Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.11.1 (protein kinase)
 81,284 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A protein kinase activity has been detected in two strains of murine Oncornaviruses, MSV/MLV and EFV. This activity phosphorylates not only endogenous viral proteins but also exogenous substrates (histones and phosvitin). The stimulation of enzyme activity by detergents along with the increase of specific activity in viruses treated with trypsin during purification suggest that the enzyme is located in the viral particle.
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PMID:[Evidence of protein kinase activity in 2 murine oncornaviruses]. 7 Dec 20

An underinvestigated aspect of the mitogenic and cell regulatory actions of vanadium is the regulation of gene expression. Among the fifteen cellular genes studied in cultured mouse C127 cells, vanadium (as 10 microM sodium vanadate) increased levels of mRNA of the actin and c-Ha-ras to four times control values. These increases represented de novo synthesis of mRNA, since they were inhibited by actinomycin D. Vanadate did not increase mRNA corresponding to c-src, c-mos, c-myc, p53, HSP70, pODC or RB genes, and expression of c-erb A, c-erb B, c-sis and c-fes genes was undetectable whether vanadium was present or not. Expression of a third gene affected by vanadium, c-jun, was augmented by addition of a reductant or oxidant together with the vanadate. Addition of NADH (marginally effective on its own) or H2O2 (effective alone) dramatically enhanced the effect of vanadate on c-jun gene expression. Catalase inhibited the effect of NADH partly. The vanadate-stimulated expression of actin and c-Ha-ras mRNA were unaffected by oxidants, reductants, metal chelators, or anti-oxidant enzymes. Evidently vanadate acts by two separate mechanisms on these two categories of genes. The alternate hypothesis that the actions of vanadate on actin and c-Ha-ras were mediated by a protein kinase cascade was inconsistent with the following observations. Neither insulin nor epidermal growth factor increased mRNA levels of c-Ha-ras or actin gene. Neither genistein (a tyrosine kinase inhibitor) nor pretreatment with 12-O-tetradecanoylphorbol-13-acetate blocked the actions of vanadate on these genes. Clearly the biological actions of vanadium depend in part on altered expression of genes. Since two of the genes are proto-oncogenes, this mechanism is potentially relevant to the mitogenic responses of cells to vanadium.
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PMID:Vanadate-induced gene expression in mouse C127 cells: roles of oxygen derived active species. 143 69

The cell division cycle in eukaryotes contains up to three major transition points; the conversion of quiescent cells to a stage of active proliferation, the initiation of DNA synthesis (S phase) and the induction of mitosis in cells with newly replicated genome (M phase). Within the past years two strategies, have converged to identify, genetically and biochemically a key protein kinase p34 cdc2 that governs the entry into mitosis. In the fission yeast Schizosaccharomyces pombe a number of mutants in the mitotic regulatory circuit have been isolated. A central gene in the network is cdc2 which is essential for the proper execution of mitosis. The cdc2 gene interacts with a number of other genes for correct mitotic control. The Amphibian oocyte, the oocyte from Xenopus laevis particularly, is arrested at the G2 phase of the first meiotic division; when it enters M phase, it contains a dominant regulatory factor known as MPF (M-phase or maturation promoting factor). Purified MPF is an heterodimer formed of two polypeptides p34cdc2 an homologue of the product of the gene cdc2 and p45cdc13 or cyclin an homologue of the product of the gene cdc13. Biochemical studies have revealed that p34cdc2 is a phosphotyrosine protein during the G2 phase of the cell cycle, both mitotic and meiotic. The tyrosine phosphorylation of p34cdc2 is regulated by the gradual accumulation of cyclin. At the onset of M phase, the complex p34cdc2/cyclin is activated as an histone H1 kinase, and p34cdc2 is tyrosine dephosphorylated. The mechanism of activation of p34cdc2 is negatively regulated by a form of protein phosphatase 2A. Ovulated vertebrate oocytes are arrested at metaphase of the second meiotic division (M II) under the control of the proto-oncogene c-mos a protein kinase. The exit of M II phase and the initiation of early embryonic mitotic cell cycles are physiologically induced by the spermatozoa at the time of fertilization. They requires the degradation of c-mos by a Ca2+ dependent proteolytic enzyme and the destruction of cyclin by an ubiquitin dependent pathway. The Xenopus oocyte has led to the molecular elucidation of MPF and identified links between cell cycle control, protein phosphorylation and proto-oncogenes. Despite the impresive progess of recent years, there is still much to be learned about the control of meiosis in Xenopus oocytes.
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PMID:[From ovocyte to biochemistry of the cell cycle]. 165 57

