Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.11.17 (CaMKII)
 4,029 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An adenosine 3':5'-monophosphate-dependent protein kinase II (ATP:protein phosphotransferase, EC 2.7.1.37) was partially purified from the cytosol fraction of an exponentially growing culture of Tetrahymena pyriformis. Protein kinase II represented approximately 90% of the cytosolic protein kinase activity. The enzyme had a high degree of substrate specificity for calf thymus and Tetrahymena histones as compared to casein, protamine and phosvitin. The enzyme incorporated the terminal phosphate of ATP into serine and threonine residues of all the histone fractions. The apparent Km of the enzyme for adenosine 3':5'-monophosphate (cyclic AMP) was 1-10-minus 8 M. Protein kinase II was also activated by other cyclic nucleotides with apparent Km values in the range 2.k-10-minus 6 M. Ther specific activity of the cyclic AMP-dependent protein kinase of Tetrahymena decreases markedly from initial high values during the transition from the lag to early log phase of growth. This is followed by a shrp increase in the activity of the enzyme as the log phase of growth progresses. The specific activity of the enzyme increases rapidly during the heat-induced synchronization of Tetrahymena cells. The capacity for rapid phosphorylation of multiple classed of organelle-specific phosphoproteins and the level of cyclic AMP were maximal in Tetrahymena during the earliest phase of growth. These results demonstrate that the cell cycle of Tetrahymena may be coordinated by marked variations in the level of cyclic AMP which in turn regulate the cyclic AMP-dependent protein kinase.
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PMID:Changes in cyclic AMP-dependent protein dinase activity in Tetrahymena pyriformis during the growth cycle. 16 17

Three protein kinases (ATP:protein phosphotransferase, EC 2.7.1.37) were detected when the soluble fraction of rabbit kidney medulla was chromatographed on DEAE-cellulose with a linear NaC1 gradient. The first two kinases eluted (Peak 1 and Peak II) were cyclic-AMP-dependent, wheras Peak III was cyclic-AMP-independent. A procedure was developed to separate the catalytic subunit of Peak II cyclic-AMP-dependent protein kinase (representing the bulk of the histone kinase activity) from Peak III protein kinase. In contrast to the catalytic subunit, Peak III protein kinase phosphorylated casein more rapidly than histone. Peak III was insensitive to the heat-stable protein inhibitor of cyclic-AMP-dependent protein kinases and appeared to have a higher requirement for ATP than did the catalytic subunit. Peak III catalyzed the conversion of glycogen synthase (UDPglucose:glycogen alpha-4-glucosyltransferase, EC 2.4.1.11) from the I (glucose-6-phosphate-independent) to the D (glucose-6-phosphate-dependent) form. This conversion was dependent on Mg-2+ and ATP and was unaffected by cyclic AMP, cyclic GMP, or the protein inhibitor. Glycogen synthase I in the soluble fraction of kidney medulla could be converted to the D form by endogenous glycogen synthase I kinase if Mg-2+ and ATP were added. Most of this glycogen synthase I kinase activity was unaffected by cyclic AMP or by the protein inhibitor, suggesting that Peak III may be of major importance in the regulation of glycogen synthase in vivo.
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PMID:Isolation of a glycogen synthase I kinase that is independent of adenosine 3':5'-monophosphate. 16 80

Guanosine 3':5'-monophosphate-dependent protein kinase (ATP:protein phosphotransferase, EC 2.7.1.37) has been isolated from silkworm pupal fat body (Bombyx mori) which is devoid of any adenosine 3':5'-monophosphate-dependent protein kinase. The enzyme displayed catalytic properties which were roughly similar to those described for adenosine 3':5'-monophosphate-dependent protein kinase. This similarity has been found in substrate specificity, optimal Mg2+ dependency, polyamines effects and the lack of dependency upon sulfhydryl compound for activation by cyclic GMP. Treatment of the enzyme with sulfhydryl reagents, N-ethylmaleimide or p-chloromercuribenzoic acid, inhibited the catalytic activity as well as the dissociation of the binding and catalytic activities as shown by means of sucrose-density gradient ultracentrifugation. In the presence of cyclic GMP or histone, the disulfide-linked structure did not dissociate into separate subunits nor did it migrate as the holoenzyme but sedimented as an intermediate form carrying both binding and catalytic activities.
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PMID:Evidence for a role of sulfhydryl groups in catalytic activity and subunit interaction of the cyclic GMP-dependent protein kinase from silkworm. 21 Aug 22

