Winkler

2015-02-01

Full Text Available The prognosis of lymphoid neoplasms has improved considerably during the last decades. However, treatment response for some lymphoid neoplasms is still poor, indicating the need for new therapeutic approaches. One promising new strategy is the inhibition of kinases regulating key signal transduction pathways, which are of central importance in tumorigenesis. Kinases of the CK1 family may represent an attractive drug target since CK1 expression and/or activity are associated with the pathogenesis of malignant diseases. Over the last years efforts were taken to develop highly potent and selective CK1-specific inhibitor compounds and their therapeutic potential has now to be proved in pre-clinical trials. Therefore, we analyzed expression and mutational status of CK1δ in several cell lines representing established lymphoma entities, and also measured the mRNA expression level in primary lymphoma tissue as well as non-neoplastic blood cells. For a selection of lymphoma cell lines we furthermore determined CK1δ kinase activity and demonstrated therapeutic potential of CK1-specific inhibitors as a putative therapeutic option in the treatment of lymphoid neoplasms.

Role of casein kinase 1A1 in the biology and targeted therapy of del(5q) MDS

Science.gov (United States)

Schneider, Rebekka K.; Ademà, Vera; Heckl, Dirk; Järås, Marcus; Mallo, Mar; Lord, Allegra M.; Chu, Lisa P.; McConkey, Marie E.; Kramann, Rafael; Mullally, Ann; Bejar, Rafael; Solé, Francesc; Ebert, Benjamin L.

2014-01-01

Summary The Casein kinase 1A1 gene (CSNK1A1) is a putative tumor suppressor gene located in the common deleted region for del(5q) myelodysplastic syndrome (MDS). We generated a murine model with conditional inactivation of Csnk1a1 and found that Csnk1a1 haploinsufficiency induces hematopoietic stem cell expansion and a competitive repopulation advantage whereas homozygous deletion induces hematopoietic stem cell failure. Based on this finding, we found that heterozygous inactivation of Csnk1a1 sensitizes cells to a CSNK1 inhibitor relative to cells with two intact alleles. In addition, we identified recurrent somatic mutations in CSNK1A1 on the non-deleted allele of patients with del(5q) MDS. These studies demonstrate that CSNK1A1 plays a central role in the biology of del(5q) MDS and is a promising therapeutic target. PMID:25242043

Virus-specific DNA sequences present in cells which carry the herpes simplex virus thymidine kinase gene.

Science.gov (United States)

Minson, A C; Darby, G K; Wildy, P

1979-11-01

Two independently derived cell lines which carry the herpes simplex type 2 thymidine kinase gene have been examined for the presence of HSV-2-specific DNA sequences. Both cell lines contained 1 to 3 copies per cell of a sequence lying within map co-ordinates 0.2 to 0.4 of the HSV-2 genome. Revertant cells, which contained no detectable thymidine kinase, did not contain this DNA sequence. The failure of EcoR1-restricted HSV-2 DNA to act as a donor of the thymidine kinase gene in transformation experiments suggests that the gene lies close to the EcoR1 restriction site within this sequence at a map position of approx. 0.3. The HSV-2 kinase gene is therefore approximately co-linear with the HSV-1 gene.

MAP Kinase Cascades Regulate the Cold Response by Modulating ICE1 Protein Stability.

Science.gov (United States)

Zhao, Chunzhao; Wang, Pengcheng; Si, Tong; Hsu, Chuan-Chih; Wang, Lu; Zayed, Omar; Yu, Zheping; Zhu, Yingfang; Dong, Juan; Tao, W Andy; Zhu, Jian-Kang

2017-12-04

Mitogen-activated protein kinase cascades are important signaling modules that convert environmental stimuli into cellular responses. We show that MPK3, MPK4, and MPK6 are rapidly activated after cold treatment. The mpk3 and mpk6 mutants display increased expression of CBF genes and enhanced freezing tolerance, whereas constitutive activation of the MKK4/5-MPK3/6 cascade in plants causes reduced expression of CBF genes and hypersensitivity to freezing, suggesting that the MKK4/5-MPK3/6 cascade negatively regulates the cold response. MPK3 and MPK6 can phosphorylate ICE1, a basic-helix-loop-helix transcription factor that regulates the expression of CBF genes, and the phosphorylation promotes the degradation of ICE1. Interestingly, the MEKK1-MKK2-MPK4 pathway constitutively suppresses MPK3 and MPK6 activities and has a positive role in the cold response. Furthermore, the MAPKKK YDA and two calcium/calmodulin-regulated receptor-like kinases, CRLK1 and CRLK2, negatively modulate the cold activation of MPK3/6. Our results uncover important roles of MAPK cascades in the regulation of plant cold response. Copyright © 2017 Elsevier Inc. All rights reserved.

Inhibition of the MEK-1/p42 MAP kinase reduces aryl hydrocarbon receptor-DNA interactions

International Nuclear Information System (INIS)

Yim, Sujin; Oh, Myoungsuk; Choi, Su Mi; Park, Hyunsung

2004-01-01

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) induces expression of the cytochrome P450 1A1 gene, cyp1a1, by binding to its receptor, aryl hydrocarbon receptor (AhR). TCDD-bound AhR translocates to the nucleus and forms a heterodimer with its partner protein, AhR nuclear translocator (Arnt). The AhR/Arnt heterodimer then binds to the dioxin-response elements (DREs) in the cyp1a1 enhancer and stimulates transcription of cyp1a1. We tested whether kinase pathways are involved in this process by treating Hepa1c1c7 cells with kinase inhibitors. The MEK-1 inhibitor PD98059 reduced TCDD-induced transcription of cyp1a1. TCDD treatment results in phosphorylation of p44/p42 mitogen-activated protein kinase (MAPK), a substrate of MEK-1. Overexpression of dominant negative form of p42 MAPK suppressed TCDD-dependent transcription of a reporter gene controlled by dioxin-response elements (DREs), and pretreatment with PD98059 also blocked this transcription. PD98059 pretreatment also inhibited TCDD-induced DRE binding of the AhR/Arnt heterodimer. Together these results indicate that TCDD activates the MEK-1/p44/p42 MAPK pathway, which in turn activates AhR and so facilitates binding of AhR to the cyp1a1 DRE

Structure of the intact ATM/Tel1 kinase

Science.gov (United States)

Wang, Xuejuan; Chu, Huanyu; Lv, Mengjuan; Zhang, Zhihui; Qiu, Shuwan; Liu, Haiyan; Shen, Xuetong; Wang, Weiwu; Cai, Gang

2016-05-01

The ataxia-telangiectasia mutated (ATM) protein is an apical kinase that orchestrates the multifaceted DNA-damage response. Normally, ATM kinase is in an inactive, homodimer form and is transformed into monomers upon activation. Besides a conserved kinase domain at the C terminus, ATM contains three other structural modules, referred to as FAT, FATC and N-terminal helical solenoid. Here we report the first cryo-EM structure of ATM kinase, which is an intact homodimeric ATM/Tel1 from Schizosaccharomyces pombe. We show that two monomers directly contact head-to-head through the FAT and kinase domains. The tandem N-terminal helical solenoid tightly packs against the FAT and kinase domains. The structure suggests that ATM/Tel1 dimer interface and the consecutive HEAT repeats inhibit the binding of kinase substrates and regulators by steric hindrance. Our study provides a structural framework for understanding the mechanisms of ATM/Tel1 regulation as well as the development of new therapeutic agents.

Two CGTCA motifs and a GHF1/Pit1 binding site mediate cAMP-dependent protein kinase A regulation of human growth hormone gene expression in rat anterior pituitary GC cells.

Science.gov (United States)

Shepard, A R; Zhang, W; Eberhardt, N L

1994-01-21

We established the cis-acting elements which mediate cAMP responsiveness of the human growth hormone (hGH) gene in transiently transfected rat anterior pituitary tumor GC cells. Analysis of the intact hGH gene or hGH 5'-flanking DNA (5'-FR) coupled to the hGh cDNA or chloramphenicol acetyltransferase or luciferase genes, indicated that cAMP primarily stimulated hGH promoter activity. Cotransfection of a protein kinase A inhibitory protein cDNA demonstrated that the cAMP response was mediated by protein kinase A. Mutational analysis of the hGH promoter identified two core cAMP response element motifs (CGTCA) located at nucleotides -187/-183 (distal cAMP response element; dCRE) and -99/-95 (proximal cAMP response element; pCRE) and a pituitary-specific transcription factor (GHF1/Pit1) binding site at nucleotides -123/-112 (dGHF1) which were required for cAMP responsiveness. GHF1 was not a limiting factor, since overexpression of GHF1 in cotransfections increased basal but not forskolin induction levels. Gel shift analyses indicated that similar, ubiquitous, thermostable protein(s) specifically bound the pCRE and dCRE motifs. The CGTCA motif-binding factors were cAMP response element binding protein (CREB)/activating transcription factor-1 (ATF-1)-related, since the DNA-protein complex was competed by unlabeled CREB consensus oligonucleotide, specifically supershifted by antisera to CREB and ATF-1 but not ATF-2, and was bound by purified CREB with the same relative binding affinity (pCRE < dCRE < CREB) and mobility as the GC nuclear extract. UV cross-linking and Southwestern blot analyses revealed multiple DNA-protein interactions of which approximately 100- and approximately 45-kDa proteins were predominant; the approximately 45-kDa protein may represent CREB. These results indicate that CREB/ATF-1-related factors act coordinately with the cell-specific factor GHF1 to mediate cAMP-dependent regulation of hGH-1 gene transcription in anterior pituitary somatotrophs.

Arabidopsis Yak1 protein (AtYak1) is a dual specificity protein kinase

KAUST Repository

Kim, Dongjin; Ntui, Valentine Otang; Zhang, Nianshu; Xiong, Liming

2015-01-01

Yak1 is a member of dual-specificity Tyr phosphorylation-regulated kinases (DYRKs) that are evolutionarily conserved. The downstream targets of Yak1 and their functions are largely unknown. Here, a homologous protein AtYAK1 was identified in Arabidopsis thaliana and the phosphoprotein profiles of the wild type and an atyak1 mutant were compared on two-dimensional gel following Pro-Q Diamond phosphoprotein gel staining. Annexin1, Annexin2 and RBD were phosphorylated at serine/ threonine residues by the AtYak1 kinase. Annexin1, Annexin2 and Annexin4 were also phosphorylated at tyrosine residues. Our study demonstrated that AtYak1 is a dual specificity protein kinase in Arabidopsis that may regulate the phosphorylation status of the annexin family proteins.

Arabidopsis Yak1 protein (AtYak1) is a dual specificity protein kinase

KAUST Repository

Kim, Dongjin

2015-10-09

Yak1 is a member of dual-specificity Tyr phosphorylation-regulated kinases (DYRKs) that are evolutionarily conserved. The downstream targets of Yak1 and their functions are largely unknown. Here, a homologous protein AtYAK1 was identified in Arabidopsis thaliana and the phosphoprotein profiles of the wild type and an atyak1 mutant were compared on two-dimensional gel following Pro-Q Diamond phosphoprotein gel staining. Annexin1, Annexin2 and RBD were phosphorylated at serine/ threonine residues by the AtYak1 kinase. Annexin1, Annexin2 and Annexin4 were also phosphorylated at tyrosine residues. Our study demonstrated that AtYak1 is a dual specificity protein kinase in Arabidopsis that may regulate the phosphorylation status of the annexin family proteins.

KSR1 is a functional protein kinase capable of serine autophosphorylation and direct phosphorylation of MEK1

International Nuclear Information System (INIS)

Goettel, Jeremy A.; Liang, Dongchun; Hilliard, Valda C.; Edelblum, Karen L.; Broadus, Matthew R.; Gould, Kathleen L.; Hanks, Steven K.; Polk, D. Brent

2011-01-01

The extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK/MAPK) pathway is a highly conserved signaling pathway that regulates diverse cellular processes including differentiation, proliferation, and survival. Kinase suppressor of Ras-1 (KSR1) binds each of the three ERK cascade components to facilitate pathway activation. Even though KSR1 contains a C-terminal kinase domain, evidence supporting the catalytic function of KSR1 remains controversial. In this study, we produced recombinant wild-type or kinase-inactive (D683A/D700A) KSR1 proteins in Escherichia coli to test the hypothesis that KSR1 is a functional protein kinase. Recombinant wild-type KSR1, but not recombinant kinase-inactive KSR1, underwent autophosphorylation on serine residue(s), phosphorylated myelin basic protein (MBP) as a generic substrate, and phosphorylated recombinant kinase-inactive MAPK/ERK kinase-1 (MEK1). Furthermore, FLAG immunoprecipitates from KSR1 -/- colon epithelial cells stably expressing FLAG-tagged wild-type KSR1 (+KSR1), but not vector (+vector) or FLAG-tagged kinase-inactive KSR1 (+D683A/D700A), were able to phosphorylate kinase-inactive MEK1. Since TNF activates the ERK pathway in colon epithelial cells, we tested the biological effects of KSR1 in the survival response downstream of TNF. We found that +vector and +D683A/D700A cells underwent apoptosis when treated with TNF, whereas +KSR1 cells were resistant. However, +KSR1 cells were sensitized to TNF-induced cell loss in the absence of MEK kinase activity. These data provide clear evidence that KSR1 is a functional protein kinase, MEK1 is an in vitro substrate of KSR1, and the catalytic activities of both proteins are required for eliciting cell survival responses downstream of TNF.

Crystallization and preliminary crystallographic analysis of Arabidopsis thaliana BRI1-associated kinase 1 (BAK1) cytoplasmic domain

International Nuclear Information System (INIS)

Gao, Jian; Ma, Yuanyuan; Sun, Yuna; Zhao, Huadong; Hong, Dapeng; Yan, Liming; Lou, Zhiyong

2012-01-01

The cytoplasmic domain of BRI1-associated kinase 1 from A. thaliana has been overexpressed in E. coli, purified and crystallized. Diffraction data were collected to 2.6 Å resolution. BRI1-associated kinase 1 (BAK1) is a member of the plant receptor-like kinase (RLK) superfamily. BAK1 has been shown to initiate brassinosteroid (BR) signalling and innate immune responses in plants by forming receptor complexes with both brassinosteroid-insensitive 1 (BRI1) and flagellin-sensing 2 (FLS2). To gain a better understanding of the structural details and the mechanism of action of the BAK1 kinase domain, recombinant BAK1 cytoplasmic domain has been expressed, purified and crystallized at 291 K using PEG 3350 as a precipitant. A 2.6 Å resolution data set was collected from a single flash-cooled crystal at 100 K. This crystal belonged to space group C2, with unit-cell parameters a = 70.3, b = 75.6, c = 71.9 Å, β = 93.1°. Assuming the presence of one molecule in the asymmetric unit, the Matthews coefficient was 2.6 Å 3 Da −1

Casein kinase 1-Like 3 is required for abscisic acid regulation of ...

African Journals Online (AJOL)

Casein kinase 1-Like 3 is required for abscisic acid regulation of seed germination, root growth, and gene expression in Arabidopsis. M Wang, D Yu, X Guo, X Li, J Zhang, L Zhao, H Chang, S Hu, C Zhang, J Shi, X Liu ...

The FOX transcription factor Hcm1 regulates oxidative metabolism in response to early nutrient limitation in yeast. Role of Snf1 and Tor1/Sch9 kinases.

Science.gov (United States)

Rodríguez-Colman, María José; Sorolla, M Alba; Vall-Llaura, Núria; Tamarit, Jordi; Ros, Joaquim; Cabiscol, Elisa

2013-08-01

Within Saccharomyces cerevisiae, Hcm1is a member of the forkhead transcription factor family with a role in chromosome organization. Our group recently described its involvement in mitochondrial biogenesis and stress resistance, and reports here that Hcm1 played a role in adaptation to respiratory metabolism when glucose or nitrogen was decreased. Regulation of Hcm1 activity occurs in at least three ways: i) protein quantity, ii) subcellular localization, and iii) transcriptional activity. Transcriptional activity was measured using a reporter gene fused to a promoter that contains a binding site for Hcm1. We also analyzed the levels of several genes whose expression is known to be regulated by Hcm1 levels and the role of the main kinases known to respond to nutrients. Lack of sucrose-nonfermenting (Snf1) kinase increases cytoplasmic localization of Hcm1, whereas Δtor1 cells showed a mild increase in nuclear Hcm1. In vitro experiments showed that Snf1 clearly phosphorylates Hcm1 while Sch9 exerts a milder phosphorylation. Although in vitroTor1 does not directly phosphorylate Hcm1, in vivo rapamycin treatment increases nuclear Hcm1. We conclude that Hcm1 participates in the adaptation of cells from fermentation to respiratory metabolism during nutrient scarcity. According to our hypothesis, when nutrient levels decrease, Snf1 phosphorylates Hcm1. This results in a shift from the cytoplasm to the nucleus and increased transcriptional activity of genes involved in respiration, use of alternative energy sources, NAD synthesis and oxidative stress resistance. Copyright © 2013 Elsevier B.V. All rights reserved.

An ethanolamine kinase Eki1 affects radial growth and cell wall integrity in Trichoderma reesei.

Science.gov (United States)

He, Ronglin; Guo, Wei; Zhang, Dongyuan

2015-09-01

Ethanolamine kinase (ATP:ethanolamine O-phosphotransferase, EC 2.7.1.82) catalyzes the committed step of phosphatidylethanolamine synthesis via the CDP-ethanolamine pathway. The functions of eki genes that encode ethanolamine kinase have been intensively studied in mammalian cells, fruit flies and yeast. However, the role of the eki gene has not yet been characterized in filamentous fungi. In this study, Treki1, an ortholog of Saccharomyces cerevisiae EKI1, was identified and functionally characterized using a target gene deletion strategy in Trichoderma reesei. A Treki deletion mutant was less sensitive to cell wall stressors calcofluor white and Congo red and released fewer protoplasts during cell wall digestion than the parent strain QM9414. Further transcription analysis showed that the expression levels of five genes that encode chitin synthases were drastically increased in the ΔTreki1 mutant. The chitin content was also increased in the null mutant of Treki1 comparing to the parent strain. In addition, the ΔTreki1 mutant exhibited defects in radial growth, conidiation and the accumulation of ethanolamine. The results indicate that Treki1 plays a key role in growth and development and in the maintenance of cell wall integrity in T. reesei. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Tyrosine kinase chromosomal translocations mediate distinct and overlapping gene regulation events

International Nuclear Information System (INIS)

Kim, Hani; Gillis, Lisa C; Jarvis, Jordan D; Yang, Stuart; Huang, Kai; Der, Sandy; Barber, Dwayne L

2011-01-01

Leukemia is a heterogeneous disease commonly associated with recurrent chromosomal translocations that involve tyrosine kinases including BCR-ABL, TEL-PDGFRB and TEL-JAK2. Most studies on the activated tyrosine kinases have focused on proximal signaling events, but little is known about gene transcription regulated by these fusions. Oligonucleotide microarray was performed to compare mRNA changes attributable to BCR-ABL, TEL-PDGFRB and TEL-JAK2 after 1 week of activation of each fusion in Ba/F3 cell lines. Imatinib was used to control the activation of BCR-ABL and TEL-PDGFRB, and TEL-JAK2-mediated gene expression was examined 1 week after Ba/F3-TEL-JAK2 cells were switched to factor-independent conditions. Microarray analysis revealed between 800 to 2000 genes induced or suppressed by two-fold or greater by each tyrosine kinase, with a subset of these genes commonly induced or suppressed among the three fusions. Validation by Quantitative PCR confirmed that eight genes (Dok2, Mrvi1, Isg20, Id1, gp49b, Cxcl10, Scinderin, and collagen Vα1(Col5a1)) displayed an overlapping regulation among the three tested fusion proteins. Stat1 and Gbp1 were induced uniquely by TEL-PDGFRB. Our results suggest that BCR-ABL, TEL-PDGFRB and TEL-JAK2 regulate distinct and overlapping gene transcription profiles. Many of the genes identified are known to be involved in processes associated with leukemogenesis, including cell migration, proliferation and differentiation. This study offers the basis for further work that could lead to an understanding of the specificity of diseases caused by these three chromosomal translocations

The kinase activity of the Ser/Thr kinase BUB1 promotes TGF-β signaling.

Science.gov (United States)

Nyati, Shyam; Schinske-Sebolt, Katrina; Pitchiaya, Sethuramasundaram; Chekhovskiy, Katerina; Chator, Areeb; Chaudhry, Nauman; Dosch, Joseph; Van Dort, Marcian E; Varambally, Sooryanarayana; Kumar-Sinha, Chandan; Nyati, Mukesh Kumar; Ray, Dipankar; Walter, Nils G; Yu, Hongtao; Ross, Brian Dale; Rehemtulla, Alnawaz

2015-01-06

Transforming growth factor-β (TGF-β) signaling regulates cell proliferation and differentiation, which contributes to development and disease. Upon binding TGF-β, the type I receptor (TGFBRI) binds TGFBRII, leading to the activation of the transcription factors SMAD2 and SMAD3. Using an RNA interference screen of the human kinome and a live-cell reporter for TGFBR activity, we identified the kinase BUB1 (budding uninhibited by benzimidazoles-1) as a key mediator of TGF-β signaling. BUB1 interacted with TGFBRI in the presence of TGF-β and promoted the heterodimerization of TGFBRI and TGFBRII. Additionally, BUB1 interacted with TGFBRII, suggesting the formation of a ternary complex. Knocking down BUB1 prevented the recruitment of SMAD3 to the receptor complex, the phosphorylation of SMAD2 and SMAD3 and their interaction with SMAD4, SMAD-dependent transcription, and TGF-β-mediated changes in cellular phenotype including epithelial-mesenchymal transition (EMT), migration, and invasion. Knockdown of BUB1 also impaired noncanonical TGF-β signaling mediated by the kinases AKT and p38 MAPK (mitogen-activated protein kinase). The ability of BUB1 to promote TGF-β signaling depended on the kinase activity of BUB1. A small-molecule inhibitor of the kinase activity of BUB1 (2OH-BNPP1) and a kinase-deficient mutant of BUB1 suppressed TGF-β signaling and formation of the ternary complex in various normal and cancer cell lines. 2OH-BNPP1 administration to mice bearing lung carcinoma xenografts reduced the amount of phosphorylated SMAD2 in tumor tissue. These findings indicated that BUB1 functions as a kinase in the TGF-β pathway in a role beyond its established function in cell cycle regulation and chromosome cohesion. Copyright © 2015, American Association for the Advancement of Science.

HTLV-1 Tax protein recruitment into IKKε and TBK1 kinase complexes enhances IFN-I expression.

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Diani, Erica; Avesani, Francesca; Bergamo, Elisa; Cremonese, Giorgia; Bertazzoni, Umberto; Romanelli, Maria Grazia

2015-02-01

The Tax protein expressed by human T-cell leukemia virus type 1 (HTLV-1) plays a pivotal role in the deregulation of cellular pathways involved in the immune response, inflammation, cell survival, and cancer. Many of these effects derive from Tax multiple interactions with host factors, including the subunits of the IKK-complex that are required for NF-κB activation. IKKɛ and TBK1 are two IKK-related kinases that allow the phosphorylation of interferon regulatory factors that trigger IFN type I gene expression. We observed that IKKɛ and TBK1 recruit Tax into cellular immunocomplexes. We also found that TRAF3, which regulates cell receptor signaling effectors, forms complexes with Tax. Transactivation analyses revealed that expression of Tax, in presence of IKKɛ and TBK1, enhances IFN-β promoter activity, whereas the activation of NF-κB promoter is not modified. We propose that Tax may be recruited into the TBK1/IKKɛ complexes as a scaffolding-adaptor protein that enhances IFN-I gene expression. Copyright © 2014 Elsevier Inc. All rights reserved.

Variation in the PTEN-induced putative kinase 1 gene associated ...

Indian Academy of Sciences (India)

with the increase risk of type 2 diabetes in northern Chinese. YANCHUN QU1†∗ ... and genetic variation analysis have indicated the involvement of PINK1 gene in the ... Qualitative variables were analysed by a chi-squared test. The level of ...

Mitogen-activated protein kinase kinase 1/2 inhibition and angiotensin II converting inhibition in mice with cardiomyopathy caused by lamin A/C gene mutation

Energy Technology Data Exchange (ETDEWEB)

Muchir, Antoine, E-mail: a.muchir@institut-myologie.org [Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY (United States); Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY (United States); Wu, Wei [Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY (United States); Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY (United States); Sera, Fusako; Homma, Shunichi [Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY (United States); Worman, Howard J., E-mail: hjw14@columbia.edu [Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY (United States); Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY (United States)

2014-10-03

Highlights: • Both ACE and MEK1/2 inhibition are beneficial on cardiac function in Lmna cardiomyopathy. • MEK1/2 inhibitor has beneficial effects beyond ACE inhibition for Lmna cardiomyopathy. • These results provide further preclinical rationale for a clinical trial of a MEK1/2 inhibitor. - Abstract: Background: Mutations in the LMNA gene encoding A-type nuclear lamins can cause dilated cardiomyopathy with or without skeletal muscular dystrophy. Previous studies have shown abnormally increased extracellular signal-regulated kinase 1/2 activity in hearts of Lmna{sup H222P/H222P} mice, a small animal model. Inhibition of this abnormal signaling activity with a mitogen-activated protein kinase kinase 1/2 (MEK1/2) inhibitor has beneficial effects on heart function and survival in these mice. However, such treatment has not been examined relative to any standard of care intervention for dilated cardiomyopathy or heart failure. We therefore examined the effects of an angiotensin II converting enzyme (ACE) inhibitor on left ventricular function in Lmna{sup H222P/H222P} mice and assessed if adding a MEK1/2 inhibitor would provide added benefit. Methods: Male Lmna{sup H222P/H222P} mice were treated with the ACE inhibitor benazepril, the MEK1/2 inhibitor selumetinib or both. Transthoracic echocardiography was used to measure left ventricular diameters and fractional shortening was calculated. Results: Treatment of Lmna{sup H222P/H222P} mice with either benazepril or selumetinib started at 8 weeks of age, before the onset of detectable left ventricular dysfunction, lead to statistically significantly increased fractional shortening compared to placebo at 16 weeks of age. There was a trend towards a great value for fractional shortening in the selumetinib-treated mice. When treatment was started at 16 weeks of age, after the onset of left ventricular dysfunction, the addition of selumetinib treatment to benazepril lead to a statistically significant increase in left

Mitogen-activated protein kinase kinase 1/2 inhibition and angiotensin II converting inhibition in mice with cardiomyopathy caused by lamin A/C gene mutation

International Nuclear Information System (INIS)

Muchir, Antoine; Wu, Wei; Sera, Fusako; Homma, Shunichi; Worman, Howard J.

2014-01-01

Highlights: • Both ACE and MEK1/2 inhibition are beneficial on cardiac function in Lmna cardiomyopathy. • MEK1/2 inhibitor has beneficial effects beyond ACE inhibition for Lmna cardiomyopathy. • These results provide further preclinical rationale for a clinical trial of a MEK1/2 inhibitor. - Abstract: Background: Mutations in the LMNA gene encoding A-type nuclear lamins can cause dilated cardiomyopathy with or without skeletal muscular dystrophy. Previous studies have shown abnormally increased extracellular signal-regulated kinase 1/2 activity in hearts of Lmna H222P/H222P mice, a small animal model. Inhibition of this abnormal signaling activity with a mitogen-activated protein kinase kinase 1/2 (MEK1/2) inhibitor has beneficial effects on heart function and survival in these mice. However, such treatment has not been examined relative to any standard of care intervention for dilated cardiomyopathy or heart failure. We therefore examined the effects of an angiotensin II converting enzyme (ACE) inhibitor on left ventricular function in Lmna H222P/H222P mice and assessed if adding a MEK1/2 inhibitor would provide added benefit. Methods: Male Lmna H222P/H222P mice were treated with the ACE inhibitor benazepril, the MEK1/2 inhibitor selumetinib or both. Transthoracic echocardiography was used to measure left ventricular diameters and fractional shortening was calculated. Results: Treatment of Lmna H222P/H222P mice with either benazepril or selumetinib started at 8 weeks of age, before the onset of detectable left ventricular dysfunction, lead to statistically significantly increased fractional shortening compared to placebo at 16 weeks of age. There was a trend towards a great value for fractional shortening in the selumetinib-treated mice. When treatment was started at 16 weeks of age, after the onset of left ventricular dysfunction, the addition of selumetinib treatment to benazepril lead to a statistically significant increase in left ventricular fractional

Chronological Lifespan in Yeast Is Dependent on the Accumulation of Storage Carbohydrates Mediated by Yak1, Mck1 and Rim15 Kinases

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Tang, Yingzhi; Quan, Zhenzhen; Zhang, Zhe; Oliver, Stephen G.; Zhang, Nianshu

2016-01-01

Upon starvation for glucose or any other macronutrient, yeast cells exit from the mitotic cell cycle and acquire a set of characteristics that are specific to quiescent cells to ensure longevity. Little is known about the molecular determinants that orchestrate quiescence entry and lifespan extension. Using starvation-specific gene reporters, we screened a subset of the yeast deletion library representing the genes encoding ‘signaling’ proteins. Apart from the previously characterised Rim15, Mck1 and Yak1 kinases, the SNF1/AMPK complex, the cell wall integrity pathway and a number of cell cycle regulators were shown to be necessary for proper quiescence establishment and for extension of chronological lifespan (CLS), suggesting that entry into quiescence requires the integration of starvation signals transmitted via multiple signaling pathways. The CLS of these signaling mutants, and those of the single, double and triple mutants of RIM15, YAK1 and MCK1 correlates well with the amount of storage carbohydrates but poorly with transition-phase cell cycle status. Combined removal of the glycogen and trehalose biosynthetic genes, especially GSY2 and TPS1, nearly abolishes the accumulation of storage carbohydrates and severely reduces CLS. Concurrent overexpression of GSY2 and TSL1 or supplementation of trehalose to the growth medium ameliorates the severe CLS defects displayed by the signaling mutants (rim15Δyak1Δ or rim15Δmck1Δ). Furthermore, we reveal that the levels of intracellular reactive oxygen species are cooperatively controlled by Yak1, Rim15 and Mck1, and the three kinases mediate the TOR1-regulated accumulation of storage carbohydrates and CLS extension. Our data support the hypothesis that metabolic reprogramming to accumulate energy stores and the activation of anti-oxidant defence systems are coordinated by Yak1, Rim15 and Mck1 kinases to ensure quiescence entry and lifespan extension in yeast. PMID:27923067

Sphingosine kinase 1 is required for mesothelioma cell proliferation: role of histone acetylation.

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Satish Kalari

Full Text Available Malignant pleural mesothelioma (MPM is a devastating disease with an overall poor prognosis. Despite the recent advances in targeted molecular therapies, there is a clear and urgent need for the identification of novel mesothelioma targets for the development of highly efficacious therapeutics.In this study, we report that the expression of Sphingosine Kinase 1 (SphK1 protein was preferentially elevated in MPM tumor tissues (49 epithelioid and 13 sarcomatoid compared to normal tissue (n = 13. In addition, we also observed significantly elevated levels of SphK1 and SphK2 mRNA and SphK1 protein expression in MPM cell lines such as H2691, H513 and H2461 compared to the non-malignant mesothelial Met5 cells. The underlying mechanism appears to be mediated by SphK1 induced upregulation of select gene transcription programs such as that of CBP/p300 and PCAF, two histone acetyl transferases (HAT, and the down regulation of cell cycle dependent kinase inhibitor genes such as p27Kip1 and p21Cip1. In addition, using immunoprecipitates of anti-acetylated histone antibody from SphK inhibitor, SphK-I2 treated Met5A and H2691 cell lysates, we also showed activation of other cell proliferation related genes, such as Top2A (DNA replication, AKB (chromosome remodeling and mitotic spindle formation, and suppression of p21 CIP1 and p27KIP1. The CDK2, HAT1 and MYST2 were, however, unaffected in the above study. Using SphK inhibitor and specific siRNA targeting either SphK1 or SphK2, we also unequivocally established that SphK1, but not SphK2, promotes H2691 mesothelioma cell proliferation. Using a multi-walled carbon nanotubes induced peritoneal mesothelioma mouse model, we showed that the SphK1-/- null mice exhibited significantly less inflammation and granulamatous nodules compared to their wild type counterparts.The lipid kinase SphK1 plays a positive and essential role in the growth and development of malignant mesothelioma and is therefore a likely

A Ser/Thr protein kinase phosphorylates MA-ACS1 (Musa acuminata 1-aminocyclopropane-1-carboxylic acid synthase 1) during banana fruit ripening.

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Choudhury, Swarup Roy; Roy, Sujit; Sengupta, Dibyendu N

2012-08-01

1-Aminocyclopropane-1-carboxylic acid synthase (ACS) catalyzes the rate-limiting step in ethylene biosynthesis during ripening. ACS isozymes are regulated both transcriptionally and post-translationally. However, in banana, an important climacteric fruit, little is known about post-translational regulation of ACS. Here, we report the post-translational modification of MA-ACS1 (Musa acuminata ACS1), a ripening inducible isozyme in the ACS family, which plays a key role in ethylene biosynthesis during banana fruit ripening. Immunoprecipitation analyses of phospholabeled protein extracts from banana fruit using affinity-purified anti-MA-ACS1 antibody have revealed phosphorylation of MA-ACS1, particularly in ripe fruit tissue. We have identified the induction of a 41-kDa protein kinase activity in pulp at the onset of ripening. The 41-kDa protein kinase has been identified as a putative protein kinase by MALDI-TOF/MS analysis. Biochemical analyses using partially purified protein kinase fraction from banana fruit have identified the protein kinase as a Ser/Thr family of protein kinase and its possible involvement in MA-ACS1 phosphorylation during ripening. In vitro phosphorylation analyses using synthetic peptides and site-directed mutagenized recombinant MA-ACS1 have revealed that serine 476 and 479 residues at the C-terminal region of MA-ACS1 are phosphorylated. Overall, this study provides important novel evidence for in vivo phosphorylation of MA-ACS1 at the molecular level as a possible mechanism of post-translational regulation of this key regulatory protein in ethylene signaling pathway in banana fruit during ripening.

Interaction of human biliverdin reductase with Akt/protein kinase B and phosphatidylinositol-dependent kinase 1 regulates glycogen synthase kinase 3 activity: a novel mechanism of Akt activation.

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Miralem, Tihomir; Lerner-Marmarosh, Nicole; Gibbs, Peter E M; Jenkins, Jermaine L; Heimiller, Chelsea; Maines, Mahin D

2016-08-01

Biliverdin reductase A (BVR) and Akt isozymes have overlapping pleiotropic functions in the insulin/PI3K/MAPK pathway. Human BVR (hBVR) also reduces the hemeoxygenase activity product biliverdin to bilirubin and is directly activated by insulin receptor kinase (IRK). Akt isoenzymes (Akt1-3) are downstream of IRK and are activated by phosphatidylinositol-dependent kinase 1 (PDK1) phosphorylating T(308) before S(473) autophosphorylation. Akt (RxRxxSF) and PDK1 (RFxFPxFS) binding motifs are present in hBVR. Phosphorylation of glycogen synthase kinase 3 (GSK3) isoforms α/β by Akts inhibits their activity; nonphosphorylated GSK3β inhibits activation of various genes. We examined the role of hBVR in PDK1/Akt1/GSK3 signaling and Akt1 in hBVR phosphorylation. hBVR activates phosphorylation of Akt1 at S(473) independent of hBVR's kinase competency. hBVR and Akt1 coimmunoprecipitated, and in-cell Förster resonance energy transfer (FRET) and glutathione S-transferase pulldown analyses identified Akt1 pleckstrin homology domain as the interactive domain. hBVR activates phosphorylation of Akt1 at S(473) independent of hBVR's kinase competency. Site-directed mutagenesis, mass spectrometry, and kinetic analyses identified S(230) in hBVR (225)RNRYLSF sequence as the Akt1 target. Underlined amino acids are the essential residues of the signaling motifs. In cells, hBVR-activated Akt1 increased both GSK3α/β and forkhead box of the O class transcription class 3 (FoxO3) phosphorylation and inhibited total GSK3 activity; depletion of hBVR released inhibition and stimulated glucose uptake. Immunoprecipitation analysis showed that PDK1 and hBVR interact through hBVR's PDK1 binding (161)RFGFPAFS motif and formation of the PDK1/hBVR/Akt1 complex. sihBVR blocked complex formation. Findings identify hBVR as a previously unknown coactivator of Akt1 and as a key mediator of Akt1/GSK3 pathway, as well as define a key role for hBVR in Akt1 activation by PDK1.-Miralem, T., Lerner

Heterochromatin protein 1 gamma and IκB kinase alpha interdependence during tumour necrosis factor gene transcription elongation in activated macrophages.

Science.gov (United States)

Thorne, James L; Ouboussad, Lylia; Lefevre, Pascal F

2012-09-01

IκB kinase α (IKKα) is part of the cytoplasmic IKK complex regulating nuclear factor-κB (NF-κB) release and translocation into the nucleus in response to pro-inflammatory signals. IKKα can also be recruited directly to the promoter of NF-κB-dependent genes by NF-κB where it phosphorylates histone H3 at serine 10, triggering recruitment of the bromodomain-containing protein 4 and the positive transcription elongation factor b. Herein, we report that IKKα travels with the elongating form of ribonucleic acid polymerase II together with heterochromatin protein 1 gamma (HP1γ) at NF-κB-dependent genes in activated macrophages. IKKα binds to and phosphorylates HP1γ, which in turn controls IKKα binding to chromatin and phosphorylation of the histone variant H3.3 at serine 31 within transcribing regions. Downstream of transcription end sites, IKKα accumulates with its inhibitor the CUE-domain containing protein 2, suggesting a link between IKKα inactivation and transcription termination.

A Single-Nucleotide Polymorphism in Serine-Threonine Kinase 11, the Gene Encoding Liver Kinase B1, Is a Risk Factor for Multiple Sclerosis

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Anne I. Boullerne

2015-02-01

Full Text Available We identified a family in which five siblings were diagnosed with multiple sclerosis (MS or clinically isolated syndrome. Several women in the maternal lineage have comorbidities typically associated with Peutz Jeghers Syndrome, a rare autosomal-dominant disease caused by mutations in the serine-threonine-kinase 11 (STK11 gene, which encodes liver kinase B1. Sequence analysis of DNA from one sibling identified a single-nucleotide polymorphism (SNP within STK11 intron 5. This SNP (dbSNP ID: rs9282860 was identified by TaqMan polymerase chain reaction (PCR assays in DNA samples available from two other siblings. Further screening was carried out in samples from 654 relapsing-remitting MS patients, 100 primary progressive MS patients, and 661 controls. The STK11-SNP has increased frequency in all female patients versus controls (odds ratio = 1.66, 95% CI = 1.05, 2.64, p = .032. The STK11-SNP was not associated with disease duration or onset; however, it was significantly associated with reduced severity (assessed by MS severity scores, with the lowest scores in patients who also harbored the HLA-DRB1*1501 allele. In vitro studies showed that peripheral blood mononuclear cells from members of the family were more sensitive to the mitochondrial inhibitor metformin than cells from MS patients with the major STK11 allele. The increased association of SNP rs9282860 in women with MS defines this variant as a genetic risk factor. The lower disease severity observed in the context of HLA-DRB1*1501 combined with limited in vitro studies raises the provocative possibility that cells harboring the STK11-SNP could be targeted by drugs which increase metabolic stress.

Haplotypes in the gene encoding protein kinase c-beta (PRKCB1) on chromosome 16 are associated with autism.

Science.gov (United States)

Philippi, A; Roschmann, E; Tores, F; Lindenbaum, P; Benajou, A; Germain-Leclerc, L; Marcaillou, C; Fontaine, K; Vanpeene, M; Roy, S; Maillard, S; Decaulne, V; Saraiva, J P; Brooks, P; Rousseau, F; Hager, J

2005-10-01

Autism is a developmental disorder characterized by impairments in social interaction and communication associated with repetitive patterns of interest or behavior. Autism is highly influenced by genetic factors. Genome-wide linkage and candidate gene association approaches have been used to try and identify autism genes. A few loci have repeatedly been reported linked to autism. Several groups reported evidence for linkage to a region on chromosome 16p. We have applied a direct physical identity-by-descent (IBD) mapping approach to perform a high-density (0.85 megabases) genome-wide linkage scan in 116 families from the AGRE collection. Our results confirm linkage to a region on chromosome 16p with autism. High-resolution single-nucleotide polymorphism (SNP) genotyping and analysis of this region show that haplotypes in the protein kinase c-beta gene are strongly associated with autism. An independent replication of the association in a second set of 167 trio families with autism confirmed our initial findings. Overall, our data provide evidence that the PRKCB1 gene on chromosome 16p may be involved in the etiology of autism.

