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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
1975-7-2
pubmed:abstractText
The phosphorylation of two purified vaccinia virus proteins (Acceptors I and II) by a protein kinase isolated from vaccinia virus cores has been studied. Phosphorylation of viral acceptor proteins by the purified enzyme was dependent on the presence of ATP, Mg2+, and protamine or other basic proteins, and was maximal at alkaline pH values. Cyclic mononucleotides did not stimulate the vaccinia protein kinase under a variety of conditions. Protamine, however, was shown to function as an enzyme activator. In its presence, the purified vaccinia protein kinase phosphorylated mainly serine residues in Acceptor I, and predominantly threonine residues in Acceptor II. Phosphorylation of protamine accounted for less than 1% of the total 23P incorporation. Tryptic peptide maps prepared from 32P-labeled Acceptors I and II demonstrated that they contained different labeled peptide sequences and were, therefore, distinct protein species. From additional studies on both purified and virus-associated protein kinase it was concluded that various proteins affected the protein kinase reaction in one of three ways. One class of proteins served as phosphate acceptors, but only when another activator protein was present. A second class consisted of proteins that were strong activators but poor phosphate acceptors. The third class contained proteins that were fair phosphate acceptors, but which also activated the phosphorylation of other acceptor proteins.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
250
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2430-7
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1975
pubmed:articleTitle
Characterization of a protein kinase and two phosphate acceptor proteins from vaccinia virions.
pubmed:publicationType
Journal Article