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)

Calcium- and lipid-dependent protein kinase (PKC) activity in the ovary of the pseudopregnant rat is masked by an endogenous inhibitor of PKC. These studies were undertaken to examine the mechanism of action of the endogenous inhibitor of PKC in the rat ovary. The addition of the phosphatase inhibitors calyculin-A (0.09 nM), microcystin-LR (6.4 nM), and okadaic acid (10 nM) resulted in the loss of PKC inhibitory activity and an increase in basal PKC activity in rat ovarian cytosol. In phosphatase assays, significant dephosphorylation of histone-III-S or myelin basic protein that had been phosphorylated by PKC occurred within 4 min after the addition of ovarian cytosol from the pseudopregnant rat. This dephosphorylation was prevented from the pseudopregnant rat. This dephosphorylation was prevented by the addition of calyculin-A (0.73 nM) and was removed by fractionation of ovarian cytosol on diethylaminoethyl cellulose. No inhibition of PKC activity was observed when the PKC-specific peptides AcMBP-(4-14) and [Ser25]PKC-(19-31) were used as the substrate for phosphorylation. In addition, rat ovarian cytosol did not exhibit phosphatase activity when the peptide AcMBP-(4-14) was used as the substrate. Addition of ovarian cytosol resulted in dephosphorylation of phosphorylase-alpha phosphorylated by phosphorylase kinase, but not dephosphorylation of histone-II-A or histone-VIII-S phosphorylated by PKA. The data suggest that the endogenous inhibitor of PKC in the rat ovary is a protein phosphatase.
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PMID:The endogenous inhibitor of protein kinase-C in the rat ovary is a protein phosphatase. 768 49

Using the cDNA fragment of chicken c-sea receptor tyrosine kinase as a probe, we isolated from a chicken lung cDNA library overlapping cDNA clones encoding a novel protein kinase, which we termed LIM-kinase (LIMK). The predicted polypeptide of 642 amino acid residues contains remarkable structural features, composed of the N-terminal two tandemly arrayed LIM/double zinc finger motifs and the C-terminal unusual protein kinase domain. To our knowledge, a protein kinase containing the LIM motif in the molecule has not heretofore been described. The protein kinase domain of LIMK shares highly conserved residues with the known protein kinases, but LIMK is unique in that it contains the sequence DLNSHN in subdomain VIB and a short, highly basic insert sequence, which may function as a signal for nuclear localization, between subdomain VII and VIII in the protein kinase domain. Northern blot analysis revealed that the single species of LIMK mRNA of 3.8 kb is expressed predominantly in the lung, and faintly in the kidney, liver, brain, spleen, gizzard, and intestine. As the LIM motif is thought to be involved in protein-protein interactions by binding to another LIM motif, and is often present in the homeodomain-containing proteins involved in cell fate determination and in the oncogenic nuclear proteins (rhombotins), it is likely that LIMK is involved in developmental or oncogenic processes through interactions with these LIM-containing proteins.
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PMID:Molecular cloning of a chicken lung cDNA encoding a novel protein kinase with N-terminal two LIM/double zinc finger motifs. 785 84

The mitogen activated protein (MAP) kinase pathway of eukaryotes is stimulated by many growth factors and is required for the integration of multiple cellular signals. In order to study the function of MAP kinases during plant ovule development we have synthesized a Petunia hybrida ovule-specific cDNA library and screened for MAP protein kinase-related sequences using a DNA probe obtained by PCR. A full-length cDNA clone was identified (PMEK for Petunia hybrida MAP/ERK-related protein kinase) and shown to encode a protein related to the family of MAP/ERK protein kinases. Southern blot analysis showed that PMEK is a member of a small multigene family in P. hybrida. The cDNA codes for a protein (PMEK1) of 44.4 kDa with an overall sequence identity of 44% to the products of the mammalian ERK/MAP kinase gene, and the budding yeast KSS1 and FUS3 genes. PMEK1 displays 96 and 80% identity respectively with the tobacco NTF3 and Arabidopsis ATMPK1 kinases, and only 50% to the more distantly related plant MAP kinase MsERK1 from alfalfa. The two phosphorylation sites found in the loop between subdomain VII and VIII in all the other MAP kinases are also present in PMEK1. RNA gel blot and RT-PCR analyses demonstrated that PMEK1 is expressed in vegetative organs and preferentially accumulated in female reproductive organs of P. hybrida. In situ hybridization experiments showed that in the reproductive organs PMEK1 is expressed only in the ovary and not in the stamen.
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PMID:A homologue of the MAP/ERK family of protein kinase genes is expressed in vegetative and in female reproductive organs of Petunia hybrida. 788 23