SMALL GRAIN 1, which encodes a mitogen-activated protein kinase kinase 4, influences grain size in rice.

Science.gov (United States)

Duan, Penggen; Rao, Yuchun; Zeng, Dali; Yang, Yaolong; Xu, Ran; Zhang, Baolan; Dong, Guojun; Qian, Qian; Li, Yunhai

2014-02-01

Although grain size is one of the most important components of grain yield, little information is known about the mechanisms that determine final grain size in crops. Here we characterize rice small grain1 (smg1) mutants, which exhibit small and light grains, dense and erect panicles and comparatively slightly shorter plants. The short grain and panicle phenotypes of smg1 mutants are caused by a defect in cell proliferation. The smg1 mutations were identified, using a map-based cloning approach, in mitogen-activated protein kinase kinase 4 (OsMKK4). Relatively higher expression of OsMKK4/SMG1 was detected in younger organs than in older ones, consistent with its role in cell proliferation. Green fluorescent protein (GFP)-OsMKK4/SMG1 fusion proteins appear to be distributed ubiquitously in plant cells. Further results revealed that OsMKK4 influenced brassinosteroid (BR) responses and the expression of BR-related genes. Thus, our findings have identified OsMKK4 as a factor for grain size, and suggest a possible link between the MAPK pathways and BRs in grain growth. © 2013 The Authors The Plant Journal © 2013 John Wiley & Sons Ltd.

Growth arrest- and DNA-damage-inducible 45beta gene inhibits c-Jun N-terminal kinase and extracellular signal-regulated kinase and decreases IL-1beta-induced apoptosis in insulin-producing INS-1E cells

DEFF Research Database (Denmark)

Larsen, Claus Morten; Døssing, M G; Papa, S

2006-01-01

IL-1beta is a candidate mediator of apoptotic beta cell destruction, a process that leads to type 1 diabetes and progression of type 2 diabetes. IL-1beta activates beta cell c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK) and p38, all of which are members of the mitogen...

STOREKEEPER RELATED1/G-Element Binding Protein (STKR1) Interacts with Protein Kinase SnRK11[OPEN

Science.gov (United States)

Nietzsche, Madlen; Guerra, Tiziana; Fernie, Alisdair R.

2018-01-01

Sucrose nonfermenting related kinase1 (SnRK1) is a conserved energy sensor kinase that regulates cellular adaptation to energy deficit in plants. Activation of SnRK1 leads to the down-regulation of ATP-consuming biosynthetic processes and the stimulation of energy-generating catabolic reactions by transcriptional reprogramming and posttranslational modifications. Although considerable progress has been made during the last years in understanding the SnRK1 signaling pathway, many of its components remain unidentified. Here, we show that the catalytic α-subunits KIN10 and KIN11 of the Arabidopsis (Arabidopsis thaliana) SnRK1 complex interact with the STOREKEEPER RELATED1/G-Element Binding Protein (STKR1) inside the plant cell nucleus. Overexpression of STKR1 in transgenic Arabidopsis plants led to reduced growth, a delay in flowering, and strongly attenuated senescence. Metabolite profiling revealed that the transgenic lines exhausted their carbohydrates during the dark period to a greater extent than the wild type and accumulated a range of amino acids. At the global transcriptome level, genes affected by STKR1 overexpression were broadly associated with systemic acquired resistance, and transgenic plants showed enhanced resistance toward a virulent strain of the biotrophic oomycete pathogen Hyaloperonospora arabidopsidis Noco2. We discuss a possible connection of STKR1 function, SnRK1 signaling, and plant immunity. PMID:29192025

Analysis of the complexity of protein kinases within the phloem sieve tube system. Characterization of Cucurbita maxima calmodulin-like domain protein kinase 1.

Science.gov (United States)

Yoo, Byung-Chun; Lee, Jung-Youn; Lucas, William J

2002-05-03

In angiosperms, functional, mature sieve elements lack nuclei, vacuoles, ribosomes, and most of the endomembrane network. In this study, the complexity, number, and nature of protein kinases within the phloem sap of Cucurbita maxima were investigated to test the hypothesis that the enucleate sieve tube system utilizes a simplified signal transduction network. Supporting evidence was obtained in that only five putative protein kinases (three calcium-independent and two calcium-dependent protein kinases) were detected within the phloem sap extracted from stem tissues. Biochemical methods were used to purify one such calcium-dependent protein kinase. The gene for this C. maxima calmodulin-like domain protein kinase 1 (CmCPK1), was cloned using peptide microsequences. A combination of mass spectrometry, peptide fingerprinting, and amino-terminal sequencing established that, in the phloem sap, CmCPK1 exists as an amino-terminally cleaved protein. A second highly homologous isoform, CmCPK2, was identified, but although transcripts could be detected in the companion cells, peptide fingerprint analysis suggested that CmCPK2 does not enter the phloem sap. Potential substrates for CmCPK1, within the phloem sap, were also detected using an on-membrane phosphorylation assay. Entry of CmCPK1 into sieve elements via plasmodesmata and the potential roles played by these phloem protein kinases are discussed.

Quantitative mass spectrometry analysis reveals similar substrate consensus motif for human Mps1 kinase and Plk1.

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Zhen Dou

Full Text Available BACKGROUND: Members of the Mps1 kinase family play an essential and evolutionarily conserved role in the spindle assembly checkpoint (SAC, a surveillance mechanism that ensures accurate chromosome segregation during mitosis. Human Mps1 (hMps1 is highly phosphorylated during mitosis and many phosphorylation sites have been identified. However, the upstream kinases responsible for these phosphorylations are not presently known. METHODOLOGY/PRINCIPAL FINDINGS: Here, we identify 29 in vivo phosphorylation sites in hMps1. While in vivo analyses indicate that Aurora B and hMps1 activity are required for mitotic hyper-phosphorylation of hMps1, in vitro kinase assays show that Cdk1, MAPK, Plk1 and hMps1 itself can directly phosphorylate hMps1. Although Aurora B poorly phosphorylates hMps1 in vitro, it positively regulates the localization of Mps1 to kinetochores in vivo. Most importantly, quantitative mass spectrometry analysis demonstrates that at least 12 sites within hMps1 can be attributed to autophosphorylation. Remarkably, these hMps1 autophosphorylation sites closely resemble the consensus motif of Plk1, demonstrating that these two mitotic kinases share a similar substrate consensus. CONCLUSIONS/SIGNIFICANCE: hMps1 kinase is regulated by Aurora B kinase and its autophosphorylation. Analysis on hMps1 autophosphorylation sites demonstrates that hMps1 has a substrate preference similar to Plk1 kinase.

Evolutionary diversification of plant shikimate kinase gene duplicates.

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Geoffrey Fucile

2008-12-01

Full Text Available Shikimate kinase (SK; EC 2.7.1.71 catalyzes the fifth reaction of the shikimate pathway, which directs carbon from the central metabolism pool to a broad range of secondary metabolites involved in plant development, growth, and stress responses. In this study, we demonstrate the role of plant SK gene duplicate evolution in the diversification of metabolic regulation and the acquisition of novel and physiologically essential function. Phylogenetic analysis of plant SK homologs resolves an orthologous cluster of plant SKs and two functionally distinct orthologous clusters. These previously undescribed genes, shikimate kinase-like 1 (SKL1 and -2 (SKL2, do not encode SK activity, are present in all major plant lineages, and apparently evolved under positive selection following SK gene duplication over 400 MYA. This is supported by functional assays using recombinant SK, SKL1, and SKL2 from Arabidopsis thaliana (At and evolutionary analyses of the diversification of SK-catalytic and -substrate binding sites based on theoretical structure models. AtSKL1 mutants yield albino and novel variegated phenotypes, which indicate SKL1 is required for chloroplast biogenesis. Extant SKL2 sequences show a strong genetic signature of positive selection, which is enriched in a protein-protein interaction module not found in other SK homologs. We also report the first kinetic characterization of plant SKs and show that gene expression diversification among the AtSK inparalogs is correlated with developmental processes and stress responses. This study examines the functional diversification of ancient and recent plant SK gene duplicates and highlights the utility of SKs as scaffolds for functional innovation.

A Genetic Screen Identifies a Requirement for Cysteine-Rich-Receptor-Like Kinases in Rice NH1 (OsNPR1-Mediated Immunity.

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Mawsheng Chern

2016-05-01

Full Text Available Systemic acquired resistance, mediated by the Arabidopsis NPR1 gene and the rice NH1 gene, confers broad-spectrum immunity to diverse pathogens. NPR1 and NH1 interact with TGA transcription factors to activate downstream defense genes. Despite the importance of this defense response, the signaling components downstream of NPR1/NH1 and TGA proteins are poorly defined. Here we report the identification of a rice mutant, snim1, which suppresses NH1-mediated immunity and demonstrate that two genes encoding previously uncharacterized cysteine-rich-receptor-like kinases (CRK6 and CRK10, complement the snim1 mutant phenotype. Silencing of CRK6 and CRK10 genes individually in the parental genetic background recreates the snim1 phenotype. We identified a rice mutant in the Kitaake genetic background with a frameshift mutation in crk10; this mutant also displays a compromised immune response highlighting the important role of crk10. We also show that elevated levels of NH1 expression lead to enhanced CRK10 expression and that the rice TGA2.1 protein binds to the CRK10 promoter. These experiments demonstrate a requirement for CRKs in NH1-mediated immunity and establish a molecular link between NH1 and induction of CRK10 expression.

Crizotinib-Resistant ROS1 Mutations Reveal a Predictive Kinase Inhibitor Sensitivity Model for ROS1- and ALK-Rearranged Lung Cancers.

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Facchinetti, Francesco; Loriot, Yohann; Kuo, Mei-Shiue; Mahjoubi, Linda; Lacroix, Ludovic; Planchard, David; Besse, Benjamin; Farace, Françoise; Auger, Nathalie; Remon, Jordi; Scoazec, Jean-Yves; André, Fabrice; Soria, Jean-Charles; Friboulet, Luc

2016-12-15

The identification of molecular mechanisms conferring resistance to tyrosine kinase inhibitor (TKI) is a key step to improve therapeutic results for patients with oncogene addiction. Several alterations leading to EGFR and anaplastic lymphoma kinase (ALK) resistance to TKI therapy have been described in non-small cell lung cancer (NSCLC). Only two mutations in the ROS1 kinase domain responsible for crizotinib resistance have been described in patients thus far. A patient suffering from a metastatic NSCLC harboring an ezrin (EZR)-ROS1 fusion gene developed acquired resistance to the ALK/ROS1 inhibitor crizotinib. Molecular analysis (whole-exome sequencing, CGH) and functional studies were undertaken to elucidate the mechanism of resistance. Based on this case, we took advantage of the structural homology of ROS1 and ALK to build a predictive model for drug sensitivity regarding future ROS1 mutations. Sequencing revealed a dual mutation, S1986Y and S1986F, in the ROS1 kinase domain. Functional in vitro studies demonstrated that ROS1 harboring either the S1986Y or the S1986F mutation, while conferring resistance to crizotinib and ceritinib, was inhibited by lorlatinib (PF-06463922). The patient's clinical response confirmed the potency of lorlatinib against S1986Y/F mutations. The ROS1 S1986Y/F and ALK C1156Y mutations are homologous and displayed similar sensitivity patterns to ALK/ROS1 TKIs. We extended this analogy to build a model predicting TKI efficacy against potential ROS1 mutations. Clinical evidence, in vitro validation, and homology-based prediction provide guidance for treatment decision making for patients with ROS1-rearranged NSCLC who progressed on crizotinib. Clin Cancer Res; 22(24); 5983-91. ©2016 AACR. ©2016 American Association for Cancer Research.

TANK-Binding Kinase 1 (TBK1 Isoforms Negatively Regulate Type I Interferon Induction by Inhibiting TBK1-IRF3 Interaction and IRF3 Phosphorylation

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Yi Wei Hu

2018-01-01

Full Text Available TANK-binding kinase 1 (TBK1 is an important serine/threonine-protein kinase that mediates phosphorylation and nuclear translocation of IRF3, which contributes to induction of type I interferons (IFNs in the innate antiviral response. In mammals, TBK1 spliced isoform negatively regulates the virus-triggered IFN-β signaling pathway by disrupting the interaction between retinoic acid-inducible gene I (RIG-I and mitochondria antiviral-signaling protein (MAVS. However, it is still unclear whether alternative splicing patterns and the function of TBK1 isoform(s exist in teleost fish. In this study, we identify two alternatively spliced isoforms of TBK1 from zebrafish, termed TBK1_tv1 and TBK1_tv2. Both TBK1_tv1 and TBK1_tv2 contain an incomplete STKc_TBK1 domain. Moreover, the UBL_TBK1_like domain is also missing for TBK1_tv2. TBK1_tv1 and TBK1_tv2 are expressed in zebrafish larvae. Overexpression of TBK1_tv1 and TBK1_tv2 inhibits RIG-I-, MAVS-, TBK1-, and IRF3-mediated activation of IFN promoters in response to spring viremia of carp virus infection. Also, TBK1_tv1 and TBK1_tv2 inhibit expression of IFNs and IFN-stimulated genes induced by MAVS and TBK1. Mechanistically, TBK1_tv1 and TBK1_tv2 competitively associate with TBK1 and IRF3 to disrupt the formation of a functional TBK1-IRF3 complex, impeding the phosphorylation of IRF3 mediated by TBK1. Collectively, these results demonstrate that TBK1 spliced isoforms are dominant negative regulators in the RIG-I/MAVS/TBK1/IRF3 antiviral pathway by targeting the functional TBK1-IRF3 complex formation. Identification and functional characterization of piscine TBK1 spliced isoforms may contribute to understanding the role of TBK1 expression in innate antiviral response.

Characterisation of the NUCKS gene on human chromosome 1q32.1 and the presence of a homologous gene in different species

International Nuclear Information System (INIS)

Grundt, Kirsten; Haga, Ingvild Vagslid; Aleporou-Marinou, Vasiliki; Drosos, Yiannis; Wanvik, Birgit; Ostvold, Anne Carine

2004-01-01

The NUCKS gene is located on human chromosome 1q32.1 and consists of seven exons and six introns. The gene lacks a TATA box but contains two Inr elements, two GC boxes, and one consensus-binding site for E2F-1. NUCKS is expressed in all human adult and foetal tissues investigated, and has all the features of being a housekeeping gene. Both data searches and Western immunoblotting experiments show that a homologous protein is present in fish, amphibians, and birds but not in insects and yeast, suggesting that NUCKS is a vertebrate specific gene. In all the species investigated, the protein contains several consensus phosphorylation sites for cyclin-dependent kinases and CK-2, and we have shown that the fish protein (like mammalian NUCKS) indeed is a substrate for CDK1 and CK-2 in vitro. The NUCKS protein is also conserved with respect to a DNA-binding domain previously characterised in mammals, and two putative bipartite nuclear localisation signals

Pancreatic cancer stimulates pancreatic stellate cell proliferation and TIMP-1 production through the MAP kinase pathway

International Nuclear Information System (INIS)

Yoshida, Seiya; Yokota, Tokuyasu; Ujiki, Michael; Ding Xianzhong; Pelham, Carolyn; Adrian, Thomas E.; Talamonti, Mark S.; Bell, Richard H.; Denham, Woody

2004-01-01

Pancreatic adenocarcinoma is characterized by an intense desmoplastic reaction that surrounds the tumor. Pancreatic stellate cells (PSCs) are thought to be responsible for production of this extracellular matrix. When activated, PSCs have a myofibroblast phenotype and produce not only components of the extracellular matrix including collagen, fibronectin, and laminin, but also matrix metalloproteinases and tissue inhibitors of metalloproteinases (TIMPs). Since PSCs are found in the stroma surrounding human pancreatic adenocarcinoma, we postulate that pancreatic cancer could impact PSC proliferation and TIMP-1 production. Rat PSCs were isolated and cultured. Isolated PSCs were exposed to PANC-1 conditioned medium (CM) and proliferation, activation of the mitogen-activated protein (MAP) kinase pathway, and TIMP-1 gene induction were determined. Exposure to PANC-1 CM increased PSC DNA synthesis, cell number, and TIMP-1 mRNA (real-time PCR) as well as activating the extracellular-regulated kinase (ERK) 1/2. Inhibition of ERK 1/2 phosphorylation (U0126) prevented the increases in growth and TIMP-1 expression. PANC-1 CM stimulates PSC proliferation and TIMP-1 through the MAP kinase (ERK 1/2) pathway

The role of the atypical kinases ABC1K7 and ABC1K8 in abscisic acid responses

Directory of Open Access Journals (Sweden)

Anna eManara

2016-03-01

Full Text Available The ABC1K family of atypical kinases (activity of bc1 complex kinase is represented in bacteria, archaea and eukaryotes. In plants they regulate diverse physiological processes in the chloroplasts and mitochondria, but their precise functions are poorly defined. ABC1K7 and ABC1K8 are probably involved in oxidative stress responses, isoprenyl lipid synthesis and distribution of iron within chloroplasts. Because reactive oxygen species take part in abscisic acid (ABA-mediated processes, we investigated the functions of ABC1K7 and ABC1K8 during germination, stomatal movement and leaf senescence. Both genes were upregulated by ABA treatment and some ABA-responsive physiological processes were affected in abc1k7 and abc1k8 mutants. Germination was more severely affected by ABA, osmotic stress and salt stress in the single and double mutants; the stomatal aperture was smaller in the mutants under standard growth conditions and was not further reduced by exogenous ABA application; ABA-induced senescence symptoms were more severe in the leaves of the single and double mutants compared to wild type leaves. Taken together, our results suggest that ABC1K7 and ABC1K8 might be involved in the cross-talk between ABA and ROS signaling.

Akt1 binds focal adhesion kinase via the Akt1 kinase domain independently of the pleckstrin homology domain.

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Basson, M D; Zeng, B; Wang, S

2015-10-01

Akt1 and focal adhesion kinase (FAK) are protein kinases that play key roles in normal cell signaling. Individually, aberrant expression of these kinases has been linked to a variety of cancers. Together, Akt1/FAK interactions facilitate cancer metastasis by increasing cell adhesion under conditions of increased extracellular pressure. Pathological and iatrogenic sources of pressure arise from tumor growth against constraining stroma or direct perioperative manipulation. We previously reported that 15 mmHg increased extracellular pressure causes Akt1 to both directly interact with FAK and to phosphorylate and activate it. We investigated the nature of the Akt1/FAK binding by creating truncations of recombinant FAK, conjugated to glutathione S-transferase (GST), to pull down full-length Akt1. Western blots probing for Akt1 showed that FAK/Akt1 binding persisted in FAK truncations consisting of only amino acids 1-126, FAK(NT1), which contains the F1 subdomain of its band 4.1, ezrin, radixin, and moesin (FERM) domain. Using FAK(NT1) as bait, we then pulled down truncated versions of recombinant Akt1 conjugated to HA (human influenza hemagglutinin). Probes for GST-FAK(NT1) showed Akt1-FAK binding to occur in the absence of the both the Akt1 (N)-terminal pleckstrin homology (PH) domain and its adjacent hinge region. The Akt1 (C)-terminal regulatory domain was equally unnecessary for Akt1/FAK co-immunoprecipitation. Truncations involving the Akt1 catalytic domain showed that the domain by itself was enough to pull down FAK. Additionally, a fragment spanning from the PH domain to half way through the catalytic domain demonstrated increased FAK binding compared to full length Akt1. These results begin to delineate the Akt1/FAK interaction and can be used to manipulate their force-activated signal interactions. Furthermore, the finding that the N-terminal half of the Akt1 catalytic domain binds so strongly to FAK when cleaved from the rest of the protein may suggest a means

Differentiation-inducing factor-1 suppresses gene expression of cyclin D1 in tumor cells

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Yasmin, Tania; Takahashi-Yanaga, Fumi; Mori, Jun; Miwa, Yoshikazu; Hirata, Masato; Watanabe, Yutaka; Morimoto, Sachio; Sasaguri, Toshiyuki

2005-01-01

To determine the mechanism by which differentiation-inducing factor-1 (DIF-1), a morphogen of Dictyostelium discoideum, inhibits tumor cell proliferation, we examined the effect of DIF-1 on the gene expression of cyclin D1. DIF-1 strongly reduced the expression of cyclin D1 mRNA and correspondingly decreased the amount of β-catenin in HeLa cells and squamous cell carcinoma cells. DIF-1 activated glycogen synthase kinase-3β (GSK-3β) and inhibition of GSK-3β attenuated the DIF-1-induced β-catenin degradation, indicating the involvement of GSK-3β in this effect. Moreover, DIF-1 reduced the activities of T-cell factor (TCF)/lymphoid enhancer factor (LEF) reporter plasmid and a reporter gene driven by the human cyclin D1 promoter. Eliminating the TCF/LEF consensus site from the cyclin D1 promoter diminished the effect of DIF-1. These results suggest that DIF-1 inhibits Wnt/β-catenin signaling, resulting in the suppression of cyclin D1 promoter activity

The PTI1-like kinase ZmPti1a from maize (Zea mays L.) co-localizes with callose at the plasma membrane of pollen and facilitates a competitive advantage to the male gametophyte.

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Herrmann, Markus M; Pinto, Sheena; Kluth, Jantjeline; Wienand, Udo; Lorbiecke, René

2006-10-06

The tomato kinase Pto confers resistance to bacterial speck disease caused by Pseudomonas syringae pv. tomato in a gene for gene manner. Upon recognition of specific avirulence factors the Pto kinase activates multiple signal transduction pathways culminating in induction of pathogen defense. The soluble cytoplasmic serine/threonine kinase Pti1 is one target of Pto phosphorylation and is involved in the hypersensitive response (HR) reaction. However, a clear role of Pti1 in plant pathogen resistance is uncertain. So far, no Pti1 homologues from monocotyledonous species have been studied. Here we report the identification and molecular analysis of four Pti1-like kinases from maize (ZmPti1a, -b, -c, -d). These kinase genes showed tissue-specific expression and their corresponding proteins were targeted to different cellular compartments. Sequence similarity, expression pattern and cellular localization of ZmPti1b suggested that this gene is a putative orthologue of Pti1 from tomato. In contrast, ZmPti1a was specifically expressed in pollen and sequestered to the plasma membrane, evidently owing to N-terminal modification by myristoylation and/or S-acylation. The ZmPti1a:GFP fusion protein was not evenly distributed at the pollen plasma membrane but accumulated as an annulus-like structure which co-localized with callose (1,3-beta-glucan) deposition. In addition, co-localization of ZmPti1a and callose was observed during stages of pollen mitosis I and pollen tube germination. Maize plants in which ZmPti1a expression was silenced by RNA interference (RNAi) produced pollen with decreased competitive ability. Hence, our data provide evidence that ZmPti1a plays an important part in a signalling pathway that accelerates pollen performance and male fitness. ZmPti1a from maize is involved in pollen-specific processes during the progamic phase of reproduction, probably in crucial signalling processes associated with regions of callose deposition. Pollen

Thymidine kinases in archaea

DEFF Research Database (Denmark)

Clausen, A.R.; Matakos, A.; Sandrini, Michael

2006-01-01

Twenty-six fully sequenced archaeal genomes were searched for genes coding for putative deoxyribonucleoside kinases (dNKs). We identified only 5 human-like thymidine kinase 1 genes (TK1s) and none for non-TK1 kinases. Four TK1s were identified in the Euryarchaea and one was found in the Crenarcha...

The cAMP Response Element Binding protein (CREB) is activated by Insulin-like Growth Factor-1 (IGF-1) and regulates myostatin gene expression in skeletal myoblast

International Nuclear Information System (INIS)

Zuloaga, R.; Fuentes, E.N.; Molina, A.; Valdés, J.A.

2013-01-01

Highlights: •IGF-1 induces the activation of CREB via IGF-1R/PI3K/PLC signaling pathway. •Calcium dependent signaling pathways regulate myostatin gene expression. •IGF-1 regulates myostatin gene expression via CREB transcription in skeletal myoblast. -- Abstract: Myostatin, a member of the Transforming Growth Factor beta (TGF-β) superfamily, plays an important role as a negative regulator of skeletal muscle growth and differentiation. We have previously reported that IGF-1 induces a transient myostatin mRNA expression, through the activation of the Nuclear Factor of Activated T cells (NFAT) in an IP 3 /calcium-dependent manner. Here we examined the activation of CREB transcription factor as downstream targets of IGF-1 during myoblast differentiation and its role as a regulator of myostatin gene expression. In cultured skeletal myoblast, IGF-1 induced the phosphorylation and transcriptional activation of CREB via IGF-1 Receptor/Phosphatidylinositol 3-Kinase (PI3K)/Phospholipase C gamma (PLC γ), signaling pathways. Also, IGF-1 induced calcium-dependent molecules such as Calmodulin Kinase II (CaMK II), Extracellular signal-regulated Kinases (ERK), Protein Kinase C (PKC). Additionally, we examined myostatin mRNA levels and myostatin promoter activity in differentiated myoblasts stimulated with IGF-1. We found a significant increase in mRNA contents of myostatin and its reporter activity after treatment with IGF-1. The expression of myostatin in differentiated myoblast was downregulated by the transfection of siRNA–CREB and by pharmacological inhibitors of the signaling pathways involved in CREB activation. By using pharmacological and genetic approaches together these data demonstrate that IGF-1 regulates the myostatin gene expression via CREB transcription factor during muscle cell differentiation

The cAMP Response Element Binding protein (CREB) is activated by Insulin-like Growth Factor-1 (IGF-1) and regulates myostatin gene expression in skeletal myoblast

Energy Technology Data Exchange (ETDEWEB)

Zuloaga, R. [Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago (Chile); Fuentes, E.N.; Molina, A. [Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago (Chile); Interdisciplinary Center for Aquaculture Research (INCAR), Víctor Lamas 1290, PO Box 160-C, Concepción (Chile); Valdés, J.A., E-mail: jvaldes@unab.cl [Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago (Chile); Interdisciplinary Center for Aquaculture Research (INCAR), Víctor Lamas 1290, PO Box 160-C, Concepción (Chile)

2013-10-18

Highlights: •IGF-1 induces the activation of CREB via IGF-1R/PI3K/PLC signaling pathway. •Calcium dependent signaling pathways regulate myostatin gene expression. •IGF-1 regulates myostatin gene expression via CREB transcription in skeletal myoblast. -- Abstract: Myostatin, a member of the Transforming Growth Factor beta (TGF-β) superfamily, plays an important role as a negative regulator of skeletal muscle growth and differentiation. We have previously reported that IGF-1 induces a transient myostatin mRNA expression, through the activation of the Nuclear Factor of Activated T cells (NFAT) in an IP{sub 3}/calcium-dependent manner. Here we examined the activation of CREB transcription factor as downstream targets of IGF-1 during myoblast differentiation and its role as a regulator of myostatin gene expression. In cultured skeletal myoblast, IGF-1 induced the phosphorylation and transcriptional activation of CREB via IGF-1 Receptor/Phosphatidylinositol 3-Kinase (PI3K)/Phospholipase C gamma (PLC γ), signaling pathways. Also, IGF-1 induced calcium-dependent molecules such as Calmodulin Kinase II (CaMK II), Extracellular signal-regulated Kinases (ERK), Protein Kinase C (PKC). Additionally, we examined myostatin mRNA levels and myostatin promoter activity in differentiated myoblasts stimulated with IGF-1. We found a significant increase in mRNA contents of myostatin and its reporter activity after treatment with IGF-1. The expression of myostatin in differentiated myoblast was downregulated by the transfection of siRNA–CREB and by pharmacological inhibitors of the signaling pathways involved in CREB activation. By using pharmacological and genetic approaches together these data demonstrate that IGF-1 regulates the myostatin gene expression via CREB transcription factor during muscle cell differentiation.

Organization and alternative splicing of the Caenorhabditis elegans cAMP-dependent protein kinase catalytic-subunit gene (kin-1).

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Tabish, M; Clegg, R A; Rees, H H; Fisher, M J

1999-04-01

The cAMP-dependent protein kinase (protein kinase A, PK-A) is multifunctional in nature, with key roles in the control of diverse aspects of eukaryotic cellular activity. In the case of the free-living nematode, Caenorhabditis elegans, a gene encoding the PK-A catalytic subunit has been identified and two isoforms of this subunit, arising from a C-terminal alternative-splicing event, have been characterized [Gross, Bagchi, Lu and Rubin (1990) J. Biol. Chem. 265, 6896-6907]. Here we report the occurrence of N-terminal alternative-splicing events that, in addition to generating a multiplicity of non-myristoylatable isoforms, also generate the myristoylated variant(s) of the catalytic subunit that we have recently characterized [Aspbury, Fisher, Rees and Clegg (1997) Biochem. Biophys. Res. Commun. 238, 523-527]. The gene spans more than 36 kb and is divided into a total of 13 exons. Each of the mature transcripts contains only 7 exons. In addition to the already characterized exon 1, the 5'-untranslated region and first intron actually contain 5 other exons, any one of which may be alternatively spliced on to exon 2 at the 5' end of the pre-mRNA. This N-terminal alternative splicing occurs in combination with either of the already characterized C-terminal alternative exons. Thus, C. elegans expresses at least 12 different isoforms of the catalytic subunit of PK-A. The significance of this unprecedented structural diversity in the family of PK-A catalytic subunits is discussed.

Reactive oxygen species-generating mitochondrial DNA mutation up-regulates hypoxia-inducible factor-1alpha gene transcription via phosphatidylinositol 3-kinase-Akt/protein kinase C/histone deacetylase pathway.

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Koshikawa, Nobuko; Hayashi, Jun-Ichi; Nakagawara, Akira; Takenaga, Keizo

2009-11-27

Lewis lung carcinoma-derived high metastatic A11 cells constitutively overexpress hypoxia-inducible factor (HIF)-1alpha mRNA compared with low metastatic P29 cells. Because A11 cells exclusively possess a G13997A mutation in the mitochondrial NADH dehydrogenase subunit 6 (ND6) gene, we addressed here a causal relationship between the ND6 mutation and the activation of HIF-1alpha transcription, and we investigated the potential mechanism. Using trans-mitochondrial cybrids between A11 and P29 cells, we found that the ND6 mutation was directly involved in HIF-1alpha mRNA overexpression. Stimulation of HIF-1alpha transcription by the ND6 mutation was mediated by overproduction of reactive oxygen species (ROS) and subsequent activation of phosphatidylinositol 3-kinase (PI3K)-Akt and protein kinase C (PKC) signaling pathways. The up-regulation of HIF-1alpha transcription was abolished by mithramycin A, an Sp1 inhibitor, but luciferase reporter and chromatin immunoprecipitation assays indicated that Sp1 was necessary but not sufficient for HIF-1alpha mRNA overexpression in A11 cells. On the other hand, trichostatin A, a histone deacetylase (HDAC) inhibitor, markedly suppressed HIF-1alpha transcription in A11 cells. In accordance with this, HDAC activity was high in A11 cells but low in P29 cells and in A11 cells treated with the ROS scavenger ebselene, the PI3K inhibitor LY294002, and the PKC inhibitor Ro31-8220. These results suggest that the ROS-generating ND6 mutation increases HIF-1alpha transcription via the PI3K-Akt/PKC/HDAC pathway, leading to HIF-1alpha protein accumulation in hypoxic tumor cells.

Protein kinase B/Akt1 inhibits autophagy by down-regulating UVRAG expression

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Yang, Wonseok; Ju, Ji-hyun; Lee, Kyung-min; Nam, KeeSoo; Oh, Sunhwa [Department of Life Science, College of Natural Science, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Shin, Incheol, E-mail: incheol@hanyang.ac.kr [Department of Life Science, College of Natural Science, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of)

2013-02-01

Autophagy, or autophagocytosis, is a selective intracellular degradative process involving the cell's own lysosomal apparatus. An essential component in cell development, homeostasis, repair and resistance to stress, autophagy may result in either cell death or survival. The targeted region of the cell is sequestered within a membrane structure, the autophagosome, for regulation of the catabolic process. A key factor in both autophagosome formation and autophagosome maturation is a protein encoded by the ultraviolet irradiation resistance-associated gene (UVRAG). Conversely, the serine/threonine-specific protein kinase B (PKB, also known as Akt), which regulates survival in various cancers, inhibits autophagy through mTOR activation. We found that Akt1 may also directly inhibit autophagy by down-regulating UVRAG both in a 293T transient transfection system and breast cancer cells stably expressing Akt1. The UVRAG with mutations at putative Akt1-phosphorylation sites were still inhibited by Akt1, and dominant-negative Akt1 also inhibited UVRAG expression, suggesting that Akt1 down-regulates UVRAG by a kinase activity-independent mechanism. We showed that Akt1 overexpression in MDA-MB-231 breast cancer cells down-regulated UVRAG transcription. Cells over-expressing Akt1 were more resistant than control cells to ultraviolet light-induced autophagy and exhibited the associated reduction in cell viability. Levels of the autophagosome indicator protein LC3B-II and mRFP-GFP-LC3 were reduced in cells that over-expressing Akt1. Inhibiting Akt1 by siRNA or reintroducing UVRAG gene rescued the level of LC3B-II in UV-irradiation. Altogether, these data suggest that Akt1 may inhibit autophagy by decreasing UVRAG expression, which also sensitizes cancer cells to UV irradiation.

Recent Advances of Colony-Stimulating Factor-1 Receptor (CSF-1R) Kinase and Its Inhibitors.

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El-Gamal, Mohammed I; Al-Ameen, Shahad K; Al-Koumi, Dania M; Hamad, Mawadda G; Jalal, Nouran A; Oh, Chang-Hyun

2018-01-17

Colony stimulation factor-1 receptor (CSF-1R), which is also known as FMS kinase, plays an important role in initiating inflammatory, cancer, and bone disorders when it is overstimulated by its ligand, CSF-1. Innate immunity, as well as macrophage differentiation and survival, are regulated by the stimulation of the CSF-1R. Another ligand, interlukin-34 (IL-34), was recently reported to activate the CSF-1R receptor in a different manner. The relationship between CSF-1R and microglia has been reviewed. Both CSF-1 antibodies and small molecule CSF-1R kinase inhibitors have now been tested in animal models and in humans. In this Perspective, we discuss the role of CSF-1 and IL-34 in producing cancer, bone disorders, and inflammation. We also review the newly discovered and improved small molecule kinase inhibitors and monoclonal antibodies that have shown potent activity toward CSF-1R, reported from 2012 until 2017.

LAMMER kinase Kic1 is involved in pre-mRNA processing

International Nuclear Information System (INIS)

Tang, Zhaohua; Luca, Maria; Portillio, Jessica; Ngo, Benson; Chang, Cathey; Wen, Teresa; Murray, Johanne; Carr, Antony

2011-01-01

The LAMMER kinases are conserved through evolution. They play vital roles in cell growth/differentiation, development, and metabolism. One of the best known functions of the kinases in animal cells is the regulation of pre-mRNA splicing. Kic1 is the LAMMER kinase in fission yeast Schizosaccharomyces pombe. Despite the reported pleiotropic effects of kic1 + deletion/overexpression on various cellular processes the involvement of Kic1 in splicing remains elusive. In this study, we demonstrate for the first time that Kic1 not only is required for efficient splicing but also affects mRNA export, providing evidence for the conserved roles of LAMMER kinases in the unicellular context of fission yeast. Consistent with the hypothesis of its direct participation in multiple steps of pre-mRNA processing, Kic1 is predominantly present in the nucleus during interphase. In addition, the kinase activity of Kic1 plays a role in modulating its own cellular partitioning. Interestingly, Kic1 expression oscillates in a cell cycle-dependent manner and the peak level coincides with mitosis and cytokinesis, revealing a potential mechanism for controlling the kinase activity during the cell cycle. The novel information about the in vivo functions and regulation of Kic1 offers insights into the conserved biological roles fundamental to LAMMER kinases in eukaryotes.

RUNX1 regulates phosphoinositide 3-kinase/AKT pathway: role in chemotherapy sensitivity in acute megakaryocytic leukemia.

Science.gov (United States)

Edwards, Holly; Xie, Chengzhi; LaFiura, Katherine M; Dombkowski, Alan A; Buck, Steven A; Boerner, Julie L; Taub, Jeffrey W; Matherly, Larry H; Ge, Yubin

2009-09-24

RUNX1 (AML1) encodes the core binding factor alpha subunit of a heterodimeric transcription factor complex which plays critical roles in normal hematopoiesis. Translocations or down-regulation of RUNX1 have been linked to favorable clinical outcomes in acute leukemias, suggesting that RUNX1 may also play critical roles in chemotherapy responses in acute leukemias; however, the molecular mechanisms remain unclear. The median level of RUNX1b transcripts in Down syndrome (DS) children with acute megakaryocytic leukemia (AMkL) were 4.4-fold (P regulation of PIK3CD by RUNX1 was further confirmed by chromatin immunoprecipitation and promoter reporter gene assays. Further, a PI3-kinase inhibitor, LY294002, and cytosine arabinoside synergized in antileukemia effects on Meg-01 and primary pediatric AMkL cells. Our results suggest that RUNX1 may play a critical role in chemotherapy response in AMkL by regulating the PI3-kinase/Akt pathway. Thus, the treatment of AMkL may be improved by integrating PI3-kinase or Akt inhibitors into the chemotherapy of this disease.

Dihydrotestosterone induces SREBP-1 expression and lipogenesis through the phosphoinositide 3-kinase/Akt pathway in HaCaT cells

Directory of Open Access Journals (Sweden)

Zhou Bing-rong

2012-11-01

Full Text Available Abstract Background The purpose of this study was to investigate the effects and mechanisms of dihydrotestosterone (DHT-induced expression of sterol regulatory element binding protein-1 (SREBP-1, and the synthesis and secretion of lipids, in HaCaT cells. HaCaT cells were treated with DHT and either the phosphoinositide 3-kinase inhibitor LY294002 or the extracellular-signal-regulated kinase (ERK inhibitor PD98059. Real time-PCR, Western blot, Oil Red staining and flow cytometry were employed to examine the mRNA and protein expressions of SREBP-1, the gene transcription of lipid synthesis, and lipid secretion in HaCaT cells. Findings We found that DHT upregulated mRNA and protein expressions of SREBP-1. DHT also significantly upregulated the transcription of lipid synthesis-related genes and increased lipid secretion, which can be inhibited by the addition of LY294002. Conclusions Collectively, these results indicate that DHT induces SREBP-1 expression and lipogenesis in HaCaT cells via activation of the phosphoinositide 3-kinase/Akt Pathway.

PPARγ activates ABCA1 gene transcription but reduces the level of ABCA1 protein in HepG2 cells

International Nuclear Information System (INIS)

Mogilenko, Denis A.; Shavva, Vladimir S.; Dizhe, Ella B.; Orlov, Sergey V.; Perevozchikov, Andrej P.

2010-01-01

Research highlights: → PPARγ activates ABCA1 gene expression but decreases ABCA1 protein content in human hepatoma cell line HepG2. → Treatment of HepG2 cells with PPARγ agonist GW1929 leads to dissociation of LXRβ from ABCA1-LXRβ complex. → Inhibition of protein kinases MEK1/2 abolishes PPARγ-mediated dissociation of LXRβ from ABCA1/LXRβ complex. → Activation of PPARγ leads to increasing of the level of LXRβ associated with LXRE within ABCA1 gene promoter. -- Abstract: Synthesis of ABCA1 protein in liver is necessary for high-density lipoproteins (HDL) formation in mammals. Nuclear receptor PPARγ is known as activator of ABCA1 expression, but details of PPARγ-mediated regulation of ABCA1 at both transcriptional and post-transcriptional levels in hepatocytes have not still been well elucidated. In this study we have shown, that PPARγ activates ABCA1 gene transcription in human hepatoma cells HepG2 through increasing of LXRβ binding with promoter region of ABCA1 gene. Treatment of HepG2 cells with PPARγ agonist GW1929 leads to dissociation of LXRβ from ABCA1/LXRβ complex and to nuclear translocation of this nuclear receptor resulting in reduction of ABCA1 protein level 24 h after treatment. Inhibition of protein kinases MEK1/2 abolishes PPARγ-mediated dissociation of LXRβ from ABCA1/LXRβ complex, but does not block PPARγ-dependent down-regulation of ABCA1 protein in HepG2 cells. These data suggest that PPARγ may be important for regulation of the level of hepatic ABCA1 protein and indicate the new interplays between PPARγ, LXRβ and MEK1/2 in regulation of ABCA1 mRNA and protein expression.