A cyclic AMP-like substance has been isolated from higher plant tissues which can be quantitated with the use of a radioimmunoassay similar to that described by A. L. Steiner, D. M. Kipnis, R. Utiger, and C. Parker [(1969) Proc. Natl. Acad. Sci. USA 64, 367-373]. This compound has been extensively purified and is chromatographically distinct from authentic cyclic AMP. This cyclic AMP-like compound inhibited beef heart 3':5'-cyclic-nucleotide phosphodietsterase (3':5'-cyclic-nucleotide 5'-nucleotidohydrolase, EC 3.1.4.17), with half-maximal inhibition occurring at a concentration of 7.6 X 10(-10) M cyclic AMP equivalents. The compound also inhibited cyclic AMP-dependent protein kinase (ATP:protein phosphotransferase; EC 2.7.1.37) from bovine heart, with half-maximal inhibition of mixed histone phosphorylation occurring at 8.0 X 10(-11) M cyclic AMP equivalents. Equipotent inhibition of phosphorylation and associated trace ATPase activity were observed with the purified catalytic subunit of cyclic AMP-dependent protein kinase from calf thymus with a synthetic heptapeptide as substrate. Moreover, steady-state kinetic analysis of this inhibition in the latter system showed it to be nonlinear and noncompetitive versus MgATP.
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PMID:Inhibition of mammalian protein kinase and phosphodiesterase activities by a cyclic AMP-like compound isolated from higher plants. 21 43

Cyclic AMP-dependent protein kinases (EC 2.7.1.37; ATP:protein phosphotransferase) in the human diploid fibroblast WI-38 and an SV40-transformant WI-38-VA13-2RA (VA13) have been compared on the basis of their concentrations in cells, isoenzyme composition and susceptibility to hormonal activation. In high population density cultures, total soluble cyclic AMP-dependent kinase activities measured with histone were essentially the same in WI-38 and VA13. Two soluble protein kinase forms separated by chromatography on DEAE-cellulose were present in both cell lines. The concentration of cyclic AMP required for half-maximal activation of both enzyme forms was 10-30 nM. Overall kinase stimulation was greater for the Peak I enzymes. Kinase activation induced in the presence of 0.5 M KCl was more rapid and complete for the Peak I enzymes. Under conditions which elevated the concentration of cyclic AMP in WI-38 and VA13 cells the activities of the soluble histone kinases were increased. Incubation of the cells with either of 5.7 micronM prostaglandin E1 or 1 micronM isopropylnorepinephrine induced complete activation of the cyclic AMP-dependent histone kinases within 5 min and maintained the effect for 20 min. When intracellular cyclic AMP levels were raised by prostaglandin E1, activation of glycogen phosphorylase (assayed-AMP) suggested that this enzyme cascade involving cyclic AMP-dependent protein kinase(s) was intact and responsive in both cell lines.
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PMID:Adenosine 3',5'-monophosphate-dependent protein kinase(s) in diploid and SV40 transformed human fibroblasts. 21 99

Protein kinase (ATP:protein phosphotransferase, EC 2.7.1.37) and cyclic adenosine 3',5'-monophosphate binding activities have been identified in zoospore extracts of the water mold Blastocladiella emersonii. More than 75% of these activities is found in the soluble fraction. Soluble protein kinase activity is resolved in three peaks(I, II and III) by DEAE-cellulose chromatography. Peak I is casein dependent and insensitive to cyclic AMP. Peak II is histone dependent and cyclic AMP independent; this enzyme is inhibited by the heat-stable inhibitor from bovine muscle. Peak III utilizes histone as substrate and is activated by cyclic AMP.
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PMID:Cyclic AMP-dependent and -independent protein kinases of the water mold, Blastocladiella emersonii. 22 Oct 23

The catalytic subunit of cyclic AMP-dependent protein kinase (from rabbit skeletal muscle; ATP:protein phosphotransferase, EC 2.7.1.37) was found to be irreversibly inactivated by chloromethyl ketone derivatives of lysine and phenylalanine, chemical reagents originally designed for labeling the active sites of the proteolytic enzymes trypsin and chymotrypsin. This inactivation was shown to occur at pH 7.5 and 22 degrees C, conditions under which chemically related alkylating reagents such as chloroacetamide and chloroacetic acid (which do not possess the amino acid side chain) fail to inactivate the enzyme. In the case of the chloromethyl ketone derivative of N alpha-tosyl-L-lysine, the enzyme could be protected by its nucleotide substrate (MgATP), by one of its protein substrates (histone H2b), and by its regulatory subunit which, upon binding, shields the active site of the catalytic subunit. Differential labeling experiments, together with kinetic studies of the rates of modification of the sulfhydryl groups in the enzyme before and after inactivation with the chloromethyl ketone, suggest that the loss of activity is associated with one (kinetically characterized) sulfhydryl group present either at the active site of the enzyme or at a site intimately associated with it. The general implications of these results regarding the interpretation of affinity labeling experiments carried out in complex mixtures of proteins or under in vivo conditions are discussed.
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PMID:Affinity labeling of the catalytic subunit of cyclic AMP-dependent protein kinase by N alpha-tosyl-L-lysine chloromethyl ketone. 22 53

