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)

A protein antigenically related to the simian virus (SV 40) A gene product has been purified to near homogeneity from cells infected with the adenovirus-SV 40 hybrid virus Ad2(+)D2 and shown to contain ATPase (ATP phosphohydrolase, EC 3.6.1.3) and protein kinase (ATP:phosphotransferase, EC 2.7.1.37) activity. Both enzymatic activities copurify with the protein through six stages including one gel filtration column, two ion exchange columns, and a heparin affinity column. Analogous fractions from extracts of cells uninfected or infected with adenovirus 2 alone do not contain these enzymatic activities. The D2 hybrid protein resolves into two forms (I and II) during ion exchange chromatography. Form I, the major species (85%) of the D2 hybrid protein, elutes from DEAE-Sephadex in 0.37 M NaCl and is able to catalyze the hydrolysis of ATP to ADP + P(i) at a rate of 3 mumol/hr per mg. The remaining 10-15% of the D2 hybrid protein consists of form II which elutes from DEAE-Sephadex in 0.29 M NaCl and is able to hydrolyze ATP as well as to incorporate phosphorus from ATP into either the D2 hybrid protein itself or other protein acceptors such as phosvitin. Although both forms are able to bind DNA, the ATPase activity of form I cosediments with SV 40 DNA more efficiently than does the protein kinase activity of form II during glycerol gradient centrifugation. The ATPase activity of form I is efficiently inhibited by addition of anti-T gamma globulin to the reaction mixture whereas control gamma globulin has no effect. Similarly, the phosphorylation of the D2 hybrid protein by form II is inhibited by anti-T gamma globulin. By contrast, phosphorylation of phosvitin is specifically inhibited by antibody only when the immune complex is removed from the reaction mixture. Thus, it appears likely that one and possibly two enzymatic activities are carried out by the D2 hybrid protein. These findings are discussed in terms of mechanisms of SV 40 DNA replication and virally induced transformation.
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PMID:Enzymatic activities associated with a purified simian virus 40 T antigen-related protein. 21 12

A cyclic AMP-independent casein (phosvitin) kinase eluted from a phosphocellulose column with 0.35 M KCl also possesses glycogen synthase kinase activity. This kinase, designated synthase kinase 1, is separable from other cyclic AMP-independent protein kinases, which also contain glycogen synthase kinase activity, by chromatography on a phosphocellulose column. This kinase was purified 15,000-fold from the crude extract. Synthase kinase activity co-purifies with casein and phosvitin kinase activities. Heat inactivation of these three kinase activities follow similar kinetics. It is suggested that these three kinase activities reside in a single protein. This kinase has a molecular weight of approximately 34,000 as determined by glycerol density gradient centrifugation and by gel filtration. The Km values for the synthase kinase-catalyzed reaction are 0.12 mg/ml (0.35 micronM) for synthase, 12 micronM for ATP, and 0.15 mM for Mg2+. The phosphorylation of glycogen synthase by the kinase results in the incorporation of 4 mol of phosphate/85,000 subunit; however, only two of the phosphate sites predominantly determine the glucose-6-P dependency of the synthase. Synthase kinase activity is sensitive to inhibition by NaCl or KCl at concentrations encountered during purification. Synthase kinase activity is insensitive to the allosteric effector (glucose-6-P) or substrate (UDP-glucose) of glycogen synthase at concentrations usually found under physiological condition.
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PMID:Purification and properties of cyclic AMP-independent glycogen synthase kinase 1 from rabbit skeletal muscle. 22 Feb 31

