ISSN:
1471-4159
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
Abstract: Various regulators of protein kinase activities were tested for their effects on the in vitro transfer of phosphate from [γ-32P]ATP to four proteins of rat brain synaptic particulate preparations. One protein, of apparent molecular weight 44,000, accepted 32P in the presence of 8 mM EDTA and no added Mg2+. It was the major phosphoprotein of brain mitochondria. Its phosphorylation was inhibited by pyruvate and stimulated by K+, and it comigrated in electrophoretic gels with authentic α-subunit of pyruvate: lipoamide oxidoreductase (decarboxylating) (EC 1.2.4.1) from bovine heart. The major kinase acting on three proteins of apparent molecular weights 24,000, 21,000, and 19,000 was stimulated by Ca2+, by preincubation with phospholipase C, and by 12-tetradecanoyl 4-β-phorbol 13-acetate. Phosphorylation of these lower-molecular-weight proteins was inhibited by ACTH1-24, by cyclic 3′,5′-adenosine monophosphate, and by 50μM trifluoperazine. The stimulatory effect of Ca2+ was antagonized by calmodulin. The kinase in question appears to be B-50 protein kinase or protein kinase C.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1471-4159.1985.tb05448.x
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