The catalytic subunit of cyclic 3':5'-AMP-dependent protein kinase (ATP:protein phosphotransferase, EC 2.7.1.37) inhibits translation in Artemia salina and wheat germ extracts. It acts, as in reticulocyte lysates [Datta, A., de Haro, C., Sierra, J. M. & Ochoa, S. (1977) Proc. Natl. Acad. Sci. USA 74, 1463-1467] by catalyzing the conversion of a proinhibitor to an inhibitor of polypeptide chain initiation. Addition of ATP and either cyclic AMP or catalytic subunit promotes the proinhibitor-inhibitor conversion in crude proinhibitor preparations from A. salina embryos. The effect of cyclic AMP is due to stimulation of cyclic AMP-dependent protein kinase, present in such preparations, and is inhibited by hemin. In similar preparations from wheat germ, addition of ATP and catalytic subunit promoted proinhibitor-inhibitor conversion, but addition of ATP and cyclic AMP has little or no effect. As assayed with histone as substrate, wheat germ preparations exhibit a protein kinase activity that is not stimulated by the addition of cyclic AMP or cyclic GMP. Our results suggest that a translational control system, similar to that existing in rabbit reticulocytes and other mammalian cells, is present in organisms evolutionarily far removed from mammals.
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PMID:Translational control by protein kinase in Artemia salina and wheat germ. 27 Jun 77

We surveyed rabbit brain cytosol for a new Ca2+/calmodulin (CaM)-dependent kinase. The renaturation blotting assay (RBA) exploits the ability of blotted SDS-denatured proteins to regain enzymic activity after guanidine treatment. Using RBA, we found that the eluate of rabbit brain cytosol from a CaM affinity column contains at least four electrophoretically distinct protein kinase bands which were autophosphorylated in a Ca2+/CaM-dependent manner. The 49 kDa band and the 60 kDa band were alpha and beta subunit of CaM kinase II, and the 42 kDa band was presumed to be CaM kinase I, but the 80 kDa band could not be attributed to any reported Ca2+/CaM-dependent protein kinases. The 80 kDa protein kinase was isolated by three-step chromatography. We examined the phosphorylation of exogenous substrates by 80 kDa protein kinase, and histone IIIs and myosin light chain were phosphorylated in a Ca2+/CaM-dependent manner. W-7, a specific inhibitor for calmodulin, inhibited this kinase activity, but KN-62, a specific inhibitor for CaM kinase II, had no effect on this protein kinase activity. Autoradiography using boiled rabbit brain homogenate as substrate showed three intrinsic substrates (80 kDa, 60 kDa and 42 kDa), which were phosphorylated in a Ca2+/CaM-dependent manner. These findings suggest that a new Ca2+/CaM-dependent protein kinase could be identified by the RBA.
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PMID:Identification of a 80 kDa calmodulin-binding protein as a new Ca2+/calmodulin-dependent kinase by renaturation blotting assay (RBA). 131 May 91

Ca2+/calmodulin-dependent protein kinase II (CaM-kinase II) has been purified from hen whole brain. The enzyme was purified 3000-fold using phosphocellulose and calmodulin-Agarose column chromatography. The specific activity was 200 nmol/min/mg protein. Microtubule associated protein-2 (MAP-2) was used as a substrate to assess the activity of the enzyme during purification and for its characterization. CaM-kinase II consisted of alpha and beta/beta' subunits of molecular weights 46,000 and 55,000/52,000, respectively. The ratio of alpha to beta/beta' subunits was 3:1 in the enzyme purified from the whole brain. The enzyme exhibited broad substrate specificity and phosphorylated myelin basic protein, MAP-2, histone II, histone VIII, casein, tubulin, myosin light chains, glycogen synthase, and phosvitin in decreasing order. Phosphorylase b was phosphorylated at a negligible rate. Autophosphorylation of CaM-kinase II for 10 min in the presence of calcium and calmodulin decreased its total activity to 33%, and calcium/calmodulin-independent activity reached 30% after 1 min and then dropped to 14% after 10 min of autophosphorylation. The Km value of ATP was 19 +/- 1.3 microM, and the K0.5 values of calcium and calmodulin were 4.4 +/- 0.5 and 3.0 +/- 0.5 microM, respectively. The latter were determined using myelin basic protein as the substrate. CaM-kinase II exhibited great differences in the calmodulin requirement for phosphorylation of MAP-2, histone II and myelin basic protein. MAP-2 required the least amount of calmodulin for its phosphorylation. Autophosphorylation of CaM-kinase II resulted in decreased mobility of the alpha-subunit but apparently not of the beta/beta' subunits in sodium dodecyl/sulfate-polyacrylamide gel. Antiserum was raised against the CaM-kinase II alpha subunit and used for testing cross-reactivity of hen brain enzyme with that of other species. The antiserum which reacted with both alpha and beta subunits of hen brain CaM-kinase II cross-reacted with only the alpha subunit of rat, mouse, rabbit, cat, dog, pig and human brain samples. The purified hen brain CaM-kinase II is a multifunctional enzyme and resembled rat brain CaM-kinase II in several properties. Immunocross-reactivity suggested that there was similarity in the alpha but not the beta/beta' subunits of the hen brain enzyme and the brain enzyme of other species.
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PMID:Ca2+/calmodulin-dependent protein kinase II from hen brain. Purification and characterization. 131 5


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