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)

Polyphosphate kinase, an enzyme which incorporated the gamma-phosphate of ATP into long-chain polyphosphate molecules, was purified more than 700-fold from Arthrobacter atrocyaneus by ammonium sulphate fractionation, DEAE-cellulose column chromatography and Ssphadex G-200 gel filtration. The enzyme had a broad pH optimum at 6-0 to 7-0 and required Mn2+ or Mg2+, histone, and inorganic phosphate for activity. The Km for Mn-ATP was 0-53 mM, and for inorganic phosphate was 1-67 mM. Free ATP concentrations greater than 8 muM inhibited the enzyme. Free Mn2+ or Mg2+ concentrations greater than 2 mM or 6 mM, respectively, were also inhibitory. Activity was strongly inhibited by 4 mM-ADP, 1 mM-PP1 or 20 mM-NaF. The effect of ADP might have resulted from reversing the equilibrium of the kinase reaction. The activation by phosphate ions might indicate a role for the enzyme in regulating intracellular phosphate levels or maintaining a phosphorus reserve. The level of enzymic activity in the bacteria responded to changes in inorganic phosphate concentration in the medium. Basic proteins, such as protamine, could substitute for histone as activator. Proteins such as casein or bovine serum albunim would also substitute for histone but only in the absence of inorganic phosphate. The presence of a protein might be necessary to form a complex with the product, thus preventing reversal of the reaction in vitro. The reaction product was characterized, and found to be labile in hydroxylamine, base, and acid at 100 degrees C. It behaved as a long-chain-polyphosphate molecule on chromatography in an Ebel's solvent. The enzymic activity was therefore not that of a protein kinase.
J Gen Microbiol 1975 May
PMID:Purification and characterization of a polyphosphate kinase from Arthrobacter atrocyaneus. 16 7

A comparative study of in vitro and in vivo phosphorylation of murine mammary tumour virus, a type Brna virus, is reported. The protein kinase activity associated with murine mammary tumour virus catalysed the in vitro phosphorylation of endogenous virus polypeptides. This kinase activity required a divalent metal cation, a non-ionic detergent, and was stimulated in the presence of dithiothreitol. Exogenous cyclic AMP was not required. The 32P-labelled products of the in vitro reaction were completely sensitive to pronase digestion and the phosphate was attached mainly by phosphomonoester linkage to serine residues. As determined by SDS-polyacrylamide gel electrophoresis, heterogeneous labelling of major and minor virus polypeptides was observed under in vitro conditions. In contrast, the in vivo labelling of type B virus produced by a continuous cell line (MuMT-73), established from pooled mammary adenocarcinomas of Balb/cfC3H mice, demonstrated specific phosphoproteins associated with murine mammary tumour virus. The major phosphorylated proteins were found to have mol. wt. of 18 000 and 12 000 (p18 and p12) after isolation by molecular sieving chromatography and analysis by gel electrophoresis.
J Gen Virol 1979 Sep
PMID:In vivo and in vitro phosphorylation of murine mammary tumour virus proteins. 23 Oct 88

Highly purified Sendai virus contained a protein kinase activity which atatlysed the phosphorylation of endogenous polypeptides or exogenous protamine sulphate. The virus contained very low levels of phosphoprotein phosphatase activity. Polyacrylamide gel analysis of the reaction product indicated that the phosphorylation was specific for certain polypeptides and varied according to whether the virus was grown in eggs or in tissue culture. This variation was partially associated with the difference in the polypeptide pattern that occurred when the virus was grown in eggs or in tissue culture. Characterization of these phosphoproteins demonstrated that the phosphate was incorporated predominantly in a phosphoester linkage with theonine residues. Using a detergent and high salt solubilization procedure, the protein kinase activity was found associated within glycoprotein free virus particles but not with the nucleocapsid-associated polypeptides. In vivo phosphorylation occurred when Sendai virus was grown in eggs or in tissue culture with [32P] and the phosphorylated polypeptides were similar to those of the protein kinase reaction product. Phosphorylation could also be detected in the infected cell and could occur once the virus particle polypeptides were being synthesized. The non-structural polypeptides were not phosphorylated.
J Gen Virol 1975 Mar
PMID:The phosphorylation of sendai virus proteins by a virus particle-associated protein kinase. 23 97

