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

---

Query: EC:2.7.11.1 (protein kinase)
81,284 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human fibroblastic cell lines morphologically transformed by either live virus or DNA fragments of human cytomegalovirus had altered plasma membrane protein composition; quantitative changes, and gains and losses in protein composition in comparison to normal parent cell lines were detected. These transformed cell lines showed altered total cell protein phosphorylation patterns when compared to parent cell lines. A two to four fold increase in in vivo protein phosphorylation at serine and threonine residues was observed; no increase in phosphorylation at total cell tyrosine residues was detected. Analysis of the in vivo phosphorylated protein by two dimensional gel electrophoresis revealed some similarities as well as differences in the types of polypeptides phosphorylated between transformed and control cell lines. Increased (two-to sixfold over parent cell extracts) casein kinase and polyamine dependent casein kinase activities were detected in HCMV transformed cell extracts.
...
PMID:Alteration of protein phosphorylation patterns in cell lines morphologically transformed by human cytomegalovirus. 244 49

Pig heart tissue have been shown to contain 3 different 60,000 Da phosphoproteins. Different purification procedures were used in order to separate them, suggesting that the 3 phosphoproteins differ in their environmental parameters. The 2 major ones appear essentially as peripheral phosphoproteins that are associated with cellular membranes through ionic forces, whereas the third minor phosphoprotein behaves as an integral plasma membrane protein. The three phosphoproteins also differ in their relative amount of phosphorylated serine, threonine and tyrosine residues after in vitro protein kinase assay. Evidence that the 3 phosphoproteins are related arises from the similarity between their respective phosphopeptide maps after partial hydrolysis with proteases, an experiment that also points out relatedness in primary structure between them and the transforming protein of Rous sarcoma virus, pp60v-src. The 3 phosphoproteins, however, do not appear to be immunologically related to pp60v-src since none of them is immunoprecipitated by sera that precipitate pp60v-src. The possibility that the three 60,000 Da phosphoproteins under study represent 3 differentially localized and phosphorylated products of c-src and/or c-src related genes is discussed.
...
PMID:Studies in pig heart tissue on various 60,000 Da phosphoproteins. 247 41

Phosphoinositide-specific phospholipase C (PLC) activity of human platelet membranes was activated by the nonhydrolyzable guanine nucleotide GTP gamma S. This activation did not occur in either membranes prepared from dibutyryl cyclic AMP-pretreated platelets (A-membranes) or those prepared from untreated cells and subsequently incubated with cyclic AMP (cAMP) (B-membranes). This cAMP-mediated inhibition was abolished in the presence of inhibitors of cAMP-dependent protein kinase (A-kinase), suggesting that the inhibition was due to phosphorylation of (a) protein component(s). No significant differences were observed in the basal PLC activity and the extent of pertussis toxin-catalyzed ADP-ribosylation among control membranes and the two types of phosphorylated membranes (A- and B-membranes). GTP-binding activities of Gs, Gi and GTP-binding proteins of lower molecular masses were not altered by the phosphorylation of the membranes. These findings suggest that a GTP-binding protein is involved in the GTP gamma S-mediated activation of PLC and that cAMP (plus A-kinase) inhibits this activation by phosphorylating a membrane protein (probably a 240-kDa protein), rather than the GTP-binding protein or PLC itself. It is likely that this phosphorylation uncouples the GTP-binding protein from PLC.
...
PMID:Inhibition by cyclic AMP of guanine nucleotide-induced activation of phosphoinositide-specific phospholipase C in human platelets. 253 21

