Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

In this study we report identification of six members of a protein kinase gene family from soybean (Glycine max L.). Two fully degenerate oligonucleotide primers corresponding to two conserved motifs (DLK-PENV and GTHEYLAPE) in the catalytic domains of eukaryotic protein serine/threonine kinases were used in a polymerase chain reaction (PCR) to amplify soybean cDNA. Sequence analysis showed that 28 of the PCR sequences represented six different putative protein serine/threonine kinases. These results not only demonstrate that catalytic domains of protein kinases are highly conserved between plants and other eukaryotes but also suggest that there are multiple genes encoding protein kinases in plants.
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PMID:Molecular identification of a soybean protein kinase gene family by using PCR. 137 8

Calcium/calmodulin dependent protein kinase II (CaMKII) is a multifunctional serine/threonine protein kinase. We have created a calcium/calmodulin independent form of this enzyme by truncation. Expression of this enzyme fragment in a rabbit reticulocyte lysate yields a constitutive enzyme with specific activity similar to the activated native enzyme. We have established mammalian cell lines that transiently express this constitutive enzyme using the glucocorticoid-inducible mouse mammary tumor virus long terminal repeat. The transient increase in kinase activity results in a complete cessation of cell cycle progression. This block develops as a consequence of a specific arrest of the cell cycle in G2. During the block, increases in histone H1 kinase activity present in p13 beads or anti-cdc2 immunoprecipitates are seen in parallel with the accumulation of cells at G2, arguing that the arrest is not due to a failure to activate cdc2 as a histone H1 kinase. These results suggest that other changes in serine/threonine protein phosphorylation besides those involved in activation of cdc2 as a histone H1 kinase may be necessary for proper G2-M transition.
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PMID:Expression of a constitutive form of calcium/calmodulin dependent protein kinase II leads to arrest of the cell cycle in G2. 137 61

The raf genes encode a family of cytoplasmic proteins with intrinsic protein-serine/threonine kinase activity. The c-raf gene is the cellular homolog of v-raf, the transforming gene of murine sarcoma virus 3611. The constitutive kinase activity of the v-Raf protein has been implicated in transformation and mitogenesis. The activity of Raf-1, the protein product of the c-raf gene, is normally suppressed by a regulatory N-terminal domain. Activation of various tyrosine-kinase growth factor receptors results in activation of Raf-1 and its hyperphosphorylation. Further, Raf-1 has been shown to act either downstream or independently of the p21ras protein, as indicated by experiments involving microinjection of anti-Ras antibodies. To investigate the potential role of p21ras in the activation of Raf-1 by tyrosine kinases, we have used the baculovirus/Sf9 cell system to overproduce various wild-type and mutant forms of pp60src, p21ras, and Raf-1 proteins. We show that either pp60v-src or p21c-ras can independently activate the autokinase activity of Raf-1, but only to a limited extent. Surprisingly, both pp60v-src and p21c-ras are required to fully activate Raf-1. Analysis of the Raf-1 autokinase activity in vitro shows that Raf-1 autophosphorylation sites are distributed equally on serine and threonine residues. When Raf-1 is analyzed by immunoblotting, as previously reported for mammalian cell experiments, a marked increase in the apparent molecular weight of Raf-1 is seen only when it is coexpressed with both pp60v-src and p21ras.
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PMID:Both p21ras and pp60v-src are required, but neither alone is sufficient, to activate the Raf-1 kinase. 137 95

