Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
1985-11-15
pubmed:abstractText
It has been shown that intracellular injection of protein kinase C (calcium/phosphatidylserine/diacylglycerol-dependent protein kinase), purified from mammalian brain, or application of the tumor-promoting phorbol diester, 12-O-tetradecanoyl-13-phorbol acetate (TPA), leads to an enhancement of calcium currents in the bag cell neurons of Aplysia. We now present evidence of an endogenous enzyme in bag cell neurons which is activated by TPA and which has properties similar to those of mammalian protein kinase C. Calcium/phosphatidylserine/diacylglycerol-dependent protein kinase activity was found in both cytosolic and particulate fractions prepared from isolated clusters of bag cell neurons. This endogenous enzyme phosphorylated an 87,000-dalton protein from bovine brain, which appears to be a specific substrate for protein kinase C, as well as several substrates present in cytosolic fractions prepared from isolated bag cell clusters. Similar results were obtained using preparations made from pooled head ganglia from Aplysia. The pharmacological properties of the calcium/phosphatidylserine/diacylglycerol-dependent protein kinase activity in the Aplysia nervous system were similar to those of protein kinase C from mammalian tissues. Thus, the same group of endogenous substrate proteins were phosphorylated when diacylglycerol was replaced by TPA in cytosolic fractions prepared from isolated bag cell clusters. Non-tumor-promoting phorbols (4-alpha-phorbol, 4-alpha-phorbol-12,13-didecanoate, and 4-O-methyl-12-O-tetradecanoylphorbol-13-acetate) did not stimulate protein phosphorylation in these preparations. Phosphorylation by the Aplysia calcium/phosphatidylserine/diacylglycerol-dependent protein kinase was inhibited by polymixin B sulfate, by calmodulin, and by the "calmodulin antagonists" trifluoperazine, calmidazolium and W7.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0270-6474
pubmed:author
pubmed:issnType
Print
pubmed:volume
5
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2672-6
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1985
pubmed:articleTitle
Calcium/phosphatidylserine/diacylglycerol-dependent protein phosphorylation in the Aplysia nervous system.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't