Phospholamban is the major membrane protein of the heart phosphorylated in response to beta-adrenergic stimulation. In cell-free systems, cAMP-dependent protein kinase catalyzes exclusive phosphorylation of serine 16 of phospholamban, whereas Ca2+/calmodulin-dependent protein kinase gives exclusive phosphorylation of threonine 17 (Simmerman, H. K. B., Collins, J. H., Theibert, J. L., Wegener, A. D., and Jones, L. R. (1986) J. Biol. Chem. 261, 13333-13341). In this work we have localized the sites of phospholamban phosphorylation in intact ventricles treated with the beta-adrenergic agonist isoproterenol. Isolation of phosphorylated phospholamban from 32P-perfused guinea pig ventricles, followed by partial acid hydrolysis and phosphoamino acid analysis, revealed phosphorylation of both serine and threonine residues. At steady state after isoproterenol exposure, phospholamban contained approximately equimolar amounts of these two phosphoamino acids. Two major tryptic phosphopeptides containing greater than 90% of the incorporated radioactivity were obtained from phospholamban labeled in intact ventricles. The amino acid sequences of these two tryptic peptides corresponded exactly to residues 14-25 and 15-25 of canine cardiac phospholamban, thus localizing the sites of in situ phosphorylation to serine 16 and threonine 17. Phosphorylation of phospholamban at two sites in heart perfused with isoproterenol was supported by detection of 11 distinct mobility forms of the pentameric protein by use of the Western blotting method, consistent with each phospholamban monomer containing two phosphorylation sites, and with each pentamer containing from 0 to 10 incorporated phosphates. Our results localize the sites of in situ phospholamban phosphorylation to serine 16 and threonine 17 and, furthermore, are consistent with the phosphorylations of these 2 residues being catalyzed by cAMP- and Ca2+/calmodulin-dependent protein kinases, respectively.
...
PMID:Phospholamban phosphorylation in intact ventricles. Phosphorylation of serine 16 and threonine 17 in response to beta-adrenergic stimulation. 254 95

Complementary DNAs for the beta subunit of the dihydropyridine-sensitive calcium channel of rabbit skeletal muscle were isolated on the basis of peptide sequences derived from the purified protein. The deduced primary structure is without homology to other known protein sequences and is consistent with the beta subunit being a peripheral membrane protein associated with the cytoplasmic aspect of the sarcolemma. The protein contains sites that might be expected to be preferentially phosphorylated by protein kinase C and guanosine 3',5'-monophosphate-dependent protein kinase. A messenger RNA for this protein appears to be expressed in brain.
...
PMID:Primary structure of the beta subunit of the DHP-sensitive calcium channel from skeletal muscle. 254 40

MP70 (a 70 kDa membrane protein) is a component of the gap junctions of the young fibre cells in the lens outer cortex. In the older fibres deeper in the mammalian lens (lens nucleus), MP70 is processed to MP38 by cleavage and removal of the carboxy terminal half. It is shown here that cortical MP70, and its derivative MP64, can be phosphorylated with cAMP-dependent protein kinase. In contrast, MP38 from the lens nucleus is not phosphorylated by the enzyme. Proteolytic processing and this lens region specific phosphorylation are relevant for the future development of functional assays for lens gap junctions.
...
PMID:cAMP-dependent protein kinase phosphorylates gap junction protein in lens cortex but not in lens nucleus. 255 83

The 18,000-dalton bovine lens fiber cell intrinsic membrane protein MP18 was phosphorylated on a serine residue by both cAMP-dependent protein kinase and protein kinase C. In addition, this protein bound calmodulin and was recognized by a monoclonal antibody (2D10). These different regions were localized using enzymatic and chemical fragmentation of electrophoretically purified MP18 that had been phosphorylated with either cAMP-dependent protein kinase or protein kinase C. Partial digestion of 32P-labeled MP18 with protease V8 resulted in a Mr = 17,000 peptide that bound calmodulin, but neither contained 32P or was recognized by the monoclonal antibody 2D10. Furthermore, the 17-kDa peptide had the same N-terminal amino acid sequence as MP18. Thus, the monoclonal antibody 2D10 recognition site and the protein kinase phosphorylation site(s) are close together and confined to a small region in the C terminus of MP18. This conclusion was confirmed in experiments where MP18 was fragmented with trypsin, endoproteinase Lys-C, or CNBr. The location of the phosphorylation site was confirmed by sequencing the small 32P-labeled, C-terminal peptide that resulted from protease V8 digestion of 32P-labeled MP18. This peptide contained a consensus sequence for cAMP-dependent protein kinase.
...
PMID:Structural organization of the lens fiber cell plasma membrane protein MP18. 258 4