The properties of two temperature-sensitive mutants ts 18 and ts 19 of adenovirus type 5 were studied. It was demonstrated that they had a defect such that they failed to assemble virus and showed defective processing of infected cell polypeptides at the restrictive temperature. Analysis, after protease digestion, of the virions produced at the permissive temperature by SDS PAGE, and of the substrate availability of the mutants to the virus protein kinase suggested that polypeptide VI was defective in these mutants.
J Gen Virol 1979 Jun
PMID:Characterization of two temperature-sensitive mutants of adenovirus type 5. 47 48

The enzymes cAMP-dependent protein kinase (PKA) and protein kinase C (PKC) regulate the activity of cardiac ion channel proteins. In this study the whole-cell arrangement of the patch clamp technique was used to examine the effect of NaI on PKA-stimulated Cl- and Ca2+ channels in isolated guinea pig ventricular myocytes. Cl- currents (ICl) activated either by the beta-adrenergic agonist isoproterenol or the membrane-soluble cAMP analogue, 8-chlorphenylthio (8-CPT) cAMP, were greatly reduced in amplitude after substitution of an external solution containing 140 mM NaCl with a solution containing 140 mM NaI. This reduction was accompanied by a shift of -7 mV in the reversal potential (Erev) for ICl and could be reversed upon return to the NaCl external solution. Inhibition of ICl by NaI occurred in a concentration-dependent manner and was more pronounced for inward ICl (IC50 = 19 mM at -60 mV) than for outward ICl (IC50 = 60 mM at +60 mV). In contrast to ICl activated by PKA, ICl activated by PKC was slightly augmented in the presence of NaI and the Erev was found to shift by -15 mV. Based on these data, the relative permeability of I- to Cl- (PI/PCl) for this channel was calculated to be 1.79. NaI produced no change in the amplitude of inward calcium currents (ICa) recorded under basal conditions, but strongly inhibited ICa augmented by isoproterenol and 8-CPT cAMP, and during dialysis of cells with the catalytic subunit of PKA (CS). The in vitro incorporation of [gamma-32P]ATP into histone IIA and Kemptide, measured in the presence of PKA and cAMP, was not significantly different in assay mixtures containing salts of Cl- and I-. However, the ability of isoproterenol to augment basal ICa in whole-cell experiments was attenuated when experiments were carried out entirely in NaI external solution. Thus, the reduction in ICl and ICa observed in this study may result from a direct effect of I- on the phosphorylation/dephosphorylation of cardiac ion channel proteins or associated regulatory proteins.
J Gen Physiol 1992 Nov
PMID:Inhibition of heart calcium and chloride currents by sodium iodide. Specific attenuation in cAMP-dependent protein kinase-mediated regulation. 128 46

A photoaffinity analogue of ATP, 8-azido-adenosine 5'-triphosphate (8-N3ATP), was used to probe ATP-binding sites in native transcription complexes of vesicular stomatitis virus (VSV) (New Jersey serotype). The analogue was found to be a substrate for a serine/threonine protein kinase that phosphorylated both the NS and L proteins of native complexes. The analogue failed to interact with the RNA polymerase, another ATP-utilizing activity associated with the transcription complex. Kinetic analyses of both ATP and 8-N3ATP utilization by the protein kinase yielded biphasic saturation curves. Photolysis of 8-N3ATP in the presence of VSV transcription complexes resulted in selective labelling of the L protein. The photolabelling of L was saturable and apparently biphasic. Photolabelling of the L protein was significantly reduced by competition with ATP whereas other nucleoside triphosphates (GTP, UTP and CTP) were ineffective competitors. The stoichiometry of photolabelling was 0.2 at 10 microM-8N3ATP and 1.3 at 100 microM-ATP. These data provide chemical evidence for a virus-encoded serine/threonine protein kinase which resides on the L protein.
J Gen Virol 1992 Jan
PMID:Identification and characterization of serine/threonine protein kinase activity intrinsic to the L protein of vesicular stomatitis virus New Jersey. 130 63

Pigs (3 and 10 weeks old) were infected intranasally with Aujeszky's disease virus (ADV) mutants that functionally lacked one of the non-essential genes in the unique short region of the genome (except the gene encoding the 11K protein). Virus excretion in oropharyngeal fluid and disease symptoms were monitored. Some pigs were killed to study pathogenesis, whereas others were challenged with virulent ADV 8 weeks after the primary infection. Mutants lacking protein kinase, or glycoproteins gp63 or gI showed reduced virulence, but mutants lacking gX or the 28K protein showed normal virulence. Glycoprotein gI appears to affect the tissue tropism of ADV in pigs, presumably by facilitating the spread of the virus through the central nervous system. In this study, there was no correlation between virulence and virus multiplication in either cultured cells or in the oropharynx in vivo. All mutants induced neutralizing antibody and complete or partial protection against challenge infection. Complete protection was obtained by inoculation with the gI and gX mutants, whereas incomplete protection was obtained using gp63 and protein kinase mutants. Complete clinical and virological protection was associated with the absence of secondary antibody responses in the serum.
J Gen Virol 1992 Feb
PMID:Contribution of single genes within the unique short region of Aujeszky's disease virus (suid herpesvirus type 1) to virulence, pathogenesis and immunogenicity. 131 54