Characterization of the human Activin-A receptor type II-like kinase 1 (ACVRL1 promoter and its regulation by Sp1

Directory of Open Access Journals (Sweden)

Botella Luisa M

2010-06-01

Full Text Available Abstract Background Activin receptor-like kinase 1 (ALK1 is a Transforming Growth Factor-β (TGF-β receptor type I, mainly expressed in endothelial cells that plays a pivotal role in vascular remodelling and angiogenesis. Mutations in the ALK1 gene (ACVRL1 give rise to Hereditary Haemorrhagic Telangiectasia, a dominant autosomal vascular dysplasia caused by a haploinsufficiency mechanism. In spite of its patho-physiological relevance, little is known about the transcriptional regulation of ACVRL1. Here, we have studied the different origins of ACVRL1 transcription, we have analyzed in silico its 5'-proximal promoter sequence and we have characterized the role of Sp1 in the transcriptional regulation of ACVRL1. Results We have performed a 5'Rapid Amplification of cDNA Ends (5'RACE of ACVRL1 transcripts, finding two new transcriptional origins, upstream of the one previously described, that give rise to a new exon undiscovered to date. The 5'-proximal promoter region of ACVRL1 (-1,035/+210 was analyzed in silico, finding that it lacks TATA/CAAT boxes, but contains a remarkably high number of GC-rich Sp1 consensus sites. In cells lacking Sp1, ACVRL1 promoter reporters did not present any significant transcriptional activity, whereas increasing concentrations of Sp1 triggered a dose-dependent stimulation of its transcription. Moreover, silencing Sp1 in HEK293T cells resulted in a marked decrease of ACVRL1 transcriptional activity. Chromatin immunoprecipitation assays demonstrated multiple Sp1 binding sites along the proximal promoter region of ACVRL1 in endothelial cells. Furthermore, demethylation of CpG islands, led to an increase in ACVRL1 transcription, whereas in vitro hypermethylation resulted in the abolishment of Sp1-dependent transcriptional activation of ACVRL1. Conclusions Our results describe two new transcriptional start sites in ACVRL1 gene, and indicate that Sp1 is a key regulator of ACVRL1 transcription, providing new insights into

Protein kinase D stabilizes aldosterone-induced ERK1/2 MAP kinase activation in M1 renal cortical collecting duct cells to promote cell proliferation.

LENUS (Irish Health Repository)

McEneaney, Victoria

2010-01-01

Aldosterone elicits transcriptional responses in target tissues and also rapidly stimulates the activation of protein kinase signalling cascades independently of de novo protein synthesis. Here we investigated aldosterone-induced cell proliferation and extra-cellular regulated kinase 1 and 2 (ERK1\\/2) mitogen activated protein (MAP) kinase signalling in the M1 cortical collecting duct cell line (M1-CCD). Aldosterone promoted the proliferative growth of M1-CCD cells, an effect that was protein kinase D1 (PKD1), PKCdelta and ERK1\\/2-dependent. Aldosterone induced the rapid activation of ERK1\\/2 with peaks of activation at 2 and 10 to 30 min after hormone treatment followed by sustained activation lasting beyond 120 min. M1-CCD cells suppressed in PKD1 expression exhibited only the early, transient peaks in ERK1\\/2 activation without the sustained phase. Aldosterone stimulated the physical association of PKD1 with ERK1\\/2 within 2 min of treatment. The mineralocorticoid receptor (MR) antagonist RU28318 inhibited the early and late phases of aldosterone-induced ERK1\\/2 activation, and also aldosterone-induced proliferative cell growth. Aldosterone induced the sub-cellular redistribution of ERK1\\/2 to the nuclei at 2 min and to cytoplasmic sites, proximal to the nuclei after 30 min. This sub-cellular distribution of ERK1\\/2 was inhibited in cells suppressed in the expression of PKD1.

A phosphoinositide 3-kinase (PI3K)-serum- and glucocorticoid-inducible kinase 1 (SGK1) pathway promotes Kv7.1 channel surface expression by inhibiting Nedd4-2 protein

DEFF Research Database (Denmark)

Andersen, Martin Nybo; Krzystanek, Katarzyna; Petersen, Frederic

2013-01-01

Epithelial cell polarization involves several kinase signaling cascades that eventually divide the surface membrane into an apical and a basolateral part. One kinase, which is activated during the polarization process, is phosphoinositide 3-kinase (PI3K). In MDCK cells, the basolateral potassium...... channel Kv7.1 requires PI3K activity for surface-expression during the polarization process. Here, we demonstrate that Kv7.1 surface expression requires tonic PI3K activity as PI3K inhibition triggers endocytosis of these channels in polarized MDCK. Pharmacological inhibition of SGK1 gave similar results...... as PI3K inhibition, whereas overexpression of constitutively active SGK1 overruled it, suggesting that SGK1 is the primary downstream target of PI3K in this process. Furthermore, knockdown of the ubiquitin ligase Nedd4-2 overruled PI3K inhibition, whereas a Nedd4-2 interaction-deficient Kv7.1 mutant...

Akt1/protein kinase Bα is critical for ischemic and VEGF-mediated angiogenesis

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Ackah, Eric; Yu, Jun; Zoellner, Stefan; Iwakiri, Yasuko; Skurk, Carsten; Shibata, Rei; Ouchi, Noriyuki; Easton, Rachael M.; Galasso, Gennaro; Birnbaum, Morris J.; Walsh, Kenneth; Sessa, William C.

2005-01-01

Akt, or protein kinase B, is a multifunctional serine-threonine protein kinase implicated in a diverse range of cellular functions including cell metabolism, survival, migration, and gene expression. However, the in vivo roles and effectors of individual Akt isoforms in signaling are not explicitly clear. Here we show that the genetic loss of Akt1, but not Akt2, in mice results in defective ischemia and VEGF-induced angiogenesis as well as severe peripheral vascular disease. Akt1 knockout (Akt1–/–) mice also have reduced endothelial progenitor cell (EPC) mobilization in response to ischemia, and reintroduction of WT EPCs, but not EPCs isolated from Akt1–/– mice, into WT mice improves limb blood flow after ischemia. Mechanistically, the loss of Akt1 reduces the basal phosphorylation of several Akt substrates, the migration of fibroblasts and ECs, and NO release. Reconstitution of Akt1–/– ECs with Akt1 rescues the defects in substrate phosphorylation, cell migration, and NO release. Thus, the Akt1 isoform exerts an essential role in blood flow control, cellular migration, and NO synthesis during postnatal angiogenesis. PMID:16075056

Chloride sensing by WNK1 kinase involves inhibition of autophosphorylation

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Piala, Alexander T.; Moon, Thomas M.; Akella, Radha; He, Haixia; Cobb, Melanie H.; Goldsmith, Elizabeth J.

2014-01-01

WNK1 [with no lysine (K)] is a serine-threonine kinase associated with a form of familial hypertension. WNK1 is at the top of a kinase cascade leading to phosphorylation of several cotransporters, in particular those transporting sodium, potassium, and chloride (NKCC), sodium and chloride (NCC), and potassium and chloride (KCC). The responsiveness of NKCC, NCC, and KCC to changes in extracellular chloride parallels their phosphorylation state, provoking the proposal that these transporters are controlled by a chloride-sensitive protein kinase. Here, we found that chloride stabilizes the inactive conformation of WNK1, preventing kinase autophosphorylation and activation. Crystallographic studies of inactive WNK1 in the presence of chloride revealed that chloride binds directly to the catalytic site, providing a basis for the unique position of the catalytic lysine. Mutagenesis of the chloride binding site rendered the kinase less sensitive to inhibition of autophosphorylation by chloride, validating the binding site. Thus, these data suggest that WNK1 functions as a chloride sensor through direct binding of a regulatory chloride ion to the active site, which inhibits autophosphorylation. PMID:24803536

Expression, purification, crystallization and preliminary crystallographic analysis of human Pim-1 kinase

International Nuclear Information System (INIS)

Qian, Kevin C.; Studts, Joey; Wang, Lian; Barringer, Kevin; Kronkaitis, Anthony; Peng, Charline; Baptiste, Alistair; LaFrance, Roger; Mische, Sheenah; Farmer, Bennett

2004-01-01

Pim kinases, belong to a distinctive serine/threonine protein-kinase family and are involved in cytokine-induced signal transduction and the development of lymphoid malignancies. Human Pim-1 kinase has been cloned, expressed and crystallized Pim kinases, including Pim-1, Pim-2 and Pim-3, belong to a distinctive serine/threonine protein-kinase family. They are involved in cytokine-induced signal transduction and the development of lymphoid malignancies. Their kinase domains are highly homologous to one another, but share low sequence identity to other kinases. Specifically, there are two proline residues in the conserved hinge-region sequence ERPXPX separated by a residue that is non-conserved among Pim kinases. Full-length human Pim-1 kinase (1–313) was cloned and expressed in Escherichia coli as a GST-fusion protein and truncated to Pim-1 (14–313) by thrombin digestion during purification. The Pim-1 (14–313) protein was purified to high homogeneity and monodispersity. This protein preparation yielded small crystals in the initial screening and large crystals after optimization. The large crystals of apo Pim-1 enzyme diffracted to 2.1 Å resolution and belong to space group P6 5 , with unit-cell parameters a = b = 95.9, c = 80.0 Å, β = 120° and one molecule per asymmetric unit

Evolutionary divergence in the catalytic activity of the CAM-1, ROR1 and ROR2 kinase domains.

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Travis W Bainbridge

Full Text Available Receptor tyrosine kinase-like orphan receptors (ROR 1 and 2 are atypical members of the receptor tyrosine kinase (RTK family and have been associated with several human diseases. The vertebrate RORs contain an ATP binding domain that deviates from the consensus amino acid sequence, although the impact of this deviation on catalytic activity is not known and the kinase function of these receptors remains controversial. Recently, ROR2 was shown to signal through a Wnt responsive, β-catenin independent pathway and suppress a canonical Wnt/β-catenin signal. In this work we demonstrate that both ROR1 and ROR2 kinase domains are catalytically deficient while CAM-1, the C. elegans homolog of ROR, has an active tyrosine kinase domain, suggesting a divergence in the signaling processes of the ROR family during evolution. In addition, we show that substitution of the non-consensus residues from ROR1 or ROR2 into CAM-1 and MuSK markedly reduce kinase activity, while restoration of the consensus residues in ROR does not restore robust kinase function. We further demonstrate that the membrane-bound extracellular domain alone of either ROR1 or ROR2 is sufficient for suppression of canonical Wnt3a signaling, and that this domain can also enhance Wnt5a suppression of Wnt3a signaling. Based on these data, we conclude that human ROR1 and ROR2 are RTK-like pseudokinases.

SH2/SH3 adaptor proteins can link tyrosine kinases to a Ste20-related protein kinase, HPK1.

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Anafi, M; Kiefer, F; Gish, G D; Mbamalu, G; Iscove, N N; Pawson, T

1997-10-31

Ste20-related protein kinases have been implicated as regulating a range of cellular responses, including stress-activated protein kinase pathways and the control of cytoskeletal architecture. An important issue involves the identities of the upstream signals and regulators that might control the biological functions of mammalian Ste20-related protein kinases. HPK1 is a protein-serine/threonine kinase that possesses a Ste20-like kinase domain, and in transfected cells activates a protein kinase pathway leading to the stress-activated protein kinase SAPK/JNK. Here we have investigated candidate upstream regulators that might interact with HPK1. HPK1 possesses an N-terminal catalytic domain and an extended C-terminal tail with four proline-rich motifs. The SH3 domains of Grb2 bound in vitro to specific proline-rich motifs in the HPK1 tail and functioned synergistically to direct the stable binding of Grb2 to HPK1 in transfected Cos1 cells. Epidermal growth factor (EGF) stimulation did not affect the binding of Grb2 to HPK1 but induced recruitment of the Grb2.HPK1 complex to the autophosphorylated EGF receptor and to the Shc docking protein. Several activated receptor and cytoplasmic tyrosine kinases, including the EGF receptor, stimulated the tyrosine phosphorylation of the HPK1 serine/threonine kinase. These results suggest that HPK1, a mammalian Ste20-related protein-serine/threonine kinase, can potentially associate with protein-tyrosine kinases through interactions mediated by SH2/SH3 adaptors such as Grb2. Such interaction may provide a possible mechanism for cross-talk between distinct biochemical pathways following the activation of tyrosine kinases.

Imaging of Herpes Simplex Virus Type 1 Thymidine Kinase Gene Expression with Radiolabeled 5-(2-iodovinyl)-2'-deoxyuridine (IVDU) in Liver by Hydrodynamic-based Procedure

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Song, In Ho; Lee, Tae Sup; Kang, Joo Hyun; Lee, Yong Jin; Kim, Kwang Il; An, Gwang Il; Chung, Wee Sup; Cheon, Gi Jeong; Choi, Chang Woon; Lim, Sang Moo [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

2009-10-15

Hydrodynamic-based procedure is a simple and effective gene delivery method to lead a high gene expression in liver tissue. Non-invasive imaging reporter gene system has been used widely with herpes simplex virus type 1 thymidine kinase (HSV1-tk) and its various substrates. In the present study, we investigated to image the expression of HSV1-tk gene with 5-(2-iodovinyl)-2'-deoxyuridine (IVDU) in mouse liver by the hydrodynamicbased procedure. HSV1-tk or enhanced green fluorescence protein (EGFP) encoded plasmid DNA was transferred into the mouse liver by hydrodynamic injection. At 24 h post-injection, RT-PCR, biodistribution, fluorescence imaging, nuclear imaging and digital wholebody autoradiography (DWBA) were performed to confirm transferred gene expression. In RT-PCR assay using mRNA from the mouse liver, specific bands of HSV1-tk and EGFP gene were observed in HSV1-tk and EGFP expressing plasmid injected mouse, respectively. Higher uptake of radiolabeled IVDU was exhibited in liver of HSV1-tk gene transferred mouse by biodistribution study. In fluorescence imaging, the liver showed specific fluorescence signal in EGFP gene transferred mouse. Gamma-camera image and DWBA results showed that radiolabeled IVDU was accumulated in the liver of HSV1-tk gene transferred mouse. In this study, hydrodynamic-based procedure was effective in liver-specific gene delivery and it could be quantified with molecular imaging methods. Therefore, co-expression of HSV1-tk reporter gene and target gene by hydrodynamic-based procedure is expected to be a useful method for the evaluation of the target gene expression level with radiolabeled IVDU.

The PTI1-like kinase ZmPti1a from maize (Zea mays L. co-localizes with callose at the plasma membrane of pollen and facilitates a competitive advantage to the male gametophyte

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Wienand Udo

2006-10-01

Full Text Available Abstract Background The tomato kinase Pto confers resistance to bacterial speck disease caused by Pseudomonas syringae pv. tomato in a gene for gene manner. Upon recognition of specific avirulence factors the Pto kinase activates multiple signal transduction pathways culminating in induction of pathogen defense. The soluble cytoplasmic serine/threonine kinase Pti1 is one target of Pto phosphorylation and is involved in the hypersensitive response (HR reaction. However, a clear role of Pti1 in plant pathogen resistance is uncertain. So far, no Pti1 homologues from monocotyledonous species have been studied. Results Here we report the identification and molecular analysis of four Pti1-like kinases from maize (ZmPti1a, -b, -c, -d. These kinase genes showed tissue-specific expression and their corresponding proteins were targeted to different cellular compartments. Sequence similarity, expression pattern and cellular localization of ZmPti1b suggested that this gene is a putative orthologue of Pti1 from tomato. In contrast, ZmPti1a was specifically expressed in pollen and sequestered to the plasma membrane, evidently owing to N-terminal modification by myristoylation and/or S-acylation. The ZmPti1a:GFP fusion protein was not evenly distributed at the pollen plasma membrane but accumulated as an annulus-like structure which co-localized with callose (1,3-β-glucan deposition. In addition, co-localization of ZmPti1a and callose was observed during stages of pollen mitosis I and pollen tube germination. Maize plants in which ZmPti1a expression was silenced by RNA interference (RNAi produced pollen with decreased competitive ability. Hence, our data provide evidence that ZmPti1a plays an important part in a signalling pathway that accelerates pollen performance and male fitness. Conclusion ZmPti1a from maize is involved in pollen-specific processes during the progamic phase of reproduction, probably in crucial signalling processes associated with regions

Molecular dynamics simulations reveal the conformational dynamics of Arabidopsis thaliana BRI1 and BAK1 receptor-like kinases.

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Moffett, Alexander S; Bender, Kyle W; Huber, Steven C; Shukla, Diwakar

2017-07-28

The structural motifs responsible for activation and regulation of eukaryotic protein kinases in animals have been studied extensively in recent years, and a coherent picture of their activation mechanisms has begun to emerge. In contrast, non-animal eukaryotic protein kinases are not as well understood from a structural perspective, representing a large knowledge gap. To this end, we investigated the conformational dynamics of two key Arabidopsis thaliana receptor-like kinases, brassinosteroid-insensitive 1 (BRI1) and BRI1-associated kinase 1 (BAK1), through extensive molecular dynamics simulations of their fully phosphorylated kinase domains. Molecular dynamics simulations calculate the motion of each atom in a protein based on classical approximations of interatomic forces, giving researchers insight into protein function at unparalleled spatial and temporal resolutions. We found that in an otherwise "active" BAK1 the αC helix is highly disordered, a hallmark of deactivation, whereas the BRI1 αC helix is moderately disordered and displays swinging behavior similar to numerous animal kinases. An analysis of all known sequences in the A. thaliana kinome found that αC helix disorder may be a common feature of plant kinases. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Thrombin selectively engages LIM kinase 1 and slingshot-1L phosphatase to regulate NF-κB activation and endothelial cell inflammation.

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Leonard, Antony; Marando, Catherine; Rahman, Arshad; Fazal, Fabeha

2013-11-01

Endothelial cell (EC) inflammation is a central event in the pathogenesis of many pulmonary diseases such as acute lung injury and its more severe form acute respiratory distress syndrome. Alterations in actin cytoskeleton are shown to be crucial for NF-κB regulation and EC inflammation. Previously, we have described a role of actin binding protein cofilin in mediating cytoskeletal alterations essential for NF-κB activation and EC inflammation. The present study describes a dynamic mechanism in which LIM kinase 1 (LIMK1), a cofilin kinase, and slingshot-1Long (SSH-1L), a cofilin phosphatase, are engaged by procoagulant and proinflammatory mediator thrombin to regulate these responses. Our data show that knockdown of LIMK1 destabilizes whereas knockdown of SSH-1L stabilizes the actin filaments through modulation of cofilin phosphorylation; however, in either case thrombin-induced NF-κB activity and expression of its target genes (ICAM-1 and VCAM-1) is inhibited. Further mechanistic analyses reveal that knockdown of LIMK1 or SSH-1L each attenuates nuclear translocation and thereby DNA binding of RelA/p65. In addition, LIMK1 or SSH-1L depletion inhibited RelA/p65 phosphorylation at Ser(536), a critical event conferring transcriptional competency to the bound NF-κB. However, unlike SSH-1L, LIMK1 knockdown also impairs the release of RelA/p65 by blocking IKKβ-dependent phosphorylation/degradation of IκBα. Interestingly, LIMK1 or SSH-1L depletion failed to inhibit TNF-α-induced RelA/p65 nuclear translocation and proinflammatory gene expression. Thus this study provides evidence for a novel role of LIMK1 and SSH-1L in selectively regulating EC inflammation associated with intravascular coagulation.

The wip1 phosphatase (PPM1D) antagonizes activation of the CHK2 tumor suppressor kinase

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Manet, Oliva-Trastoy; Berthonaud, V.; Chevalier, A.; Ducrot, C.; Marsolier-Kergoat, M.C.; Mann, C.; Leteurtre, F. [CEA Saclay, DSV, DBJC, SBGM, Lab. du Controle du Cycle Cellulaire, 91 - Gif-sur-Yvette (France)

2006-07-01

The DNA checkpoints are signal transduction pathways that sense DNA damage and coordinate various responses such as cell cycle arrests, DNA repair or cell death. These pathways are particularly well conserved in eukaryotes and the family of the 'Checkpoint Kinases 2' genes (or CHK2) plays a major role in them. This family includes the Rad53 protein of the yeast Saccharomyces cerevisiae and its Chk2 human homologue. Rad53 plays a central part in DNA checkpoint: rad53d mutants (whose RAD53 gene has been deleted) are hypersensitive to all genotoxic stresses. Mice Chk2-1- cells are defective in the G1, the intra-S, and the G2/M checkpoints. Mutations in CHK2 have been associated to many forms o f cancer, either sporadic or hereditary which demonstrates Chk2 tumor suppressor function. Chk2 proteins are characterized by several conserved elements: (i) an N-terminal domain with a series of SQ/TQ motifs, preferential phosphorylation sites for the ATM/ATR kinases, (ii) an FHA domain (ForkHead Associated) that binds specifically to phosphorylated residues within TXXY motifs (with the Y residue depending on the FHA domain and conferring an extra specificity) and (iii) a kinase domain including an activation loop. The Chk2 protein is activated by phosphorylation of its threonine T68, mainly by ATM, upon DNA double-strand breaks. This phosphorylation allows for the homo-dimerization of Chk2 through the binding of phospho-T68 from one molecule to the FHA domain of another molecule. It results in trans auto-phosphorylations, especially at threonines T383 and T387 in the activation T-loop. Fully active Chk2 becomes monomeric and, diffusing through the whole nucleus, phosphorylates its targets (CDC25 A and CDC25C/cell cycle arrest; p53, E2F, PML/apoptosis; BRCA2/DNA repair). Chk2/Rad53 inactivation occurs in two cases: once the DNA lesions have been repaired (it is called recovery) or, under certain conditions, in the presence of unrepaired DNA damage (it is then called

The wip1 phosphatase (PPM1D) antagonizes activation of the CHK2 tumor suppressor kinase

International Nuclear Information System (INIS)

Manet, Oliva-Trastoy; Berthonaud, V.; Chevalier, A.; Ducrot, C.; Marsolier-Kergoat, M.C.; Mann, C.; Leteurtre, F.

2006-01-01

The DNA checkpoints are signal transduction pathways that sense DNA damage and coordinate various responses such as cell cycle arrests, DNA repair or cell death. These pathways are particularly well conserved in eukaryotes and the family of the 'Checkpoint Kinases 2' genes (or CHK2) plays a major role in them. This family includes the Rad53 protein of the yeast Saccharomyces cerevisiae and its Chk2 human homologue. Rad53 plays a central part in DNA checkpoint: rad53d mutants (whose RAD53 gene has been deleted) are hypersensitive to all genotoxic stresses. Mice Chk2-1- cells are defective in the G1, the intra-S, and the G2/M checkpoints. Mutations in CHK2 have been associated to many forms o f cancer, either sporadic or hereditary which demonstrates Chk2 tumor suppressor function. Chk2 proteins are characterized by several conserved elements: (i) an N-terminal domain with a series of SQ/TQ motifs, preferential phosphorylation sites for the ATM/ATR kinases, (ii) an FHA domain (ForkHead Associated) that binds specifically to phosphorylated residues within TXXY motifs (with the Y residue depending on the FHA domain and conferring an extra specificity) and (iii) a kinase domain including an activation loop. The Chk2 protein is activated by phosphorylation of its threonine T68, mainly by ATM, upon DNA double-strand breaks. This phosphorylation allows for the homo-dimerization of Chk2 through the binding of phospho-T68 from one molecule to the FHA domain of another molecule. It results in trans auto-phosphorylations, especially at threonines T383 and T387 in the activation T-loop. Fully active Chk2 becomes monomeric and, diffusing through the whole nucleus, phosphorylates its targets (CDC25 A and CDC25C/cell cycle arrest; p53, E2F, PML/apoptosis; BRCA2/DNA repair). Chk2/Rad53 inactivation occurs in two cases: once the DNA lesions have been repaired (it is called recovery) or, under certain conditions, in the presence of unrepaired DNA damage (it is then called adaptation

Insulin stimulates the expression of the SHARP-1 gene via multiple signaling pathways.

Science.gov (United States)

Takagi, K; Asano, K; Haneishi, A; Ono, M; Komatsu, Y; Yamamoto, T; Tanaka, T; Ueno, H; Ogawa, W; Tomita, K; Noguchi, T; Yamada, K

2014-06-01

The rat enhancer of split- and hairy-related protein-1 (SHARP-1) is a basic helix-loop-helix transcription factor. An issue of whether SHARP-1 is an insulin-inducible transcription factor was examined. Insulin rapidly increased the level of SHARP-1 mRNA both in vivo and in vitro. Then, signaling pathways involved with the increase of SHARP-1 mRNA by insulin were determined in H4IIE rat hepatoma cells. Pretreatments with LY294002, wortmannin, and staurosporine completely blocked the induction effect, suggesting the involvement of both phosphoinositide 3-kinase (PI 3-K) and protein kinase C (PKC) pathways. In fact, overexpression of a dominant negative form of atypical protein kinase C lambda (aPKCλ) significantly decreased the induction of the SHARP-1 mRNA. In addition, inhibitors for the small GTPase Rac or Jun N-terminal kinase (JNK) also blocked the induction of SHARP-1 mRNA by insulin. Overexpression of a dominant negative form of Rac1 prevented the activation by insulin. Furthermore, actinomycin D and cycloheximide completely blocked the induction of SHARP-1 mRNA by insulin. Finally, when a SHARP-1 expression plasmid was transiently transfected with various reporter plasmids into H4IIE cells, the promoter activity of PEPCK reporter plasmid was specifically decreased. Thus, we conclude that insulin induces the SHARP-1 gene expression at the transcription level via a both PI 3-K/aPKCλ/JNK- and a PI 3-K/Rac/JNK-signaling pathway; protein synthesis is required for this induction; and that SHARP-1 is a potential repressor of the PEPCK gene expression. © Georg Thieme Verlag KG Stuttgart · New York.

The NDR kinase scaffold HYM1/MO25 is essential for MAK2 map kinase signaling in Neurospora crassa.

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Anne Dettmann

2012-09-01

Full Text Available Cell communication is essential for eukaryotic development, but our knowledge of molecules and mechanisms required for intercellular communication is fragmentary. In particular, the connection between signal sensing and regulation of cell polarity is poorly understood. In the filamentous ascomycete Neurospora crassa, germinating spores mutually attract each other and subsequently fuse. During these tropic interactions, the two communicating cells rapidly alternate between two different physiological states, probably associated with signal delivery and response. The MAK2 MAP kinase cascade mediates cell-cell signaling. Here, we show that the conserved scaffolding protein HYM1/MO25 controls the cell shape-regulating NDR kinase module as well as the signal-receiving MAP kinase cascade. HYM1 functions as an integral part of the COT1 NDR kinase complex to regulate the interaction with its upstream kinase POD6 and thereby COT1 activity. In addition, HYM1 interacts with NRC1, MEK2, and MAK2, the three kinases of the MAK2 MAP kinase cascade, and co-localizes with MAK2 at the apex of growing cells. During cell fusion, the three kinases of the MAP kinase module as well as HYM1 are recruited to the point of cell-cell contact. hym-1 mutants phenocopy all defects observed for MAK2 pathway mutants by abolishing MAK2 activity. An NRC1-MEK2 fusion protein reconstitutes MAK2 signaling in hym-1, while constitutive activation of NRC1 and MEK2 does not. These data identify HYM1 as a novel regulator of the NRC1-MEK2-MAK2 pathway, which may coordinate NDR and MAP kinase signaling during cell polarity and intercellular communication.

[Changes of biological behavioral of E. coli K1 after ppk1 gene deletion].

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Peng, Liang; Pan, Jiayun; Luo, Su; Yang, Zhenghui; Huang, Mufang; Cao, Hong

2014-06-01

To study the changes in biological behaviors of meningitis E. coli K1 strain E44 after deletion of polyphosphate kinase 1 (ppk1) gene and explore the role of ppk1 in the pathogenesis of E. coli K1-induced meningitis. The wild-type strain E. coli K1 and ppk1 deletion mutant were exposed to heat at 56 degrees celsius; for 6 min, and their survival rates were determined. The adhesion and invasion of the bacteria to human brain microvascular endothelial cells (HBMECs) were observed using electron microscopy and quantitative tests. HBMECs were co-incubated with wild-type strain or ppk1 deletion mutant, and the cytoskeleton rearrangement was observed under laser scanning confocal microscope. The survival rate of the ppk1 deletion mutant was significantly lower than that of the wild-type strain after heat exposure. The ppk1 deletion mutant also showed lowered cell adhesion and invasion abilities and weakened ability to induce cytoskeleton rearrangement in HBMECs. ppk1 gene is important for E.coli K1 for heat resistance, cell adhesion and invasion, and for inducing cytoskeletal rearrangement in HBMECs.

Regulation of cellular sphingosine-1-phosphate by sphingosine kinase 1 and sphingosine-1-phopshate lyase determines chemotherapy resistance in gastroesophageal cancer

International Nuclear Information System (INIS)

Matula, Kasia; Collie-Duguid, Elaina; Murray, Graeme; Parikh, Khyati; Grabsch, Heike; Tan, Patrick; Lalwani, Salina; Garau, Roberta; Ong, Yuhan; Bain, Gillian; Smith, Asa-Dahle; Urquhart, Gordon; Bielawski, Jacek; Finnegan, Michael; Petty, Russell

2015-01-01

Resistance to chemotherapy is common in gastroesophageal cancer. Mechanisms of resistance are incompletely characterised and there are no predictive biomarkers in clinical practice for cytotoxic drugs. We used new cell line models to characterise novel chemotherapy resistance mechanisms and validated them in tumour specimens to identify new targets and biomarkers for gastroesophageal cancer. Cell lines were selected for resistance to oxaliplatin, cisplatin and docetaxel and gene expression examined using Affymetrix Exon 1.0 ST arrays. Leads were validated by qRT-PCR and HPLC of tumour metabolites. Protein expression and pharmacological inhibition of lead target SPHK1 was evaluated in independent cell lines, and by immunohistochemistry in gastroesophageal cancer patients. Genes with differential expression in drug resistant cell lines compared to the parental cell line they were derived from, were identified for each drug resistant cell line. Biological pathway analysis of these gene lists, identified over-represented pathways, and only 3 pathways - lysosome, sphingolipid metabolism and p53 signalling- were identified as over-represented in these lists for all three cytotoxic drugs investigated. The majority of genes differentially expressed in chemoresistant cell lines from these pathways, were involved in metabolism of glycosphingolipids and sphingolipids in lysosomal compartments suggesting that sphingolipids might be important mediators of cytotoxic drug resistance in gastroeosphageal cancers . On further investigation, we found that drug resistance (IC50) was correlated with increased sphingosine kinase 1(SPHK1) mRNA and also with decreased sphingosine-1-phosphate lysase 1(SGPL1) mRNA. SPHK1 and SGPL1 gene expression were inversely correlated. SPHK1:SGPL1 ratio correlated with increased cellular sphingosine-1-phosphate (S1P), and S1P correlated with drug resistance (IC50). High SPHK1 protein correlated with resistance to cisplatin (IC50) in an independent

Gene expression analysis after receptor tyrosine kinase activation reveals new potential melanoma proteins

International Nuclear Information System (INIS)

Teutschbein, Janka; Haydn, Johannes M; Samans, Birgit; Krause, Michael; Eilers, Martin; Schartl, Manfred; Meierjohann, Svenja

2010-01-01

Melanoma is an aggressive tumor with increasing incidence. To develop accurate prognostic markers and targeted therapies, changes leading to malignant transformation of melanocytes need to be understood. In the Xiphophorus melanoma model system, a mutated version of the EGF receptor Xmrk (Xiphophorus melanoma receptor kinase) triggers melanomagenesis. Cellular events downstream of Xmrk, such as the activation of Akt, Ras, B-Raf or Stat5, were also shown to play a role in human melanomagenesis. This makes the elucidation of Xmrk downstream targets a useful method for identifying processes involved in melanoma formation. Here, we analyzed Xmrk-induced gene expression using a microarray approach. Several highly expressed genes were confirmed by realtime PCR, and pathways responsible for their induction were revealed using small molecule inhibitors. The expression of these genes was also monitored in human melanoma cell lines, and the target gene FOSL1 was knocked down by siRNA. Proliferation and migration of siRNA-treated melanoma cell lines were then investigated. Genes with the strongest upregulation after receptor activation were FOS-like antigen 1 (Fosl1), early growth response 1 (Egr1), osteopontin (Opn), insulin-like growth factor binding protein 3 (Igfbp3), dual-specificity phosphatase 4 (Dusp4), and tumor-associated antigen L6 (Taal6). Interestingly, most genes were blocked in presence of a SRC kinase inhibitor. Importantly, we found that FOSL1, OPN, IGFBP3, DUSP4, and TAAL6 also exhibited increased expression levels in human melanoma cell lines compared to human melanocytes. Knockdown of FOSL1 in human melanoma cell lines reduced their proliferation and migration. Altogether, the data show that the receptor tyrosine kinase Xmrk is a useful tool in the identification of target genes that are commonly expressed in Xmrk-transgenic melanocytes and melanoma cell lines. The identified molecules constitute new possible molecular players in melanoma development

Gene expression analysis after receptor tyrosine kinase activation reveals new potential melanoma proteins

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Krause Michael

2010-07-01

Full Text Available Abstract Background Melanoma is an aggressive tumor with increasing incidence. To develop accurate prognostic markers and targeted therapies, changes leading to malignant transformation of melanocytes need to be understood. In the Xiphophorus melanoma model system, a mutated version of the EGF receptor Xmrk (Xiphophorus melanoma receptor kinase triggers melanomagenesis. Cellular events downstream of Xmrk, such as the activation of Akt, Ras, B-Raf or Stat5, were also shown to play a role in human melanomagenesis. This makes the elucidation of Xmrk downstream targets a useful method for identifying processes involved in melanoma formation. Methods Here, we analyzed Xmrk-induced gene expression using a microarray approach. Several highly expressed genes were confirmed by realtime PCR, and pathways responsible for their induction were revealed using small molecule inhibitors. The expression of these genes was also monitored in human melanoma cell lines, and the target gene FOSL1 was knocked down by siRNA. Proliferation and migration of siRNA-treated melanoma cell lines were then investigated. Results Genes with the strongest upregulation after receptor activation were FOS-like antigen 1 (Fosl1, early growth response 1 (Egr1, osteopontin (Opn, insulin-like growth factor binding protein 3 (Igfbp3, dual-specificity phosphatase 4 (Dusp4, and tumor-associated antigen L6 (Taal6. Interestingly, most genes were blocked in presence of a SRC kinase inhibitor. Importantly, we found that FOSL1, OPN, IGFBP3, DUSP4, and TAAL6 also exhibited increased expression levels in human melanoma cell lines compared to human melanocytes. Knockdown of FOSL1 in human melanoma cell lines reduced their proliferation and migration. Conclusion Altogether, the data show that the receptor tyrosine kinase Xmrk is a useful tool in the identification of target genes that are commonly expressed in Xmrk-transgenic melanocytes and melanoma cell lines. The identified molecules constitute

Therapeutic Value of PLK1 Knockdown in Combination with Prostate Cancer Drugs in PIM-1 Overexpressing Prostate Cancer Cells

Science.gov (United States)

2014-11-13

targeting a total of 570 genes involved in key cancer relevant pathways (111 cell cycle, 318 apoptosis, 87 serine- threonine kinase and 54 tyrosine kinase...siRNAs that target genes encoding selected serine/threonine kinases, tyrosine kinases, cell cycle protein and apoptosis proteins to identify genes...PIM1 (Santa Cruz, sc-13513), PLK1 (Santa Cruz, sc-17783), phospho-PLK1 (Thr 210; Cell Signaling, #5472), phospho-histone H3 (Upstate, #06- 570 ), cleaved

Sensitization of TRPA1 by Protein Kinase A.

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Jannis E Meents

Full Text Available The TRPA1 ion channel is expressed in nociceptive (pain-sensitive somatosensory neurons and is activated by a wide variety of chemical irritants, such as acrolein in smoke or isothiocyanates in mustard. Here, we investigate the enhancement of TRPA1 function caused by inflammatory mediators, which is thought to be important in lung conditions such as asthma and COPD. Protein kinase A is an important kinase acting downstream of inflammatory mediators to cause sensitization of TRPA1. By using site-directed mutagenesis, patch-clamp electrophysiology and calcium imaging we identify four amino acid residues, S86, S317, S428, and S972, as the principal targets of PKA-mediated phosphorylation and sensitization of TRPA1.

Carboxylesterase 1 genes

DEFF Research Database (Denmark)

Rasmussen, Henrik Berg; Madsen, Majbritt Busk

2018-01-01

The carboxylesterase 1 gene (CES1) encodes a hydrolase that metabolizes commonly used drugs. The CES1-related pseudogene, carboxylesterase 1 pseudogene 1 (CES1P1), has been implicated in gene exchange with CES1 and in the formation of hybrid genes including the carboxylesterase 1A2 gene (CES1A2...

Purification and characterization of the three Snf1-activating kinases of Saccharomyces cerevisiae.

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Elbing, Karin; McCartney, Rhonda R; Schmidt, Martin C

2006-02-01

Members of the Snf1/AMPK family of protein kinases are activated by distinct upstream kinases that phosphorylate a conserved threonine residue in the Snf1/AMPK activation loop. Recently, the identities of the Snf1- and AMPK-activating kinases have been determined. Here we describe the purification and characterization of the three Snf1-activating kinases of Saccharomyces cerevisiae. The identities of proteins associated with the Snf1-activating kinases were determined by peptide mass fingerprinting. These kinases, Sak1, Tos3 and Elm2 do not appear to require the presence of additional subunits for activity. Sak1 and Snf1 co-purify and co-elute in size exclusion chromatography, demonstrating that these two proteins form a stable complex. The Snf1-activating kinases phosphorylate the activation loop threonine of Snf1 in vitro with great specificity and are able to do so in the absence of beta and gamma subunits of the Snf1 heterotrimer. Finally, we showed that the Snf1 kinase domain isolated from bacteria as a GST fusion protein can be activated in vitro and shows substrate specificity in the absence of its beta and gamma subunits.

Purification and characterization of the three Snf1-activating kinases of Saccharomyces cerevisiae

OpenAIRE

Elbing, Karin; McCartney, Rhonda R.; Schmidt, Martin C.

2006-01-01

Members of the Snf1/AMPK family of protein kinases are activated by distinct upstream kinases that phosphorylate a conserved threonine residue in the Snf1/AMPK activation loop. Recently, the identities of the Snf1- and AMPK-activating kinases have been determined. Here we describe the purification and characterization of the three Snf1-activating kinases of Saccharomyces cerevisiae. The identities of proteins associated with the Snf1-activating kinases were determined by peptide mass fingerpr...

Differential effect of CLK SR Kinases on HIV-1 gene expression: potential novel targets for therapy

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Dobson Wendy

2011-06-01

Full Text Available Abstract Background RNA processing plays a critical role in the replication of HIV-1, regulated in part through the action of host SR proteins. To explore the impact of modulating SR protein activity on virus replication, the effect of increasing or inhibiting the activity of the Cdc2-like kinase (CLK family of SR protein kinases on HIV-1 expression and RNA processing was examined. Results Despite their high homology, increasing individual CLK expression had distinct effects on HIV-1, CLK1 enhancing Gag production while CLK2 inhibited the virus. Parallel studies on the anti-HIV-1 activity of CLK inhibitors revealed a similar discrepant effect on HIV-1 expression. TG003, an inhibitor of CLK1, 2 and 4, had no effect on viral Gag synthesis while chlorhexidine, a CLK2, 3 and 4 inhibitor, blocked virus production. Chlorhexidine treatment altered viral RNA processing, decreasing levels of unspliced and single spliced viral RNAs, and reduced Rev accumulation. Subsequent experiments in the context of HIV-1 replication in PBMCs confirmed the capacity of chlorhexidine to suppress virus replication. Conclusions Together, these findings establish that HIV-1 RNA processing can be targeted to suppress virus replication as demonstrated by manipulating individual CLK function and identified chlorhexidine as a lead compound in the development of novel anti-viral therapies.

Analysis of Kinase Gene Expression in the Frontal Cortex of Suicide Victims: Implications of Fear and Stress

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Kwang eChoi

2011-07-01

Full Text Available Suicide is a serious public health issue that results from an interaction between multiple risk factors including individual vulnerabilities to complex feelings of hopelessness, fear and stress. Although kinase genes have been implicated in fear and stress, including the consolidation and extinction of fearful memories, expression profiles of those genes in the brain of suicide victims are less clear. Using gene expression microarray data from the Online Stanley Genomics Database (www.stanleygenomics.org and a quantitative PCR, we investigated the expression profiles of multiple kinase genes including the calcium calmodulin-dependent kinase (CAMK, the cyclin-dependent kinase (CDK, the mitogen-activated protein kinase (MAPK, and the protein kinase C (PKC in the prefrontal cortex (PFC of mood disorder patients died with suicide (n=45 and without suicide (N=38. We also investigated the expression pattern of the same genes in the PFC of developing humans ranging in age from birth to 49 year (n=46. The expression levels of CAMK2B, CDK5, MAPK9, and PRKCI were increased in the PFC of suicide victims as compared to non-suicide controls (FDR-adjusted p < 0.05, fold change > 1.1. Those genes also showed changes in expression pattern during the postnatal development (FDR-adjusted p < 0.05. These results suggest that multiple kinase genes undergo age-dependent changes in normal brains as well as pathological changes in suicide brains. These findings may provide an important link to protein kinases known to be important for the development of fear memory, stress-associated neural plasticity and up-regulation in the PFC of suicide victims. More research is needed to better understand the functional role of these kinase genes that may be associated with the pathophysiology of suicide.