The mos proto-oncogene product, pp39mos, is a protein kinase and has been equated with cytostatic factor (CSF), an activity in unfertilized eggs that is thought to be responsible for the arrest of meiosis at metaphase II. The biochemical properties and potential substrates of pp39mos were examined in unfertilized eggs and in transformed cells in order to study how the protein functions both as CSF and in transformation. The pp39mos protein associated with polymers under conditions that favor tubulin oligomerization and was present in an approximately 500-kilodalton "core" complex under conditions that favor depolymerization. beta-Tubulin was preferentially coprecipitated in pp39mos immunoprecipitates and was the major phosphorylated product in a pp39mos-dependent immune complex kinase assay. Immunofluorescence analysis of NIH 3T3 cells transformed with Xenopus c-mos showed that pp39mos colocalizes with tubulin in the spindle during metaphase and in the midbody and asters during telophase. Disruption of microtubules with nocodazole affected tubulin and pp39mos organization in the same way. It therefore appears that pp39mos is a tubulin-associated protein kinase and may thus participate in the modification of microtubules and contribute to the formation of the spindle. This activity expressed during interphase in somatic cells may be responsible for the transforming activity of pp39mos.
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PMID:Ability of the c-mos product to associate with and phosphorylate tubulin. 182 42

Using Xenopus eggs and NIH3T3 cells as assay systems, we have compared the physiological (i.e., maturation-inducing and cleavage-arresting) and in vitro transforming activities of the c-mos genes from various species as well as their mutant genes. These analyses show that the three biological activities all depend upon the intrinsic protein kinase activity of Mos and correlate well with each other. Furthermore, our results demonstrate that a well conserved N-terminal 14-amino acid sequence of Mos, termed the Mos-box, is essential for all three activities. These results indicate that the in vitro transforming activity of Mos can be ascribed to the same kinase activity of Mos that exerts the physiological activities.
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PMID:Correlation between physiological and transforming activities of the c-mos proto-oncogene product and identification of an essential Mos domain for these activities. 182 90

The c-mos gene product is required for activation of the maturation-promoting factor (MPF) during oocyte maturation. The c-mos protein also acts as a cytostatic factor which is responsible for meiotic metaphase arrest of vertebrate eggs via stabilization of MPF. Here we show that mouse zygotes contain the c-mos protein. Introduction of a kinase-inhibitory anti-mos antibody into mouse zygotes 12 h after fertilization prevented the first cleavage of zygotes at the pronuclei stage. A second anti-mos antibody, known to allow the mos kinase to function, did not interfere with the formation of two-cell embryos. In addition to its known role in MPF activation in oocyte maturation and meiotic metaphase arrest, our findings indicate that the c-mos protein kinase is also required for completion of pronuclei breakdown following fertilization of mouse eggs.
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PMID:Inhibition of c-mos protein kinase blocks mouse zygotes at the pronuclei stage. 183 16