Histone kinase activity was purified from human polymorphonuclear leukocytes by ammonium sulphate precipitation of a 180 000 x g supernatant, followed by DEAE-cellulose chromatography and gelfiltration. On DEAE-cellulose cAMP dependent kinase activity eluted in two peaks, I and III, at 1.2 mmho and 6.5 mmho, respectively. Catalytic subunit (C) from both peaks had Mr 33 000, 3.0S. Regulatory subunit (R) from peak I and III both had Mr 33 000 upon gelfiltration, but sedimented at 2.8--3.0S and 3.0--3.2S, respectively. R2 and R4 subunits were identified. The R-C dimer from peak I and III sedimented at 4.8S and (4.8)--5.1S, respectively. The holoenzyme from peak I had Mr 165 000, 6.7S, which suggest a R2C2 structure, while that of peak III sedimented at 6.7S, but eluted at Mr 330 000 (2R2C2) by gelfiltration. The Kmapp for peak I and III enzymes were, respectively: histone IIA 0.5 mg/ml (both forms), ATP 18 microM and 23 microM, and cAMP 5 X 10(-8) M and 6.3 x 10(-8) M. Both enzymes had pH optimum 6.7--6.9 and were equally sensitive to Ca2+, temperature and protein kinase inhibitor. The substrate specificity was histone VS greater than histone IIA = histone VIS greater than casein greater than phosvitin. Peak I enzyme, but not peak III enzyme, was dissociated by histone and high ionic strength and reassociation of R and C subunits were facilitated by ATP-Mg. It is concluded that peak I and III enzymes represent type I and II cAMP dependent protein kinases, respectively. Type I comprises 20--30% of cAMP dependent protein kinase activity and is absent from the 180 000 x g supernatant of gently disrupted cells. Purified catalytic subunit had Kmapp (ATP) 20 microM with rabbit muscle glycogen synthease I as substrates. Synthase I from rabbit muscle and human leukocytes were phosphorylated by catalytic subunit to synthase D (ratio of independence less than 0.07). cAMP independent histone kinase activity eluted in one peak (Peak II) at3 mmho. The enzymatic activity sedimented at 3.4S and eluted from gelfiltration with Mr 78 000. Kmapp for ATP was 78 microM and for histone IIA 0.5 mg/ml. The enzyme was sensitive to temperature, but less sensitive than cAMP dependent protein kinase to Ca2+, and insensitive to protein kinase inhibitor. The substrate specificity was histone IIA greater than histone VS = histone VIS, while casein and phosvitin were poor substrates. Glycogen synthase I was not phosphorylated. The cAMP independent histone kinase activity comprised 15% of the total histone kinase activity in a crude homogenate of leukocytes. Its physiological substrate is unknown.
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PMID:Purification and properies of cAMP dependent and independent histone kinases from human leukocytes. 22 66

A protein phosphokinase (EC 2.7.1.1.37) was isolated from baker's yeast (Saccharomyces cerevisiae) after a 17,000-fold purification; the purified enzyme is homogeneous according to the criteria of gel electrophoresis and ultracentrifuge analysis. The enzyme has a high isoelectric point of ca. 9 and appears to exist as a monomer with a molecular weight of 42,000 plus or minus 1500. It is neither stimulated by cyclic 3',5'-AMP, -GMP, -CMP or -ump nor inhibited by the regulatory subunit of rabbit muscle protein kinase (Reimann, E. M., Walsh, D. A., and Krebs, E. G. (1971), J. Biol. Chem. 246, 1986). In the presence of divalent metal ions, preferably Mg-2+ or Mn-2+, the enzyme readily transfers the terminal phosphate group of ATP to phosvitin, alphaS1B- and beta a-casein and an NH2-terminal tryptic peptide derived from beta a-casein, but not to protamine, lysine, or arginine-rich histones or to yeast enzymes such as phosphorylase, phosphofructokinase, or pyruvate carboxylase; serine and polyserine were also inactive as phosphate acceptors. Km values of 0.17 mM for beta a-casein and 0.2 mMfor ATP were determined at 10 mM Mg-2+. The urified yeast protein kinase also catalyzes the reverse reaction, namely, the transfer of phosphate from fully phosphorylated beta a-casein or its NH2-terminal peptide to ADP resulting in the formation of ATP. AMP, GDP, UDP, and CDP did not serve as phosphate acceptors in this reaction. As observed by Rabinowitz and Lipmann (Rabinowitz, M., and Lipmann, F. (1960), J. Biol. Chem. 235, 1043) both reactions have different pHoptima with values of 7.5 for the forward reaction (phosphorylation of the proteins) and ca 5.2 for the formation of ATP; both are differently affected by salts. Phosphorylation of beta a-casein with [gamma-32-P]ATP followed by digestion of the labeled protein with trypsin indicated that all the radioactivity was exclusively introduced in an NH2-terminal peptide possessing the unique sequence: Glu-Ser(P)-Leu-Ser(P)-Ser(P)-Ser(P)-Glu-Glu...(Ribadeau-Dumas, B., Brignon, G., Grosclaude, F., and Mercier, J.-C. (1971), eur J. Biochem. 20, 264). By subjecting beta a-casein and its NH2-terminal peptide to the combined action of almond acid phosphatease and purified yeast protein kinase, it was determined that the phosphorylation and dephosphorylation reactions proceed randomly, i.e., all seryl phosphate residues are equally susceptible and that the rate of phosphorylation decreases drastically as the number of bound phosphate groups in the substrate diminishes.
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PMID:Purification and properties of a yeast protein kinase. 23 75