A molecular cDNA clone (P1 KIN) was isolated that encodes the human RNA-dependent P1/eIF-2 alpha protein kinase. The complete cDNA sequence of the P1 KIN cDNA was determined; the longest open reading frame (ORF) encoded a 551 amino acid protein with a deduced molecular weight of 62055 Da. Transcripts prepared from the P1 KIN cDNA by transcription in vitro with T7 RNA polymerase programmed the cell-free synthesis of a protein indistinguishable by immunoprecipitation and immunoblot gel analyses from the authentic 67-kDa P1 protein synthesized in human U cells treated with interferon (IFN). Furthermore, by use of a sensitive primer extension assay with T7 DNA polymerase, the major site of translation initiation within the deduced ORF of the P1 KIN cDNA was directly identified. Northern RNA gel-blot analysis revealed that the P1 KIN cDNA strongly hybridized to two IFN-induced mRNAs present in both human amnion U cells and HeLa cells; their sizes were 2.5 and 6 kb. Both transcripts were efficiently induced by IFN-alpha, but poorly by IFN-gamma. Polyclonal antibody was prepared against the product of the P1 KIN cDNA expressed in Escherichia coli. In Western blot analysis the antibody recognized a 67-kDa protein induced in human cells by IFN-alpha and, in addition, a 90-kDa protein whose level was not greatly altered by IFN treatment. The IFN-induced 67-kDa protein was found associated with the ribosomal salt-wash fraction of IFN-treated human cells, whereas the 90-kDa protein was predominantly in the S100 soluble fraction. The time course for the induction by IFN-alpha of RNA-dependent protein P1 kinase activity measured by immunoprecipitation was comparable to the time course for protein P1 induction measured by Western immunoblot analysis. The amino acid sequence of P1/eIF-2 alpha protein kinase deduced from the cDNA was 62% identical with the 518-residue murine TIK kinase and contained, within the carboxy-terminal half of the protein, the motifs commonly conserved among protein-serine/threonine kinases. The amino-terminal half of the P1 protein did not possess conserved kinase motifs, but did show extensive homology with vaccinia virus-predicted protein E3L.
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PMID:Mechanism of interferon action: cDNA structure, expression, and regulation of the interferon-induced, RNA-dependent P1/eIF-2 alpha protein kinase from human cells. 137 53

A novel protein kinase, the Esk kinase, has been isolated from an embryonal carcinoma (EC) cell line by using an expression cloning strategy. Sequence analysis of two independent cDNA clones (2.97 and 2.85 kb) suggested the presence of two Esk isoforms in EC cells. The esk-1 cDNA sequence predicted an 857-amino-acid protein kinase with a putative membrane-spanning domain, while the esk-2 cDNA predicted an 831-amino-acid kinase which lacked this domain. In adult mouse cells, esk mRNA levels were highest in tissues possessing a high proliferation rate or a sizeable stem cell compartment, suggesting that the Esk kinase may play some role in the control of cell proliferation or differentiation. As anticipated from the screening procedure, bacterial expression of the Esk kinase reacted with antiphosphotyrosine antibodies on immunoblots. Furthermore, in in vitro kinase assays, the Esk kinase was shown to phosphorylate both itself and the exogenous substrate myelin basic protein on serine, threonine, and tyrosine residues, confirming that the Esk kinase is a novel member of the serine/threonine/tyrosine family of protein kinases.
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PMID:Multiple cDNAs encoding the esk kinase predict transmembrane and intracellular enzyme isoforms. 137 25

The microtubule-associated protein tau is a major component of the paired helical filaments (PHFs) observed in Alzheimer's disease brains. The pathological tau is distinguished from normal tau by its state of phosphorylation, higher apparent M(r) and reaction with certain antibodies. However, the protein kinase(s) have not been characterized so far. Here we describe a protein kinase from brain which specifically induces the Alzheimer-like state in tau protein. The 42 kDa protein belongs to the family of mitogen activated protein kinases (MAPKs) and is activated by tyrosine phosphorylation. It is capable of phosphorylating Ser-Pro and Thr-Pro motifs in tau protein (approximately 14-16 P1 per tau molecule). By contrast, other proline directed Ser/Thr kinases such as p34(cdc2) combined with cyclin A or B have only minor effects on tau phosphorylation. We propose that MAP kinase is abnormally active in Alzheimer brain tissue, or that the corresponding phosphatases are abnormally passive, due to a breakdown of the normal regulatory mechanisms.
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PMID:Mitogen activated protein (MAP) kinase transforms tau protein into an Alzheimer-like state. 137 45

A cDNA for branched-chain alpha-ketoacid dehydrogenase kinase was cloned from a rat heart cDNA library. The cDNA had an open reading frame encoding a protein of 382 amino acid residues with a calculated molecular weight of 43,280. The clone codes for the branched-chain alpha-ketoacid dehydrogenase kinase based on the following: 1) the deduced amino acid sequence contained the partial sequence of the kinase determined by direct sequencing; 2) expression of the cDNA in Escherichia coli resulted in synthesis of a 43,000-Da protein that was recognized specifically by kinase antibodies; and 3) enzyme activity that phosphorylated and inactivated the branched-chain alpha-ketoacid dehydrogenase complex was found in extracts of E. coli expressing the protein. Northern blot analysis indicated the mRNA for the branched-chain alpha-ketoacid dehydrogenase kinase was more abundant in rat heart than in rat liver, as expected from the relative amounts of kinase activity expressed in these tissues. The deduced sequence of the kinase aligned with a high degree of similarity within subdomains characteristic of procaryotic histidine protein kinases. This first mitochondrial protein kinase to be cloned appears more closely related in sequence to procaryotic histidine protein kinases than to eucaryotic serine/threonine protein kinases.
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PMID:Branched-chain alpha-ketoacid dehydrogenase kinase. Molecular cloning, expression, and sequence similarity with histidine protein kinases. 137 77