Mitogen activated protein kinases selectively regulate palytoxin-stimulated gene expression in mouse keratinocytes

International Nuclear Information System (INIS)

Zeliadt, Nicholette A.; Warmka, Janel K.; Wattenberg, Elizabeth V.

2003-01-01

We have been investigating how the novel skin tumor promoter palytoxin transmits signals through mitogen activated protein kinases (MAPKs). Palytoxin activates three major MAPKs, extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38, in a keratinocyte cell line derived from initiated mouse skin (308). We previously showed that palytoxin requires ERK to increase matrix metalloproteinase-13 (MMP-13) gene expression, an enzyme implicated in carcinogenesis. Diverse stimuli require JNK and p38 to increase MMP-13 gene expression, however. We therefore used the JNK and p38 inhibitors SP 600125 and SB 202190, respectively, to investigate the role of these MAPKs in palytoxin-induced MMP-13 gene expression. Surprisingly, palytoxin does not require JNK and p38 to increase MMP-13 gene expression. Accordingly, ERK activation, independent of palytoxin and in the absence of JNK and p38 activation, is sufficient to induce MMP-13 gene expression in 308 keratinocytes. Dexamethasone, a synthetic glucocorticoid that inhibits activator protein-1 (AP-1), blocked palytoxin-stimulated MMP-13 gene expression. Therefore, the AP-1 site present in the promoter of the MMP-13 gene appears to be functional and to play a key role in palytoxin-stimulated gene expression. Previous studies showed that palytoxin simulates an ERK-dependent selective increase in the c-Fos content of AP-1 complexes that bind to the promoter of the MMP-13 gene. JNK and p38 can also modulate c-Fos. Palytoxin does not require JNK or p38 to increase c-Fos binding, however. Altogether, these studies indicate that ERK plays a distinctly essential role in transmitting palytoxin-stimulated signals to specific nuclear targets in keratinocytes derived from initiated mouse skin

Subunits of the Snf1 kinase heterotrimer show interdependence for association and activity.

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Elbing, Karin; Rubenstein, Eric M; McCartney, Rhonda R; Schmidt, Martin C

2006-09-08

The Snf1 kinase and its mammalian orthologue, the AMP-activated protein kinase (AMPK), function as heterotrimers composed of a catalytic alpha-subunit and two non-catalytic subunits, beta and gamma. The beta-subunit is thought to hold the complex together and control subcellular localization whereas the gamma-subunit plays a regulatory role by binding to and blocking the function of an auto-inhibitory domain (AID) present in the alpha-subunit. In addition, catalytic activity requires phosphorylation by a distinct upstream kinase. In yeast, any one of three Snf1-activating kinases, Sak1, Tos3, or Elm1, can fulfill this role. We have previously shown that Sak1 is the only Snf1-activating kinase that forms a stable complex with Snf1. Here we show that the formation of the Sak1.Snf1 complex requires the beta- and gamma-subunits in vivo. However, formation of the Sak1.Snf1 complex is not necessary for glucose-regulated phosphorylation of the Snf1 activation loop. Snf1 kinase purified from cells lacking the beta-subunits do not contain any gamma-subunit, indicating that the Snf1 kinase does not form a stable alphagamma dimer in vivo. In vitro kinase assays using purified full-length and truncated Snf1 proteins demonstrate that the kinase domain, which lacks the AID, is significantly more active than the full-length Snf1 protein. Addition of purified beta- and gamma-subunits could stimulate the kinase activity of the full-length alpha-subunit but only when all three subunits were present, suggesting an interdependence of all three subunits for assembly of a functional complex.

PNL1 and PNL2 : Arabidopsis homologs of maize PAN1

OpenAIRE

Clark, Lauren Gail

2010-01-01

PNL1 and PNL2 are the closest Arabidopsis relatives of maize pan1. pan1 and the PNL family of 11 genes encode leucine-rich repeat, receptor-like kinases, however none of these putative kinases is predicted to have actual kinase function, due to one or more amino acid substitutions in residues necessary for kinase function. Because PAN1 plays a role in subsidiary cell formation in maize, it is hypothesized that PNL1 and PNL2 are involved in stomatal formation in Arabidopsis. YFP fusions of the...

Functional, genetic and bioinformatic characterization of a calcium/calmodulin kinase gene in Sporothrix schenckii

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Rodriguez-del Valle Nuri

2007-11-01

Full Text Available Abstract Background Sporothrix schenckii is a pathogenic, dimorphic fungus, the etiological agent of sporotrichosis, a subcutaneous lymphatic mycosis. Dimorphism in S. schenckii responds to second messengers such as cAMP and calcium, suggesting the possible involvement of a calcium/calmodulin kinase in its regulation. In this study we describe a novel calcium/calmodulin-dependent protein kinase gene in S. schenckii, sscmk1, and the effects of inhibitors of calmodulin and calcium/calmodulin kinases on the yeast to mycelium transition and the yeast cell cycle. Results Using the PCR homology approach a new member of the calcium/calmodulin kinase family, SSCMK1, was identified in this fungus. The cDNA sequence of sscmk1 revealed an open reading frame of 1,221 nucleotides encoding a 407 amino acid protein with a predicted molecular weight of 45.6 kDa. The genomic sequence of sscmk1 revealed the same ORF interrupted by five introns. Bioinformatic analyses of SSCMK1 showed that this protein had the distinctive features that characterize a calcium/calmodulin protein kinase: a serine/threonine protein kinase domain and a calmodulin-binding domain. When compared to homologues from seven species of filamentous fungi, SSCMK1 showed substantial similarities, except for a large and highly variable region that encompasses positions 330 – 380 of the multiple sequence alignment. Inhibition studies using calmodulin inhibitor W-7, and calcium/calmodulin kinase inhibitors, KN-62 and lavendustin C, were found to inhibit budding by cells induced to re-enter the yeast cell cycle and to favor the yeast to mycelium transition. Conclusion This study constitutes the first evidence of the presence of a calcium/calmodulin kinase-encoding gene in S. schenckii and its possible involvement as an effector of dimorphism in this fungus. These results suggest that a calcium/calmodulin dependent signaling pathway could be involved in the regulation of dimorphism in this fungus

RhMKK9, a rose MAP KINASE KINASE gene, is involved in rehydration-triggered ethylene production in rose gynoecia.

Science.gov (United States)

Chen, Jiwei; Zhang, Qian; Wang, Qigang; Feng, Ming; Li, Yang; Meng, Yonglu; Zhang, Yi; Liu, Guoqin; Ma, Zhimin; Wu, Hongzhi; Gao, Junping; Ma, Nan

2017-02-23

Flower opening is an important process in the life cycle of flowering plants and is influenced by various endogenous and environmental factors. Our previous work demonstrated that rose (Rosa hybrida) flowers are highly sensitive to dehydration during flower opening and the water recovery process after dehydration induced ethylene production rapidly in flower gynoecia. In addition, this temporal- and spatial-specific ethylene production is attributed to a transient but robust activation of the rose MAP KINASE6-ACC SYNTHASE1 (RhMPK6-RhACS1) cascade in gynoecia. However, the upstream component of RhMPK6-RhACS1 is unknown, although RhMKK9 (MAP KINASE KINASE9), a rose homologue of Arabidopsis MKK9, could activate RhMPK6 in vitro. In this study, we monitored RhMKK2/4/5/9 expression, the potential upstream kinase to RhMPK6, in rose gynoecia during dehydration and rehydration. We found only RhMKK9 was rapidly and strongly induced by rehydration. Silencing of RhMKK9 significantly decreased rehydration-triggered ethylene production. Consistently, the expression of several ethylene-responsive genes was down regulated in the petals of RhMKK9-silenced flowers. Moreover, we detected the DNA methylation level in the promoter and gene body of RhMKK9 by Chop-PCR. The results showed that rehydration specifically elevated the DNA methylation level on the RhMKK9 gene body, whereas it resulted in hypomethylation in its promoter. Our results showed that RhMKK9 possibly acts as the upstream component of the RhMKK9-RhMPK6-RhACS1 cascade and is responsible for water recovery-triggered ethylene production in rose gynoecia, and epigenetic DNA methylation is involved in the regulation of RhMKK9 expression by rehydration.

KSHV encoded LANA upregulates Pim-1 and is a substrate for its kinase activity

International Nuclear Information System (INIS)

Bajaj, Bharat G.; Verma, Subhash C.; Lan, Ke; Cotter, Murray A.; Woodman, Zenda L.; Robertson, Erle S.

2006-01-01

Pim kinases are proto-oncogenes that are upregulated in a number of B cell cancers, including Epstein-Barr Virus (EBV) associated Burkitt's lymphoma. They have also been shown to be upregulated in Kaposi sarcoma-associated herpes virus (KSHV) infected primary B cells. Most cells in KSHV-associated tumors are latently infected and express only a small subset of viral genes, with KSHV latency associated nuclear antigen (LANA) being constitutively expressed. LANA regulates the transcription of a large number of cellular and viral genes. Here, we show that LANA upregulates transcription from the Pim-1 promoter (pPim-1) and map this activation to a region in the promoter located within the sequence (-681 to +37). We show that LANA expressing cells can proliferate faster and are better protected from drug induced apoptosis. Since transition through cell cycle check points and anti-apoptosis are functions associated with Pim-1, it is likely that higher Pim-1 expression in cells expressing LANA is responsible, at least in part, for this effect. A Pim-1 phosphorylation site was also identified within the amino-terminal domain of LANA. Using in vitro kinase assays, we confirmed that LANA was indeed a Pim-1 substrate, and the failure of Pim-1 to phosphorylate LANA mutated at SS205/6RR identified this site as the specific serine residues phosphorylated by Pim-1. This report provides valuable insight into yet another cellular signaling pathway subverted by KSHV LANA and suggests a contribution to KSHV related oncogenesis

Role of nongenomic activation of phosphatidylinositol 3-kinase/Akt and mitogen-activated protein kinase/extracellular signal-regulated kinase kinase/extracellular signal-regulated kinase 1/2 pathways in 1,25D3-mediated apoptosis in squamous cell carcinoma cells.

Science.gov (United States)

Ma, Yingyu; Yu, Wei-Dong; Kong, Rui-Xian; Trump, Donald L; Johnson, Candace S

2006-08-15

Vitamin D is a steroid hormone that regulates calcium homeostasis and bone metabolism. The active form of vitamin D [1 alpha,25-dihydroxyvitamin D(3) (1,25D3)] acts through both genomic and nongenomic pathways. 1,25D3 has antitumor effects in a variety of cancers, including colorectal, prostate, breast, ovarian, and skin cancers. 1,25D3 exerts growth-inhibitory effects in cancer cells through the induction of apoptosis, cell cycle arrest, and differentiation. The mechanisms regulating 1,25D3-induced apoptosis remain unclear. We investigated the role of nongenomic signaling in 1,25D3-mediated apoptosis in squamous cell carcinoma (SCC) cells. 1,25D3 induced rapid and sustained activation of phosphatidylinositol 3-kinase/Akt and mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK) 1/2 pathways in SCC cells. These effects were nongenomic: they occurred rapidly and were not inhibited by cycloheximide or actinomycin D. To examine whether the nongenomic activation of Akt and ERK1/2 plays a role in 1,25D3-mediated apoptosis, the expression of Akt or ERK1/2 was reduced by small interfering RNA (siRNA). siRNA-Akt significantly enhanced 1,25D3-induced apoptosis as indicated by increased levels of Annexin V-positive cells and increased sub-G(1) population and DNA fragmentation. In contrast, siRNA-ERK1/2 had no effects on 1,25D3-induced apoptosis. In addition, siRNA-Akt transfection followed by 1,25D3 treatment induced apoptosis much sooner than 1,25D3 alone. siRNA-Akt and 1,25D3 induced caspase-10 activation, suppressed the expression of c-IAP1 and XIAP, and promoted 1,25D3-induced caspase-3 activation. These results support a link between 1,25D3-induced nongenomic signaling and apoptosis. 1,25D3 induces the activation of phosphatidylinositol 3-kinase/Akt, which suppresses 1,25D3-mediated apoptosis and prolongs the survival of SCC cells.

Induced overexpression of protein kinase D1 stimulates mitogenic signaling in human pancreatic carcinoma PANC-1 cells.

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Kisfalvi, Krisztina; Hurd, Cliff; Guha, Sushovan; Rozengurt, Enrique

2010-05-01

Neurotensin (NT) stimulates protein kinase D1 (PKD1), extracellular signal regulated kinase (ERK), c-Jun N-terminal Kinase (JNK), and DNA synthesis in the human pancreatic adenocarcinoma cell line PANC-1. To determine the effect of PKD1 overexpression on these biological responses, we generated inducible stable PANC-1 clones that express wild-type (WT) or kinase-dead (K618N) forms of PKD1 in response to the ecdysone analog ponasterone-A (PonA). NT potently stimulated c-Jun Ser(63) phosphorylation in both wild type and clonal derivatives of PANC-1 cells. PonA-induced expression of WT, but not K618N PKD1, rapidly blocked NT-mediated c-Jun Ser(63) phosphorylation either at the level of or upstream of MKK4, a dual-specificity kinase that leads to JNK activation. This is the first demonstration that PKD1 suppresses NT-induced JNK/cJun activation in PANC-1 cells. In contrast, PKD1 overexpression markedly increased the duration of NT-induced ERK activation in these cells. The reciprocal influence of PKD1 signaling on pro-mitogenicERK and pro-apopotic JNK/c-Jun pathways prompted us to examine whether PKD1 overexpression promotes DNA synthesis and proliferation of PANC-1 cells. Our results show that PKD1 overexpression increased DNA synthesis and cell numbers of PANC-1 cells cultured in regular dishes or in polyhydroxyethylmethacrylate [Poly-(HEMA)]-coated dishes to eliminate cell adhesion (anchorage-independent growth). Furthermore, PKD1 overexpression markedly enhanced DNA synthesis induced by NT (1-10 nM). These results indicate that PKD1 mediates mitogenic signaling in PANC-1 and suggests that this enzyme could be a novel target for the development of therapeutic drugs that restrict the proliferation of these cells.

Cyclin-dependent kinase suppression by WEE1 kinase protects the genome through control of replication initiation and nucleotide consumption

DEFF Research Database (Denmark)

Beck, Halfdan; Nähse-Kumpf, Viola; Larsen, Marie Sofie Yoo

2012-01-01

Activation of oncogenes or inhibition of WEE1 kinase deregulates Cyclin-dependent kinase (CDK) activity and leads to replication stress, however, the underlying mechanism is not understood. We now show that elevation of CDK activity by inhibiting WEE1 kinase rapidly increases initiation of replic......Activation of oncogenes or inhibition of WEE1 kinase deregulates Cyclin-dependent kinase (CDK) activity and leads to replication stress, however, the underlying mechanism is not understood. We now show that elevation of CDK activity by inhibiting WEE1 kinase rapidly increases initiation...... of replication. This leads to nucleotide shortage and reduces replication fork speed, which is followed by SLX4/MUS81-mediated DNA double-strand breakage. Fork speed is normalized and DNA double-strand break (DSB) formation is suppressed when CDT1, a key factor for replication initiation, is depleted...

Phosphorylation of Dgk1 Diacylglycerol Kinase by Casein Kinase II Regulates Phosphatidic Acid Production in Saccharomyces cerevisiae.

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Qiu, Yixuan; Hassaninasab, Azam; Han, Gil-Soo; Carman, George M

2016-12-16

In the yeast Saccharomyces cerevisiae, Dgk1 diacylglycerol (DAG) kinase catalyzes the CTP-dependent phosphorylation of DAG to form phosphatidic acid (PA). The enzyme in conjunction with Pah1 PA phosphatase controls the levels of PA and DAG for the synthesis of triacylglycerol and membrane phospholipids, the growth of the nuclear/endoplasmic reticulum membrane, and the formation of lipid droplets. Little is known about how DAG kinase activity is regulated by posttranslational modification. In this work, we examined the phosphorylation of Dgk1 DAG kinase by casein kinase II (CKII). When phosphate groups were globally reduced using nonspecific alkaline phosphatase, Triton X-100-solubilized membranes from DGK1-overexpressing cells showed a 7.7-fold reduction in DAG kinase activity; the reduced enzyme activity could be increased 5.5-fold by treatment with CKII. Dgk1(1-77) expressed heterologously in Escherichia coli was phosphorylated by CKII on a serine residue, and its phosphorylation was dependent on time as well as on the concentrations of CKII, ATP, and Dgk1(1-77). We used site-specific mutagenesis, coupled with phosphorylation analysis and phosphopeptide mapping, to identify Ser-45 and Ser-46 of Dgk1 as the CKII target sites, with Ser-46 being the major phosphorylation site. In vivo, the S46A and S45A/S46A mutations of Dgk1 abolished the stationary phase-dependent stimulation of DAG kinase activity. In addition, the phosphorylation-deficient mutations decreased Dgk1 function in PA production and in eliciting pah1Δ phenotypes, such as the expansion of the nuclear/endoplasmic reticulum membrane, reduced lipid droplet formation, and temperature sensitivity. This work demonstrates that the CKII-mediated phosphorylation of Dgk1 regulates its function in the production of PA. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Phosphorylation of Dgk1 Diacylglycerol Kinase by Casein Kinase II Regulates Phosphatidic Acid Production in Saccharomyces cerevisiae*

Science.gov (United States)

Qiu, Yixuan; Hassaninasab, Azam; Han, Gil-Soo; Carman, George M.

2016-01-01

In the yeast Saccharomyces cerevisiae, Dgk1 diacylglycerol (DAG) kinase catalyzes the CTP-dependent phosphorylation of DAG to form phosphatidic acid (PA). The enzyme in conjunction with Pah1 PA phosphatase controls the levels of PA and DAG for the synthesis of triacylglycerol and membrane phospholipids, the growth of the nuclear/endoplasmic reticulum membrane, and the formation of lipid droplets. Little is known about how DAG kinase activity is regulated by posttranslational modification. In this work, we examined the phosphorylation of Dgk1 DAG kinase by casein kinase II (CKII). When phosphate groups were globally reduced using nonspecific alkaline phosphatase, Triton X-100-solubilized membranes from DGK1-overexpressing cells showed a 7.7-fold reduction in DAG kinase activity; the reduced enzyme activity could be increased 5.5-fold by treatment with CKII. Dgk1(1–77) expressed heterologously in Escherichia coli was phosphorylated by CKII on a serine residue, and its phosphorylation was dependent on time as well as on the concentrations of CKII, ATP, and Dgk1(1–77). We used site-specific mutagenesis, coupled with phosphorylation analysis and phosphopeptide mapping, to identify Ser-45 and Ser-46 of Dgk1 as the CKII target sites, with Ser-46 being the major phosphorylation site. In vivo, the S46A and S45A/S46A mutations of Dgk1 abolished the stationary phase-dependent stimulation of DAG kinase activity. In addition, the phosphorylation-deficient mutations decreased Dgk1 function in PA production and in eliciting pah1Δ phenotypes, such as the expansion of the nuclear/endoplasmic reticulum membrane, reduced lipid droplet formation, and temperature sensitivity. This work demonstrates that the CKII-mediated phosphorylation of Dgk1 regulates its function in the production of PA. PMID:27834677

Genetic and biochemical characterization of the thymidine kinase gene from herpesvirus of turkeys

International Nuclear Information System (INIS)

Martin, S.L.; Aparisio, D.I.; Bandyopadhyay, P.K.

1989-01-01

The thymidine kinase gene encoded by herpesvirus of turkeys has been identified and characterized. A viral mutant (ATR 0 ) resistant to 1-β-D-arabinofuranosylthymine was isolated. This mutant was also resistant to 1-(2-fluoro-2-deoxy-β-D-arabinofuronosyl)-5-methyluracil and was unable to incorporate [ 125 I]deoxycytidine into DNA. The mutant phenotype was rescued by a cloned region of the turkey herpesvirus genome whose DNA sequence was found to contain an open reading frame similar to that for known thymidine kinases from other viruses. When expressed in Escherichia coli, this open reading frame complemented a thymidine kinase-deficient strain and resulted in thymidine kinase activity in extracts assayed in vitro

CrWSKP1, an SKP1-like Gene, Is Involved in the Self-Incompatibility Reaction of "Wuzishatangju" (Citrus reticulata Blanco).

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Li, Peng; Miao, Hongxia; Ma, Yuewen; Wang, Lu; Hu, Guibing; Ye, Zixing; Zhao, Jietang; Qin, Yonghua

2015-09-09

Plant S-phase kinase-associated protein 1 (SKP1) genes play crucial roles in plant development and differentiation. However, the role of SKP1 in citrus is unclear. Herein, we described a novel SKP1-like gene, designated as CrWSKP1, from "Wuzishatangju" (Citrus reticulata Blanco). The cDNA sequence of CrWSKP1 is 779 base pairs (bp) and contains an open reading frame (ORF) of 477 bp. The genomic sequence of the CrWSKP1 gene is 1296 bp with two exons and one intron. CrWSKP1 has high identity with SKP1-like genes from other plant species within two conserved regions. Approximately 85% of pollen tubes of self-pollinated CrWSKP1 transgenic tobaccos became twisted at four days after self-pollination. Pollen tube numbers of self-pollinated CrWSKP1 transformants entering into ovules were significantly fewer than that of the control. Seed number of self-pollinated CrWSKP1 transformants was significantly reduced. These results suggested that the CrWSKP1 is involved in the self-incompatibility (SI) reaction of "Wuzishatangju".

Toxoplasma DJ-1 Regulates Organelle Secretion by a Direct Interaction with Calcium-Dependent Protein Kinase 1

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Child, Matthew A.; Garland, Megan; Foe, Ian; Madzelan, Peter; Treeck, Moritz; van der Linden, Wouter A.; Oresic Bender, Kristina; Weerapana, Eranthie; Wilson, Mark A.; Boothroyd, John C.; Reese, Michael L.

2017-01-01

ABSTRACT Human DJ-1 is a highly conserved and yet functionally enigmatic protein associated with a heritable form of Parkinson’s disease. It has been suggested to be a redox-dependent regulatory scaffold, binding to proteins to modulate their function. Here we present the X-ray crystal structure of the Toxoplasma orthologue Toxoplasma gondii DJ-1 (TgDJ-1) at 2.1-Å resolution and show that it directly associates with calcium-dependent protein kinase 1 (CDPK1). The TgDJ-1 structure identifies an orthologously conserved arginine dyad that acts as a phospho-gatekeeper motif to control complex formation. We determined that the binding of TgDJ-1 to CDPK1 is sensitive to oxidation and calcium, and that this interaction potentiates CDPK1 kinase activity. Finally, we show that genetic deletion of TgDJ-1 results in upregulation of CDPK1 expression and that disruption of the CDPK1/TgDJ-1 complex in vivo prevents normal exocytosis of parasite virulence-associated organelles called micronemes. Overall, our data suggest that TgDJ-1 functions as a noncanonical kinase-regulatory scaffold that integrates multiple intracellular signals to tune microneme exocytosis in T. gondii. PMID:28246362

The development of functional mapping by three sex-related loci on the third whorl of different sex types of Carica papaya L.

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Chen-Yu Lee

Full Text Available Carica papaya L. is an important economic crop worldwide and is used as a model plant for sex-determination research. To study the different flower sex types, we screened sex-related genes using alternative splicing sequences (AS-seqs from a transcriptome database of the three flower sex types, i.e., males, females, and hermaphrodites, established at 28 days before flowering using 15 bacterial artificial chromosomes (BACs of C. papaya L. After screening, the cDNA regions of the three sex-related loci, including short vegetative phase-like (CpSVPL, the chromatin assembly factor 1 subunit A-like (CpCAF1AL, and the somatic embryogenesis receptor kinase (CpSERK, which contained eight sex-related single-nucleotide polymorphisms (SNPs from the different sex types of C. papaya L., were genotyped using high-resolution melting (HRM. The three loci were examined regarding the profiles of the third whorl, as described below. CpSVPL, which had one SNP associated with the three sex genotypes, was highly expressed in the male and female sterile flowers (abnormal hermaphrodite flowers that lacked the fourth whorl structure. CpCAF1AL, which had three SNPs associated with the male genotype, was highly expressed in male and normal hermaphrodite flowers, and had no AS-seqs, whereas it exhibited low expression and an AS-seqs in intron 11 in abnormal hermaphrodite flowers. Conversely, carpellate flowers (abnormal hermaphrodite flowers showed low expression of CpSVPL and AS-seqs in introns 5, 6, and 7 of CpSERK, which contained four SNPs associated with the female genotype. Specifically, the CpSERK and CpCAF1AL loci exhibited no AS-seq expression in the third whorl of the male and normal hermaphrodite flowers, respectively, and variance in the AS-seq expression of all other types of flowers. Functional mapping of the third whorl of normal hermaphrodites indicated no AS-seq expression in CpSERK, low CpSVPL expression, and, for CpCAF1AL, high expression and no AS

PTP1B Inhibition Causes Rac1 Activation by Enhancing Receptor Tyrosine Kinase Signaling

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Ayako Tsuchiya

2014-04-01

Full Text Available Background/Aims: The present study investigated the signaling pathway underlying Rac1 activation induced by the linoleic acid derivative 8-[2-(2-pentyl-cyclopropylmethyl-cyclopropyl]-octanoic acid (DCP-LA. Methods: Activity of protein tyrosine phosphatase 1B (PTP1B was assayed under cell-free conditions. Western blot was carried out to quantify phosphorylation of insulin receptor substrate-1 (IRS-1 and Akt in PC-12 cells. Rac1 activity was monitored in the föerster resonance energy transfer (FRET analysis using living and fixed PC-12 cells. Results: DCP-LA markedly suppressed PTP1B activity in a concentration (100 pM-100 µM-dependent manner. In the DCP-LA binding assay, fluorescein-conjugated DCP-LA produced a single fluorescent signal band at 60 kDa, corresponding to the molecule of PTP1B, and the signal was attenuated or abolished by co-treatment or pretreatment with non-conjugated DCP-LA. DCP-LA significantly enhanced nerve growth factor (NGF-stimulated phosphorylation of IRS-1 at Tyr1222 and Akt1/2 at Thr308/309 and Ser473/474 in PC-12 cells. In the FRET analysis, DCP-LA significantly enhanced NGF-stimulated Rac1 activation, which is abrogated by the phosphatidylinositol 3 kinase (PI3K inhibitor wortmannin, the 3-phosphoinositide-dependent protein kinase-1 (PDK1 inhibitor BX912, or the Akt inhibitor MK2206. Conclusion: The results of the present study show that DCP-LA-induced PTP1B inhibition, possibly through its direct binding, causes Rac1 activation by enhancing a pathway along a receptor tyrosine kinase (RTK/IRS-1/PI3K/Akt/Rac1 axis.

Dectin-1-mediated signaling leads to characteristic gene expressions and cytokine secretion via spleen tyrosine kinase (Syk) in rat mast cells.

Science.gov (United States)

Kimura, Yukihiro; Chihara, Kazuyasu; Honjoh, Chisato; Takeuchi, Kenji; Yamauchi, Shota; Yoshiki, Hatsumi; Fujieda, Shigeharu; Sada, Kiyonao

2014-11-07

Dectin-1 recognizes β-glucan and plays important roles for the antifungal immunity through the activation of spleen tyrosine kinase (Syk) in dendritic cells or macrophages. Recently, expression of Dectin-1 was also identified in human and mouse mast cells, although its physiological roles were largely unknown. In this report, rat mast cell line RBL-2H3 was analyzed to investigate the molecular mechanism of Dectin-1-mediated activation and responses of mast cells. Treatment of cells with Dectin-1-specific agonist curdlan induced tyrosine phosphorylation of cellular proteins and the interaction of Dectin-1 with the Src homology 2 domain of Syk. These responses depended on tyrosine phosphorylation of the hemi-immunoreceptor tyrosine-based activation motif in the cytoplasmic tail of Dectin-1, whereas they were independent of the γ-subunit of high-affinity IgE receptor. DNA microarray and real-time PCR analyses showed that Dectin-1-mediated signaling stimulated gene expression of transcription factor Nfkbiz and inflammatory cytokines, such as monocyte chemoattractant protein-1, IL-3, IL-4, IL-13, and tumor necrosis factor (TNF)-α. The response was abrogated by pretreatment with Syk inhibitor R406. These results suggest that Syk is critical for Dectin-1-mediated activation of mast cells, although the signaling differs from that triggered by FcϵRI activation. In addition, these gene expressions induced by curdlan stimulation were specifically observed in mast cells, suggesting that Dectin-1-mediated signaling of mast cells offers new insight into the antifungal immunity. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Luteolin suppresses cancer cell proliferation by targeting vaccinia-related kinase 1.

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Ye Seul Kim

Full Text Available Uncontrolled proliferation, a major feature of cancer cells, is often triggered by the malfunction of cell cycle regulators such as protein kinases. Recently, cell cycle-related protein kinases have become attractive targets for anti-cancer therapy, because they play fundamental roles in cellular proliferation. However, the protein kinase-targeted drugs that have been developed so far do not show impressive clinical results and also display severe side effects; therefore, there is undoubtedly a need to investigate new drugs targeting other protein kinases that are critical in cell cycle progression. Vaccinia-related kinase 1 (VRK1 is a mitotic kinase that functions in cell cycle regulation by phosphorylating cell cycle-related substrates such as barrier-to-autointegration factor (BAF, histone H3, and the cAMP response element (CRE-binding protein (CREB. In our study, we identified luteolin as the inhibitor of VRK1 by screening a small-molecule natural compound library. Here, we evaluated the efficacy of luteolin as a VRK1-targeted inhibitor for developing an effective anti-cancer strategy. We confirmed that luteolin significantly reduces VRK1-mediated phosphorylation of the cell cycle-related substrates BAF and histone H3, and directly interacts with the catalytic domain of VRK1. In addition, luteolin regulates cell cycle progression by modulating VRK1 activity, leading to the suppression of cancer cell proliferation and the induction of apoptosis. Therefore, our study suggests that luteolin-induced VRK1 inhibition may contribute to establish a novel cell cycle-targeted strategy for anti-cancer therapy.

Sphingosine kinase-1 mediates androgen-induced osteoblast cell growth

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Martin, Claire [CNRS, Institut de Pharmacologie et de Biologie Structurale, Toulouse F-31000 (France); Universite de Toulouse, UPS, IPBS, Toulouse F-31000 (France); Lafosse, Jean-Michel [CHU Toulouse, Hopital Rangueil, Service d' orthopedie et Traumatologie, Toulouse F-31000 (France); Malavaud, Bernard [CNRS, Institut de Pharmacologie et de Biologie Structurale, Toulouse F-31000 (France); Universite de Toulouse, UPS, IPBS, Toulouse F-31000 (France); CHU Toulouse, Hopital Rangueil, Service d' Urologie et de Transplantation Renale, Toulouse F-31000 (France); Cuvillier, Olivier, E-mail: olivier.cuvillier@ipbs.fr [CNRS, Institut de Pharmacologie et de Biologie Structurale, Toulouse F-31000 (France); Universite de Toulouse, UPS, IPBS, Toulouse F-31000 (France)

2010-01-01

Herein we report that the lipid kinase sphingosine kinase-1 (SphK1) is instrumental in mediating androgen-induced cell proliferation in osteoblasts. Dihydrotestosterone (DHT) triggered cell growth in steroid-deprived MC3T3 cells, which was associated with a rapid stimulation of SphK1 and activation of both Akt and ERK signaling pathways. This mechanism relied on functional androgen receptor/PI3K/Akt nongenotropic signaling as pharmacological antagonists could block SphK1 stimulation by DHT and its consequences. Finally, SphK1 inhibition not only abrogated DHT-induced ERK activation but also blocked cell proliferation, while ERK inhibition had no impact, suggesting that SphK1 was critical for DHT signaling yet independently of the ERK.

Mitogen activated protein kinase 6 and MAP kinase phosphatase 1 are involved in the response of Arabidopsis roots to L-glutamate.

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López-Bucio, Jesús Salvador; Raya-González, Javier; Ravelo-Ortega, Gustavo; Ruiz-Herrera, León Francisco; Ramos-Vega, Maricela; León, Patricia; López-Bucio, José; Guevara-García, Ángel Arturo

2018-03-01

The function and components of L-glutamate signaling pathways in plants have just begun to be elucidated. Here, using a combination of genetic and biochemical strategies, we demonstrated that a MAPK module is involved in the control of root developmental responses to this amino acid. Root system architecture plays an essential role in plant adaptation to biotic and abiotic factors via adjusting signal transduction and gene expression. L-Glutamate (L-Glu), an amino acid with neurotransmitter functions in animals, inhibits root growth, but the underlying genetic mechanisms are poorly understood. Through a combination of genetic analysis, in-gel kinase assays, detailed cell elongation and division measurements and confocal analysis of expression of auxin, quiescent center and stem cell niche related genes, the critical roles of L-Glu in primary root growth acting through the mitogen-activated protein kinase 6 (MPK6) and the dual specificity serine-threonine-tyrosine phosphatase MKP1 could be revealed. In-gel phosphorylation assays revealed a rapid and dose-dependent induction of MPK6 and MPK3 activities in wild-type Arabidopsis seedlings in response to L-Glu. Mutations in MPK6 or MKP1 reduced or increased root cell division and elongation in response to L-Glu, possibly modulating auxin transport and/or response, but in a PLETHORA1 and 2 independent manner. Our data highlight MPK6 and MKP1 as components of an L-Glu pathway linking the auxin response, and cell division for primary root growth.

In Vitro and In Vivo Characterization of a Dual-Function Green Fluorescent Protein–HSV1-Thymidine Kinase Reporter Gene Driven by the Human Elongation Factor 1α Promoter

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Gary D. Luker

2002-04-01

Full Text Available Toward the goal of monitoring activity of native mammalian promoters with molecular imaging techniques, we stably transfected DU145 prostate carcinoma cells with a fusion construct of enhanced green fluorescent protein (EGFP and wild-type herpes simplex virus-1 thymidine kinase (HSV1-TK as a reporter gene driven by the promoter for human elongation factor 1α (EF-1α-EGFP-TK. Using this model system, expression of EGFP was quantified by flow cytometry and fluorescence microscopy, while the HSV1-TK component of the reporter was quantified with 8-[3H]ganciclovir (8-[3H]GCV. As analyzed by flow cytometry, passage of EGFP-TK-DU145 transfected cells (ETK in vitro resulted in populations of cells with high and low expression of EGFP over time. High and low ETK cells retained 23-fold and 5-fold more GCV, respectively, than control. While differences in uptake and retention of GCV corresponded to relative expression of the reporter gene in each subpopulation of cells as determined by both flow cytometry (EGFP and quantitative RT-PCR, the correlation was not linear. Furthermore, in high ETK cells, net retention of various radiolabeled nucleoside analogues varied; the rank order was 8-[3H]GCV < 9-(4-fluoro-3-hydroxymethylbutylguanine ([18F]FHBG ≈ 8-[3H]penciclovir (8-[3H]PCV < 2′-fluoro-2′-deoxy-5-iodouracil-beta-d-arabinofuranoside (2-[14C]FIAU. Xenograft tumors of ETK cells in vivo accumulated 2.5-fold more 8-[3H]GCV per gram of tissue and showed greater fluorescence from EGFP than control DU145 cells, demonstrating that the reporter gene functioned in vivo. These data extend previous reports by showing that a human promoter can be detected in vitro and in vivo with a dual-function reporter exploiting optical and radiotracer techniques.

The Arabidopsis Cysteine-Rich Receptor-Like Kinase CRK36 Regulates Immunity through Interaction with the Cytoplasmic Kinase BIK1

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Dong Sook Lee

2017-10-01

Full Text Available Receptor-like kinases are important signaling components that regulate a variety of cellular processes. In this study, an Arabidopsis cDNA microarray analysis led to the identification of the cysteine-rich receptor-like kinase CRK36 responsive to the necrotrophic fungal pathogen, Alternaria brassicicola. To determine the function of CRK36 in plant immunity, T-DNA-insertion knockdown (crk36 and overexpressing (CRK36OE plants were prepared. CRK36OE plants exhibited increased hypersensitive cell death and ROS burst in response to avirulent pathogens. Treatment with a typical pathogen-associated molecular pattern, flg22, markedly induced pattern-triggered immune responses, notably stomatal defense, in CRK36OE plants. The immune responses were weakened in crk36 plants. Protein-protein interaction assays revealed the in vivo association of CRK36, FLS2, and BIK1. CRK36 enhanced flg22-triggered BIK1 phosphorylation, which showed defects with Cys mutations in the DUF26 motifs of CRK36. Disruption of BIK1 and RbohD/RbohF genes further impaired CRK36-mediated stomatal defense. We propose that CRK36, together with BIK1 and NADPH oxidases, may form a positive activation loop that enhances ROS burst and leads to the promotion of stomatal immunity.

Effects of overexpression of IL-1 receptor-associated kinase on NFkappaB activation, IL-2 production and stress-activated protein kinases in the murine T cell line EL4.

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Knop, J; Wesche, H; Lang, D; Martin, M U

1998-10-01

The association and activation of the IL-1 receptor-associated protein kinase (IRAK) to the IL-1 receptor complex is one of the earliest events detectable in IL-1 signal transduction. We generated permanent clones of the murine T cell line EL4 6.1 overexpressing human (h)IRAK to evaluate the role of this kinase in IL-1 signaling. Overexpression of hIRAK enhanced IL-1-stimulated activation of the transcription factor NFkappaB, whereas a truncated form (N-IRAK) specifically inhibited IL-1-dependent NFkappaB activity. In clones stably overexpressing hIRAK a weak constitutive activation of NFkappaB correlated with a low basal IL-2 production which was enhanced in an IL-1-dependent manner. Compared to the parental cell line the dose-response curve of IL-1-induced IL-2 production was shifted in both potency and efficacy. These results demonstrate that IRAK directly triggers NFkappaB-mediated gene expression in EL4 cells. Qualitatively different effects were observed for the IL-1-induced activation of stress-activated protein (SAP) kinases: permanent overexpression of IRAK did not affect the dose dependence but prolonged the kinetics of IL-1-induced activation of SAP kinases, suggesting that this signaling branch may be regulated by distinct mechanisms.

