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)

The protein kinase activity located in the cytosol of hereditary spherocytosis erythrocytes is due to multiple forms which can be resolved by Sepharose 6B filtration at high ionic strength into two fractions phosphorylating the whole casein on different sites. The membrane-bound protein kinases, solubilized by 0.7 M NaCl, display an elution volume from Sepharose column and a phosphorylation behaviour towards casein quite similar to those of the more retarded fraction of hemolysate. When compared with the multiple protein kinase forms from normal human erythrocytes, no significant difference has been found.
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PMID:Partial characterization of cytosol and membrane-bound protein kinases in hereditary spherocytosis erythrocytes. 42 46

Enzymatic phosphorylation of cytoplasmic proteins by a cyclic nucleotide-independent protein kinase (casein kinase of a classical type) in rat liver is stimulated greatly, sometimes more than 10-fold, by polycations, particularly by basic polypeptides such as polylysine, histone, and protamine. These basic polypeptides themselves do not serve as phosphate acceptors but act as stimulators for the reaction by interacting with cytoplasmic proteins rather than with enzyme. The stimulatory effect varies with substrates employed; with casein and phosvitin the stimulation does not exceed 2- to 3-fold. The cytoplasmic endogenous phosphate acceptor proteins measurable in the presence of basic polypeptides are abundant for this species of protein kinase.
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PMID:A hepatic soluble cyclic nucleotide-independent protein kinase. Stimulation by basic polypeptides. 44 34

Casein kinase from lactating bovine mammary gland catalyses the transfer of the terminal phosphoryl group of ATP to specific serine residues in dephosphorylated caseins. Best substrates for casein kinase are the dephosphorylated proteins (bovine alpha S1- and beta-caseins and pepsin), unphosphorylated human beta-casein and the dephosphorylated peptide (residues 1-25) from bovine beta-casein. Results obtained with bovine and human beta-caseins indicate that the two serines underlined in the cluster Ser-Leu-Ser-Ser-Ser are particularly susceptible to the action of casein kinase. Since a similar sequence is found in dephosphorylated alpha S1-casein, it is probable that serines in this region of alpha S1-casein are also phosphorylated. The results support the concept that certain serines in casein are particularly susceptible to phosphorylation by casein kinase.
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PMID:Role of mammary casein kinase in the phosphorylation of milk proteins. 46 41

The protein kinase previously described as an endogenous activity present in ribonucleoprotein particles containing heterogenous RNA from HeLa cells (Blanchard et al, Eur. J. Biochem (1977), 79, 11-131) has been partially purified by a combination of chromatography on DEAE cellulose, phosphocellulose and Sephacryl S-200. It is able to phosphorylate exogenous substrates, among which casein is the most efficient. Its enzymatic properties were found to be quite similar to those described for the endogenous activity. Its activity is independent of cyclic AMP as well as of the calcium-dependent regulator protein and is inhibited by hemin. Its native molecular weight is around 48,000 as determined by gel filtration.
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PMID:Protein kinase associated with hnRNP from Hela cell nuclei. Partial purification and properties. 51 27

Reuber H 35 hepatoma cells were synchronized by transfer in a serum free medium. Growth was re-initiated by addition of serum. Under these conditions DNA synthesis exhibited a maximum after 24 hours. Chromatin non-histone proteins prepared from cells at various phases of the cell cycle were incubated with [gamma-32P] ATP and the radioactive pattern of protein bound 32P was analysed by electrophoresis on polyacrylamide gels. No radioactive peak was observed in G0. Several peaks appeared 3 hours after the addition of serum. The radioactivity progressively increased until the cells reached the S phase. When most of the cells were in the S phase the radioactivity strongly decreased. Chromatin protein kinase activities were found to increase in late G1 and continued to increase in the S phase. The increase was 65% when phosvitin was the substrate, 100% with casein and histone H1. It is suggested that chromatin phosphorylated proteins could be involved in the mechanism which initiates DNA synthesis in G1 phase cells.
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PMID:Variations in some molecular events during the early phases of the Reuber H 35 cell cycle. II.-Chromatin protein phosphorylation and protein kinases. 51 30

The B variant of beta-casein was phosphorylated with [gamma-32P]ATP using four different protein kinases isolated from rabbit reticulocytes. Casein was maximally phosphorylated by the individual protein kinase activities and subjected to chymotrptic digestion. The peptides were separated by a two-dimensional peptide fingerprinting technique, and the phosphorylated peptides were identified by autoradiography, The two phosphorylated peptides obtained from the action of casein kinase I were shown to have different migration patterns from those obtained with casein kinase II. The cAMP-regulated protein kinases had the same substrate specificity with beta-casein B, and the two phosphorylated peptides obtained using these enzymes were distinct from those phosphorylated by the cAMP-independent enzymes. Thus, the different protein kinases can be identified by substrate specificity using beta-casein.
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PMID:Site-specific phosphorylation of beta-casein by proetin kinases from rabbit reticulocytes. 63 39