1. A protein kinase activity which is cAMP-independent, inhibited by the bioflavonoid quercetin and probably connected to the growth of mammary gland cells was isolated and partially purified from cytosol. 2. Another protein kinase activity was demonstrated in crude membranes of lactating mouse mammary gland. 3. By the use of several different synthetic peptides as a substrate, it was demonstrated that the cytosol enzyme was a serine kinase, while the membrane protein kinase activity was mainly due to tyrosine kinase.
...
PMID:The difference between cytosol and membrane growth-related protein kinase activities in lactating mouse mammary gland. 274 6

In contrast with previous reports, it was found that membrane-protein phosphorylation by the catalytic subunit (CS) of cyclic AMP-dependent protein kinase had no effect on Ca2+ uptake into platelet membrane vesicles or on subsequent Ca2+ release by inositol 1,4,5-trisphosphate (IP3). Furthermore, IP-20, a highly potent synthetic peptide inhibitor of CS, which totally abolished membrane protein phosphorylation by endogenous or exogenous CS, also had no effect on either Ca2+ uptake or release by IP3. Commercial preparations of protein kinase inhibitor protein (PKI) usually had no effect, but one preparation partially inhibited Ca2+ uptake, which is attributable to the gross impurity of the commercial PKI preparation. IP3-induced release of Ca2+ was also unaffected by the absence of ATP from the medium, supporting the conclusion that Ca2+ release by IP3 does not require the phosphorylation of membrane protein.
...
PMID:Release of Ca2+ by inositol 1,4,5-trisphosphate in platelet membrane vesicles is not dependent on cyclic AMP-dependent protein kinase. 278 69

The recently cloned human beta-adrenergic cDNA and several mutated forms have been expressed in Xenopus laevis oocytes by injection of RNA made from the cDNA under the control of the bacteriophage SP6 promoter. The cDNA and gene of the beta 2-adrenergic receptor possess the unusual feature of having a second upstream ATG (-101 base pairs) and a 19-codon open reading frame 5' to the initiator methionine codon of the receptor (Kobilka, B. K., Dixon, R. A. F., Frielle, T., Dohlman, H. G., Bolanowski, M., Sigal, I. S., Yang-Feng, T. L., Francke, U., Caron, M. G., and Lefkowitz, R. J. (1987) Proc. Natl. Acad. Sci. U.S.A. 84, 46-50). RNA lacking this upstream AUG and open reading frame was translated approximately 10-fold more efficiently both in an in vitro rabbit reticulocyte system and in oocytes. Injected oocytes but not water injected controls expressed typical beta 2-adrenergic receptors as assessed by ligand binding (450 fmol/mg membrane protein) and catecholamine-stimulated adenylate cyclase (approximately 20 fold). Moreover, these receptors displayed typical agonist-induced homologous desensitization when oocytes were incubated with isoproterenol at room temperature for 3-24 h. Among a series of mutations, truncations of the membrane-anchored core of the receptor eliminated receptor binding and cyclase stimulating activity. In contrast, disruption of one of the cAMP-dependent protein kinase phosphorylation sites or removal of the serine/threonine-rich carboxyl terminus had little or no effect on these functions or on the extent of agonist-induced desensitization relative to that observed with native receptor. These studies validate the beta 2-adrenergic nature of the cloned human beta-adrenergic cDNA, document the utility of the Xenopus oocyte system for studying functional and regulatory properties of receptors coupled to adenylate cyclase, and suggest the possibility that elements in the 5' untranslated region of the beta 2-adrenergic receptor RNA may regulate its translation in vivo.
...
PMID:Functional activity and regulation of human beta 2-adrenergic receptors expressed in Xenopus oocytes. 282 67


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---