A protein kinase (ATP: protein phosphotransferase, EC 2.7.1.37) which preferentially phosphorylates protamine is purified about 250-fold from the soluble fraction of baker's yeast (Saccharomyces cerevisiae). This enzyme is not sensitive to activation by cyclic nucleotides. Histone is about 5% as active as protamine in the reaction rate. Neither casein, phosvitin nor glycogen phosphorylase is active as substrate. The enzyme is distinguishable from casein kinase of the classical type (Rabinowitz, M. and Lipmann, F. (1960) J. Biol. Chem. 235, 1043-1050) and from adenoshine 3', 5'-monophosphate-dependent protein kinase described earlier (Takai, Y., Yamamura, H. and Nishizuka, Y. (1974) J. Biol. Chem. 249,530-535).
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PMID:Protamine kinase from yeast. 23 28

Crude ribosomes from Saccharomyces cerevisiae cultures were phosphorylated in vitro when incubated in the presence of [gamma-32P]ATP. Analysis of the ribosomal proteins with two-dimensional electrophoresis revealed that of the 29 proteins identified in the small subunit, only protein S6 was phosphorylated. Of the 37 proteins identified in the large subunit, one was highly phosphorylated (L3) and two only slightly phosphorylated (L11 and L14). The protein kinase activity associated with the ribosomes was extracted with 1 M KCl and was not dependent on adenosine 3':5'-monophosphate; it preferentially phosphorylated casein and phosvitin, but was less active on histones. Structural ribosomal proteins were also phosphorylated in vivo when the yeast cultures were incubated with [32P]orthophosphate; the radioactivity resistant to hydrolysis by hot perchloric acid was incorporated into the proteins of the two subunits. Radioactive phosphoserine was found by subjecting hydrolysates of ribosomal proteins to high-voltage electrophoresis. After two-dimensional electrophoresis, one poorly phosphorylated protein (S10) was identified in the small subunit. In the large subunit, one protein (L3) was highly labelled, and two proteins (L11 and L24) only slightly labelled.
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PMID:Phosphorylation in vitro and in vivo of ribosomal proteins from Saccharomyces cerevisia. 31 98

Evidence for phosphorylation of proteins by protein kinases has been found in Salmonella typhimurium despite previous indications that protein kinase action is absent in prokaryotes. At least four proteins have been found to be phosphorylated. Serine and threonine phosphates have been isolated from acid hydrolysates of these proteins after in vivo and in vitro labeling. The kinases do not phosphorylate histones, casein, or phosvitin. It would appear that phosphorylation as a regulatory control exists in prokaryotes.
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PMID:Evidence for protein kinase activities in the prokaryote Salmonella typhimurium. 35 51

An interaction of polyamines with protein kinases activities from T. cruzi epimastigotes is demonstrated. Spermine and spermidine and less pronounced putrescine are found to inhibit protein kinases activities. In the extract of T. cruzi three protein kinases are distinguished on account of molecular weight (greater than 200 000, 95 000 and 40 000) and preference for acceptor proteins (phosvitin and histones). Especially the activity of the high molecular weight protein kinase which phosphorylates phosvitin is strongly inhibited by spermine and spermidine. The type of inhibition by both polyamines is found to be non-competitive with respect to ATP as well as phosvitin. The inhibition constants for spermine and spermidine are determined to be 1.4 mM and 2.0 nM, respectively.
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PMID:Effect of polyamines on protein kinases activities from Trypanosoma cruzi. 37 14

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

Rat hepatocytes taken a different stages of the perinatal period were partially purified. On sodium dodecylsulphate acrylamide electrophoresis chromosomal non-histone proteins showed important variations in complexity during development. Chromosomal phosvitin kinase strongly increased during the last days of fetal life; it strongly decreased just after birth and increased again for a short time, while the cytosol phosvitin kinase increased more significantly after birth. Chromosomal non-histone proteins prepared at varoius stages were incubated with [gamma-32P]ATP and resolved on polyacrylamide gel. The incorporation was very low in sample taken at the 15th say of the fetal life. A dramatic increase was observed at the 17th day. This incorporation strongly decreased in the samples taken thereafter and it was negligible in proteins from adult rats. The variations in protein kinase and in 32P incorporation into non-histone proteins were correlated with the pattern of appearance of enzymes in this period of life, with cell growth and with the hormone-induced maturation.
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PMID:Hepatocyte chromosomal non-histone proteins in developing rats. 45 54


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