Previously we reported that c-mos proto-oncogene RNA was developmentally up-regulated during post-natal maturation of the rat skeletal muscle. Using two different site-directed affinity-purified antipeptide antibodies we can observe that c-mos product (p43 c-mos) accumulates increasingly during post-natal development of the skeletal muscle and exhibits protein kinase activity. We find that in adult rat p43 c-mos is 10-fold higher in skeletal muscle than in ovaries, and 20- to 40-fold higher than in heart, lung, testis and liver, and may represent about 0.005% of the total soluble proteins. In addition adult skeletal muscle from Xenopus, mouse and man was found to contain p43 c-mos. These data argue in favour of a novel muscle-specific function of c-mos.
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PMID:Accumulation of the c-mos protein is correlated with post-natal development of skeletal muscle. 183 18

The deduced amino acid sequences of the open reading frames (ORFs) mapping in the short unique segment (US) of Marek's disease virus (MDV) reported in the accompanying paper have been analysed using computer programs to determine their relationships to herpesvirus proteins. Analysis of the catalytic domains of protein kinases showed that the MDV kinase (MDV PK) was closely related to the alphaherpesvirus protein kinase mapping in US. The results also showed that the MDV PK was more closely related to the cellular kinases that control cell division than to the proto-oncogenes c-src and c-mos and it was predicted that the MDV PK would phosphorylate serine/threonine. The MDV homologue of herpes simplex virus (HSV) glycoprotein D (gD) contained several residues that were conserved in mammalian herpesviruses. In particular, six cysteines were perfectly aligned in all the gDs and there were numerous conservative substitutions. Although only approximately 65% of the MDV homologue of glycoprotein I (gI) of HSV has been sequenced, it was clear that a significant number of amino acid residues including four cysteines were conserved in the gI homologues of MDV and mammalian herpesviruses. Further analysis suggested that MDV gD was more closely related to the gDs of pseudorabies virus (PRV) and equine herpesvirus 1 than to the gD of HSV-1 and HSV-2. It was noted that HSV-2 glycoprotein G (gG), PRV gX and MDV gD were related and that MDV ORF4 was related to MDV gD and probably to HSV-1 gG. The results have shown a clear relationship between the genes of MDV and their counterparts in mammalian alphaherpesviruses and are consistent with the idea that MDV glycoprotein genes in US might have arisen by a process of gene duplication and independent evolution.
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PMID:Properties and evolutionary relationships of the Marek's disease virus homologues of protein kinase, glycoprotein D and glycoprotein I of herpes simplex virus. 184 76

The oncogene v-mos transforms mammalian fibroblasts and encodes a serine/threonine protein kinase. Expression of the c-mos protooncogene is most abundant in germ cells, suggesting a normal role for c-mos in meiosis. Here we describe the isolation of cDNA clones containing the complete coding region of the Xenopus laevis homolog of c-mos (mosxe). The mosxe gene is transforming when introduced into murine NIH 3T3 cells, and transformation is abrogated by a lysine-to-arginine mutation in the canonical ATP-binding site. Microinjection of in vitro transcribed mosxe RNA into prophase-arrested Xenopus oocytes causes a resumption of meiosis, leading to germinal vesicle breakdown and oocyte maturation. Oocyte maturation was not observed after microinjection of in vitro transcribed mosxe RNA encoding the lysine-to-arginine mutation. These results demonstrate that the mosxe-encoded protein can induce progression through the cell cycle for both meiotic and mitotic cells and that this property is dependent on the presumptive ATP-binding domain in the protein kinase.
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PMID:Xenopus homolog of the mos protooncogene transforms mammalian fibroblasts and induces maturation of Xenopus oocytes. 252 65

The Xenopus c-mos proto-oncogene product, pp39mos, accumulates in the unfertilized egg during maturation, is hyperphosphorylated and exhibits protein kinase activity. On fertilization, or soon after the completion of meiosis, the accumulated pp39mos undergoes selective proteolysis. Using an in vitro protease assay system, we show here that this specific proteolysis is caused by the calcium-dependent cysteine protease, calpain.
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PMID:Specific proteolysis of the c-mos proto-oncogene product by calpain on fertilization of Xenopus eggs. 253 Dec 91


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