The p34cdc2 protein kinase is a component of maturation-promoting factor, the master regulator of the cell cycle in all eukaryotes. The activity of p34cdc2 is itself tightly regulated by phosphorylation and dephosphorylation. Predicted regulatory phosphorylation sites of Xenopus p34cdc2 were mutated in vitro, and in vitro-transcribed RNAs were injected into Xenopus oocytes. The cdc2 single mutants Thr-14----Ala and Tyr-15----Phe did not induce germinal vesicle breakdown (BVBD) upon microinjection into oocytes. In contrast, the cdc2 double mutant Ala-14/Phe-15 did induce GVBD. Both the Ala-14 and Ala-14/Phe-15p34cdc2 mutants were shown to coimmunoprecipitate cyclin B1 and to phosphorylate histone H1 in immune complex kinase assays. Microinjection of antisense oligonucleotides to c-mosXe was used to demonstrate the role of mos protein synthesis in the induction of GVBD by the Ala-14/Phe-15 cdc2 mutant. Thr-161 was also mutated. p34cdc2 single mutants Ala-161 and Glu-161 and triple mutants Ala-14/Phe-15/Ala-161 and Ala-14/Phe-15/Glu-161 failed to induce GVBD in oocytes and showed a decreased binding to cyclin B1 in coimmunoprecipitations. Each of the cdc2 mutants was also assayed by coinjection with cyclin B1 or c-mosXe RNA into oocytes. Several of the cdc2 mutants were found to affect the kinetics of cyclin B1 and/or mos-induced GVBD upon coinjection, although none affected the rate of progesterone-induced maturation. We demonstrate here the significance of Thr-14, Tyr-15, and Thr-161 of p34cdc2 in Xenopus oocyte maturation. In addition, these results suggest a regulatory role for mosXe in induction of oocyte maturation by the cdc2 mutant Ala-14/Phe-15.
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PMID:Requirement of mosXe protein kinase for meiotic maturation of Xenopus oocytes induced by a cdc2 mutant lacking regulatory phosphorylation sites. 137 75

A putative protein kinase gene (PfPK2) has been isolated from the human parasite Plasmodium falciparum by using a mixed oligonucleotide pool which corresponds to a highly conserved region of serine/threonine protein kinases. The complete nucleotide sequence of 5 kb suggests the existence of a second transcriptional unit besides that of the PfPK2 gene, separated by a highly (A+T)-rich region and transcribed in a different orientation. No intron sequence exists in PfPK2. The predicted amino acid sequence of PfPK2 contains features characteristic of eukaryotic serine/threonine protein kinases. Within its putative catalytic domain it shares 33%, 30%, and 28% amino acid identities with rat calcium-calmodulin-dependent protein kinase, human protein kinase C, and bovine cAMP-dependent protein kinase, respectively. Outside the catalytic domain, however, PfPK2 has no homology with regulatory domains of other protein kinases, indicating PfPK2 might be modulated by signals different from those of higher eukaryotes or might be associated with other regulatory subunits. Using a specific antiserum raised in rabbits against a recombinant fragment of the protein expressed in Escherichia coli, PfPK2 was found to be expressed in a stage-specific fashion and mainly localized in the parasitic membrane.
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PMID:Molecular cloning, stage-specific expression and cellular distribution of a putative protein kinase from Plasmodium falciparum. 137 3

We report the purification to near homogeneity of a 45-kDa phorbol ester-stimulated protein kinase that phosphorylates and activates the Erk-1 gene product. This kinase, which we provisionally denote MEK for MAPK/Erk kinase, phosphorylated kinase-inactive Erk-1 protein primarily on a tyrosine residue and, to a lesser extent, on a threonine. We extend our previous results and show that two forms of purified MEK activated the myelin basic protein kinase encoded by Erk-1. MEK was inactivated by the serine/threonine phosphatase 2A but not by the protein-tyrosine phosphatase 1B. Sequence analysis of peptides generated by trypsin digestion of MEK revealed similarity to the proteins encoded by the Schizosaccharomyces pombe byr1 and Saccharomyces cerevisiae STE7 genes. These data are discussed with regard to a possible signal transduction mechanism.
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PMID:Purification of a murine protein-tyrosine/threonine kinase that phosphorylates and activates the Erk-1 gene product: relationship to the fission yeast byr1 gene product. 138 7


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