Differential gene expression and Hog1 interaction with osmoresponsive genes in the extremely halotolerant black yeast Hortaea werneckii

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Plemenitaš Ana

2007-08-01

Full Text Available Abstract Background Fluctuations in external salinity force eukaryotic cells to respond by changes in the gene expression of proteins acting in protective biochemical processes, thus counteracting the changing osmotic pressure. The high-osmolarity glycerol (HOG signaling pathway is essential for the efficient up-regulation of the osmoresponsive genes. In this study, the differential gene expression of the extremely halotolerant black yeast Hortaea werneckii was explored. Furthermore, the interaction of mitogen-activated protein kinase HwHog1 and RNA polymerase II with the chromatin in cells adapted to an extremely hypersaline environment was analyzed. Results A cDNA subtraction library was constructed for H. werneckii, adapted to moderate salinity or an extremely hypersaline environment of 4.5 M NaCl. An uncommon osmoresponsive set of 95 differentially expressed genes was identified. The majority of these had not previously been connected with the adaptation of salt-sensitive S. cerevisiae to hypersaline conditions. The transcriptional response in hypersaline-adapted and hypersaline-stressed cells showed that only a subset of the identified genes responded to acute salt-stress, whereas all were differentially expressed in adapted cells. Interaction with HwHog1 was shown for 36 of the 95 differentially expressed genes. The majority of the identified osmoresponsive and HwHog1-dependent genes in H. werneckii have not been previously reported as Hog1-dependent genes in the salt-sensitive S. cerevisiae. The study further demonstrated the co-occupancy of HwHog1 and RNA polymerase II on the chromatin of 17 up-regulated and 2 down-regulated genes in 4.5 M NaCl-adapted H. werneckii cells. Conclusion Extremely halotolerant H. werneckii represents a suitable and highly relevant organism to study cellular responses to environmental salinity. In comparison with the salt-sensitive S. cerevisiae, this yeast shows a different set of genes being expressed at

Structural aspects of protein kinase ASK1 regulation

Czech Academy of Sciences Publication Activity Database

Obšil, Tomáš; Obšilová, Veronika

2017-01-01

Roč. 66, 1 Dec (2017), s. 31-36 ISSN 2212-4926 R&D Projects: GA ČR(CZ) GA16-02739S; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:67985823 Keywords : ASK1 kinase * apoptosis * thioredoxin * 14-3-3 protein Subject RIV: CE - Biochemistry OBOR OECD: Biochemistry and molecular biology

In vivo imaging of herpes simplex virus type 1 thymidine kinase gene expression: early kinetics of radiolabelled FIAU

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Haubner, R.; Avril, N.; Schwaiger, M. [Technische Univ. Muenchen (Germany). Nuklearmedizinische Klinik und Poliklinik; Hantzopoulos, P.A.; Gansbacher, B. [Inst. of Experimental Oncology, Technische Univ. Muenchen (Germany)

2000-03-01

The aim of our study was to examine the early kinetics of I*-FIAU and the possibility of utilising iodine-123-labelled FIAU for imaging of gene expression. CMS-5 fibrosarcoma cells were transduced in vitro with the retroviral vector STK containing the HSV1-tk gene. BALB/c mice were inoculated subcutaneously with HSV1-tk(+) and tk(-) cells into both flanks. FAU (2'-fluoro-2'-deoxy-1-{beta}-d-arabinofuranosyluracil was radioiodinated ({sup 123}I, {sup 125}I)) using the iodogen method. High-performance liquid chromatography purification resulted in high specific activity and radiochemical purity for both tracers ([{sup 123}I]FIAU and [{sup 125}I]FIAU). Biodistribution studies and gamma camera imaging were performed at 0.5, 1, 2 and 4 h p.i. In addition, the genomic DNA of the tumours was isolated for measurement of the activity accumulation resulting from the [{sup 125}I]FIAU incorporation. Biodistribution studies 0.5 h p.i. showed tumour/blood and tumour/muscle ratios of 3.8 and 7.2, respectively, for the HSV1-tk(+) tumours, and 0.6 and 1.2, respectively, for negative control tumours. Fast renal elimination of the tracer from the body resulted in rapidly increasing tumour/blood and tumour/muscle ratios which reached values of 32 and 88 at 4 h p.i., respectively. Tracer clearance from blood was bi-exponential, with an initial half-life of 0.6 h followed by a half-life of 4.6 h. The tracer half-life in herpes simplex viral thymidine kinase-expressing tumours was 35.7 h. The highest activity accumulation (20.3%{+-}5.7% ID/g) in HSV1-tk(+) tumours was observed 1 h p.i. At that time, about 46% of the total activity found in HSV1-tk(+) tumours was incorporated into genomic DNA. Planar gamma camera imaging showed a distinct tracer accumulation as early as 0.5 h p.i., with an increase in contrast over time. These results suggest that sufficient tumour/background ratios for in vivo imaging of HSV1-tk expression with [{sup 123}I]FIAU are reached as early as 1 h p

Serum and Glucocorticoid Regulated Kinase 1 (SGK1) Regulates Neutrophil Clearance During Inflammation Resolution

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Burgon, Joseph; Robertson, Anne L.; Sadiku, Pranvera; Wang, Xingang; Hooper-Greenhill, Edward; Prince, Lynne R.; Walker, Paul; Hoggett, Emily E.; Ward, Jonathan R.; Farrow, Stuart N.; Zuercher, William J.; Jeffrey, Philip; Savage, Caroline O.; Ingham, Philip W.; Hurlstone, Adam F.; Whyte, Moira K. B.; Renshaw, Stephen A.

2013-01-01

The inflammatory response is integral to maintaining health, by functioning to resist microbial infection and repair tissue damage. Large numbers of neutrophils are recruited to inflammatory sites to neutralise invading bacteria through phagocytosis and the release of proteases and reactive oxygen species into the extracellular environment. Removal of the original inflammatory stimulus must be accompanied by resolution of the inflammatory response, including neutrophil clearance, to prevent inadvertent tissue damage. Neutrophil apoptosis and its temporary inhibition by survival signals provides a target for anti-inflammatory therapeutics, making it essential to better understand this process. GM-CSF, a neutrophil survival factor, causes a significant increase in mRNA levels for the known anti-apoptotic protein Serum and Glucocorticoid Regulated Kinase 1 (SGK1). We have characterised the expression patterns and regulation of SGK family members in human neutrophils, and shown that inhibition of SGK activity completely abrogates the anti-apoptotic effect of GM-CSF. Using a transgenic zebrafish model, we have disrupted sgk1 gene function and shown this specifically delays inflammation resolution, without altering neutrophil recruitment to inflammatory sites in vivo. These data suggest SGK1 plays a key role in regulating neutrophil survival signalling, and thus may prove a valuable therapeutic target for the treatment of inflammatory disease. PMID:24431232

β-Catenin is required for intrinsic but not extrinsic BCR-ABL1 kinase-independent resistance to tyrosine kinase inhibitors in chronic myeloid leukemia.

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Eiring, A M; Khorashad, J S; Anderson, D J; Yu, F; Redwine, H M; Mason, C C; Reynolds, K R; Clair, P M; Gantz, K C; Zhang, T Y; Pomicter, A D; Kraft, I L; Bowler, A D; Johnson, K; Partlin, M Mac; O'Hare, T; Deininger, M W

2015-12-01

Activation of nuclear β-catenin and expression of its transcriptional targets promotes chronic myeloid leukemia (CML) progression, tyrosine kinase inhibitor (TKI) resistance, and leukemic stem cell self-renewal. We report that nuclear β-catenin has a role in leukemia cell-intrinsic but not -extrinsic BCR-ABL1 kinase-independent TKI resistance. Upon imatinib inhibition of BCR-ABL1 kinase activity, β-catenin expression was maintained in intrinsically resistant cells grown in suspension culture and sensitive cells cultured in direct contact (DC) with bone marrow (BM) stromal cells. Thus, TKI resistance uncouples β-catenin expression from BCR-ABL1 kinase activity. In β-catenin reporter assays, intrinsically resistant cells showed increased transcriptional activity versus parental TKI-sensitive controls, and this was associated with restored expression of β-catenin target genes. In contrast, DC with BM stromal cells promoted TKI resistance, but had little effects on Lef/Tcf reporter activity and no consistent effects on cytoplasmic β-catenin levels, arguing against a role for β-catenin in extrinsic TKI resistance. N-cadherin or H-cadherin blocking antibodies abrogated DC-based resistance despite increasing Lef/Tcf reporter activity, suggesting that factors other than β-catenin contribute to extrinsic, BM-derived TKI resistance. Our data indicate that, while nuclear β-catenin enhances survival of intrinsically TKI-resistant CML progenitors, it is not required for extrinsic resistance mediated by the BM microenvironment.

Torilin Inhibits Inflammation by Limiting TAK1-Mediated MAP Kinase and NF-κB Activation

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Mehari Endale

2017-01-01

Full Text Available Torilin, a sesquiterpene isolated from the fruits of Torilis japonica, has shown antimicrobial, anticancer, and anti-inflammatory properties. However, data on the mechanism of torilin action against inflammation is limited. This study aimed at determining the anti-inflammatory property of torilin in LPS-induced inflammation using in vitro model of inflammation. We examined torilin’s effect on expression levels of inflammatory mediators and cytokines in LPS-stimulated RAW 264.7 macrophages. The involvement of NF-kB and AP-1, MAP kinases, and adaptor proteins were assessed. Torilin strongly inhibited LPS-induced NO release, iNOS, PGE2, COX-2, NF-α, IL-1β, IL-6, and GM-CSF gene and protein expressions. In addition, MAPKs were also suppressed by torilin pretreatment. Involvement of ERK1/2, P38MAPK, and JNK1/2 was further confirmed by PD98059, SB203580, and SP600125 mediated suppression of iNOS and COX-2 proteins. Furthermore, torilin attenuated NF-kB and AP-1 translocation, DNA binding, and reporter gene transcription. Interestingly, torilin inhibited TAK1 kinase activation with the subsequent suppression of MAPK-mediated JNK, p38, ERK1/2, and AP-1 (ATF-2 and c-jun activation and IKK-mediated I-κBα degradation, p65/p50 activation, and translocation. Together, the results revealed the suppression of NF-κB and AP-1 regulated inflammatory mediator and cytokine expressions, suggesting the test compound’s potential as a candidate anti-inflammatory agent.

SH2-B promotes insulin receptor substrate 1 (IRS1)- and IRS2-mediated activation of the phosphatidylinositol 3-kinase pathway in response to leptin.

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Duan, Chaojun; Li, Minghua; Rui, Liangyou

2004-10-15

Leptin regulates energy homeostasis primarily by binding and activating its long form receptor (LRb). Deficiency of either leptin or LRb causes morbid obesity. Leptin stimulates LRb-associated JAK2, thus initiating multiple pathways including the Stat3 and phosphatidylinositol (PI) 3-kinase pathways that mediate leptin biological actions. Here we report that SH2-B, a JAK2-interacting protein, promotes activation of the PI 3-kinase pathway by recruiting insulin receptor substrate 1 (IRS1) and IRS2 in response to leptin. SH2-B directly bound, via its PH and SH2 domain, to both IRS1 and IRS2 both in vitro and in intact cells and mediated formation of a JAK2/SH2-B/IRS1 or IRS2 tertiary complex. Consequently, SH2-B dramatically enhanced leptin-stimulated tyrosine phosphorylation of IRS1 and IRS2 in HEK293 cells stably expressing LRb, thus promoting association of IRS1 and IRS2 with the p85 regulatory subunit of PI 3-kinase and phosphorylation and activation of Akt. SH2-B mutants with lower affinity for IRS1 and IRS2 exhibited reduced ability to promote association of JAK2 with IRS1, tyrosine phosphorylation of IRS1, and association of IRS1 with p85 in response to leptin. Moreover, deletion of the SH2-B gene impaired leptin-stimulated tyrosine phosphorylation of endogenous IRS1 in mouse embryonic fibroblasts (MEF), which was reversed by reintroduction of SH2-B. Similarly, SH2-B promoted growth hormone-stimulated tyrosine phosphorylation of IRS1 in both HEK293 and MEF cells. Our data suggest that SH2-B is a novel mediator of the PI 3-kinase pathway in response to leptin or other hormones and cytokines that activate JAK2.

A Cytosolic Arabidopsis d-Xylulose Kinase Catalyzes the Phosphorylation of 1-Deoxy-d-Xylulose into a Precursor of the Plastidial Isoprenoid Pathway1

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Hemmerlin, Andréa; Tritsch, Denis; Hartmann, Michael; Pacaud, Karine; Hoeffler, Jean-François; van Dorsselaer, Alain; Rohmer, Michel; Bach, Thomas J.

2006-01-01

Plants are able to integrate exogenous 1-deoxy-d-xylulose (DX) into the 2C-methyl-d-erythritol 4-phosphate pathway, implicated in the biosynthesis of plastidial isoprenoids. Thus, the carbohydrate needs to be phosphorylated into 1-deoxy-d-xylulose 5-phosphate and translocated into plastids, or vice versa. An enzyme capable of phosphorylating DX was partially purified from a cell-free Arabidopsis (Arabidopsis thaliana) protein extract. It was identified by mass spectrometry as a cytosolic protein bearing d-xylulose kinase (XK) signatures, already suggesting that DX is phosphorylated within the cytosol prior to translocation into the plastids. The corresponding cDNA was isolated and enzymatic properties of a recombinant protein were determined. In Arabidopsis, xylulose kinases are encoded by a small gene family, in which only two genes are putatively annotated. The additional gene is coding for a protein targeted to plastids, as was proved by colocalization experiments using green fluorescent protein fusion constructs. Functional complementation assays in an Escherichia coli strain deleted in xk revealed that the cytosolic enzyme could exclusively phosphorylate xylulose in vivo, not the enzyme that is targeted to plastids. xk activities could not be detected in chloroplast protein extracts or in proteins isolated from its ancestral relative Synechocystis sp. PCC 6803. The gene encoding the plastidic protein annotated as “xylulose kinase” might in fact yield an enzyme having different phosphorylation specificities. The biochemical characterization and complementation experiments with DX of specific Arabidopsis knockout mutants seedlings treated with oxo-clomazone, an inhibitor of 1-deoxy-d-xylulose 5-phosphate synthase, further confirmed that the cytosolic protein is responsible for the phosphorylation of DX in planta. PMID:16920870

Calcium/calmodulin kinase1 and its relation to thermotolerance and HSP90 in Sporothrix schenckii: an RNAi and yeast two-hybrid study

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Gonzalez-Mendez Ricardo

2011-07-01

Full Text Available Abstract Background Sporothrix schenckii is a pathogenic dimorphic fungus of worldwide distribution. It grows in the saprophytic form with hyaline, regularly septated hyphae and pyriform conidia at 25°C and as the yeast or parasitic form at 35°C. Previously, we characterized a calcium/calmodulin kinase in this fungus. Inhibitors of this kinase were observed to inhibit the yeast cell cycle in S. schenckii. Results The presence of RNA interference (RNAi mechanism in this fungus was confirmed by the identification of a Dicer-1 homologue in S. schenckii DNA. RNAi technology was used to corroborate the role of calcium/calmodulin kinase I in S. schenckii dimorphism. Yeast cells were transformed with the pSilent-Dual2G (pSD2G plasmid w/wo inserts of the coding region of the calcium/calmodulin kinase I (sscmk1 gene. Transformants were selected at 35°C using resistance to geneticin. Following transfer to liquid medium at 35°C, RNAi transformants developed as abnormal mycelium clumps and not as yeast cells as would be expected. The level of sscmk1 gene expression in RNAi transformants at 35°C was less than that of cells transformed with the empty pSD2G at this same temperature. Yeast two-hybrid analysis of proteins that interact with SSCMK1 identified a homologue of heat shock protein 90 (HSP90 as interacting with this kinase. Growth of the fungus similar to that of the RNAi transformants was observed in medium with geldanamycin (GdA, 10 μM, an inhibitor of HSP90. Conclusions Using the RNAi technology we silenced the expression of sscmk1 gene in this fungus. RNAi transformants were unable to grow as yeast cells at 35°C showing decreased tolerance to this temperature. The interaction of SSCMK1 with HSP90, observed using the yeast two-hybrid assay suggests that this kinase is involved in thermotolerance through its interaction with HSP90. SSCMK1 interacted with the C terminal domain of HSP90 where effector proteins and co-chaperones interact. These

Multifunctional Role of ATM/Tel1 Kinase in Genome Stability: From the DNA Damage Response to Telomere Maintenance

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2014-01-01

The mammalian protein kinase ataxia telangiectasia mutated (ATM) is a key regulator of the DNA double-strand-break response and belongs to the evolutionary conserved phosphatidylinositol-3-kinase-related protein kinases. ATM deficiency causes ataxia telangiectasia (AT), a genetic disorder that is characterized by premature aging, cerebellar neuropathy, immunodeficiency, and predisposition to cancer. AT cells show defects in the DNA damage-response pathway, cell-cycle control, and telomere maintenance and length regulation. Likewise, in Saccharomyces cerevisiae, haploid strains defective in the TEL1 gene, the ATM ortholog, show chromosomal aberrations and short telomeres. In this review, we outline the complex role of ATM/Tel1 in maintaining genomic stability through its control of numerous aspects of cellular survival. In particular, we describe how ATM/Tel1 participates in the signal transduction pathways elicited by DNA damage and in telomere homeostasis and its importance as a barrier to cancer development. PMID:25247188

MBNL142 and MBNL143 gene isoforms, overexpressed in DM1-patient muscle, encode for nuclear proteins interacting with Src family kinases.

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Botta, A; Malena, A; Tibaldi, E; Rocchi, L; Loro, E; Pena, E; Cenci, L; Ambrosi, E; Bellocchi, M C; Pagano, M A; Novelli, G; Rossi, G; Monaco, H L; Gianazza, E; Pantic, B; Romeo, V; Marin, O; Brunati, A M; Vergani, L

2013-08-15

Myotonic dystrophy type-1 (DM1) is the most prevalent form of muscular dystrophy in adults. This disorder is an RNA-dominant disease, caused by expansion of a CTG repeat in the DMPK gene that leads to a misregulation in the alternative splicing of pre-mRNAs. The longer muscleblind-like-1 (MBNL1) transcripts containing exon 5 and the respective protein isoforms (MBNL142-43) were found to be overexpressed in DM1 muscle and localized exclusively in the nuclei. In vitro assays showed that MBNL142-43 bind the Src-homology 3 domain of Src family kinases (SFKs) via their proline-rich motifs, enhancing the SFK activity. Notably, this association was also confirmed in DM1 muscle and myotubes. The recovery, mediated by an siRNA target to Ex5-MBNL142-43, succeeded in reducing the nuclear localization of both Lyn and MBNL142-43 proteins and in decreasing the level of tyrosine phosphorylated proteins. Our results suggest an additional molecular mechanism in the DM1 pathogenesis, based on an altered phosphotyrosine signalling pathway.

The kinase TBK1 functions in dendritic cells to regulate T cell homeostasis, autoimmunity, and antitumor immunity.

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Xiao, Yichuan; Zou, Qiang; Xie, Xiaoping; Liu, Ting; Li, Haiyan S; Jie, Zuliang; Jin, Jin; Hu, Hongbo; Manyam, Ganiraju; Zhang, Li; Cheng, Xuhong; Wang, Hui; Marie, Isabelle; Levy, David E; Watowich, Stephanie S; Sun, Shao-Cong

2017-05-01

Dendritic cells (DCs) are crucial for mediating immune responses but, when deregulated, also contribute to immunological disorders, such as autoimmunity. The molecular mechanism underlying the function of DCs is incompletely understood. In this study, we have identified TANK-binding kinase 1 (TBK1), a master innate immune kinase, as an important regulator of DC function. DC-specific deletion of Tbk1 causes T cell activation and autoimmune symptoms and also enhances antitumor immunity in animal models of cancer immunotherapy. The TBK1-deficient DCs have up-regulated expression of co-stimulatory molecules and increased T cell-priming activity. We further demonstrate that TBK1 negatively regulates the induction of a subset of genes by type I interferon receptor (IFNAR). Deletion of IFNAR1 could largely prevent aberrant T cell activation and autoimmunity in DC-conditional Tbk1 knockout mice. These findings identify a DC-specific function of TBK1 in the maintenance of immune homeostasis and tolerance. © 2017 Xiao et al.

Suppressor of cytokine signaling 1 interacts with oncogenic lymphocyte-specific protein tyrosine kinase.

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Venkitachalam, Srividya; Chueh, Fu-Yu; Leong, King-Fu; Pabich, Samantha; Yu, Chao-Lan

2011-03-01

Lymphocyte-specific protein tyrosine kinase (Lck) plays a key role in T cell signal transduction and is tightly regulated by phosphorylation and dephosphorylation. Lck can function as an oncoprotein when overexpressed or constantly activated by mutations. Our previous studies showed that Lck-induced cellular transformation could be suppressed by enforced expression of suppressor of cytokine signaling 1 (SOCS1), a SOCS family member involved in the negative feedback control of cytokine signaling. We observed attenuated Lck kinase activity in SOCS1-expressing cells, suggesting an important role of SOCS in regulating Lck functions. It remains largely unknown whether and how SOCS proteins interact with the oncogenic Lck kinase. Here, we report that among four SOCS family proteins, SOCS1, SOCS2, SOCS3 and CIS (cytokine-inducible SH2 domain containing protein), SOCS1 has the highest affinity in binding to the oncogenic Lck kinase. We identified the positive regulatory phosphotyrosine 394 residue in the kinase domain as the key interacting determinant in Lck. Additionally, the Lck kinase domain alone is sufficient to bind SOCS1. While the SH2 domain in SOCS1 is important in its association with the oncogenic Lck kinase, other functional domains may also contribute to overall binding affinity. These findings provide important mechanistic insights into the role of SOCS proteins as tumor suppressors in cells transformed by oncogenic protein tyrosine kinases.

New Variants of Tomato Thymidine Kinase 1 Selected for Increased Sensitivity of E. coli KY895 towards Azidothymidine

International Nuclear Information System (INIS)

Slot Christiansen, Louise; Egeblad, Louise; Munch-Petersen, Birgitte; Piškur, Jure; Knecht, Wolfgang

2015-01-01

Nucleoside analogues (NA) are prodrugs that are phosphorylated by deoxyribonucleoside kinases (dNKs) as the first step towards a compound toxic to the cell. During the last 20 years, research around dNKs has gone into new organisms other than mammals and viruses. Newly discovered dNKs have been tested as enzymes for suicide gene therapy. The tomato thymidine kinase 1 (ToTK1) is a dNK that has been selected for its in vitro kinetic properties and then successfully been tested in vivo for the treatment of malignant glioma. We present the selection of two improved variants of ToTK1 generated by random protein engineering for suicide gene therapy with the NA azidothymidine (AZT). We describe their selection, recombinant production and a subsequent kinetic and biochemical characterization. Their improved performance in killing of E. coli KY895 is accompanied by an increase in specificity for the NA AZT over the natural substrate thymidine as well as a decrease in inhibition by dTTP, the end product of the nucleoside salvage pathway for thymidine. The understanding of the enzymatic properties improving the variants efficacy is instrumental to further develop dNKs for use in suicide gene therapy

New Variants of Tomato Thymidine Kinase 1 Selected for Increased Sensitivity of E. coli KY895 towards Azidothymidine

Energy Technology Data Exchange (ETDEWEB)

Slot Christiansen, Louise [Department of Biology, Lund University, Lund 22362 (Sweden); Lund Protein Production Platform, Lund University, Lund 22362 (Sweden); Egeblad, Louise [Lund Protein Production Platform, Lund University, Lund 22362 (Sweden); Munch-Petersen, Birgitte [Department of Science, Systems and Models, Roskilde University, Roskilde 4000 (Denmark); Piškur, Jure [Department of Biology, Lund University, Lund 22362 (Sweden); Knecht, Wolfgang, E-mail: Louise.Slot_Christiansen@biol.lu.se [Department of Biology, Lund University, Lund 22362 (Sweden); Lund Protein Production Platform, Lund University, Lund 22362 (Sweden)

2015-06-08

Nucleoside analogues (NA) are prodrugs that are phosphorylated by deoxyribonucleoside kinases (dNKs) as the first step towards a compound toxic to the cell. During the last 20 years, research around dNKs has gone into new organisms other than mammals and viruses. Newly discovered dNKs have been tested as enzymes for suicide gene therapy. The tomato thymidine kinase 1 (ToTK1) is a dNK that has been selected for its in vitro kinetic properties and then successfully been tested in vivo for the treatment of malignant glioma. We present the selection of two improved variants of ToTK1 generated by random protein engineering for suicide gene therapy with the NA azidothymidine (AZT). We describe their selection, recombinant production and a subsequent kinetic and biochemical characterization. Their improved performance in killing of E. coli KY895 is accompanied by an increase in specificity for the NA AZT over the natural substrate thymidine as well as a decrease in inhibition by dTTP, the end product of the nucleoside salvage pathway for thymidine. The understanding of the enzymatic properties improving the variants efficacy is instrumental to further develop dNKs for use in suicide gene therapy.

MAP kinase genes and colon and rectal cancer

Science.gov (United States)

Slattery, Martha L.

2012-01-01

Mitogen-activated protein kinase (MAPK) pathways regulate many cellular functions including cell proliferation, differentiation, migration and apoptosis. We evaluate genetic variation in the c-Jun-N-terminal kinases, p38, and extracellular regulated kinases 1/2 MAPK-signaling pathways and colon and rectal cancer risk using data from population-based case-control studies (colon: n = 1555 cases, 1956 controls; rectal: n = 754 cases, 959 controls). We assess 19 genes (DUSP1, DUSP2, DUSP4, DUSP6, DUSP7, MAP2K1, MAP3K1, MAP3K2, MAP3K3, MAP3K7, MAP3K9, MAP3K10, MAP3K11, MAPK1, MAPK3, MAPK8, MAPK12, MAPK14 and RAF1). MAP2K1 rs8039880 [odds ratio (OR) = 0.57, 95% confidence interval (CI) = 0.38, 0.83; GG versus AA genotype] and MAP3K9 rs11625206 (OR = 1.41, 95% CI = 1.14, 1.76; recessive model) were associated with colon cancer (P adj value rectal cancer (P adj cancer risk. Genetic variants had unique associations with KRAS, TP53 and CIMP+ tumors. DUSP2 rs1724120 [hazard rate ratio (HRR) = 0.72, 95%CI = 0.54, 0.96; AA versus GG/GA), MAP3K10 rs112956 (HRR = 1.40, 95% CI = 1.10, 1.76; CT/TT versus CC) and MAP3K11 (HRR = 1.76, 95% CI 1.18, 2.62 TT versus GG/GT) influenced survival after diagnosis with colon cancer; MAP2K1 rs8039880 (HRR = 2.53, 95% CI 1.34, 4.79 GG versus AG/GG) and Raf1 rs11923427 (HRR = 0.59 95% CI = 0.40, 0.86; AA versus TT/TA) were associated with rectal cancer survival. These data suggest that genetic variation in the MAPK-signaling pathway influences colorectal cancer risk and survival after diagnosis. Associations may be modified by lifestyle factors that influence inflammation and oxidative stress. PMID:23027623

The Craterostigma plantagineum glycine-rich protein CpGRP1 interacts with a cell wall-associated protein kinase 1 (CpWAK1) and accumulates in leaf cell walls during dehydration.

Science.gov (United States)

Giarola, Valentino; Krey, Stephanie; von den Driesch, Barbara; Bartels, Dorothea

2016-04-01

Craterostigma plantagineum tolerates extreme desiccation. Leaves of this plant shrink and extensively fold during dehydration and expand again during rehydration, preserving their structural integrity. Genes were analysed that may participate in the reversible folding mechanism. Analysis of transcripts abundantly expressed in desiccated leaves identified a gene putatively coding for an apoplastic glycine-rich protein (CpGRP1). We studied the expression, regulation and subcellular localization of CpGRP1 and its ability to interact with a cell wall-associated protein kinase (CpWAK1) to understand the role of CpGRP1 in the cell wall during dehydration. The CpGRP1 protein accumulates in the apoplast of desiccated leaves. Analysis of the promoter revealed that the gene expression is mainly regulated at the transcriptional level, is independent of abscisic acid (ABA) and involves a drought-responsive cis-element (DRE). CpGRP1 interacts with CpWAK1 which is down-regulated in response to dehydration. Our data suggest a role of the CpGRP1-CpWAK1 complex in dehydration-induced morphological changes in the cell wall during dehydration in C. plantagineum. Cell wall pectins and dehydration-induced pectin modifications are predicted to be involved in the activity of the CpGRP1-CpWAK1 complex. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Structure-Based Design of Potent and Selective 3-Phosphoinositide-Dependent Kinase-1 (PDK1) Inhibitors

Energy Technology Data Exchange (ETDEWEB)

Medina, Jesus R.; Becker, Christopher J.; Blackledge, Charles W.; Duquenne, Celine; Feng, Yanhong; Grant, Seth W.; Heerding, Dirk; Li, William H.; Miller, William H.; Romeril, Stuart P.; Scherzer, Daryl; Shu, Arthur; Bobko, Mark A.; Chadderton, Antony R.; Dumble, Melissa; Gardiner, Christine M.; Gilbert, Seth; Liu, Qi; Rabindran, Sridhar K.; Sudakin, Valery; Xiang, Hong; Brady, Pat G.; Campobasso, Nino; Ward, Paris; Axten, Jeffrey M. (GSKPA)

2014-10-02

Phosphoinositide-dependent protein kinase-1(PDK1) is a master regulator of the AGC family of kinases and an integral component of the PI3K/AKT/mTOR pathway. As this pathway is among the most commonly deregulated across all cancers, a selective inhibitor of PDK1 might have utility as an anticancer agent. Herein we describe our lead optimization of compound 1 toward highly potent and selective PDK1 inhibitors via a structure-based design strategy. The most potent and selective inhibitors demonstrated submicromolar activity as measured by inhibition of phosphorylation of PDK1 substrates as well as antiproliferative activity against a subset of AML cell lines. In addition, reduction of phosphorylation of PDK1 substrates was demonstrated in vivo in mice bearing OCl-AML2 xenografts. These observations demonstrate the utility of these molecules as tools to further delineate the biology of PDK1 and the potential pharmacological uses of a PDK1 inhibitor.

Regulation of Kv1.4 potassium channels by PKC and AMPK kinases

DEFF Research Database (Denmark)

Andersen, Martin Nybo; Skibsbye, Lasse; Saljic, Arnela

2018-01-01

around the ubiquitin ligase Nedd4-2. In the present study we examined whether Kv1.4, constituting the cardiac Ito,s current, is subject to similar regulation. In the epithelial Madin-Darby Canine Kidney (MDCK) cell line, which constitutes a highly reproducible model system for addressing membrane...... targeting, we find, by confocal microscopy, that Kv1.4 cell surface expression is downregulated by activation of protein kinase C (PKC) and AMP-activated protein kinase (AMPK). In contrast, manipulating the activities of phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) and serum and glucocorticoid......-regulated kinase 1 (SGK1) were without effect on channel localization. The PKC and AMPK-mediated downregulation of Kv1.4 membrane surface localization was confirmed by two-electrode voltage clamp in Xenopus laevis oocytes, where pharmacological activation of PKC and AMPK reduced Kv1.4 current levels. We further...

Simian Immunodeficiency Virus and Human Immunodeficiency Virus Type 1 Nef Proteins Show Distinct Patterns and Mechanisms of Src Kinase Activation

Science.gov (United States)

Greenway, Alison L.; Dutartre, Hélène; Allen, Kelly; McPhee, Dale A.; Olive, Daniel; Collette, Yves

1999-01-01

The nef gene from human and simian immunodeficiency viruses (HIV and SIV) regulates cell function and viral replication, possibly through binding of the nef product to cellular proteins, including Src family tyrosine kinases. We show here that the Nef protein encoded by SIVmac239 interacts with and also activates the human Src kinases Lck and Hck. This is in direct contrast to the inhibitory effect of HIV type 1 (HIV-1) Nef on Lck catalytic activity. Unexpectedly, however, the interaction of SIV Nef with human Lck or Hck is not mediated via its consensus proline motif, which is known to mediate HIV-1 Nef binding to Src homology 3 (SH3) domains, and various experimental analyses failed to show significant interaction of SIV Nef with the SH3 domain of either kinase. Instead, SIV Nef can bind Lck and Hck SH2 domains, and its N-terminal 50 amino acid residues are sufficient for Src kinase binding and activation. Our results provide evidence for multiple mechanisms by which Nef binds to and regulates Src kinases. PMID:10364375

Characterization of receptor of activated C kinase 1 (RACK1) and functional analysis during larval metamorphosis of the oyster Crassostrea angulata.

Science.gov (United States)

Yang, Bingye; Pu, Fei; Qin, Ji; You, Weiwei; Ke, Caihuan

2014-03-10

During a large-scale screen of the larval transcriptome library of the Portuguese oyster, Crassostrea angulata, the oyster gene RACK, which encodes a receptor of activated protein kinase C protein was isolated and characterized. The cDNA is 1,148 bp long and has a predicted open reading frame encoding 317 aa. The predicted protein shows high sequence identity to many RACK proteins of different organisms including molluscs, fish, amphibians and mammals, suggesting that it is conserved during evolution. The structural analysis of the Ca-RACK1 genomic sequence implies that the Ca-RACK1 gene has seven exons and six introns, extending approximately 6.5 kb in length. It is expressed ubiquitously in many oyster tissues as detected by RT-PCR analysis. The Ca-RACK1 mRNA expression pattern was markedly increased at larval metamorphosis; and was further increased along with Ca-RACK1 protein synthesis during epinephrine-induced metamorphosis. These results indicate that the Ca-RACK1 plays an important role in tissue differentiation and/or in cell growth during larval metamorphosis in the oyster, C. angulata. Copyright © 2013 Elsevier B.V. All rights reserved.

Glucose, other secretagogues, and nerve growth factor stimulate mitogen-activated protein kinase in the insulin-secreting beta-cell line, INS-1

DEFF Research Database (Denmark)

Frödin, M; Sekine, N; Roche, E

1995-01-01

The signaling pathways whereby glucose and hormonal secretagogues regulate insulin-secretory function, gene transcription, and proliferation of pancreatic beta-cells are not well defined. We show that in the glucose-responsive beta-cell line INS-1, major secretagogue-stimulated signaling pathways...... converge to activate 44-kDa mitogen-activated protein (MAP) kinase. Thus, glucose-induced insulin secretion was found to be associated with a small stimulatory effect on 44-kDa MAP kinase, which was synergistically enhanced by increased levels of intracellular cAMP and by the hormonal secretagogues......-1. Phorbol ester, an activator of protein kinase C, stimulated 44-kDa MAP kinase by both Ca(2+)-dependent and -independent pathways. Nerve growth factor, independently of changes in cytosolic Ca2+, efficiently stimulated 44-kDa MAP kinase without causing insulin release, indicating that activation...

Aberrant status and clinicopathologic characteristic associations of 11 target genes in 1,321 Chinese patients with lung adenocarcinoma.

Science.gov (United States)

Zhao, Mengnan; Zhan, Cheng; Li, Ming; Yang, Xiaodong; Yang, Xinyu; Zhang, Yong; Lin, Miao; Xia, Yifeng; Feng, Mingxiang; Wang, Qun

2018-01-01

The aberrant status of target genes and their associations with clinicopathologic characteristics are still unclear in primary lung adenocarcinoma. The common mutations and translocations of nine target genes were evaluated in 1,247 specimens of surgically-resected primary lung adenocarcinoma. Immunohistochemistry was used to analyze the expressions of programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1) in 731 specimens. The frequency of the aberrations and their associations with clinicopathologic characteristics were analyzed. Overall, 952 (76.3%) of 1,247 patients harbored at least one target mutation or translocation: epidermal growth factor receptor ( EGFR ) (729, 58.5%), v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog ( KRAS ) (83, 6.7%), human epidermal growth factor receptor 2 ( HER2 ) (82, 6.6%), anaplastic lymphoma kinase ( ALK) (23, 1.8%), phosphoinositide-3-kinase catalytic alpha polypeptide ( PIK3CA ) (20, 1.6%), Ret proto-oncogene RET (15, 1.2%), ROS proto-oncogene 1 receptor tyrosine kinase ( ROS1 ) (12, 1.0%), B-raf proto-oncogene ( BRAF ) (9, 0.7%), neuroblastoma RAS viral (v-ras) oncogene homolog ( NRAS ) (3, 0.2%). Fourteen (1.9%) of 731 patients were PD-1 positive and 95 (13.0%) were PD-L1 positive in tumor cells. In men and smokers, there were more frequent KRAS mutations (both Ppatients, while HER2 (Ppatients with EGFR mutations (all Ppatients with primary lung adenocarcinoma harbored target gene aberrations. The frequency of each alteration differed in patients depending on clinicopathologic characteristics.

Functional Analysis of the Arabidopsis thaliana CDPK-Related Kinase Family: AtCRK1 Regulates Responses to Continuous Light

Directory of Open Access Journals (Sweden)

Abu Imran Baba

2018-04-01

Full Text Available The Calcium-Dependent Protein Kinase (CDPK-Related Kinase family (CRKs consists of eight members in Arabidopsis. Recently, AtCRK5 was shown to play a direct role in the regulation of root gravitropic response involving polar auxin transport (PAT. However, limited information is available about the function of the other AtCRK genes. Here, we report a comparative analysis of the Arabidopsis CRK genes, including transcription regulation, intracellular localization, and biological function. AtCRK transcripts were detectable in all organs tested and a considerable variation in transcript levels was detected among them. Most AtCRK proteins localized at the plasma membrane as revealed by microscopic analysis of 35S::cCRK-GFP (Green Fluorescence Protein expressing plants or protoplasts. Interestingly, 35S::cCRK1-GFP and 35S::cCRK7-GFP had a dual localization pattern which was associated with plasma membrane and endomembrane structures, as well. Analysis of T-DNA insertion mutants revealed that AtCRK genes are important for root growth and control of gravitropic responses in roots and hypocotyls. While Atcrk mutants were indistinguishable from wild type plants in short days, Atcrk1-1 mutant had serious growth defects under continuous illumination. Semi-dwarf phenotype of Atcrk1-1 was accompanied with chlorophyll depletion, disturbed photosynthesis, accumulation of singlet oxygen, and enhanced cell death in photosynthetic tissues. AtCRK1 is therefore important to maintain cellular homeostasis during continuous illumination.

Aldehyde Dehydrogenase 1 and Raf Kinase Inhibitor Protein ...

African Journals Online (AJOL)

Aldehyde Dehydrogenase 1 and Raf Kinase Inhibitor Protein Expression Defines the Proliferative Nature of Cervical Cancer Stem Cells. ... of cervical cancer stem cells and also to validate them in initial and advanced stages of cervical cancer. Keywords: Cervical cancer, ALDH1, BALB/c-nu/nu, HeLa cells, RKIP, Sox2 ...

A Global Analysis of Kinase Function in Candida albicans Hyphal Morphogenesis Reveals a Role for the Endocytosis Regulator Akl1.

Science.gov (United States)

Bar-Yosef, Hagit; Gildor, Tsvia; Ramírez-Zavala, Bernardo; Schmauch, Christian; Weissman, Ziva; Pinsky, Mariel; Naddaf, Rawi; Morschhäuser, Joachim; Arkowitz, Robert A; Kornitzer, Daniel

2018-01-01

The human pathogenic fungus Candida albicans can switch between yeast and hyphal morphologies as a function of environmental conditions and cellular physiology. The yeast-to-hyphae morphogenetic switch is activated by well-established, kinase-based signal transduction pathways that are induced by extracellular stimuli. In order to identify possible inhibitory pathways of the yeast-to-hyphae transition, we interrogated a collection of C. albicans protein kinases and phosphatases ectopically expressed under the regulation of the TETon promoter. Proportionately more phosphatases than kinases were identified that inhibited hyphal morphogenesis, consistent with the known role of protein phosphorylation in hyphal induction. Among the kinases, we identified AKL1 as a gene that significantly suppressed hyphal morphogenesis in serum. Akl1 specifically affected hyphal elongation rather than initiation: overexpression of AKL1 repressed hyphal growth, and deletion of AKL1 resulted in acceleration of the rate of hyphal elongation. Akl1 suppressed fluid-phase endocytosis, probably via Pan1, a putative clathrin-mediated endocytosis scaffolding protein. In the absence of Akl1, the Pan1 patches were delocalized from the sub-apical region, and fluid-phase endocytosis was intensified. These results underscore the requirement of an active endocytic pathway for hyphal morphogenesis. Furthermore, these results suggest that under standard conditions, endocytosis is rate-limiting for hyphal elongation.

Polo-like kinase 1 (PLK1) and protein phosphatase 6 (PP6) regulate DNA-dependent protein kinase catalytic subunit (DNA-PKcs) phosphorylation in mitosis.

Science.gov (United States)

Douglas, Pauline; Ye, Ruiqiong; Trinkle-Mulcahy, Laura; Neal, Jessica A; De Wever, Veerle; Morrice, Nick A; Meek, Katheryn; Lees-Miller, Susan P

2014-06-25

The protein kinase activity of the DNA-PKcs (DNA-dependent protein kinase catalytic subunit) and its autophosphorylation are critical for DBS (DNA double-strand break) repair via NHEJ (non-homologous end-joining). Recent studies have shown that depletion or inactivation of DNA-PKcs kinase activity also results in mitotic defects. DNA-PKcs is autophosphorylated on Ser2056, Thr2647 and Thr2609 in mitosis and phosphorylated DNA-PKcs localize to centrosomes, mitotic spindles and the midbody. DNA-PKcs also interacts with PP6 (protein phosphatase 6), and PP6 has been shown to dephosphorylate Aurora A kinase in mitosis. Here we report that DNA-PKcs is phosphorylated on Ser3205 and Thr3950 in mitosis. Phosphorylation of Thr3950 is DNA-PK-dependent, whereas phosphorylation of Ser3205 requires PLK1 (polo-like kinase 1). Moreover, PLK1 phosphorylates DNA-PKcs on Ser3205 in vitro and interacts with DNA-PKcs in mitosis. In addition, PP6 dephosphorylates DNA-PKcs at Ser3205 in mitosis and after IR (ionizing radiation). DNA-PKcs also phosphorylates Chk2 on Thr68 in mitosis and both phosphorylation of Chk2 and autophosphorylation of DNA-PKcs in mitosis occur in the apparent absence of Ku and DNA damage. Our findings provide mechanistic insight into the roles of DNA-PKcs and PP6 in mitosis and suggest that DNA-PKcs' role in mitosis may be mechanistically distinct from its well-established role in NHEJ.