A temperature-sensitive (ts) mutation of Drosophila melanogaster for D-raf, encoding a serine/threonine protein kinase, was newly induced by EMS-treatment. Temperature-shift experiments on the ts mutant revealed that D-raf is required during most of the developmental stages, and confirmed the previously reported roles of D-raf in the regulation of cell proliferation and in the determination of cell fates at terminal regions of the embryo (Nishida et al., EMBO J. 7:775-781, 1988; Ambrosio et al., Nature 342:288-291, 1989a). Detailed analysis of cell proliferation demonstrated the role of D-raf at other than M-phase in cell cycle. TSP analysis during pupal stages revealed yet another role of D-raf in eclosion. Mosaic analysis of an eclosion-defective hypomorphic mutation revealed the tissue responsible for this defect to be the muscle and/or nervous system in the thorax. Molecular lesion associated with the ts mutation was found to be an alteration of an amino acid residue in a highly conserved region that defines the kinase subdomain VIII. Molecular analysis of null mutations also suggested the importance of the kinase domain for the biological functions of D-raf. Elucidation of the multi-functional nature of signal transducers is of great importance for our understanding of the molecular mechanisms of development, and the ts mutation for pleiotropic D-raf obtained in this study promises to be useful for dissecting signal transduction pathways during development.
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PMID:Multiple functions of raf proto-oncogene during development from analysis of a temperature-sensitive mutation of Drosophila. 798 Oct 41

Eleven Entamoeba histolytica protein-serine/threonine-kinase gene segments were identified using the polymerase chain reaction (PCR) and degenerate oligonucleotide primers to conserved amino acids in subdomains VI and VIII of the catalytic domain of protein-serine/threonine kinases. These ameba gene segments were homologous to myosin light chain kinases, protein kinase C, phosphorylase b kinase, and kinases that regulate glucose repression in yeast and cell growth in mammalian cells. One of these PCR products, which was homologous to the Dictyostelium discoideum protein kinase 2, was used to identify a full-length protein-serine/threonine-kinase gene (Eh rac1) from an E. histolytica genomic library. The open reading frame of Eh rac1 was 409 amino acids long (encoding a 47-kDa protein) and included an amino terminal segment containing 87 mostly charged and polar amino acids and a 322-amino acid carboxyl terminal segment containing the catalytic domain. The catalytic domain of Eh rac1 was homologous to the rac family of protein-serine/threonine-kinases, which are related to cAMP-dependent protein kinases and protein kinase Cs. Southern blots of ameba DNA showed that the Eh rac1 gene was present as a single copy in all strains tested, however pathogenic amebae expressed four times more Eh rac1 mRNAs than did nonpathogenic amebae. These studies suggest that E. histolytica, a primitive unicellular eukaryote, has a complex protein kinase family.
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PMID:Molecular cloning of a rac family protein kinase and identification of a serine/threonine protein kinase gene family of Entamoeba histolytica. 823 9

The phosphorylation of histones and glycogen synthase by protein kinases was analysed by SDS-polyacrylamide gel electrophoresis and autoradiography. The phosphorylation of histone III-S by the catalytic subunit of cyclic AMP-dependent protein kinase (A-PK) or cGMP-dependent protein kinase (G-PK) was inhibited by archidonic acid, sphingosine and staurosporine. Using the catalytic subunit of A-PK, the phosphorylation of histone VIII-S was inhibited by Ca2+, arachidonic acid and staurosporine; the phosphorylation of histone II-S was inhibited by phosphatidyl ethanolamine, phosphatidyl inositol, arachidonic acid and staurosporine; and the phosphorylation of glycogen synthase was inhibited by arachidonic acid and staurosporine. After being phosphorylated by the catalytic subunit of A-PK, calpain II with 4 microM Ca2+ was less effective in degrading histone III-S, which had been prephosphorylated by PK-C.
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PMID:Regulation of the phosphorylation of histones and glycogen synthase. 824 12

Although the cascade theory is the main story which explains mechanisms of blood coagulation, the interactions among the enzymes (i. e. coagulation factors) involved in this cascade has not been well characterized. In this paper, protein kinase C (phospholipid/Ca(2+)-dependent protein kinase) was found to involve in the phosphorylation of the coagulation factors (I, II and VIII), which require both phospholipid and Ca2+ for their activations. In the phosphorylation of prothrombin (blood coagulation factor II), the apparent Km value of 0.86 microM was obtained. The value was comparable to that reported for most known substrates of protein kinase C. A 2-dimensional separation-analysis revealed that serine residue was apparently phosphorylated by PKC. The phosphorylation was inhibited by protein kinase C inhibitors such as gossypol and staurosporine. Prothrombin seemed to have a tendency to be increased in its coagulation activity (1. e. shortening of prothrombin time), when it was phosphorylated by PKC. These phenomena suggest that PKC may be involved in the mechanism of blood coagulation.
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PMID:[A study on the participation of protein kinase C in the blood coagulation]. 831 35