The phosphorylation of the single casein subfractions occurring when whole casein is incubated with [gamma-32P]ATP in the presence of two different rat liver 'casein kinases', both cyclic AMP-insensitive, has been studied. "Casein kinase TS", active on both threonine and serine residues of whole casein, was found to be active towards a minor protein fraction, running slightly ahead of beta-casein during gel electrophoresis, and accounting for most, if not all, of the [32P]Thr residues labeled in whole casein ("[32P]Thr-rich fraction"). The [32P]Ser residues labeled by this enzyme were recovered in an heterogeneous "[32P]Ser-rich fraction" including alphas1-casein together with minor alphas fractions, following alphas1-casein during gel electrophoresis. "Casein kinase S", on the other hand, active only towards serine residues of whole casein, is active almost exclusively towards the minor alphas casein fractions, with the exclusion of both the "[32P]Thr-rich fraction" and alphas1-casein itself. Therefore, of the major casein components, beta- and K-caseins apparently play a quite unimportant role in the overall phosphorylation of whole casein by both the protein kinases tested, while alphas1-casein itself, unlabeled by casein kinase S, accounts for no more than 20--30% of 32P incorporated in the presence of casein kinase TS.
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PMID:Different susceptibility of whole casein components to enzymatic phosphorylation by two forms of rat liver 'casein kinase'. 66 79

Platelet tubulin isolated by two successive cycles of polymerization-depolymerization was shown to contain protein kinase activity. The phosphorylating activity measured by incorporation of [32P]phosphate from [gamma-32P]ATP was cAMP-independent and behaved with respect to substrate specificity, cation requirement, and maximum incorporation of phosphate similarly to tubulin of brain. Contrary to tubulin from that source, however, platelet tubulin itself, not one of its co-purifying proteins appeared to be the source of the protein kinase activity. This was suggested by assays of tubulin freed from its associated proteins by chromatography on DEAE-Sephadex and on immunosorbent columns containing monospecific antibody to human platelet tubulin. Further corroboration was obtained from experiments in which tubulin was applied to casein affinity columns. No separation of protein kinase from colchicine binding activity could be obtained. Gel filtration showed that all of the in vitro phosphorylated tubulin was aggregated. Tryptic peptide patterns of 32P-labeled alpha- and beta-tubulin subunits were analyzed by ion exchange chromatography. Multiple peptides in both tubulin subunits were identified as acceptors of [32P]phosphate. In vivo phosphorylated tubulin was demonstrated to contain an average of 5 phosphoserine residues/monomer.
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PMID:Phosphylation and protein kinase activity of platelet tubulin. 75 25

A protein kinase specific for casein and acidic ribosomal proteins was isolated and partly characterized. It was found that the enzyme utilizes GTP and ATP as phosphoryl donors. Its affinity for ATP was considerably higher than for GTP with the km values of 7.6 X 10(-6)M and 5.5 X 10(-5)M, respectively. Two-dimensional acrylamide gel electrophoresis revealed the phosphorylation of the same ribosomal proteins with either of the [gamma-32P] nucleotides used. It was also shown that one acidic protein (S1 or S2) of 40 S and two acidic proteins (L2 and L3) of 60 S ribosomal subunits were predominantly phosphorylated in vitro. The phosphorylated proteins: L2 and L3 seem to correspond to the proteins of L7 and L12 of E. coli ribosomes. The isolated kinase phosphorylated several basic ribosomal proteins though to a lower extent than the acidic ones.
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PMID:Ribosomal protein as substrate for a GTP-dependent protein kinase from yeast. 79 85

Protein kinase activities were determined in liver from normal, thyroidectomized and triiodothyronine (T3)-treated rats. Changes related to thyroid hormone were observed in cytosol and nuclear protein kinase activities. When protamine was used as substrate for phosphorylation, thyroidectomy induced a decrease of protein kinase activity associated with nuclei but an increase of activity was found in the cytosol. Fifteen hours after injection of T3 the levels in nuclei and cytosol were restored to normal. When casein was used as substrate, hypothyroidism led to a lowering of protein kinase activity in both fractions and T3 treatment augmented the activity in both. These studies suggest that thyroid hormones modify hepatic protein kinase activity. Results differ depending upon the substrate used. The hormones also appear to alter the subcellular distribution of some protein kinase activities.
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PMID:Liver protein kinase activity and triiodothyronine. 83 87


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