Herpes simplex virus type 1 (HSV-1) induces a protein kinase (PK) activity in infected cell nuclei. In vitro, the enzyme is able to phosphorylate exogenous casein (albeit inefficiently) but not protamine, can use ATP or GTP as a phosphate donor, is stimulated by high salt concentrations and is insensitive to inhibition by heparin. On the basis of these properties, the PK appears to be distinct from previously described cellular enzymes and from the cytoplasmic PK encoded by the viral US3 gene. A major substrate of the enzyme in vitro is a virus-induced protein with an Mr of 57000 (Vmw57). The gene encoding Vmw57 was mapped using recombinants between HSV-1 and HSV-2 to a region of the virus genome containing genes UL9 to UL15. Use of a monospecific rabbit antiserum showed that Vmw57 is a virion structural protein encoded by gene UL13. These results, in conjunction with previous reports that the UL13 protein contains PK sequence motifs, support the notions that the nuclear PK and Vmw57 are identical, and that the observed reactivity is due to autophosphorylation.
J Gen Virol 1992 Feb
PMID:The UL13 virion protein of herpes simplex virus type 1 is phosphorylated by a novel virus-induced protein kinase. 131 59

Respiration of fat body (Periplaneta americana) mitochondria is increased by pretreatment of the tissue with corpus cardiacum (CC) extract. The magnitude of the increase depends on the type of substrate supplied for oxidation. With 5 mM pyruvate the respiration increased 22%, decreasing to 0 with 1 mM pyruvate. In contrast, 50 microM and 0.2 mM palmitic acid supported an increase in CC-stimulated respiration of 14 and 44%, respectively. Unlike crude CC extract, the synthetic hyperglycemic peptides CCI and CCII failed to alter the respiratory activity of fat body mitochondria. In common with the action of CC extract pretreatment of the fat body in vitro with 10(-5) M cyclic AMP, 10(-5) M 8-bromo-cyclic AMP, or 10(-5) M forskolin increased mitochondrial respiration approximately 30%. Octopamine (10(-4) M) elicited a response similar to that obtained with CC extract. Neither 10(-5) M cyclic AMP nor 10(-5) M 8-bromo-cyclic AMP stimulated respiration when applied directly to the mitochondria. These results suggest that the factor in CC extract manifests its effect intracellularly through the activation of a cyclic AMP-dependent protein kinase. This interpretation is also based on the finding that diamide, an inhibitor of protein kinase, inhibits CC-dependent and cyclic AMP-dependent mitochondrial respiration. The physiological role of the CC factor responsible is not known.
Gen Comp Endocrinol 1992 Mar
PMID:Regulation of fat body mitochondrial respiration in Periplaneta americana by a novel factor from the corpus cardiacum. 131 1

The p34cdc2 protein kinase plays a central role in the regulation of the eukaryotic cell cycle, being required both in late G1 for the commitment to S-phase and in late G2 for the initiation of mitosis. p34cdc2 also determines the precise timing of entry into mitosis in fission yeast, where a number of gene products that regulate p34cdc2 activity have been identified and characterised. To investigate further the mitotic role of p34cdc2 in this organism we have isolated new cold-sensitive p34cdc2 mutants. These are defective only in their G2 function and are extragenic suppressors of the lethal premature entry into mitosis brought about by mutating the mitotic inhibitor p107wee1 and overproducing the mitotic activator p80cdc25. One of the mutant proteins p34cdc2-E8 is only functional in the absence of p107wee1, and all the mutant strains have reduced histone H1 kinase activity in vitro. Each mutant allele has been cloned and sequenced, and the lesions responsible for the cold-sensitive phenotypes identified. All the mutations were found to map to regions that are conserved between the fission yeast p34cdc2 and functional homologues from higher eukaryotes.
Mol Gen Genet 1992 Apr
PMID:Cold-sensitive mutants of p34cdc2 that suppress a mitotic catastrophe phenotype in fission yeast. 131 96


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