We previously isolated human cDNA coding for LIMK1 (LIM motif-containing protein kinase-1), a putative protein kinase containing two LIM motifs at the N terminus and an unusual protein kinase domain at the C terminus. In the present study, we isolated human cDNA encoding LIMK2, a second member of a LIMK family, with a domain structure similar to LIMK1 and 50% overall amino acid identity with LIMK1. The protein kinase domains of LIMK1 and LIMK2 are unique in that they contain an unusual sequence motif Asp-Leu-Asn-Ser-His-Asn in subdomain VIB and a highly basic insert between subdomains VII and VIII. Expression patterns of LIMK1 and LIMK2 mRNAs in human tissues differ significantly. Chromosomal localization of human LIMK1 and LIMK2 genes was assigned to 7q11.23 and 22q12, respectively, by fluorescence in situ hybridization. The Myc epitope-tagged LIMK1 and LIMK2 proteins transiently expressed in COS cells exhibited serine/threonine-specific kinase activity toward myelin basic protein and histone in in vitro kinase assay. Immunofluorescence and subcellular fractionation analysis revealed that Myc-tagged LIMK1 and LIMK2 were localized mainly in the cytoplasm. The "native" LIMK1 protein endogenously expressed in A431 epidermoid carcinoma cells also exhibited serine/threonine kinase activity. The specific activity of native LIMK1 from A431 cells was apparently much higher than that of "recombinant" LIMK1 ectopically expressed in COS cells, hence, it is likely that there is a mechanism, by which native LIMK1 is activated. A 140-kDa tyrosine-phosphorylated protein (pp140) was co-immunoprecipitated with native LIMK1 form A431 cell lysates; therefore, pp140 may be a LIMK1-associated protein involved in the regulation of LIMK1 function.
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PMID:Identification and characterization of a novel family of serine/threonine kinases containing two N-terminal LIM motifs. 853 3

To explore the structural basis required for the holoenzyme formation of cAMP-dependent protein kinase, we have prepared rabbit anti-peptide antibodies that can block the holoenzyme formation without affecting the catalytic activity of the enzyme. The antibodies were raised against a specific site in the catalytic (C)-subunit, termed IDA (Inter-DFG-APE) region, which lies between the kinase subdomains VII and VIII. Although the C-subunit immunoprecipitated with anti-IDA antibodies could not form a stable complex with regulatory (R)-subunit, it was still susceptible to inhibition by the R-subunit or by PKI, a specific inhibitor peptide containing a pseudosubstrate site. These results indicate that there exists an IDA region-mediated interaction between the R- and C-subunits, which is distinct from that mediated through the substrate site and substrate binding site. In accordance with this idea, association of synthetic IDA peptides with the R-subunit was directly demonstrated by resonance mirror analysis. The calculated association constants of IDA peptides were high enough to suggest a possible involvement of the IDA region in the initial step of holoenzyme formation.
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PMID:Biochemical evidence for the interaction of regulatory subunit of cAMP-dependent protein kinase with IDA (Inter-DFG-APE) region of catalytic subunit. 861 10

The cDNA of a novel, ubiquitously expressed protein kinase (Dyrk) was cloned from a rat brain cDNA library. The deduced amino acid sequence (763 amino acids) contains a catalytic domain that is only distantly related to that of other mammalian protein kinases. Its closest relative is the protein kinase Mnb of Drosophila, which is presumably involved in postembryonic neurogenesis (85% identical amino acids within the catalytic domain). Outside the catalytic domain, the sequence comprises several striking structural features: a bipartite nuclear translocation signal, a tyrosine-rich hydrophilic motif flanking the nuclear localization signal, a PEST region, a repeat of 13 histidines, a repeat of 17 serine/threonine residues, and an alternatively spliced insertion of nine codons. A recombinant glutathione S-transferase-Dyrk fusion protein catalyzed autophosphorylation and histone phosphorylation on tyrosine and serine/threonine residues with an apparent Km of approximately 3.4 microM. Exchange of two tyrosine residues in the "activation loop" between subdomains VII and VIII for phenylalanine almost completely suppressed the activity and tyrosine autophosphorylation of Dyrk. Tyrosine autophosphorylation was also reduced by exchange of the tyrosine (Tyr-219) in a tyrosine phosphorylation consensus motif. The data suggest that Dyrk is a dual specificity protein kinase that is regulated by tyrosine phosphorylation in the activation loop and might be a component of a signaling pathway regulating nuclear functions.
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PMID:Dyrk, a dual specificity protein kinase with unique structural features whose activity is dependent on tyrosine residues between subdomains VII and VIII. 863 52


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