Molecular cloning and characterization of arginine kinase gene of Toxocara canis.

Science.gov (United States)

Sahu, Shivani; Samanta, S; Harish, D R; Sudhakar, N R; Raina, O K; Shantaveer, S B; Madhu, D N; Kumar, Ashok

2015-06-01

Toxocara canis is an important gastrointestinal nematode of dogs and also a causative agent of visceral larva migrans in humans. Arginine kinase (AK) gene is one of the important biomolecule of phosphagen kinase of T. canis which is emerging as an exciting novel diagnostic target in toxocarosis. The present study was carried out to clone and characterize AK gene of T. canis for future utilization as a diagnostic molecule. Total RNA was extracted from intact adult worms and reverse transcription was done with oligo dT primers to obtain complementary DNA (cDNA). Polymerase chain reaction (PCR) was carried out using cDNA as template with specific primers which amplified a product of 1,202 bp. The amplicon was cloned into pDrive cloning vector and clone was confirmed by colony PCR and restriction endonuclease analysis. Sequence analysis of the gene showed 99.8 and 77.9 % homology with the published AK gene of T. canis (EF015466.1) and Ascaris suum respectively. Structural analysis shown that the mature AK protein consist of 400 amino acids with a molecular wt of 45360.73 Da. Further expression studies are required for producing the recombinant protein for its evaluation in the diagnosis of T. canis infection in humans as well as in adult dogs.

Leucine-rich repeat kinase-1 regulates osteoclast function by modulating RAC1/Cdc42 Small GTPase phosphorylation and activation.

Science.gov (United States)

Zeng, Canjun; Goodluck, Helen; Qin, Xuezhong; Liu, Bo; Mohan, Subburaman; Xing, Weirong

2016-10-01

Leucine-rich repeat kinase-1 (Lrrk1) consists of ankyrin repeats (ANK), leucine-rich repeats (LRR), a GTPase-like domain of Roc (ROC), a COR domain, a serine/threonine kinase domain (KD), and WD40 repeats (WD40). Previous studies have revealed that knockout (KO) of Lrrk1 in mice causes severe osteopetrosis, and a human mutation of Lrrk1 leads to osteosclerotic metaphysial dysplasia. The molecular mechanism by which Lrrk1 regulates osteoclast function is unknown. In this study, we generated a series of Lrrk1 mutants and evaluated their ability to rescue defective bone resorption in Lrrk1-deficient osteoclasts by use of pit formation assays. Overexpression of Lrrk1 or LRR-truncated Lrrk1, but not ANK-truncated Lrrk1, WD40-truncated Lrrk1, Lrrk1-KD, or K651A mutant Lrrk1, rescued bone resorption function of Lrrk1 KO osteoclasts. We next examined whether RAC1/Cdc42 small GTPases are direct substrates of Lrrk1 in osteoclasts. Western blot and pull-down assays revealed that Lrrk1 deficiency in osteoclasts resulted in reduced phosphorylation and activation of RAC1/Cdc42. In vitro kinase assays confirmed that recombinant Lrrk1 phosphorylated RAC1-GST protein, and immunoprecipitation showed that the interaction of Lrrk1 with RAC1 occurred within 10 min after RANKL treatment. Overexpression of constitutively active Q61L RAC1 partially rescued the resorptive function of Lrrk1-deficient osteoclasts. Furthermore, lack of Lrrk1 in osteoclasts led to reduced autophosphorylation of p21 protein-activated kinase-1 at Ser 144 , catalyzed by RAC1/Cdc42 binding and activation. Our data indicate that Lrrk1 regulates osteoclast function by directly modulating phosphorylation and activation of small GTPase RAC1/Cdc42 and that its function depends on ANK, ROC, WD40, and kinase domains. Copyright © 2016 the American Physiological Society.

Identification of Cyclin-dependent Kinase 1 Specific Phosphorylation Sites by an In Vitro Kinase Assay.

Science.gov (United States)

Cui, Heying; Loftus, Kyle M; Noell, Crystal R; Solmaz, Sozanne R

2018-05-03

Cyclin-dependent kinase 1 (Cdk1) is a master controller for the cell cycle in all eukaryotes and phosphorylates an estimated 8 - 13% of the proteome; however, the number of identified targets for Cdk1, particularly in human cells is still low. The identification of Cdk1-specific phosphorylation sites is important, as they provide mechanistic insights into how Cdk1 controls the cell cycle. Cell cycle regulation is critical for faithful chromosome segregation, and defects in this complicated process lead to chromosomal aberrations and cancer. Here, we describe an in vitro kinase assay that is used to identify Cdk1-specific phosphorylation sites. In this assay, a purified protein is phosphorylated in vitro by commercially available human Cdk1/cyclin B. Successful phosphorylation is confirmed by SDS-PAGE, and phosphorylation sites are subsequently identified by mass spectrometry. We also describe purification protocols that yield highly pure and homogeneous protein preparations suitable for the kinase assay, and a binding assay for the functional verification of the identified phosphorylation sites, which probes the interaction between a classical nuclear localization signal (cNLS) and its nuclear transport receptor karyopherin α. To aid with experimental design, we review approaches for the prediction of Cdk1-specific phosphorylation sites from protein sequences. Together these protocols present a very powerful approach that yields Cdk1-specific phosphorylation sites and enables mechanistic studies into how Cdk1 controls the cell cycle. Since this method relies on purified proteins, it can be applied to any model organism and yields reliable results, especially when combined with cell functional studies.

E3B1, a human homologue of the mouse gene product Abi-1, sensitizes activation of Rap1 in response to epidermal growth factor

International Nuclear Information System (INIS)

Jenei, Veronika; Andersson, Tommy; Jakus, Judit; Dib, Karim

2005-01-01

E3B1, a human homologue of the mouse gene product Abi-1, has been implicated in growth-factor-mediated regulation of the small GTPases p21 Ras and Rac. E3b1 is a regulator of Rac because it can form a complex with Sos-1 and eps8, and such a Sos-1-e3B1-eps8 complex serves as a guanine nucleotide exchange factor for Rac. In the present study, we found that overexpression of e3B1 in NIH3T3/EGFR cells sensitized EGF-induced activation of Rac1, whereas it had no impact on EGF-induced activation of p21 Ras . Remarkably, we found that EGF-induced activation of the p21 Ras -related GTPase Rap1 was also sensitized in NIH3T3/EGFR-e3B1 cells. Thus, in NIH3T3/EGFR-e3B1 cells, maximal EGF-induced activation of Rap1 occurs with a dose of EGF much lower than in NIH3T3/EGFR cells. We also report that overexpression of e3B1 in NIH3T3/EGFR cells renders EGF-induced activation of Rap1 completely dependent on Src tyrosine kinases but not on c-Abl. However, EGF-induced tyrosine phosphorylation of the Rap GEF C3G occurred regardless of whether e3B1 was overexpressed or not, and this did not involve Src tyrosine kinases. Accordingly, we propose that overexpression of e3B1 in NIH3T3/EGFR cells leads to mobilization of Src tyrosine kinases that participate in EGF-induced activation of Rap1 and inhibition of cell proliferation

Light-induced conformational changes of LOV1 (light oxygen voltage-sensing domain 1) and LOV2 relative to the kinase domain and regulation of kinase activity in Chlamydomonas phototropin.

Science.gov (United States)

Okajima, Koji; Aihara, Yusuke; Takayama, Yuki; Nakajima, Mihoko; Kashojiya, Sachiko; Hikima, Takaaki; Oroguchi, Tomotaka; Kobayashi, Amane; Sekiguchi, Yuki; Yamamoto, Masaki; Suzuki, Tomomi; Nagatani, Akira; Nakasako, Masayoshi; Tokutomi, Satoru

2014-01-03

Phototropin (phot), a blue light (BL) receptor in plants, has two photoreceptive domains named LOV1 and LOV2 as well as a Ser/Thr kinase domain (KD) and acts as a BL-regulated protein kinase. A LOV domain harbors a flavin mononucleotide that undergoes a cyclic photoreaction upon BL excitation via a signaling state in which the inhibition of the kinase activity by LOV2 is negated. To understand the molecular mechanism underlying the BL-dependent activation of the kinase, the photochemistry, kinase activity, and molecular structure were studied with the phot of Chlamydomonas reinhardtii. Full-length and LOV2-KD samples of C. reinhardtii phot showed cyclic photoreaction characteristics with the activation of LOV- and BL-dependent kinase. Truncation of LOV1 decreased the photosensitivity of the kinase activation, which was well explained by the fact that the signaling state lasted for a shorter period of time compared with that of the phot. Small angle x-ray scattering revealed monomeric forms of the proteins in solution and detected BL-dependent conformational changes, suggesting an extension of the global molecular shapes of both samples. Constructed molecular model of full-length phot based on the small angle x-ray scattering data proved the arrangement of LOV1, LOV2, and KD for the first time that showed a tandem arrangement both in the dark and under BL irradiation. The models suggest that LOV1 alters its position relative to LOV2-KD under BL irradiation. This finding demonstrates that LOV1 may interact with LOV2 and modify the photosensitivity of the kinase activation through alteration of the duration of the signaling state in LOV2.

Extracellular signal-regulated kinases 1/2 as regulators of cardiac hypertrophy

Directory of Open Access Journals (Sweden)

Michael eMutlak

2015-07-01

Full Text Available Cardiac hypertrophy results from increased mechanical load on the heart and through the actions of local and systemic neuro-humoral factors, cytokines and growth factors. These mechanical and neuroendocrine effectors act through stretch, G protein-coupled receptors and tyrosine kinases to induce the activation of a myriad of intracellular signaling pathways including the extracellular signal-regulated kinases 1/2 (ERK1/2. Since most stimuli that provoke myocardial hypertrophy also elicit an acute phosphorylation of the threonine-glutamate-tyrosine (TEY motif within the activation loops of ERK1 and ERK2 kinases, resulting in their activation, ERKs have long been considered promotors of cardiac hypertrophy. Several mouse models were generated in order to directly understand the causal role of ERK1/2 activation in the heart. These models include direct manipulation of ERK1/2 such as overexpression, mutagenesis or knockout models, manipulations of upstream kinases such as MEK1 and manipulations of the phosphatases that depohosphorylate ERK1/2 such as DUSP6. The emerging understanding from these studies, as will be discussed here, is more complex than originally considered. While there is little doubt that ERK1/2 activation or the lack of it modulates the hypertrophic process or the type of hypertrophy that develops, it appears that not all ERK1/2 activation events are the same. While much has been learned, some questions remain regarding the exact role of ERK1/2 in the heart, the upstream events that result in ERK1/2 activation and the downstream effector in hypertrophy.

Loss of mutL homolog-1 (MLH1) expression promotes acquisition of oncogenic and inhibitor-resistant point mutations in tyrosine kinases.

Science.gov (United States)

Springuel, Lorraine; Losdyck, Elisabeth; Saussoy, Pascale; Turcq, Béatrice; Mahon, François-Xavier; Knoops, Laurent; Renauld, Jean-Christophe

2016-12-01

Genomic instability drives cancer progression by promoting genetic abnormalities that allow for the multi-step clonal selection of cells with growth advantages. We previously reported that the IL-9-dependent TS1 cell line sequentially acquired activating substitutions in JAK1 and JAK3 upon successive selections for growth factor independent and JAK inhibitor-resistant cells, suggestive of a defect in mutation avoidance mechanisms. In the first part of this paper, we discovered that the gene encoding mutL homolog-1 (MLH1), a key component of the DNA mismatch repair system, is silenced by promoter methylation in TS1 cells. By means of stable ectopic expression and RNA interference methods, we showed that the high frequencies of growth factor-independent and inhibitor-resistant cells with activating JAK mutations can be attributed to the absence of MLH1 expression. In the second part of this paper, we confirm the clinical relevance of our findings by showing that chronic myeloid leukemia relapses upon ABL-targeted therapy correlated with a lower expression of MLH1 messenger RNA. Interestingly, the mutational profile observed in our TS1 model, characterized by a strong predominance of T:A>C:G transitions, was identical to the one described in the literature for primitive cells derived from chronic myeloid leukemia patients. Taken together, our observations demonstrate for the first time a causal relationship between MLH1-deficiency and incidence of oncogenic point mutations in tyrosine kinases driving cell transformation and acquired resistance to kinase-targeted cancer therapies.

Structural Insight into the 14-3-3 Protein-dependent Inhibition of Protein Kinase ASK1 (Apoptosis Signal-regulating kinase 1)

Czech Academy of Sciences Publication Activity Database

Petrvalská, Olivia; Košek, Dalibor; Kukačka, Zdeněk; Tošner, Z.; Man, Petr; Večeř, J.; Herman, P.; Obšilová, Veronika; Obšil, Tomáš

2016-01-01

Roč. 291, č. 39 (2016), s. 20753-20765 ISSN 0021-9258 R&D Projects: GA ČR(CZ) GA14-10061S Institutional support: RVO:67985823 ; RVO:61388971 Keywords : 14-3-3 protein * apoptosis signal-regulating kinase 1 (ASK1) * fluorescence * nuclear magnetic resonance (NMR) * protein cross-linking * small-angle x-ray scattering (SAXS) Subject RIV: CE - Biochemistry Impact factor: 4.125, year: 2016

Homeodomain-Interacting Protein Kinase (HPK-1) regulates stress responses and ageing in C. elegans.

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Berber, Slavica; Wood, Mallory; Llamosas, Estelle; Thaivalappil, Priya; Lee, Karen; Liao, Bing Mana; Chew, Yee Lian; Rhodes, Aaron; Yucel, Duygu; Crossley, Merlin; Nicholas, Hannah R

2016-01-21

Proteins of the Homeodomain-Interacting Protein Kinase (HIPK) family regulate an array of processes in mammalian systems, such as the DNA damage response, cellular proliferation and apoptosis. The nematode Caenorhabditis elegans has a single HIPK homologue called HPK-1. Previous studies have implicated HPK-1 in longevity control and suggested that this protein may be regulated in a stress-dependent manner. Here we set out to expand these observations by investigating the role of HPK-1 in longevity and in the response to heat and oxidative stress. We find that levels of HPK-1 are regulated by heat stress, and that HPK-1 contributes to survival following heat or oxidative stress. Additionally, we show that HPK-1 is required for normal longevity, with loss of HPK-1 function leading to a faster decline of physiological processes that reflect premature ageing. Through microarray analysis, we have found that HPK-1-regulated genes include those encoding proteins that serve important functions in stress responses such as Phase I and Phase II detoxification enzymes. Consistent with a role in longevity assurance, HPK-1 also regulates the expression of age-regulated genes. Lastly, we show that HPK-1 functions in the same pathway as DAF-16 to regulate longevity and reveal a new role for HPK-1 in development.

Hydroxyurea enhances the activity of acyclovir and cidofovir against herpes simplex virus type 1 resistant strains harboring mutations in the thymidine kinase and/or the DNA polymerase genes.

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Sergerie, Yan; Boivin, Guy

2008-01-01

Drug-resistant herpes simplex virus type 1 (HSV-1) recombinant strains harboring mutations in the thymidine kinase and/or the DNA polymerase genes were evaluated for their susceptibility to various antivirals in the presence of 25 microg/ml of hydroxyurea (HyU). The latter compound decreased the 50% inhibitory concentrations of acyclovir by 1.5-3.8-fold and that of cidofovir by 2.7-14.4-fold. However, HyU did not affect the susceptibilities of the various recombinant mutants to foscarnet. Hydroxyurea, a ribonucleotide reductase inhibitor, can increase the activity of nucleoside/nucleotide analogues against drug-resistant viruses.

The involvement of Gab1 and PI 3-kinase in β1 integrin signaling in keratinocytes

International Nuclear Information System (INIS)

Kuwano, Yoshihiro; Fujimoto, Manabu; Watanabe, Rei; Ishiura, Nobuko; Nakashima, Hiroko; Komine, Mayumi; Hamazaki, Tatsuo S.; Tamaki, Kunihiko; Okochi, Hitoshi

2007-01-01

The control of the stem cell compartment in epidermis is closely linked to the regulation of keratinocyte proliferation and differentiation. β1 integrins are expressed 2-fold higher by stem cells than transit-amplifying cells. Signaling from these β1 integrins is critical for the regulation of the epidermal stem cell compartment. To clarify the functional relevance of this differential expression of β1 integrins, we established HaCaT cells with high β1integrin expression by repeated flow cytometric sorting of this population from the parental cell line. In these obtained cells expressing β1 integrins by 5-fold, MAPK activation was markedly increased. Regarding the upstream of MAPK, Gab1 phosphorylation was also higher with high β1 integrin expression, while Shc phosphorylation was not altered. In addition, enhanced phosphatidylinositol 3-kinase activation was also observed. These observations suggest that Gab1 and phosphatidylinositol 3-kinase play pivotal roles in the β1 integrin-mediated regulation of the epidermal stem cell compartment

Systems biology approach identifies the kinase Csnk1a1 as a regulator of the DNA damage response in embryonic stem cells.

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Carreras Puigvert, Jordi; von Stechow, Louise; Siddappa, Ramakrishnaiah; Pines, Alex; Bahjat, Mahnoush; Haazen, Lizette C J M; Olsen, Jesper V; Vrieling, Harry; Meerman, John H N; Mullenders, Leon H F; van de Water, Bob; Danen, Erik H J

2013-01-22

In pluripotent stem cells, DNA damage triggers loss of pluripotency and apoptosis as a safeguard to exclude damaged DNA from the lineage. An intricate DNA damage response (DDR) signaling network ensures that the response is proportional to the severity of the damage. We combined an RNA interference screen targeting all kinases, phosphatases, and transcription factors with global transcriptomics and phosphoproteomics to map the DDR in mouse embryonic stem cells treated with the DNA cross-linker cisplatin. Networks derived from canonical pathways shared in all three data sets were implicated in DNA damage repair, cell cycle and survival, and differentiation. Experimental probing of these networks identified a mode of DNA damage-induced Wnt signaling that limited apoptosis. Silencing or deleting the p53 gene demonstrated that genotoxic stress elicited Wnt signaling in a p53-independent manner. Instead, this response occurred through reduced abundance of Csnk1a1 (CK1α), a kinase that inhibits β-catenin. Together, our findings reveal a balance between p53-mediated elimination of stem cells (through loss of pluripotency and apoptosis) and Wnt signaling that attenuates this response to tune the outcome of the DDR.

A Myb transcription factor of Phytophthora sojae, regulated by MAP kinase PsSAK1, is required for zoospore development.

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Meng Zhang

Full Text Available PsSAK1, a mitogen-activated protein (MAP kinase from Phytophthora sojae, plays an important role in host infection and zoospore viability. However, the downstream mechanism of PsSAK1 remains unclear. In this study, the 3'-tag digital gene expression (DGE profiling method was applied to sequence the global transcriptional sequence of PsSAK1-silenced mutants during the cysts stage and 1.5 h after inoculation onto susceptible soybean leaf tissues. Compared with the gene expression levels of the recipient P. sojae strain, several candidates of Myb family were differentially expressed (up or down in response to the loss of PsSAK1, including of a R2R3-type Myb transcription factor, PsMYB1. qRT-PCR indicated that the transcriptional level of PsMYB1 decreased due to PsSAK1 silencing. The transcriptional level of PsMYB1 increased during sporulating hyphae, in germinated cysts, and early infection. Silencing of PsMYB1 results in three phenotypes: a no cleavage of the cytoplasm into uninucleate zoospores or release of normal zoospores, b direct germination of sporangia, and c afunction in zoospore-mediated plant infection. Our data indicate that the PsMYB1 transcription factor functions downstream of MAP kinase PsSAK1 and is required for zoospore development of P. sojae.

Lemur tyrosine kinase-2 signalling regulates kinesin-1 light chain-2 phosphorylation and binding of Smad2 cargo.

LENUS (Irish Health Repository)

Manser, C

2012-05-31

A recent genome-wide association study identified the gene encoding lemur tyrosine kinase-2 (LMTK2) as a susceptibility gene for prostate cancer. The identified genetic alteration is within intron 9, but the mechanisms by which LMTK2 may impact upon prostate cancer are not clear because the functions of LMTK2 are poorly understood. Here, we show that LMTK2 regulates a known pathway that controls phosphorylation of kinesin-1 light chain-2 (KLC2) by glycogen synthase kinase-3β (GSK3β). KLC2 phosphorylation by GSK3β induces the release of cargo from KLC2. LMTK2 signals via protein phosphatase-1C (PP1C) to increase inhibitory phosphorylation of GSK3β on serine-9 that reduces KLC2 phosphorylation and promotes binding of the known KLC2 cargo Smad2. Smad2 signals to the nucleus in response to transforming growth factor-β (TGFβ) receptor stimulation and transport of Smad2 by kinesin-1 is required for this signalling. We show that small interfering RNA loss of LMTK2 not only reduces binding of Smad2 to KLC2, but also inhibits TGFβ-induced Smad2 signalling. Thus, LMTK2 may regulate the activity of kinesin-1 motor function and Smad2 signalling.

LeCPK1, a Calcium-Dependent Protein Kinase from Tomato. Plasma Membrane Targeting and Biochemical Characterization1

Science.gov (United States)

Rutschmann, Frank; Stalder, Urs; Piotrowski, Markus; Oecking, Claudia; Schaller, Andreas

2002-01-01

The cDNA of LeCPK1, a calcium-dependent protein kinase, was cloned from tomato (Lycopersicon esculentum Mill.). LeCPK1 was expressed in Escherichia coli and purified from bacterial extracts. The recombinant protein was shown to be a functional protein kinase using a synthetic peptide as the substrate (syntide-2, Km = 85 μm). Autophosphorylation of LeCPK1 was observed on threonine and serine residues, one of which was identified as serine-439. Kinase activity was shown to be Ca2+ dependent and required the C-terminal, calmodulin-like domain of LeCPK1. Two classes of high- and low-affinity Ca2+-binding sites were observed, exhibiting dissociation constants of 0.6 and 55 μm, respectively. LeCPK1 was found to phosphorylate the regulatory C-terminal domain of the plasma membrane H+-ATPase in vitro. A potential role in the regulation of proton pump activity is corroborated by the apparent colocalization of the plasma membrane H+-ATPase and LeCPK1 in vivo. Upon transient expression in suspension-cultured cells, a C-terminal fusion of LeCPK1 with the green fluorescent protein was targeted to the plasma membrane. Myristoylation of the LeCPK1 N terminus was found to be required for plasma membrane targeting. PMID:12011347

Synthesis and Biological Evaluation of a New Acyclic Pyrimidine Derivative as a Probe for Imaging Herpes Simplex Virus Type 1 Thymidine Kinase Gene Expression

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Simon M. Ametamey

2013-07-01

Full Text Available With the idea of finding a more selective radiotracer for imaging herpes simplex virus type 1 thymidine kinase (HSV1-tk gene expression by means of positron emission tomography (PET, a novel [18F]fluorine radiolabeled pyrimidine with 4-hydroxy-3-(hydroxymethylbutyl side chain at N-1 (HHB-5-[18F]FEP was prepared and evaluated as a potential PET probe. Unlabeled reference compound, HHB-5-FEP, was synthesized via a five-step reaction sequence starting from 5-(2-acetoxyethyl-4-methoxypyrimidin-2-one. The radiosynthesis of HHB-[18F]-FEP was accomplished by nucleophilic radiofluorination of a tosylate precursor using [18F]fluoride-cryptate complex in 45% ± 4 (n = 4 radiochemical yields and high purity (>99%. The biological evaluation indicated the feasibility of using HHB-5-[18F]FEP as a PET radiotracer for monitoring HSV1-tk expression in vivo.

Subcellular distribution of cyclin-dependent kinase-like 5 (CDKL5) is regulated through phosphorylation by dual specificity tyrosine-phosphorylation-regulated kinase 1A (DYRK1A).

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Oi, Ami; Katayama, Syouichi; Hatano, Naoya; Sugiyama, Yasunori; Kameshita, Isamu; Sueyoshi, Noriyuki

2017-01-08

Cyclin-dependent kinase-like 5 (CDKL5) is a Ser/Thr protein kinase primarily expressed in the central nervous system and is known to cause X-linked neurodevelopmental disorders such as Rett syndrome. However, the mechanisms regulating CDKL5 have not yet been fully clarified. Therefore, in this study, we investigated the protein kinase that directly phosphorylates CDKL5, identifying it as dual specificity tyrosine-phosphorylation-regulated kinase 1A (DYRK1A), an enzyme binding to and phosphorylating CDKL5. We showed that subcellular distribution of CDKL5 was regulated by its phosphorylation by DYRK1A. In mouse neuroblastoma Neuro2a cells, CDKL5 was localized in both the cytosol and nucleus, whereas DYRK1A showed a typical nuclear localization. When CDKL5 and DYRK1A were co-expressed, the cytosolic localization of CDKL5 was significantly increased. Results of site-directed mutagenesis revealed that the phosphorylation site was Ser-308, in the vicinity of the nuclear localization signal. A mutation mimicking the phosphorylated serine residue by aspartate substitution (S308D) changed CDKL5 localization to the cytosol, whereas the corresponding alanine-substituted analog, CDKL5(S308A), was primarily localized to the nucleus. Taken together, these results strongly suggested that DYRK1A bound to CDKL5 and phosphorylated it on Ser-308, thus interfering with its nuclear localization. Copyright © 2016 Elsevier Inc. All rights reserved.

High Level of Soluble FMS-Like Tyrosine Kinase-1 (sFlt-1 Serum in Pregnancy as a Risk Factor of Preeclampsia

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I Gede Mega Putra

2016-07-01

Full Text Available Background: Recently, etiology and pathogenesis of preeclampsia remain unknown. One of the theory indicating that hypoxia and ischemic placenta caused by abnormal cytotrophoblast invasion in preeclampsia. Soluble Fms-like tyrosine kinase-1 (sFlt-1 serum as a laboratory marker of hypoxia condition that contributes to the occurrence of endothelial damage and clinical manifestations in preeclampsia. Objective: This study was aimed at proving that high level of soluble Fms-like tyrosine kinase-1 (sFlt-1 serum in pregnancy as a risk factor for preeclampsia. Methods: This study was a case control. Among 58 pregnant women studied, 29 women with preeclampsia as a case group and 29 women with normal pregnancy as a control group. Soluble Fms-like tyrosine kinase-1 (sFlt-1 serum was analyzed in the Prodia Laboratory. Collected data were tested for normality using Kolmogorov-Smirnov, then analyzed with independent sample test. Chi-Square test used to determine soluble Fms-like tyrosine kinase-1 (sFlt-1 serum level in preeclampsia. Results: This research concluded that the average level of soluble Fms-like tyrosine kinase-1 (sFlt-1 serum in preeclampsia were 11231.00 ± 8390.3 pg/mL and 3981.62 ± 4921.5 pg/mL in normal pregnancy. Analysis of significance with independent t-test concluded that the value of t = 4.01 and p = 0.001. This mean the average levels of soluble Fms-like tyrosine kinase-1 (sFlt-1serum levels in both groups were difference significantly (p <0.05. Based on the cut-off point of sFlt-1 serum levels was 4505.50 pg/mL with 79.3% sensitivity and 82.8% specificity, the relative risk of preeclampsia was 18 times (OR = 18.40, IK 95% = 4.93 to 68.70, p = 0.001. Conclusion:  Based on this research, high levels of soluble Fms-like tyrosine kinase-1 (sFlt-1 in pregnancy was proved as a risk factor for preeclampsia.

Deciphering the role of the signal- and Sty1 kinase-dependent phosphorylation of the stress-responsive transcription factor Atf1 on gene activation.

Science.gov (United States)

Salat-Canela, Clàudia; Paulo, Esther; Sánchez-Mir, Laura; Carmona, Mercè; Ayté, José; Oliva, Baldo; Hidalgo, Elena

2017-08-18

Adaptation to stress triggers the most dramatic shift in gene expression in fission yeast ( Schizosaccharomyces pombe ), and this response is driven by signaling via the MAPK Sty1. Upon activation, Sty1 accumulates in the nucleus and stimulates expression of hundreds of genes via the nuclear transcription factor Atf1, including expression of atf1 itself. However, the role of stress-induced, Sty1-mediated Atf1 phosphorylation in transcriptional activation is unclear. To this end, we expressed Atf1 phosphorylation mutants from a constitutive promoter to uncouple Atf1 activity from endogenous, stress-activated Atf1 expression. We found that cells expressing a nonphosphorylatable Atf1 variant are sensitive to oxidative stress because of impaired transcription of a subset of stress genes whose expression is also controlled by another transcription factor, Pap1. Furthermore, cells expressing a phospho-mimicking Atf1 mutant display enhanced stress resistance, and although expression of the Pap1-dependent genes still relied on stress induction, another subset of stress-responsive genes was constitutively expressed in these cells. We also observed that, in cells expressing the phospho-mimicking Atf1 mutant, the presence of Sty1 was completely dispensable, with all stress defects of Sty1-deficient cells being suppressed by expression of the Atf1 mutant. We further demonstrated that Sty1-mediated Atf1 phosphorylation does not stimulate binding of Atf1 to DNA but, rather, establishes a platform of interactions with the basal transcriptional machinery to facilitate transcription initiation. In summary, our results provide evidence that Atf1 phosphorylation by the MAPK Sty1 is required for oxidative stress responses in fission yeast cells by promoting transcription initiation. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Co-ordinate regulation of lactate metabolism genes in yeast: the role of the lactate permease gene JEN1.

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Lodi, T; Fontanesi, F; Guiard, B

2002-01-01

In the yeast Saccharomyces cerevisiae, the first step in lactate metabolism is its transport across the plasma membrane, a proton symport process mediated by the product of the gene JEN1. Under aerobic conditions, the expression of JEN1 is regulated by the carbon source: the gene is repressed by glucose and induced by non-fermentable substrates. JEN1 expression is also controlled by oxygen availability, but is unaffected by the absence of haem biosynthesis. JEN1 is negatively regulated by the repressors Mig1p and Mig2p, and requires Cat8p for full derepression. In this report we demonstrate that, in addition to these regulators, the Hap2/3/4/5 complex interacts specifically with a CAAT-box element in the JEN1 promoter, and acts to derepress JEN1 expression. We also provide evidence for transcriptional stimulation of JEN1 by the protein kinase Snf1p. Data are presented which provide a better understanding of the molecular mechanisms implicated in the co-regulation of genes involved in the metabolism of lactate.

Enhancement of myocardial regeneration through genetic engineering of cardiac progenitor cells expressing Pim-1 kinase.

Science.gov (United States)

Fischer, Kimberlee M; Cottage, Christopher T; Wu, Weitao; Din, Shabana; Gude, Natalie A; Avitabile, Daniele; Quijada, Pearl; Collins, Brett L; Fransioli, Jenna; Sussman, Mark A

2009-11-24

Despite numerous studies demonstrating the efficacy of cellular adoptive transfer for therapeutic myocardial regeneration, problems remain for donated cells with regard to survival, persistence, engraftment, and long-term benefits. This study redresses these concerns by enhancing the regenerative potential of adoptively transferred cardiac progenitor cells (CPCs) via genetic engineering to overexpress Pim-1, a cardioprotective kinase that enhances cell survival and proliferation. Intramyocardial injections of CPCs overexpressing Pim-1 were given to infarcted female mice. Animals were monitored over 4, 12, and 32 weeks to assess cardiac function and engraftment of Pim-1 CPCs with echocardiography, in vivo hemodynamics, and confocal imagery. CPCs overexpressing Pim-1 showed increased proliferation and expression of markers consistent with cardiogenic lineage commitment after dexamethasone exposure in vitro. Animals that received CPCs overexpressing Pim-1 also produced greater levels of cellular engraftment, persistence, and functional improvement relative to control CPCs up to 32 weeks after delivery. Salutary effects include reduction of infarct size, greater number of c-kit(+) cells, and increased vasculature in the damaged region. Myocardial repair is significantly enhanced by genetic engineering of CPCs with Pim-1 kinase. Ex vivo gene delivery to enhance cellular survival, proliferation, and regeneration may overcome current limitations of stem cell-based therapeutic approaches.

A Global Analysis of Kinase Function in Candida albicans Hyphal Morphogenesis Reveals a Role for the Endocytosis Regulator Akl1

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Hagit Bar-Yosef

2018-02-01

Full Text Available The human pathogenic fungus Candida albicans can switch between yeast and hyphal morphologies as a function of environmental conditions and cellular physiology. The yeast-to-hyphae morphogenetic switch is activated by well-established, kinase-based signal transduction pathways that are induced by extracellular stimuli. In order to identify possible inhibitory pathways of the yeast-to-hyphae transition, we interrogated a collection of C. albicans protein kinases and phosphatases ectopically expressed under the regulation of the TETon promoter. Proportionately more phosphatases than kinases were identified that inhibited hyphal morphogenesis, consistent with the known role of protein phosphorylation in hyphal induction. Among the kinases, we identified AKL1 as a gene that significantly suppressed hyphal morphogenesis in serum. Akl1 specifically affected hyphal elongation rather than initiation: overexpression of AKL1 repressed hyphal growth, and deletion of AKL1 resulted in acceleration of the rate of hyphal elongation. Akl1 suppressed fluid-phase endocytosis, probably via Pan1, a putative clathrin-mediated endocytosis scaffolding protein. In the absence of Akl1, the Pan1 patches were delocalized from the sub-apical region, and fluid-phase endocytosis was intensified. These results underscore the requirement of an active endocytic pathway for hyphal morphogenesis. Furthermore, these results suggest that under standard conditions, endocytosis is rate-limiting for hyphal elongation.

A novel mutation of sgk-1 gene in central serous chorioretinopathy

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Mahmut Akyol

2015-02-01

Full Text Available AIM: To investigate the association of serum glucocorticoid kinase gene-1 (SGK-1 DNA variants with chronic central serous chorioretinopathy (CSC. METHODS: We enrolled 32 eyes of 32 patients who were diagnosed with chronic CSC and composed 32 normal eyes as a control group. Peripheral blood was used for DNA extraction and polymerase chain reaction (PCR amplification. SGK1 gene was sequenced by using BigDye® Terminator v3.1 cycle sequencing KIT (Applied Biosystems, Foster City, CA, USA. The SGK1 gene and its variants were investigated in CSC patient group and control group. RESULTS: We identified a new polymorphism M32V in two person in the patient group (Minor allele frequency (MAF=0.009 on the region of 1-60 amino acids. The rs1057293 was located in the encoder region of the SGK 1 gene but not associated with CSC (P=0.68. An intrinsic rs1743966 is also not associated (P=0.28. CONCLUSIONS: The new polymorphism M32V is located on the region of 1-60 amino acids which is necessary for localization to the mitochondria in CSC patient. This mutation is probably important for the energy metabolism and plays an important role in the cellular response to hyperosmotic stress and other stress stimuli. Both rs1057293 and rs1743966 are not associated with CSC.

Very late-onset group B Streptococcus meningitis, sepsis, and systemic shigellosis due to interleukin-1 receptor-associated kinase-4 deficiency.

Science.gov (United States)

Krause, Jens C; Ghandil, Pegah; Chrabieh, Maya; Casanova, Jean-Laurent; Picard, Capucine; Puel, Anne; Creech, C Buddy

2009-11-01

We describe a child with very late-onset group B Streptococcus sepsis and meningitis, systemic shigellosis, and chronic osteomyelitis. Peripheral blood cells obtained from the patient and her brother did not respond to stimulation with either interleukin-1beta or lipopolysaccharide. Sequencing of the interleukin-1 receptor-associated kinase-4 gene revealed 2 novel mutations.

Impaired spatial learning strategies and novel object recognition in mice haploinsufficient for the dual specificity tyrosine-regulated kinase-1A (Dyrk1A.

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Glòria Arqué

Full Text Available BACKGROUND: Pathogenic aneuploidies involve the concept of dosage-sensitive genes leading to over- and underexpression phenotypes. Monosomy 21 in human leads to mental retardation and skeletal, immune and respiratory function disturbances. Most of the human condition corresponds to partial monosomies suggesting that critical haploinsufficient genes may be responsible for the phenotypes. The DYRK1A gene is localized on the human chromosome 21q22.2 region, and has been proposed to participate in monosomy 21 phenotypes. It encodes a dual-specificity kinase involved in neuronal development and in adult brain physiology, but its possible role as critical haploinsufficient gene in cognitive function has not been explored. METHODOLOGY/PRINCIPAL FINDINGS: We used mice heterozygous for a Dyrk1A targeted mutation (Dyrk1A+/- to investigate the implication of this gene in the cognitive phenotypes of monosomy 21. Performance of Dyrk1A+/- mice was assayed 1/ in a navigational task using the standard hippocampally related version of the Morris water maze, 2/ in a swimming test designed to reveal potential kinesthetic and stress-related behavioral differences between control and heterozygous mice under two levels of aversiveness (25 degrees C and 17 degrees C and 3/ in a long-term novel object recognition task, sensitive to hippocampal damage. Dyrk1A+/- mice showed impairment in the development of spatial learning strategies in a hippocampally-dependent memory task, they were impaired in their novel object recognition ability and were more sensitive to aversive conditions in the swimming test than euploid control animals. CONCLUSIONS/SIGNIFICANCE: The present results are clear examples where removal of a single gene has a profound effect on phenotype and indicate that haploinsufficiency of DYRK1A might contribute to an impairment of cognitive functions and stress coping behavior in human monosomy 21.

Nemo-like kinase as a negative regulator of nuclear receptor Nurr1 gene transcription in prostate cancer

International Nuclear Information System (INIS)

Wang, Jian; Yang, Zhi-Hong; Chen, Hua; Li, Hua-Hui; Chen, Li-Yong; Zhu, Zhu; Zou, Ying; Ding, Cong-Cong; Yang, Jing; He, Zhi-Wei

2016-01-01

Nurr1, a member of the orphan receptor family, plays an important role in several types of cancer. Our previous work demonstrated that increased expression of Nurr1 plays a significant role in the initiation and progression of prostate cancer (PCa), though the mechanisms for regulation of Nurr1 expression remain unknown. In this study, we investigated the hypothesis that Nemo-like kinase (NLK) is a key regulator of Nurr1 expression in PCa. Immunohistochemistry and Western blot analysis were used to evaluate levels of NLK and Nurr1 in prostatic tissues and cell lines. The effects of overexpression or knockdown of Nurr1 were evaluated in PCa cells through use of PCR, Western blots and promoter reporter assays. The role of Nurr1 promoter cis element was studied by creation of two mutant Nurr1 promoter luciferase constructs, one with a mutated NF-κB binding site and one with a mutated CREB binding site. In addition, three specific inhibitors were used to investigate the roles of these proteins in transcriptional activation of Nurr1, including BAY 11–7082 (NF-κB inhibitor), KG-501 (CREB inhibitor) and ICG-001 (CREB binding protein, CBP, inhibitor). The function of CBP in NLK-mediated regulation of Nurr1 expression was investigated using immunofluorescence, co-immunoprecipitation (Co-IP) and chromatin immunoprecipitation assays (ChIPs). NLK expression was inversely correlated with Nurr1 expression in prostate cancer tissues and cell lines. Overexpression of NLK suppressed Nurr1 promoter activity, leading to downregulation of Nurr1 expression. In contrast, knockdown of NLK demonstrated opposite results, leading to upregulation of Nurr1. When compared with the wild-type Nurr1 promoter, mutation of NF-κB- and CREB-binding sites of the Nurr1 promoter region significantly reduced the upregulation of Nurr1 induced by knockdown of NLK in LNCaP cells; treatment with inhibitors of CREB, CBP and NF-κB led to similar results. We also found that NLK directly interacts with CBP

Subcellular distribution of cyclin-dependent kinase-like 5 (CDKL5) is regulated through phosphorylation by dual specificity tyrosine-phosphorylation-regulated kinase 1A (DYRK1A)

International Nuclear Information System (INIS)

Oi, Ami; Katayama, Syouichi; Hatano, Naoya; Sugiyama, Yasunori; Kameshita, Isamu; Sueyoshi, Noriyuki

2017-01-01

Cyclin-dependent kinase-like 5 (CDKL5) is a Ser/Thr protein kinase primarily expressed in the central nervous system and is known to cause X-linked neurodevelopmental disorders such as Rett syndrome. However, the mechanisms regulating CDKL5 have not yet been fully clarified. Therefore, in this study, we investigated the protein kinase that directly phosphorylates CDKL5, identifying it as dual specificity tyrosine-phosphorylation-regulated kinase 1A (DYRK1A), an enzyme binding to and phosphorylating CDKL5. We showed that subcellular distribution of CDKL5 was regulated by its phosphorylation by DYRK1A. In mouse neuroblastoma Neuro2a cells, CDKL5 was localized in both the cytosol and nucleus, whereas DYRK1A showed a typical nuclear localization. When CDKL5 and DYRK1A were co-expressed, the cytosolic localization of CDKL5 was significantly increased. Results of site-directed mutagenesis revealed that the phosphorylation site was Ser-308, in the vicinity of the nuclear localization signal. A mutation mimicking the phosphorylated serine residue by aspartate substitution (S308D) changed CDKL5 localization to the cytosol, whereas the corresponding alanine-substituted analog, CDKL5(S308A), was primarily localized to the nucleus. Taken together, these results strongly suggested that DYRK1A bound to CDKL5 and phosphorylated it on Ser-308, thus interfering with its nuclear localization. - Highlights: • We investigated the mechanism regulating subcellular localization of CDKL5. • DYRK1A was identified as an enzyme that bound to and phosphorylated CDKL5. • The phosphorylation site of CDKL5 was Ser-308, in the vicinity of the NLS. • When DYRK1A was co-expressed, the cytosolic CDKL5 was significantly increased. • In conclusion, DYRK1A regulates CDKL5 localization via phosphorylation on Ser-308.

