Linked Life Data

1848101

Source:http://linkedlifedata.com/resource/pubmed/id/1848101

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
1991-4-18
pubmed:abstractText
We recently reported that autophosphorylated rat brain protein kinase C (PKC) catalyzes a Ca2(+)- and phosphatidylserine- (PS-) dependent ATPase reaction. The Ca2(+)- and PS-dependent ATPase and histone kinase reactions of PKC each had a Km app(ATP) of 6 microM. Remarkably, the catalytic fragment of PKC lacked detectable ATPase activity. In this paper, we show that subsaturating concentrations of protein substrates accelerate the ATPase reaction catalyzed by PKC and that protein and peptide substrates of PKC induce ATPase catalysis by the catalytic fragment. At subsaturating concentrations, histone III-S and protamine sulfate each accelerated the ATPase activity of PKC in the presence of Ca2+ and PS by as much as 1.5-fold. At saturating concentrations, the protein substrates were inhibitory. Poly(L-lysine) failed to accelerate the ATPase activity, indicating that the acceleration observed with histone III-S and protamine sulfate was not simply a result of their gross physical properties. Furthermore, histone III-S induced the ATPase activity of the catalytic fragment of PKC, at both subsaturating and saturating histone concentrations. The induction of ATPase activity was also elicited by the peptide substrate Arg-Arg-Lys-Ala-Ser-Gly-Pro-Pro-Val, when the peptide was present at concentrations near its Km app. The induction of the ATPase activity by the nonapeptide provides strong evidence that the binding of phospho acceptor substrates to the active site of PKC can stimulate ATP hydrolysis. Taken together, our results indicate that PKC-catalyzed protein phosphorylation is inefficient, since it is accompanied by Pi production.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
30
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2549-54
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Stimulation of the ATPase activity of rat brain protein kinase C by phospho acceptor substrates of the enzyme.
pubmed:affiliation
Department of Cell Biology, University of Texas M.D. Anderson Cancer Center, Houston 77030.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't