Transforming growth factor β-activated kinase 1 negatively regulates interleukin-1α-induced stromal-derived factor-1 expression in vascular smooth muscle cells

Energy Technology Data Exchange (ETDEWEB)

Yang, Bin [Department of Hepatobiliary Surgery, Union Hospital, Tongji Medical College, Huangzhong University of Science and Technology, Wuhan 430022 (China); Li, Wei [Department of Gerontology, Union Hospital, Tongji Medical College, Huangzhong University of Science and Technology, Wuhan 430022 (China); Zheng, Qichang [Department of Hepatobiliary Surgery, Union Hospital, Tongji Medical College, Huangzhong University of Science and Technology, Wuhan 430022 (China); Qin, Tao [Department of Hepatobiliary Pancreatic Surgery, People' s Hospital of Zhengzhou University, School of Medicine, Zhengzhou University, Zhengzhou 450003 (China); Wang, Kun; Li, Jinjin; Guo, Bing; Yu, Qihong; Wu, Yuzhe; Gao, Yang; Cheng, Xiang; Hu, Shaobo; Kumar, Stanley Naveen [Department of Hepatobiliary Surgery, Union Hospital, Tongji Medical College, Huangzhong University of Science and Technology, Wuhan 430022 (China); Liu, Sanguang, E-mail: sanguang1998@sina.com [Department of Hepatobiliary Surgery, The Second Hospital, Hebei Medical University, Shijiazhuang 050000 (China); Song, Zifang, E-mail: zsong@hust.edu.cn [Department of Hepatobiliary Surgery, Union Hospital, Tongji Medical College, Huangzhong University of Science and Technology, Wuhan 430022 (China)

2015-07-17

Stromal-derived Factor-1 (SDF-1) derived from vascular smooth muscle cells (VSMCs) contributes to vascular repair and remodeling in various vascular diseases. In this study, the mechanism underlying regulation of SDF-1 expression by interleukin-1α (IL-1α) was investigated in primary rat VSMCs. We found IL-1α promotes SDF-1 expression by up-regulating CCAAT-enhancer-binding protein β (C/EBPβ) in an IκB kinase β (IKKβ) signaling-dependent manner. Moreover, IL-1α-induced expression of C/EBPβ and SDF-1 was significantly potentiated by knockdown of transforming growth factor β-activated kinase 1 (TAK1), an upstream activator of IKKβ signaling. In addition, we also demonstrated that TAK1/p38 mitogen-activated protein kinase (p38 MAPK) signaling exerted negative effect on IL-1α-induced expression of C/EBPβ and SDF-1 through counteracting ROS-dependent up-regulation of nuclear factor erythroid 2-related factor 2 (NRF2). In conclusion, TAK1 acts as an important regulator of IL-1α-induced SDF-1 expression in VSMCs, and modulating activity of TAK1 may serve as a potential strategy for modulating vascular repair and remodeling. - Highlights: • IL-1α induces IKKβ signaling-dependent SDF-1 expression by up-regulating C/EBPβ. • Activation of TAK1 by IL-1α negatively regulates C/EBPβ-dependent SDF-1 expression. • IL-1α-induced TAK1/p38 MAPK signaling counteracts ROS-dependent SDF-1 expression. • TAK1 counteracts IL-1α-induced SDF-1 expression by attenuating NRF2 up-regulation.

Transforming growth factor β-activated kinase 1 negatively regulates interleukin-1α-induced stromal-derived factor-1 expression in vascular smooth muscle cells

International Nuclear Information System (INIS)

Yang, Bin; Li, Wei; Zheng, Qichang; Qin, Tao; Wang, Kun; Li, Jinjin; Guo, Bing; Yu, Qihong; Wu, Yuzhe; Gao, Yang; Cheng, Xiang; Hu, Shaobo; Kumar, Stanley Naveen; Liu, Sanguang; Song, Zifang

2015-01-01

Stromal-derived Factor-1 (SDF-1) derived from vascular smooth muscle cells (VSMCs) contributes to vascular repair and remodeling in various vascular diseases. In this study, the mechanism underlying regulation of SDF-1 expression by interleukin-1α (IL-1α) was investigated in primary rat VSMCs. We found IL-1α promotes SDF-1 expression by up-regulating CCAAT-enhancer-binding protein β (C/EBPβ) in an IκB kinase β (IKKβ) signaling-dependent manner. Moreover, IL-1α-induced expression of C/EBPβ and SDF-1 was significantly potentiated by knockdown of transforming growth factor β-activated kinase 1 (TAK1), an upstream activator of IKKβ signaling. In addition, we also demonstrated that TAK1/p38 mitogen-activated protein kinase (p38 MAPK) signaling exerted negative effect on IL-1α-induced expression of C/EBPβ and SDF-1 through counteracting ROS-dependent up-regulation of nuclear factor erythroid 2-related factor 2 (NRF2). In conclusion, TAK1 acts as an important regulator of IL-1α-induced SDF-1 expression in VSMCs, and modulating activity of TAK1 may serve as a potential strategy for modulating vascular repair and remodeling. - Highlights: • IL-1α induces IKKβ signaling-dependent SDF-1 expression by up-regulating C/EBPβ. • Activation of TAK1 by IL-1α negatively regulates C/EBPβ-dependent SDF-1 expression. • IL-1α-induced TAK1/p38 MAPK signaling counteracts ROS-dependent SDF-1 expression. • TAK1 counteracts IL-1α-induced SDF-1 expression by attenuating NRF2 up-regulation

Biological Education of IVFRU and FIAU for HSV1-TK Reporter Gene Monitoring

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Hong, Su Hee; Kim, Eun Jung; Lee, Eun Ah; Lee, Jong Chan; Choi, Tae Hyun; Lee, Kyo Chul; An, Gwang Il; Cheon, Gi Jeong [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

2006-07-01

The Herpes Simplex Virus Type1-thymidine kinase (HSV1-TK) system is a useful gene therapy monitoring method. HSV1-TK is one of the most widely used effector gene systems used for imaging gene expression, in association with its use as a reporter gene. It has resulted the development of a number of radiolabeled HSV1-TK substrates for the non-invasive detection of HSV1-TK expression. In non-invasive imaging of the HSV1-TK system, many nucleoside derivatives have been developed as prodrugs for tumor proliferation imaging or as anti-viral drugs. Prodrug activation or sucide gene therapy has been shown to be successful in potentiating the therapeutic index by sensitizing genetically modified tumor cells to various prodrugs or enhancing the action of commonly used chemotherapeutic agents. The most studied prodrug activation approaches involve transfection of tumors with HSV1-TK gene. (Z)-5-(2-iodovinyl)-2'-fluoro- 2'-deoxyuridine (IVFRU) possesses a 2'-fluoro substituent in the ribose configuration, is considered to protect IVFRU from enzyme mediated degradation in vivo. It is obviously potential substrates for HSV1-TK imaging. 2'-Fiuoro-2'-deoxy-1-{beta}-D-arabinofuranosyl- 5-iodo-uridine (FIAU), an anticancer drug widely used in clinical practice, is an analogue of thymidine. In a series of studies using adenovirus vector for gene transfer described the appropriate combination of exogenously introduced HSV1-TK as a 'marker/reporter gene' and radiolabelled FIAU as a 'marker substrate/reporter probe' for monitoring gene therapy and gene expression.

Biological Education of IVFRU and FIAU for HSV1-TK Reporter Gene Monitoring

International Nuclear Information System (INIS)

Hong, Su Hee; Kim, Eun Jung; Lee, Eun Ah; Lee, Jong Chan; Choi, Tae Hyun; Lee, Kyo Chul; An, Gwang Il; Cheon, Gi Jeong

2006-01-01

The Herpes Simplex Virus Type1-thymidine kinase (HSV1-TK) system is a useful gene therapy monitoring method. HSV1-TK is one of the most widely used effector gene systems used for imaging gene expression, in association with its use as a reporter gene. It has resulted the development of a number of radiolabeled HSV1-TK substrates for the non-invasive detection of HSV1-TK expression. In non-invasive imaging of the HSV1-TK system, many nucleoside derivatives have been developed as prodrugs for tumor proliferation imaging or as anti-viral drugs. Prodrug activation or sucide gene therapy has been shown to be successful in potentiating the therapeutic index by sensitizing genetically modified tumor cells to various prodrugs or enhancing the action of commonly used chemotherapeutic agents. The most studied prodrug activation approaches involve transfection of tumors with HSV1-TK gene. (Z)-5-(2-iodovinyl)-2'-fluoro- 2'-deoxyuridine (IVFRU) possesses a 2'-fluoro substituent in the ribose configuration, is considered to protect IVFRU from enzyme mediated degradation in vivo. It is obviously potential substrates for HSV1-TK imaging. 2'-Fiuoro-2'-deoxy-1-β-D-arabinofuranosyl- 5-iodo-uridine (FIAU), an anticancer drug widely used in clinical practice, is an analogue of thymidine. In a series of studies using adenovirus vector for gene transfer described the appropriate combination of exogenously introduced HSV1-TK as a 'marker/reporter gene' and radiolabelled FIAU as a 'marker substrate/reporter probe' for monitoring gene therapy and gene expression

Synthesis of 5-radioiodoarabinosyl uridine analog for probing HSV-1 thymidine kinase gene: an unexpected chelating effect

Energy Technology Data Exchange (ETDEWEB)

Yu, C.-S. [Department of Nuclear Science, National Tsing-Hua University, Hsinchu 300, Taiwan (China)]. E-mail: csyu@mx.nthu.edu.tw; Chiang, L.-W. [Department of Nuclear Science, National Tsing-Hua University, Hsinchu 300, Taiwan (China); Wu, C.-H. [Department of Nuclear Science, National Tsing-Hua University, Hsinchu 300, Taiwan (China); Wang, R.-T. [Department of Nuclear Science, National Tsing-Hua University, Hsinchu 300, Taiwan (China); Chen, S.-W. [Department of Nuclear Science, National Tsing-Hua University, Hsinchu 300, Taiwan (China); Wang, H.-Y. [Department of Nuclear Science, National Tsing-Hua University, Hsinchu 300, Taiwan (China); Yeh, C.-H. [Department of Nuclear Science, National Tsing-Hua University, Hsinchu 300, Taiwan (China)

2006-04-15

Tumor cells transduced with herpes simplex virus thymidine kinase gene has been intensively applied to the field of positron emission tomography via imaging of its substrate. As a pilot synthesis approach, a facial preparation of 5-[{sup 125}I]iodoarabinosyl uridine starting from commercial available uridine is reported herein. Interestingly, the tin group in 5-trimethylstannyl arabinosyluridine was easily removed during purification. The destannylation through the formation of a six-ligand coordination involving 2'-hydroxyl and tin was thereby proposed.

Loss of dysbindin-1, a risk gene for schizophrenia, leads to impaired group 1 metabotropic glutamate receptor function in mice.

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Sanjeev K Bhardwaj

2015-03-01

Full Text Available The expression of dysbindin-1, a protein coded by the risk gene dtnbp1, is reduced in the brains of schizophrenia patients. Evidence indicates a role of dysbindin-1 in dopaminergic and glutamatergic transmission. Glutamatergic transmission and plasticity at excitatory synapses is critically regulated by G-protein coupled metabotropic glutamate receptor (mGluR family members, that have been implicated in schizophrenia. Here, we report a role of dysbindin-1 in hippocampal group 1 mGluR (mGluRI function in mice. In hippocampal synaptoneurosomal preparations from sandy (sdy mice, that have a loss of function mutation in dysbindin-1 gene, we observed a striking reduction in mGluRI agonist [(S-3,5-dihydroxyphenylglycine] (DHPG-induced phosphorylation of extracellular signal regulated kinase 1/2 (ERK1/2. This mGluR-ERK1/2 deficit occurred in the absence of significant changes in protein levels of the two members of the mGluRI family (i.e., mGluR1 and mGluR5 or in another mGluRI signaling pathway, i.e., protein kinase C (PKC. Aberrant mGluRI-ERK1/2 signaling affected hippocampal synaptic plasticity in the sdy mutants as DHPG-induced long-term depression (LTD at CA1 excitatory synapses was significantly reduced. Behavioral data suggest that the mGluRI hypofunction may underlie some of the cognitive abnormalities described in sdy mice as the administration of CDPPB (3-cyano-N-(1,3-diphenyl-1H-pyrazol-5-yl benzamide, a positive allosteric modulator of mGluR5, rescued short-term object recognition and spatial learning and memory deficits in these mice. Taken together, our data suggest a novel role of dysbindin-1 in regulating mGluRI functions.

Silencing of the integrin-linked kinase gene suppresses the proliferation, migration and invasion of pancreatic cancer cells (Panc-1).

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Zhu, Xiang-Yu; Liu, Ning; Liu, Wei; Song, Shao-Wei; Guo, Ke-Jian

2012-04-01

Integrin-linked kinase (ILK) is an ankyrin repeat-containing serine-threonine protein kinase that is involved in the regulation of integrin-mediated processes such as cancer cell proliferation, migration and invasion. In this study, we examined the effect of a lentivirus-mediated knockdown of ILK on the proliferation, migration and invasion of pancreatic cancer (Panc-1) cells. Immunohistochemical staining showed that ILK expression was enhanced in pancreatic cancer tissue. The silencing of ILK in human Panc-1 cells led to cell cycle arrest in the G0/G1 phase and delayed cell proliferation, in addition to down-regulating cell migration and invasion. The latter effects were mediated by up-regulating the expression of E-cadherin, a key protein in cell adhesion. These findings indicate that ILK may be a new diagnostic marker for pancreatic cancer and that silencing ILK could be a potentially useful therapeutic approach for treating pancreatic cancer.

Regulation of mTORC1 Signaling by Src Kinase Activity Is Akt1-Independent in RSV-Transformed Cells

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Martina Vojtěchová

2008-02-01

Full Text Available Increased activity of the Src tyrosine protein kinase that has been observed in a large number of human malignancies appears to be a promising target for drug therapy. In the present study, a critical role of the Src activity in the deregulation of mTOR signaling pathway in Rous sarcoma virus (RSV-transformed hamster fibroblasts, H19 cells, was shown using these cells treated with the Src-specific inhibitor, SU6656, and clones of fibroblasts expressing either the active Src or the dominant-negative Src kinase-dead mutant. Disruption of the Src kinase activity results in substantial reduction of the phosphorylation and activity of the Akt/protein kinase B (PKB, phosphorylation of tuberin (TSC2, mammalian target of rapamycin (mTOR, S6K1, ribosomal protein S6, and eukaryotic initiation factor 4E-binding protein 4E-BP1. The ectopic, active Akt1 that was expressed in Src-deficient cells significantly enhanced phosphorylation of TSC2 in these cells, but it failed to activate the inhibited components of the mTOR pathway that are downstream of TSC2. The data indicate that the Src kinase activity is essential for the activity of mTOR-dependent signaling pathway and suggest that mTOR targets may be controlled by Src independently of Akt1/TSC2 cascade in cells expressing hyperactive Src protein. These observations might have an implication in drug resistance to mTOR inhibitor-based cancer therapy in certain cell types.

Discovery and characterization of a novel CCND1/MRCK gene fusion in mantle cell lymphoma

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Chioniso Patience Masamha

2016-03-01

Full Text Available Abstract The t(11;14 translocation resulting in constitutive cyclin D1 expression is an early event in mantle cell lymphoma (MCL transformation. Patients with a highly proliferative phenotype produce cyclin D1 transcripts with truncated 3′UTRs that evade miRNA regulation. Here, we report the recurrence of a novel gene fusion in MCL cell lines and MCL patient isolates that consists of the full protein coding region of cyclin D1 (CCND1 and a 3′UTR consisting of sequences from both the CCND1 3′UTR and myotonic dystrophy kinase-related Cdc42-binding kinase's (MRCK intron one. The resulting CCND1/MRCK mRNA is resistant to CCND1-targeted miRNA regulation, and targeting the MRCK region of the chimeric 3′UTR with siRNA results in decreased CCND1 levels.

Targeting apoptosis signalling kinase-1 (ASK-1 does not prevent the development of neuropathy in streptozotocin-induced diabetic mice.

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Victoria L Newton

Full Text Available Apoptosis signal-regulating kinase-1 (ASK1 is a mitogen-activated protein 3 kinase (MAPKKK/MAP3K which lies upstream of the stress-activated MAPKs, JNK and p38. ASK1 may be activated by a variety of extracellular and intracellular stimuli. MAP kinase activation in the sensory nervous system as a result of diabetes has been shown in numerous preclinical and clinical studies. As a common upstream activator of both p38 and JNK, we hypothesised that activation of ASK1 contributes to nerve dysfunction in diabetic neuropathy. We therefore wanted to characterize the expression of ASK1 in sensory neurons, and determine whether the absence of functional ASK1 would protect against the development of neuropathy in a mouse model of experimental diabetes. ASK1 mRNA and protein is constitutively expressed by multiple populations of sensory neurons of the adult mouse lumbar DRG. Diabetes was induced in male C57BL/6 and transgenic ASK1 kinase-inactive (ASK1n mice using streptozotocin. Levels of ASK1 do not change in the DRG, spinal cord, or sciatic nerve following induction of diabetes. However, levels of ASK2 mRNA increase in the spinal cord at 4 weeks of diabetes, which could represent a future target for this field. Neither motor nerve conduction velocity deficits, nor thermal or mechanical hypoalgesia were prevented or ameliorated in diabetic ASK1n mice. These results suggest that activation of ASK1 is not responsible for the nerve deficits observed in this mouse model of diabetic neuropathy.

Casein Kinase I Isoform Hrr25 Is a Negative Regulator of Haa1 in the Weak Acid Stress Response Pathway in Saccharomyces cerevisiae.

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Collins, Morgan E; Black, Joshua J; Liu, Zhengchang

2017-07-01

Haa1 is a transcription factor that adapts Saccharomyces cerevisiae cells to weak organic acid stresses by activating the expression of various genes. Many of these genes encode membrane proteins, such as TPO2 and YRO2 How Haa1 is activated by weak acids is not clear. Here, we show that casein kinase I isoform Hrr25 is an important negative regulator of Haa1. Haa1 is known to be multiply phosphorylated. We found that mutations in HRR25 lead to reduced Haa1 phosphorylation and increased expression of Haa1 target genes and that Hrr25 interacts with Haa1. The other three casein kinase I isoforms, Yck1, Yck2, and Yck3, do not seem to play critical roles in Haa1 regulation. Hrr25 has a 200-residue C-terminal region, including a proline- and glutamine-rich domain. Our data suggest that the C-terminal region of Hrr25 is required for normal inhibition of expression of Haa1 target genes TPO2 and YRO2 and is important for cell growth but is not required for cell morphogenesis. We propose that Hrr25 is an important regulator of cellular adaptation to weak acid stress by inhibiting Haa1 through phosphorylation. IMPORTANCE Our study has revealed the casein kinase I protein Hrr25 to be a negative regulator of Haa1, a transcription factor mediating the cellular response to stresses caused by weak acids. Many studies have focused on the target genes of Haa1 and their roles in weak acid stress responses, but little has been reported on the regulatory mechanism of Haa1. Weak acids, such as acetic acid, have long been used for food preservation by slowing down the growth of fungal species, including S. cerevisiae In the biofuel industry, acetic acid in the lignocellulosic hydrolysates limits the production of ethanol, which is undesirable. By understanding how Haa1 is regulated, we can make advances in the field of food sciences to better preserve food and engineer acetic acid-resistant strains that will increase productivity in the biofuel industry. Copyright © 2017 American

Altered AKT1 and MAPK1 Gene Expression on Peripheral Blood Mononuclear Cells and Correlation with T-Helper-Transcription Factors in Systemic Lupus Erythematosus Patients

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Sonia Garcia-Rodriguez

2012-01-01

Full Text Available Kinases have been implicated in the immunopathological mechanisms of Systemic Lupus Erythematosus (SLE. v-akt murine-thymoma viral-oncogene-homolog 1 (AKT1 and mitogen-activated-protein-kinase 1 (MAPK1 gene expressions in peripheral mononuclear cells from thirteen SLE patients with inactive or mild disease were evaluated using quantitative real-time reverse-transcription polymerase-chain-reaction and analyzed whether there was any correlation with T-helper (Th transcription factors (TF gene expression, cytokines, and S100A8/S100A9-(Calprotectin. Age- and gender-matched thirteen healthy controls were examined. AKT1 and MAPK1 expressions were upregulated in SLE patients and correlated with Th17-(Retinoic acid-related orphan receptor (ROR-C, T-regulatory-(Treg-(Transforming Growth Factor Beta (TGFB-2, and Th2-(interleukin (IL-5-related genes. MAPK1 expression correlated with Th1-(IL-12A, T-box TF-(T-bet, Th2-(GATA binding protein-(GATA-3, and IL-10 expressions. IL-10 expression was increased and correlated with plasma Tumor Necrosis Factor (TNF-α and Th0-(IL-2, Th1-(IL-12A, T-bet, GATA3, Treg-(Forkhead/winged-helix transcription factor- (FOXP-3, and IL-6 expressions. FOXP3 expression, FOXP3/RORC, and FOXP3/GATA3 expression ratios were increased. Plasma IL-1β, IL-12(p70, Interferon-(IFN-γ, and IL-6 cytokines were augmented. Plasma IL-1β, IL-6, IL-2, IFN-γ, TNF-α, IL-10, and IL-13 correlated with C-reactive protein, respectively. Increased Calprotectin correlated with neutrophils. Conclusion, SLE patients presented a systemic immunoinflammatory activity, augmented AKT1 and MAPK1 expressions, proinflammatory cytokines, and Calprotectin, together with increased expression of Treg-related genes, suggesting a regulatory feedback opposing the inflammatory activity.

[Clinical utility of real-time fluorescent PCR for combined detection of anaplastic lymphoma kinase and c-ros oncogene 1 receptor tyrosine kinase in non-small cell lung cancer].

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Bai, D Y; Zhang, H P; Zhong, S; Suo, W H; Gao, D H; Ding, Y; Tu, J H

2016-12-23

Objective: To investigate the clinical application value of combined detection of ALK fusion gene and c-ros oncogene 1 receptor tyrosine kinase (ROS1) fusion gene in non-small cell lung cancer (NSCLC) using real-time fluorescent PCR. Methods: A kit for combined detection of ALK fusion gene and ROS1 fusion gene based on fluorescent PCR was used to simultaneously detect the two fusion genes in 302 cases of NSCLC specimens. The results were validated through Sanger sequencing. The consistency of the two detection methods was analyzed. Results: All 302 cases of NSCLC specimens were successfully analyzed through fluorescent PCR (302/302). 12 cases (4.0%) were found to contain ALK fusion gene, including 3 cases with ALK-M1, 3 with ALK-M2, 3 with ALK-M3, 1 with ALK-M4, and 2 with ALK-M6 fusion gene.12 cases (4.0%) were found to contain ROS1 fusion gene, including 1 case with ROS1-M7, 8 cases with ROS1-M8, 1 case with ROS1-M12, 1 case with ROS1-M14, and 1 case with double-positive ROS1-M3 and ROS1-M8 fusion genes. The total detection rate of ALK fusion gene and ROS1 fusion gene was 7.9% (24/302) and 278 cases showed to be negative for ALK fusion gene and ROS1 fusion gene. The successful detection rates for Sanger DNA sequencing were also 100%. The positive, negative and total coincidence rates obtained by real-time fluorescent PCR and by Sanger DNA sequencing were all 100%. Conclusions: The results of Sanger DNA sequencing demonstrate that the real-time fluorescent PCR assay is equally effective in detecting ALK and ROS1 fusion genes in NSCLC tissues. Furthermore, real-time fluorescent PCR assay can be used to detect trace ALK and ROS1 fusion gene simultaneously in tiny samples, and can save time and avoid repeated sampling. It is worthy of recommendation as a rapid and reliable detection technique.

Learning-dependent gene expression of CREB1 isoforms in the molluscan brain

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Hisayo Sadamoto

2010-05-01

Full Text Available Cyclic AMP-responsive element binding protein1 (CREB1 has multiple functions in gene regulation. Various studies have reported that CREB1-dependent gene induction is necessary for memory formation and long-lasting behavioral changes in both vertebrates and invertebrates. In the present study, we characterized Lymnaea CREB1 (LymCREB1 mRNA isoforms of spliced variants in the central nervous system (CNS of the pond snail Lymnaea stagnalis. Among these spliced variants, the three isoforms that code a whole LymCREB1 protein are considered to be the activators for gene regulation. The other four isoforms, which code truncated LymCREB1 proteins with no kinase inducible domain, are the repressors. For a better understanding of the possible roles of different LymCREB1 isoforms, the expression level of these isoform mRNAs was investigated by a real-time quantitative RT-PCR method. Further, we examined the changes in gene expression for all the isoforms in the CNS after conditioned taste aversion (CTA learning or backward conditioning as a control. The results showed that CTA learning increased LymCREB1 gene expression, but it did not change the activator/repressor ratio. Our findings showed that the repressor isoforms, as well as the activator ones, are expressed in large amounts in the CNS, and the gene expression of CREB1 isoforms appeared to be specific for the given stimulus. This was the first quantitative analysis of the expression patterns of CREB1 isoforms at the mRNA level and their association with learning behavior.

SOS2-LIKE PROTEIN KINASE5, an SNF1-RELATED PROTEIN KINASE3-Type Protein Kinase, Is Important for Abscisic Acid Responses in Arabidopsis through Phosphorylation of ABSCISIC ACID-INSENSITIVE51[OPEN

Science.gov (United States)

Zhou, Xiaona; Hao, Hongmei; Zhang, Yuguo; Bai, Yili; Zhu, Wenbo; Qin, Yunxia; Yuan, Feifei; Zhao, Feiyi; Wang, Mengyao; Hu, Jingjiang; Xu, Hong; Guo, Aiguang; Zhao, Huixian; Zhao, Yang; Cao, Cuiling; Yang, Yongqing; Schumaker, Karen S.; Guo, Yan; Xie, Chang Gen

2015-01-01

Abscisic acid (ABA) plays an essential role in seed germination. In this study, we demonstrate that one SNF1-RELATED PROTEIN KINASE3-type protein kinase, SOS2-LIKE PROTEIN KINASE5 (PKS5), is involved in ABA signal transduction via the phosphorylation of an interacting protein, ABSCISIC ACID-INSENSITIVE5 (ABI5). We found that pks5-3 and pks5-4, two previously identified PKS5 superactive kinase mutants with point mutations in the PKS5 FISL/NAF (a conserved peptide that is necessary for interaction with SOS3 or SOS3-LIKE CALCIUM BINDING PROTEINs) motif and the kinase domain, respectively, are hypersensitive to ABA during seed germination. PKS5 was found to interact with ABI5 in yeast (Saccharomyces cerevisiae), and this interaction was further confirmed in planta using bimolecular fluorescence complementation. Genetic studies revealed that ABI5 is epistatic to PKS5. PKS5 phosphorylates a serine (Ser) residue at position 42 in ABI5 and regulates ABA-responsive gene expression. This phosphorylation was induced by ABA in vivo and transactivated ABI5. Expression of ABI5, in which Ser-42 was mutated to alanine, could not fully rescue the ABA-insensitive phenotypes of the abi5-8 and pks5-4abi5-8 mutants. In contrast, mutating Ser-42 to aspartate rescued the ABA insensitivity of these mutants. These data demonstrate that PKS5-mediated phosphorylation of ABI5 at Ser-42 is critical for the ABA regulation of seed germination and gene expression in Arabidopsis (Arabidopsis thaliana). PMID:25858916

Inhibition of protein kinase CK2 reduces CYP24A1 expression and enhances 1,25-dihydroxyvitamin D3 anti-tumor activity in human prostate cancer cells

Science.gov (United States)

Luo, Wei; Yu, Wei-Dong; Ma, Yingyu; Chernov, Mikhail; Trump, Donald L.; Johnson, Candace S.

2013-01-01

Vitamin D has broad range of physiological functions and anti-tumor effects. 24-hydroxylase, encoded by the CYP24A1 gene, is the key enzyme for degrading many forms of vitamin D including the most active form, 1,25D3. Inhibition of CYP24A1 enhances 1,25D3 anti-tumor activity. In order to isolate regulators of CYP24A1 expression in prostate cancer cells, we established a stable prostate cancer cell line PC3 with CYP24A1 promoter driving luciferase expression to screen a small molecular library for compounds that inhibit CYP24A1 promoter activity. From this screening, we identified, 4,5,6,7-tetrabromobenzimidazole (TBBz), a protein kinase CK2 selective inhibitor as a disruptor of CYP24A1 promoter activity. We show that TBBz inhibits CYP24A1 promoter activity induced by 1,25D3 in prostate cancer cells. In addition, TBBz downregulates endogenous CYP24A1 mRNA level in TBBz treated PC3 cells. Furthermore, siRNA-mediated CK2 knockdown reduces 1,25D3 induced CYP24A1 mRNA expression in PC3 cells. These results suggest that CK2 contributes to 1,25D3 mediated target gene expression. Lastly, inhibition of CK2 by TBBz or CK2 siRNA significantly enhanced 1,25D3 mediated anti-proliferative effect in vitro and in vivo in a xenograft model. In summary, our findings reveal that protein kinase CK2 is involved in the regulation of CYP24A1 expression by 1,25D3 and CK2 inhibitor enhances 1,25D3 mediated anti-tumor effect. PMID:23358686

AMP-activated protein kinase phosphorylates CtBP1 and down-regulates its activity

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Kim, Jae-Hwan; Choi, Soo-Youn; Kang, Byung-Hee; Lee, Soon-Min [National Creative Research Center for Epigenome Reprogramming Network, Departments of Biomedical Sciences and Biochemistry and Molecular Biology, Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of); Park, Hyung Soon; Kang, Gum-Yong; Bang, Joo Young [Center for Biomedical Mass Spectrometry, Diatech Korea Co., Ltd., Seoul (Korea, Republic of); Cho, Eun-Jung [National Research Laboratory for Chromatin Dynamics, College of Pharmacy, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Youn, Hong-Duk, E-mail: hdyoun@snu.ac.kr [National Creative Research Center for Epigenome Reprogramming Network, Departments of Biomedical Sciences and Biochemistry and Molecular Biology, Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of); WCU Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence and Technology, Seoul National University, Seoul (Korea, Republic of)

2013-02-01

Highlights: ► AMPK phosphorylates CtBP1 on serine 158. ► AMPK-mediated phosphorylation of CtBP1 causes the ubiquitination and nuclear export of CtBP1. ► AMPK downregulates the CtBP1-mediated repression of Bax transcription. -- Abstract: CtBP is a transcriptional repressor which plays a significant role in the regulation of cell proliferation and tumor progression. It was reported that glucose withdrawal causes induction of Bax due to the dissociation of CtBP from the Bax promoter. However, the precise mechanism involved in the regulation of CtBP still remains unclear. In this study, we found that an activated AMP-activated protein kinase (AMPK) phosphorylates CtBP1 on Ser-158 upon metabolic stresses. Moreover, AMPK-mediated phosphorylation of CtBP1 (S158) attenuates the repressive function of CtBP1. We also confirmed that triggering activation of AMPK by various factors resulted in an increase of Bax gene expression. These findings provide connections of AMPK with CtBP1-mediated regulation of Bax expression for cell death under metabolic stresses.

MARK/Par1 Kinase Is Activated Downstream of NMDA Receptors through a PKA-Dependent Mechanism.

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Laura P Bernard

Full Text Available The Par1 kinases, also known as microtubule affinity-regulating kinases (MARKs, are important for the establishment of cell polarity from worms to mammals. Dysregulation of these kinases has been implicated in autism, Alzheimer's disease and cancer. Despite their important function in health and disease, it has been unclear how the activity of MARK/Par1 is regulated by signals from cell surface receptors. Here we show that MARK/Par1 is activated downstream of NMDA receptors in primary hippocampal neurons. Further, we show that this activation is dependent on protein kinase A (PKA, through the phosphorylation of Ser431 of Par4/LKB1, the major upstream kinase of MARK/Par1. Together, our data reveal a novel mechanism by which MARK/Par1 is activated at the neuronal synapse.

Scaffold Protein Ahk1, Which Associates with Hkr1, Sho1, Ste11, and Pbs2, Inhibits Cross Talk Signaling from the Hkr1 Osmosensor to the Kss1 Mitogen-Activated Protein Kinase

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Nishimura, Akiko; Yamamoto, Katsuyoshi; Oyama, Masaaki; Kozuka-Hata, Hiroko

2016-01-01

In the budding yeast Saccharomyces cerevisiae, osmostress activates the Hog1 mitogen-activated protein kinase (MAPK), which regulates diverse osmoadaptive responses. Hkr1 is a large, highly glycosylated, single-path transmembrane protein that is a putative osmosensor in one of the Hog1 upstream pathways termed the HKR1 subbranch. The extracellular region of Hkr1 contains both a positive and a negative regulatory domain. However, the function of the cytoplasmic domain of Hkr1 (Hkr1-cyto) is unknown. Here, using a mass spectrometric method, we identified a protein, termed Ahk1 (Associated with Hkr1), that binds to Hkr1-cyto. Deletion of the AHK1 gene (in the absence of other Hog1 upstream branches) only partially inhibited osmostress-induced Hog1 activation. In contrast, Hog1 could not be activated by constitutively active mutants of the Hog1 pathway signaling molecules Opy2 or Ste50 in ahk1Δ cells, whereas robust Hog1 activation occurred in AHK1+ cells. In addition to Hkr1-cyto binding, Ahk1 also bound to other signaling molecules in the HKR1 subbranch, including Sho1, Ste11, and Pbs2. Although osmotic stimulation of Hkr1 does not activate the Kss1 MAPK, deletion of AHK1 allowed Hkr1 to activate Kss1 by cross talk. Thus, Ahk1 is a scaffold protein in the HKR1 subbranch and prevents incorrect signal flow from Hkr1 to Kss1. PMID:26787842

Silencing of the integrin-linked kinase gene suppresses the proliferation, migration and invasion of pancreatic cancer cells (Panc-1

Directory of Open Access Journals (Sweden)

Xiang-Yu Zhu

2012-01-01

Full Text Available Integrin-linked kinase (ILK is an ankyrin repeat-containing serine-threonine protein kinase that is involved in the regulation of integrin-mediated processes such as cancer cell proliferation, migration and invasion. In this study, we examined the effect of a lentivirus-mediated knockdown of ILK on the proliferation, migration and invasion of pancreatic cancer (Panc-1 cells. Immunohistochemical staining showed that ILK expression was enhanced in pancreatic cancer tissue. The silencing of ILK in human Panc-1 cells led to cell cycle arrest in the G0/G1 phase and delayed cell proliferation, in addition to down-regulating cell migration and invasion. The latter effects were mediated by up-regulating the expression of E-cadherin, a key protein in cell adhesion. These findings indicate that ILK may be a new diagnostic marker for pancreatic cancer and that silencing ILK could be a potentially useful therapeutic approach for treating pancreatic cancer.

GIT1/beta PIX signaling proteins and PAK1 kinase regulate microtubule nucleation

Czech Academy of Sciences Publication Activity Database

Černohorská, Markéta; Sulimenko, Vadym; Hájková, Zuzana; Sulimenko, Tetyana; Sládková, Vladimíra; Vinopal, Stanislav; Dráberová, Eduarda; Dráber, Pavel

2016-01-01

Roč. 1863, č. 6 (2016), s. 1282-1297 ISSN 0167-4889 R&D Projects: GA ČR GAP302/12/1673; GA ČR GA15-22194S; GA MŠk LH12050; GA MZd NT14467; GA ČR GA16-23702S Institutional support: RVO:68378050 Keywords : Centrosome * Microtubule nucleation * gamma-tubulin * GIT1/beta PIX signaling proteins * PAK1 kinase Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.521, year: 2016

Control of Saccharomyces cerevisiae catalase T gene (CTT1) expression by nutrient supply via the RAS-cyclic AMP pathway.

Science.gov (United States)

Bissinger, P H; Wieser, R; Hamilton, B; Ruis, H

1989-03-01

In Saccharomyces cerevisiae, lack of nutrients triggers a pleiotropic response characterized by accumulation of storage carbohydrates, early G1 arrest, and sporulation of a/alpha diploids. This response is thought to be mediated by RAS proteins, adenylate cyclase, and cyclic AMP (cAMP)-dependent protein kinases. This study shows that expression of the S. cerevisiae gene coding for a cytoplasmic catalase T (CTT1) is controlled by this pathway: it is regulated by the availability of nutrients. Lack of a nitrogen, sulfur, or phosphorus source causes a high-level expression of the gene. Studies with strains with mutations in the RAS-cAMP pathway and supplementation of a rca1 mutant with cAMP show that CTT1 expression is under negative control by a cAMP-dependent protein kinase and that nutrient control of CTT1 gene expression is mediated by this pathway. Strains containing a CTT1-Escherichia coli lacZ fusion gene have been used to isolate mutants with mutations in the pathway. Mutants characterized in this investigation fall into five complementation groups. Both cdc25 and ras2 alleles were identified among these mutants.

Sphingosine kinase 1 is a relevant molecular target in gastric cancer

DEFF Research Database (Denmark)

Fuereder, Thorsten; Hoeflmayer, Doris; Jaeger-Lansky, Agnes

2011-01-01

Sphingosine kinase 1 (Sphk1), a lipid kinase implicated in cell transformation and tumor growth, is overexpressed in gastric cancer and is linked with a poor prognosis. The biological relevance of Sphk1 expression in gastric cancer is unclear. Here, we studied the functional significance of Sphk1...... as a novel molecular target for gastric cancer by using an antisense oligonucleotide approach in vitro and in vivo. Gastric cancer cell lines (MKN28 and N87) were treated with Sphk1 with locked nucleic acid-antisense oligonucleotides (LNA-ASO). Sphk1 target regulation, cell growth, and apoptosis were...... assessed for single-agent Sphk1 LNA-ASO and for combinations with doxorubicin. Athymic nude mice xenografted with gastric cancer cells were treated with Sphk1 LNA and assessed for tumor growth and Sphk1 target regulation, in vivo. In vitro, nanomolar concentrations of Sphk1 LNA-ASO induced an approximately...

Comparative active-site mutation study of human and Caenorhabditis elegans thymidine kinase 1

DEFF Research Database (Denmark)

Skovgaard, Tine; Uhlin, Ulla; Munch-Petersen, Birgitte

2012-01-01

surrounding the substrate base. In CeTK1, some of these mutations led to increased activity with deoxycytidine and deoxyguanosine, two unusual substrates for TK1-like kinases. In HuTK1, mutation of T163 to S resulted in a kinase with a 140-fold lower K(m) for the antiviral nucleoside analogue 3'-azido-3...

Image of HSV1-TK gene expression with {sup 123}IVDU

Energy Technology Data Exchange (ETDEWEB)

Kim, S. Y.; Woo, K. S.; Chung, W. S. [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

2005-07-01

The liver is an important target organ for gene transfer due to its capacity for synthesizing serum protein and its involvement in numerous genetic diseases. So livertargeted gene transfer is significant tool for expanding the treatment options and gene function studies. Gene transfer methods commonly use recombinant viral vector. However, viral vectors also have various disadvantages for example immune recognition after adenoviral vector delivery and potential viralassociated toxicity including helper virus replication and insertional mutagenesis. In contrast, nonviral vectors such as naked plasmid DNA(pDNA) and cationic liposomal systems exhibit low immunogenicity and repeated administration is possible(Ledley et al.,1992; Nabel et al.,1993). These are attractive vectors for in vivo gene transfer because of their suitable characteristics such as biodegradability, minimal toxicity, nonimmunogenicity, and simplicity of use. But non-viral gene delivery, has problems associated with limited efficiency at gene expression. hydrodynamic-based produce has very high level efficiency of gene extraction in liver or soild tumor. In mice, hydrodynamic-based produce was reported that a high level of transgene expression could be obtained in the liver by intravenous injection of large volume( 8{approx}10% of body weight) and high-speed ( Kobayashi N et al., 2004 ). HSV1-TK is one of the most widely use effect gene systems sued for imaging gene expression, in association with its use as a suicide gene, or as a reporter gene In non-invasive imaging of the HSV1-TK system, many nucleoside derivatives have developed as prodrug for tumor proliferation imaging or as anti-viral drugs. Several 5-substituted uracil nucleoside derivatives have been identified to have high sensitivity and selective accumulation in HSV1-TK expression cell. This producer has been used hydrodynamic-based produce, we investigated to image of herpes simplex virus type 1 thymidine kinase (HSV1-tk) gene with (E

Kinase Screening in Pichia pastoris Identified Promising Targets Involved in Cell Growth and Alcohol Oxidase 1 Promoter (PAOX1 Regulation.

Directory of Open Access Journals (Sweden)

Wei Shen

Full Text Available As one of the most commonly used eukaryotic recombinant protein expression systems, P. pastoris relies heavily on the AOX1 promoter (PAOX1, which is strongly induced by methanol but strictly repressed by glycerol and glucose. However, the complicated signaling pathways involved in PAOX1 regulation when supplemented with different carbon sources are poorly understood. Here we constructed a kinase deletion library in P. pastoris and identified 27 mutants which showed peculiar phenotypes in cell growth or PAOX1 regulation. We analyzed both annotations and possible functions of these 27 targets, and then focused on the MAP kinase Hog1. In order to locate its potential downstream components, we performed the phosphoproteome analysis on glycerol cultured WT and Δhog1 strains and identified 157 differentially phosphorylated proteins. Our results identified important kinases involved in P. pastoris cell growth and PAOX1 regulation, which could serve as valuable targets for further mechanistic studies.

Activation of the ATR kinase by the RPA-binding protein ETAA1

DEFF Research Database (Denmark)

Haahr, Peter; Hoffmann, Saskia; Tollenaere, Maxim A X

2016-01-01

Activation of the ATR kinase following perturbations to DNA replication relies on a complex mechanism involving ATR recruitment to RPA-coated single-stranded DNA via its binding partner ATRIP and stimulation of ATR kinase activity by TopBP1. Here, we discovered an independent ATR activation pathway...... in vertebrates, mediated by the uncharacterized protein ETAA1 (Ewing's tumour-associated antigen 1). Human ETAA1 accumulates at DNA damage sites via dual RPA-binding motifs and promotes replication fork progression and integrity, ATR signalling and cell survival after genotoxic insults. Mechanistically...

The Arabidopsis Malectin-Like/LRR-RLK IOS1 Is Critical for BAK1-Dependent and BAK1-Independent Pattern-Triggered Immunity

Science.gov (United States)

Kadota, Yasuhiro; Huang, Pin-Yao; Chien, Hsiao-Chiao; Chu, Po-Wei; Zimmerli, Laurent

2016-01-01

Plasma membrane-localized pattern recognition receptors (PRRs) such as FLAGELLIN SENSING2 (FLS2), EF-TU RECEPTOR (EFR), and CHITIN ELICITOR RECEPTOR KINASE1 (CERK1) recognize microbe-associated molecular patterns (MAMPs) to activate pattern-triggered immunity (PTI). A reverse genetics approach on genes responsive to the priming agent β-aminobutyric acid (BABA) revealed IMPAIRED OOMYCETE SUSCEPTIBILITY1 (IOS1) as a critical PTI player. Arabidopsis thaliana ios1 mutants were hypersusceptible to Pseudomonas syringae bacteria. Accordingly, ios1 mutants showed defective PTI responses, notably delayed upregulation of the PTI marker gene FLG22-INDUCED RECEPTOR-LIKE KINASE1, reduced callose deposition, and mitogen-activated protein kinase activation upon MAMP treatment. Moreover, Arabidopsis lines overexpressing IOS1 were more resistant to bacteria and showed a primed PTI response. In vitro pull-down, bimolecular fluorescence complementation, coimmunoprecipitation, and mass spectrometry analyses supported the existence of complexes between the membrane-localized IOS1 and BRASSINOSTEROID INSENSITIVE1-ASSOCIATED KINASE1 (BAK1)-dependent PRRs FLS2 and EFR, as well as with the BAK1-independent PRR CERK1. IOS1 also associated with BAK1 in a ligand-independent manner and positively regulated FLS2-BAK1 complex formation upon MAMP treatment. In addition, IOS1 was critical for chitin-mediated PTI. Finally, ios1 mutants were defective in BABA-induced resistance and priming. This work reveals IOS1 as a novel regulatory protein of FLS2-, EFR-, and CERK1-mediated signaling pathways that primes PTI activation. PMID:27317676

Temperature-sensitive defects of the GSP1gene, yeast Ran homologue, activate the Tel1-dependent pathway

International Nuclear Information System (INIS)

Hayashi, Naoyuki; Murakami, Seishi; Tsurusaki, Susumu; Nagaura, Zen-ichiro; Oki, Masaya; Nishitani, Hideo; Kobayashi, Masahiko; Shimizu, Hiroko; Yamamoto, Ken-ichi; Nishimoto, Takeharu

2007-01-01

RanGTPase is involved in many cellular processes. It functions in nuclear-cytosolic transport and centrosome formation. Ran also localizes to chromatin as RCC1 does, its guanine nucleotide exchange factor, but Ran's function on chromatin is not known. We found that gsp1, a temperature-sensitive mutant of GSP1, a Saccharomyces cerevisiae Ran homologue, suppressed the hydroxyurea (HU) and ultra violet (UV) sensitivities of the mec1 mutant. In UV-irradiated mec1 gsp1 cells, Rad53 was phosphorylated despite the lack of Mec1. This suppression depended on the TEL1 gene, given that the triple mutant, mec1 gsp1 tel1, was unable to grow. The gsp1 mutations also suppressed the HU sensitivity of the rad9 mutant in a Tel1-dependent manner, but not the HU sensitivity of the rad53 mutant. These results indicated that Rad53 was activated by the Tel1 pathway in mec1 gsp1 cells, suggesting that Gsp1 helps regulate the role switching the ATM family kinases Mec1 and Tel1

Tofacitinib and analogs as inhibitors of the histone kinase PRK1 (PKN1).

Science.gov (United States)

Ostrovskyi, Dmytro; Rumpf, Tobias; Eib, Julia; Lumbroso, Alexandre; Slynko, Inna; Klaeger, Susan; Heinzlmeir, Stephanie; Forster, Michael; Gehringer, Matthias; Pfaffenrot, Ellen; Bauer, Silke Mona; Schmidtkunz, Karin; Wenzler, Sandra; Metzger, Eric; Kuster, Bernhard; Laufer, Stefan; Schüle, Roland; Sippl, Wolfgang; Breit, Bernhard; Jung, Manfred

2016-09-01

The histone kinase PRK1 has been identified as a potential target to combat prostate cancer but selective PRK1 inhibitors are lacking. The US FDA -approved JAK1-3 inhibitor tofacitinib also potently inhibits PRK1 in vitro. We show that tofacitinib also inhibits PRK1 in a cellular setting. Using tofacitinib as a starting point for structure-activity relationship studies, we identified a more potent and another more selective PRK1 inhibitor compared with tofacitinib. Furthermore, we found two potential PRK1/JAK3-selectivity hotspots. The identified inhibitors and the selectivity hotspots lay the basis for the development of selective PRK1 inhibitors. The identification of PRK1, but also of other cellular tofacitinib targets, has implications on its clinical use and on future development of tofacitinib-like JAK inhibitors. [Formula: see text].

The isothiocyanate class of bioactive nutrients covalently inhibit the MEKK1 protein kinase

International Nuclear Information System (INIS)

Cross, Janet V; Foss, Frank W; Rady, Joshua M; Macdonald, Timothy L; Templeton, Dennis J

2007-01-01

Dietary isothiocyanates (ITCs) are electrophilic compounds that have diverse biological activities including induction of apoptosis and effects on cell cycle. They protect against experimental carcinogenesis in animals, an activity believed to result from the transcriptional induction of 'Phase 2' enzymes. The molecular mechanism of action of ITCs is unknown. Since ITCs are electrophiles capable of reacting with sulfhydryl groups on amino acids, we hypothesized that ITCs induce their biological effects through covalent modification of proteins, leading to changes in cell regulatory events. We previously demonstrated that stress-signaling kinase pathways are inhibited by other electrophilic compounds such as menadione. We therefore tested the effects of nutritional ITCs on MEKK1, an upstream regulator of the SAPK/JNK signal transduction pathway. The activity of MEKK1 expressed in cells was monitored using in vitro kinase assays to measure changes in catalytic activity. The activity of endogenous MEKK1, immunopurified from ITC treated and untreated LnCAP cells was also measured by in vitro kinase assay. A novel labeling and affinity reagent for detection of protein modification by ITCs was synthesized and used in competition assays to monitor direct modification of MEKK1 by ITC. Finally, immunoblots with phospho-specific antibodies were used to measure the activity of MAPK protein kinases. ITCs inhibited the MEKK1 protein kinase in a manner dependent on a specific cysteine residue in the ATP binding pocket. Inhibition of MEKK1 catalytic activity was due to direct, covalent and irreversible modification of the MEKK1 protein itself. In addition, ITCs inhibited the catalytic activity of endogenous MEKK1. This correlated with inhibition of the downstream target of MEKK1 activity, i.e. the SAPK/JNK kinase. This inhibition was specific to SAPK, as parallel MAPK pathways were unaffected. These results demonstrate that MEKK1 is directly modified and inhibited by

Phosphoinositide protein kinase PDPK1 is a crucial cell signaling mediator in multiple myeloma.

Science.gov (United States)

Chinen, Yoshiaki; Kuroda, Junya; Shimura, Yuji; Nagoshi, Hisao; Kiyota, Miki; Yamamoto-Sugitani, Mio; Mizutani, Shinsuke; Sakamoto, Natsumi; Ri, Masaki; Kawata, Eri; Kobayashi, Tsutomu; Matsumoto, Yosuke; Horiike, Shigeo; Iida, Shinsuke; Taniwaki, Masafumi

2014-12-15

Multiple myeloma is a cytogenetically/molecularly heterogeneous hematologic malignancy that remains mostly incurable, and the identification of a universal and relevant therapeutic target molecule is essential for the further development of therapeutic strategy. Herein, we identified that 3-phosphoinositide-dependent protein kinase 1 (PDPK1), a serine threonine kinase, is expressed and active in all eleven multiple myeloma-derived cell lines examined regardless of the type of cytogenetic abnormality, the mutation state of RAS and FGFR3 genes, or the activation state of ERK and AKT. Our results revealed that PDPK1 is a pivotal regulator of molecules that are essential for myelomagenesis, such as RSK2, AKT, c-MYC, IRF4, or cyclin Ds, and that PDPK1 inhibition caused the growth inhibition and the induction of apoptosis with the activation of BIM and BAD, and augmented the in vitro cytotoxic effects of antimyeloma agents in myeloma cells. In the clinical setting, PDPK1 was active in myeloma cells of approximately 90% of symptomatic patients at diagnosis, and the smaller population of patients with multiple myeloma exhibiting myeloma cells without active PDPK1 showed a significantly less frequent proportion of the disease stage III by the International Staging System and a significantly more favorable prognosis, including the longer overall survival period and the longer progression-free survival period by bortezomib treatment, than patients with active PDPK1, suggesting that PDPK1 activation accelerates the disease progression and the resistance to treatment in multiple myeloma. Our study demonstrates that PDPK1 is a potent and a universally targetable signaling mediator in multiple myeloma regardless of the types of cytogenetic/molecular profiles. ©2014 American Association for Cancer Research.

Antisense imaging of epidermal growth factor-induced p21{sup WAF-1/CIP-1} gene expression in MDA-MB-468 human breast cancer xenografts

Energy Technology Data Exchange (ETDEWEB)

Wang, Judy; Chen, Paul; Mrkobrada, Marko [Leslie Dan Faculty of Pharmacy, University of Toronto, 19 Russell Street, M5S 2S2, Toronto, Ontario (Canada); Hu, Meiduo [Leslie Dan Faculty of Pharmacy, University of Toronto, 19 Russell Street, M5S 2S2, Toronto, Ontario (Canada); Department of Pharmaceutical Sciences, University of Toronto, Toronto, Ontario (Canada); Vallis, Katherine A. [Department of Radiation Oncology, Princess Margaret Hospital, University Health Network, 610 University Avenue, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); Department of Medical Biophysics, University of Toronto, Toronto, Ontario (Canada); Reilly, Raymond M. [Department of Medical Imaging, University of Toronto, Toronto, Ontario (Canada)

2003-09-01

Molecular imaging of the expression of key genes which determine the response to DNA damage following cancer treatment may predict the effectiveness of a particular treatment strategy. A prominent early response gene for DNA damage is the gene encoding p21{sup WAF-1/CIP-1}, a cyclin-dependent kinase inhibitor that regulates progression through the cell cycle. In this study, we explored the feasibility of imaging p21{sup WAF-1/CIP-1} gene expression at the mRNA level using an 18-mer phosphorothioated antisense oligodeoxynucleotide (ODN) labeled with {sup 111}In. The known induction of the p21{sup WAF-1/CIP-1} gene in MDA-MB-468 human breast cancer cells following exposure to epidermal growth factor (EGF) was used as an experimental tool. Treatment of MDA-MB-468 cells in vitro with EGF (20 nM) increased the ratio of p21{sup WAF-1/CIP-1} mRNA/{beta}-actin mRNA threefold within 2 h as measured by the reverse transcription polymerase chain reaction (RT-PCR). A concentration-dependent inhibition of EGF-induced p21{sup WAF-1/CIP-1} protein expression was achieved in MDA-MB-468 cells by treatment with antisense ODNs with up to a tenfold decrease observed at 1 {mu}M. There was a fourfold lower inhibition of p21{sup WAF-1/CIP-1} protein expression by control sense or random sequence ODNs. Intratumoral injections of EGF (15 {mu}g/day x 3 days) were employed to induce p21{sup WAF-1/CIP-1} gene expression in MDA-MB-468 xenografts implanted subcutaneously into athymic mice. RT-PCR of explanted tumors showed a threefold increased level of p21{sup WAF-1/CIP-1} mRNA compared with normal saline-treated tumors. Successful imaging of EGF-induced p21{sup WAF-1/CIP-1} gene expression in MDA-MB-468 xenografts was achieved at 48 h post injection of {sup 111}In-labeled antisense ODNs (3.7 MBq; 2 {mu}g). Tumors displaying basal levels of p21{sup WAF-1/CIP-1} gene expression in the absence of EGF treatment could not be visualized. Biodistribution studies showed a significantly higher tumor

Expression Profiling of Tyrosine Kinase Genes

National Research Council Canada - National Science Library

Weier, Heinz

2000-01-01

... of these genes parallels the progression of tumors to a more malignant phenotype. We developed a DNA micro-array based screening system to monitor the level of expression of tyrosine kinase (tk...

Reconstruction of the yeast Snf1 kinase regulatory network reveals its role as a global energy regulator

Science.gov (United States)

Usaite, Renata; Jewett, Michael C; Oliveira, Ana Paula; Yates, John R; Olsson, Lisbeth; Nielsen, Jens

2009-01-01

Highly conserved among eukaryotic cells, the AMP-activated kinase (AMPK) is a central regulator of carbon metabolism. To map the complete network of interactions around AMPK in yeast (Snf1) and to evaluate the role of its regulatory subunit Snf4, we measured global mRNA, protein and metabolite levels in wild type, Δsnf1, Δsnf4, and Δsnf1Δsnf4 knockout strains. Using four newly developed computational tools, including novel DOGMA sub-network analysis, we showed the benefits of three-level ome-data integration to uncover the global Snf1 kinase role in yeast. We for the first time identified Snf1's global regulation on gene and protein expression levels, and showed that yeast Snf1 has a far more extensive function in controlling energy metabolism than reported earlier. Additionally, we identified complementary roles of Snf1 and Snf4. Similar to the function of AMPK in humans, our findings showed that Snf1 is a low-energy checkpoint and that yeast can be used more extensively as a model system for studying the molecular mechanisms underlying the global regulation of AMPK in mammals, failure of which leads to metabolic diseases. PMID:19888214

The pkI gene encoding pyruvate kinase I links to the luxZ gene which enhances bioluminescence of the lux operon from Photobacterium leiognathi.

Science.gov (United States)

Lin, J W; Lu, H C; Chen, H Y; Weng, S F

1997-10-09

Partial 3'-end nucleotide sequence of the pkI gene (GenBank accession No. AF019143) from Photobacterium leiognathi ATCC 25521 has been determined, and the encoded pyruvate kinase I is deduced. Pyruvate kinase I is the key enzyme of glycolysis, which converts phosphoenol pyruvate to pyruvate. Alignment and comparison of pyruvate kinase Is from P. leiognathi, E. coli and Salmonella typhimurium show that they are homologous. Nucleotide sequence reveals that the pkI gene is linked to the luxZ gene that enhances bioluminescence of the lux operon from P. leiognathi. The gene order of the pkI and luxZ genes is-pk1-ter-->-R&R"-luxZ-ter"-->, whereas ter is transcriptional terminator for the pkI and related genes, and R&R" is the regulatory region and ter" is transcriptional terminator for the luxZ gene. It clearly elicits that the pkI gene and luxZ gene are divided to two operons. Functional analysis confirms that the potential hairpin loop omega T is the transcriptional terminator for the pkI and related genes. It infers that the pkI and related genes are simply linked to the luxZ gene in P. leiognathi genome.

Ceramide-mediated macroautophagy involves inhibition of protein kinase B and up-regulation of beclin 1.

Science.gov (United States)

Scarlatti, Francesca; Bauvy, Chantal; Ventruti, Annamaria; Sala, Giusy; Cluzeaud, Françoise; Vandewalle, Alain; Ghidoni, Riccardo; Codogno, Patrice

2004-04-30

The sphingolipid ceramide is involved in the cellular stress response. Here we demonstrate that ceramide controls macroautophagy, a major lysosomal catabolic pathway. Exogenous C(2)-ceramide stimulates macroautophagy (proteolysis and accumulation of autophagic vacuoles) in the human colon cancer HT-29 cells by increasing the endogenous pool of long chain ceramides as demonstrated by the use of the ceramide synthase inhibitor fumonisin B(1). Ceramide reverted the interleukin 13-dependent inhibition of macroautophagy by interfering with the activation of protein kinase B. In addition, C(2)-ceramide stimulated the expression of the autophagy gene product beclin 1. Ceramide is also the mediator of the tamoxifen-dependent accumulation of autophagic vacuoles in the human breast cancer MCF-7 cells. Monodansylcadaverine staining and electron microscopy showed that this accumulation was abrogated by myriocin, an inhibitor of de novo synthesis ceramide. The tamoxifen-dependent accumulation of vacuoles was mimicked by 1-phenyl-2-decanoylamino-3-morpholino-1-propanol, an inhibitor of glucosylceramide synthase. 1-Phenyl-2-decanoylamino-3-morpholino-1-propanol, tamoxifen, and C(2)-ceramide stimulated the expression of beclin 1, whereas myriocin antagonized the tamoxifen-dependent up-regulation. Tamoxifen and C(2)-ceramide interfere with the activation of protein kinase B, whereas myriocin relieved the inhibitory effect of tamoxifen. In conclusion, the control of macroautophagy by ceramide provides a novel function for this lipid mediator in a cell process with major biological outcomes.

Non-invasive in vivo imaging with radiolabelled FIAU for monitoring cancer gene therapy using herpes simplex virus type 1 thymidine kinase and ganciclovir

Energy Technology Data Exchange (ETDEWEB)

Deng, Win-Ping; Lai, Wen-Fu [Graduate Institute of Biomedical Materials, Taipei Medical University, Taipei (Taiwan); Yang, Wen K.; Yang, Den-Mei [Institute of Biological Science, Academic Sinica, Taipei (Taiwan); Liu, Ren-Shyan [Department of Nuclear Medicine and National PET Cyclotron Center, Veterans General Hospital, Taipei (Taiwan); Hwang, Jeng-Jong; Wang, Hsin-Ell [Institute of Radiological Science, National Yang-Ming University, 155, Sec. 2, Lih-Nong Street, 112, Pei-tou, Taipei (Taiwan); Fu, Ying-Kai [Institute of Nuclear Energy, Atomic Energy Council, Taoyuan (Taiwan)

2004-01-01

An experimental cancer gene therapy model was employed to develop a non-invasive imaging procedure using radiolabelled 2'-fluoro-2'-deoxy-5-iodo-1-{beta}-d-arabinofuranosyluracil (FIAU) as an enzyme substrate for monitoring retroviral vector-mediated herpes simplex virus type 1 thymidine kinase gene (HSV1-tk) transgene expression. Iodine-131 labelled FIAU was prepared by a no-carrier-added (n.c.a.) synthesis process and lyophilised to give ''hot kits''. The labelling yield was over 95%, with a radiochemical purity of more than 98%. The stability of [{sup 131}I]FIAU in the form of lyophilised powder (the hot kit) was much better than that in the normal saline solution. The shelf life of the final [{sup 131}I]FIAU hot kit product is as long as 4 weeks. Cellular uptake of [{sup 131}I]FIAU after different periods of storage was investigated in vitro with HSV1-tk-retroviral vector transduced NG4TL4-STK and parental non-transduced NG4TL4 murine sarcoma cell lines over an 8-h incubation period. The NG4TL4-STK cells accumulated more radioactivity than NG4TL4 cells in all conditions, and accumulation increased with time up to 8 h. The kinetic profile of the cellular uptake of n.c.a. [{sup 131}I]FIAU formulated from the lyophilised hot kit or from the stock solution was qualitatively similar. For animal model cancer gene therapy studies, FVB/N mice were inoculated subcutaneously with the HSV1-tk(+) and tk(-) sarcoma cells into the flank to produce tumours. Biodistribution studies showed that tumour/blood ratios were 2, 3.5, 8.2 and 386.8 at 1, 4, 8 and 24 h post injection, respectively, for the HSV1-tk(+) tumours, and 0.5, 0.5, 0.7 and 5.4, respectively, for the HSV1-tk(-) tumours. Radiotracer clearance from blood was completed in 24 h and was bi-exponential. A significant difference in radioactivity accumulation was revealed among the HSV1-tk(+) tumours, the tk(-) tumours and other tissues. At 24 h p.i., higher activity retention was observed

Activation of c-Raf-1 kinase signal transduction pathway in alpha(7) integrin-deficient mice.

Science.gov (United States)

Saher, G; Hildt, E

1999-09-24

Integrin alpha(7)-deficient mice develop a novel form of muscular dystrophy. Here we report that deficiency of alpha(7) integrin causes an activation of the c-Raf-1/mitogen-activated protein (MAP) 2 kinase signal transduction pathway in muscle cells. The observed activation of c-Raf-1/MAP2 kinases is a specific effect, because the alpha(7) integrin deficiency does not cause unspecific stress as determined by measurement of the Hsp72/73 level and activity of the JNK2 kinase. Because an increased level of activated FAK was found in muscle of alpha(7) integrin-deficient mice, the activation of c-Raf-1 kinase is triggered most likely by an integrin-dependent pathway. In accordance with this, in the integrin alpha(7)-deficient mice, part of the integrin beta(1D) variant in muscle is replaced by the beta(1A) variant, which permits the FAK activation. A recent report describes that integrin activity can be down-modulated by the c-Raf-1/MAP2 kinase pathway. Specific activation of the c-Raf-1/MAP2 kinases by cell-permeable peptides in skeletal muscle of rabbits causes degeneration of muscle fibers. Therefore, we conclude that in alpha(7) integrin-deficient mice, the continuous activation of c-Raf-1 kinase causes a permanent reduction of integrin activity diminishing integrin-dependent cell-matrix interactions and thereby contributing to the development of the dystrophic phenotype.

Synapses of Amphids Defective (SAD-A) Kinase Promotes Glucose-stimulated Insulin Secretion through Activation of p21-activated Kinase (PAK1) in Pancreatic β-Cells*

Science.gov (United States)

Nie, Jia; Sun, Chao; Faruque, Omar; Ye, Guangming; Li, Jia; Liang, Qiangrong; Chang, Zhijie; Yang, Wannian; Han, Xiao; Shi, Yuguang

2012-01-01

The p21-activated kinase-1 (PAK1) is implicated in regulation of insulin exocytosis as an effector of Rho GTPases. PAK1 is activated by the onset of glucose-stimulated insulin secretion (GSIS) through phosphorylation of Thr-423, a major activation site by Cdc42 and Rac1. However, the kinase(s) that phosphorylates PAK1 at Thr-423 in islet β-cells remains elusive. The present studies identified SAD-A (synapses of amphids defective), a member of AMP-activated protein kinase-related kinases exclusively expressed in brain and pancreas, as a key regulator of GSIS through activation of PAK1. We show that SAD-A directly binds to PAK1 through its kinase domain. The interaction is mediated by the p21-binding domain (PBD) of PAK1 and requires both kinases in an active conformation. The binding leads to direct phosphorylation of PAK1 at Thr-423 by SAD-A, triggering the onset of GSIS from islet β-cells. Consequently, ablation of PAK1 kinase activity or depletion of PAK1 expression completely abolishes the potentiating effect of SAD-A on GSIS. Consistent with its role in regulating GSIS, overexpression of SAD-A in MIN6 islet β-cells significantly stimulated cytoskeletal remodeling, which is required for insulin exocytosis. Together, the present studies identified a critical role of SAD-A in the activation of PAK1 during the onset of insulin exocytosis. PMID:22669945

Synapses of amphids defective (SAD-A) kinase promotes glucose-stimulated insulin secretion through activation of p21-activated kinase (PAK1) in pancreatic β-Cells.

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Nie, Jia; Sun, Chao; Faruque, Omar; Ye, Guangming; Li, Jia; Liang, Qiangrong; Chang, Zhijie; Yang, Wannian; Han, Xiao; Shi, Yuguang

2012-07-27

The p21-activated kinase-1 (PAK1) is implicated in regulation of insulin exocytosis as an effector of Rho GTPases. PAK1 is activated by the onset of glucose-stimulated insulin secretion (GSIS) through phosphorylation of Thr-423, a major activation site by Cdc42 and Rac1. However, the kinase(s) that phosphorylates PAK1 at Thr-423 in islet β-cells remains elusive. The present studies identified SAD-A (synapses of amphids defective), a member of AMP-activated protein kinase-related kinases exclusively expressed in brain and pancreas, as a key regulator of GSIS through activation of PAK1. We show that SAD-A directly binds to PAK1 through its kinase domain. The interaction is mediated by the p21-binding domain (PBD) of PAK1 and requires both kinases in an active conformation. The binding leads to direct phosphorylation of PAK1 at Thr-423 by SAD-A, triggering the onset of GSIS from islet β-cells. Consequently, ablation of PAK1 kinase activity or depletion of PAK1 expression completely abolishes the potentiating effect of SAD-A on GSIS. Consistent with its role in regulating GSIS, overexpression of SAD-A in MIN6 islet β-cells significantly stimulated cytoskeletal remodeling, which is required for insulin exocytosis. Together, the present studies identified a critical role of SAD-A in the activation of PAK1 during the onset of insulin exocytosis.

The Hog1p kinase regulates Aft1p transcription factor to control iron accumulation.

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Martins, Telma S; Pereira, Clara; Canadell, David; Vilaça, Rita; Teixeira, Vítor; Moradas-Ferreira, Pedro; de Nadal, Eulàlia; Posas, Francesc; Costa, Vítor

2018-01-01

Iron acquisition systems have to be tightly regulated to assure a continuous supply of iron, since it is essential for survival, but simultaneously to prevent iron overload that is toxic to the cells. In budding yeast, the low‑iron sensing transcription factor Aft1p is a master regulator of the iron regulon. Our previous work revealed that bioactive sphingolipids modulate iron homeostasis as yeast cells lacking the sphingomyelinase Isc1p exhibit an upregulation of the iron regulon. In this study, we show that Isc1p impacts on iron accumulation and localization. Notably, Aft1p is activated in isc1Δ cells due to a decrease in its phosphorylation and an increase in its nuclear levels. Consistently, the expression of a phosphomimetic version of Aft1p-S210/S224 that favours its nuclear export abolished iron accumulation in isc1Δ cells. Notably, the Hog1p kinase, homologue of mammalian p38, interacts with and directly phosphorylates Aft1p at residues S210 and S224. However, Hog1p-Aft1p interaction decreases in isc1Δ cells, which likely contributes to Aft1p dephosphorylation and consequently to Aft1p activation and iron overload in isc1Δ cells. These results suggest that alterations in sphingolipid composition in isc1Δ cells may impact on iron homeostasis by disturbing the regulation of Aft1p by Hog1p. To our knowledge, Hog1p is the first kinase reported to directly regulate Aft1p, impacting on iron homeostasis. Copyright © 2017 Elsevier B.V. All rights reserved.

FvBck1, a Component of Cell Wall Integrity MAP Kinase Pathway, is Required for Virulence and Oxidative Stress Response in Sugarcane Pokkah Boeng Pathogen

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Chengkang eZhang

2015-10-01

Full Text Available Fusarium verticillioides (formerly F. moniliforme is suggested as one of the causal agents of Pokkah Boeng, a serious disease of sugarcane worldwide. Currently, detailed molecular and physiological mechanism of pathogenesis is unknown. In this study, we focused on cell wall integrity MAPK pathway as one of the potential signaling mechanisms associated with Pokkah Boeng pathogenesis. We identified FvBCK1 gene that encodes a MAP kinase kinase kinase homolog and determined that it is not only required for growth, micro- and macro-conidia production, and cell wall integrity but also for response to osmotic and oxidative stresses. The deletion of FvBCK1 caused a significant reduction in virulence and FB1 production, a carcinogenic mycotoxin produced by the fungus. Moreover, we found the expression levels of three genes, which are known to be involved in superoxide scavenging, were down regulated in the mutant. We hypothesized that the loss of superoxide scavenging capacity was one of the reasons for reduced virulence, but overexpression of catalase or peroxidase gene failed to restore the virulence defect in the deletion mutant. When we introduced Magnaporthe oryzae MCK1 into the FvBck1 deletion mutant, while certain phenotypes were restored, the complemented strain failed to gain full virulence. In summary, FvBck1 plays a diverse role in F. verticillioides, and detailed investigation of downstream signaling pathways will lead to a better understanding of how this MAPK pathway regulates Pokkah Boeng on sugarcane.

Tyrosine kinase receptor c-ros-oncogene 1 inhibition alleviates aberrant bone formation of TWIST-1 haploinsufficient calvarial cells from Saethre-Chotzen syndrome patients.

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Camp, Esther; Anderson, Peter J; Zannettino, Andrew C W; Glackin, Carlotta A; Gronthos, Stan

2018-09-01

Saethre-Chotzen syndrome (SCS), associated with TWIST-1 mutations, is characterized by premature fusion of cranial sutures. TWIST-1 haploinsufficiency, leads to alterations in suture mesenchyme cellular gene expression patterns, resulting in aberrant osteogenesis and craniosynostosis. We analyzed the expression of the TWIST-1 target, Tyrosine kinase receptor c-ros-oncogene 1 (C-ROS-1) in TWIST-1 haploinsufficient calvarial cells derived from SCS patients and calvaria of Twist-1 del/+ mutant mice and found it to be highly expressed when compared to TWIST-1 wild-type controls. Knock-down of C-ROS-1 expression in TWIST-1 haploinsufficient calvarial cells derived from SCS patients was associated with decreased capacity for osteogenic differentiation in vitro. Furthermore, treatment of human SCS calvarial cells with the tyrosine kinase chemical inhibitor, Crizotinib, resulted in reduced C-ROS-1 activity and the osteogenic potential of human SCS calvarial cells with minor effects on cell viability or proliferation. Cultured human SCS calvarial cells treated with Crizotinib exhibited a dose-dependent decrease in alkaline phosphatase activity and mineral deposition, with an associated decrease in expression levels of Runt-related transcription factor 2 and OSTEOPONTIN, with reduced PI3K/Akt signalling in vitro. Furthermore, Crizotinib treatment resulted in reduced BMP-2 mediated bone formation potential of whole Twist-1 del/+ mutant mouse calvaria organotypic cultures. Collectively, these results suggest that C-ROS-1 promotes osteogenic differentiation of TWIST-1 haploinsufficient calvarial osteogenic progenitor cells. Furthermore, the aberrant osteogenic potential of these cells is inhibited by the reduction of C-ROS-1. Therefore, targeting C-ROS-1 with a pharmacological agent, such as Crizotinib, may serve as a novel therapeutic strategy to alleviate craniosynostosis associated with aberrant TWIST-1 function. © 2018 Wiley Periodicals, Inc.

Dominant negative selection of vaccinia virus using a thymidine kinase/thymidylate kinase fusion gene and the prodrug azidothymidine

International Nuclear Information System (INIS)

Holzer, Georg W.; Mayrhofer, Josef; Gritschenberger, Werner; Falkner, Falko G.

2005-01-01

The Escherichia coli thymidine kinase/thymidylate kinase (tk/tmk) fusion gene encodes an enzyme that efficiently converts the prodrug 3'-azido-2',3'-dideoxythymidine (AZT) into its toxic triphosphate derivative, a substance which stops DNA chain elongation. Integration of this marker gene into vaccinia virus that normally is not inhibited by AZT allowed the establishment of a powerful selection procedure for recombinant viruses. In contrast to the conventional vaccinia thymidine kinase (tk) selection that is performed in tk-negative cell lines, AZT selection can be performed in normal (tk-positive) cell lines. The technique is especially useful for the generation of replication-deficient vaccinia viruses and may also be used for gene knock-out studies of essential vaccinia genes

Gene expression profiles in Parkinson disease prefrontal cortex implicate FOXO1 and genes under its transcriptional regulation.

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Alexandra Dumitriu

2012-06-01

Full Text Available Parkinson disease (PD is a complex neurodegenerative disorder with largely unknown genetic mechanisms. While the degeneration of dopaminergic neurons in PD mainly takes place in the substantia nigra pars compacta (SN region, other brain areas, including the prefrontal cortex, develop Lewy bodies, the neuropathological hallmark of PD. We generated and analyzed expression data from the prefrontal cortex Brodmann Area 9 (BA9 of 27 PD and 26 control samples using the 44K One-Color Agilent 60-mer Whole Human Genome Microarray. All samples were male, without significant Alzheimer disease pathology and with extensive pathological annotation available. 507 of the 39,122 analyzed expression probes were different between PD and control samples at false discovery rate (FDR of 5%. One of the genes with significantly increased expression in PD was the forkhead box O1 (FOXO1 transcription factor. Notably, genes carrying the FoxO1 binding site were significantly enriched in the FDR-significant group of genes (177 genes covered by 189 probes, suggesting a role for FoxO1 upstream of the observed expression changes. Single-nucleotide polymorphisms (SNPs selected from a recent meta-analysis of PD genome-wide association studies (GWAS were successfully genotyped in 50 out of the 53 microarray brains, allowing a targeted expression-SNP (eSNP analysis for 52 SNPs associated with PD affection at genome-wide significance and the 189 probes from FoxO1 regulated genes. A significant association was observed between a SNP in the cyclin G associated kinase (GAK gene and a probe in the spermine oxidase (SMOX gene. Further examination of the FOXO1 region in a meta-analysis of six available GWAS showed two SNPs significantly associated with age at onset of PD. These results implicate FOXO1 as a PD-relevant gene and warrant further functional analyses of its transcriptional regulatory mechanisms.

Cloning and characterisation of two CTR1-like genes in Cucurbita pepo: regulation of their expression during male and female flower development.

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Manzano, Susana; Martínez, Cecilia; Gómez, Pedro; Garrido, Dolores; Jamilena, Manuel

2010-12-01

Ethylene is an essential regulator of flower development in Cucurbita pepo, controlling the sexual expression, and the differentiation and maturation of floral organs. To study the action mechanism of ethylene during the male and female flower development, we have identified two CTR1 homologues from C. pepo, CpCTR1 and CpCTR2, and analysed their expressions during female and male flower development and in response to external treatments with ethylene. CpCTR1 and CpCTR2 share a high homology with plant CTR1-like kinases, but differ from other related kinases such as the Arabidopsis EDR1 and the tomato LeCTR2. The C-terminal ends of both CpCTR1 and CpCTR2 have all the conserved motifs of Ser/Thr kinase domains, including the ATP-binding signature and the protein kinase active site consensus sequence, which suggests that CpCTR1 and CpCTR2 could have the same function as CTR1 in ethylene signalling. The transcripts of both genes were detected in different organs of the plant, including roots, leaves and shoots, but were mostly accumulated in mature flowers. During the development of male and female flowers, CpCTR1 and CpCTR2 expressions were concomitant with ethylene production, which indicates that both genes could be upregulated by ethylene, at least in flowers. Moreover, external treatments with ethylene, although did not alter the expression of these two genes in seedlings and leaves, were able to upregulate their expression in flowers. In the earlier stages of flower development, when ethylene production is very low, the expression of CpCTR1 and CpCTR2 is higher in male floral organs, which agrees with the role of these genes as negative regulators of ethylene signalling, and explain the lower ethylene sensitivity of male flowers in comparison with female flowers. The function of the upregulation of these two genes in later stages of female flower development, when the production of ethylene is also increased, is discussed.

The Set1/COMPASS histone H3 methyltransferase helps regulate mitosis with the CDK1 and NIMA mitotic kinases in Aspergillus nidulans.

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Govindaraghavan, Meera; Anglin, Sarah Lea; Osmani, Aysha H; Osmani, Stephen A

2014-08-01

Mitosis is promoted and regulated by reversible protein phosphorylation catalyzed by the essential NIMA and CDK1 kinases in the model filamentous fungus Aspergillus nidulans. Protein methylation mediated by the Set1/COMPASS methyltransferase complex has also been shown to regulate mitosis in budding yeast with the Aurora mitotic kinase. We uncover a genetic interaction between An-swd1, which encodes a subunit of the Set1 protein methyltransferase complex, with NIMA as partial inactivation of nimA is poorly tolerated in the absence of swd1. This genetic interaction is additionally seen without the Set1 methyltransferase catalytic subunit. Importantly partial inactivation of NIMT, a mitotic activator of the CDK1 kinase, also causes lethality in the absence of Set1 function, revealing a functional relationship between the Set1 complex and two pivotal mitotic kinases. The main target for Set1-mediated methylation is histone H3K4. Mutational analysis of histone H3 revealed that modifying the H3K4 target residue of Set1 methyltransferase activity phenocopied the lethality seen when either NIMA or CDK1 are partially functional. We probed the mechanistic basis of these genetic interactions and find that the Set1 complex performs functions with CDK1 for initiating mitosis and with NIMA during progression through mitosis. The studies uncover a joint requirement for the Set1 methyltransferase complex with the CDK1 and NIMA kinases for successful mitosis. The findings extend the roles of the Set1 complex to include the initiation of mitosis with CDK1 and mitotic progression with NIMA in addition to its previously identified interactions with Aurora and type 1 phosphatase in budding yeast. Copyright © 2014 by the Genetics Society of America.

Fatty acid represses insulin receptor gene expression by impairing HMGA1 through protein kinase Cε

International Nuclear Information System (INIS)

Dey, Debleena; Bhattacharya, Anirban; Roy, SibSankar; Bhattacharya, Samir

2007-01-01

It is known that free fatty acid (FFA) contributes to the development of insulin resistance and type2 diabetes. However, the underlying mechanism in FFA-induced insulin resistance is still unclear. In the present investigation we have demonstrated that palmitate significantly (p < 0.001) inhibited insulin-stimulated phosphorylation of PDK1, the key insulin signaling molecule. Consequently, PDK1 phosphorylation of plasma membrane bound PKCε was also inhibited. Surprisingly, phosphorylation of cytosolic PKCε was greatly stimulated by palmitate; this was then translocated to the nuclear region and associated with the inhibition of insulin receptor (IR) gene transcription. A PKCε translocation inhibitor peptide, εV1, suppressed this inhibitory effect of palmitate, suggesting requirement of phospho-PKCε migration to implement palmitate effect. Experimental evidences indicate that phospho-PKCε adversely affected HMGA1. Since HMGA1 regulates IR promoter activity, expression of IR gene was impaired causing reduction of IR on cell surface and that compromises with insulin sensitivity