Linked Life Data

11574070

Source:http://linkedlifedata.com/resource/pubmed/id/11574070

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2001-9-27
pubmed:abstractText
Ca(2+)/calmodulin-dependent protein kinases (CaM-kinases) I and IV are activated upon phosphorylation of their Thr(177) and Thr(196), respectively, by the upstream Ca(2+)/calmodulin-dependent protein kinases CaM-kinase kinase alpha and beta, and deactivated upon dephosphorylation by protein phosphatases such as CaM-kinase phosphatase. Recent studies demonstrated that the activity of CaM-kinase kinase alpha is decreased upon phosphorylation by cAMP-dependent protein kinase (PKA), and the relationship between the inhibition and phosphorylation of CaM-kinase kinase alpha by PKA has been studied. In the present study, we demonstrate that the activity of CaM-kinase kinase alpha toward PKIV peptide, which contains the sequence surrounding Thr(196) of CaM-kinase IV, is increased by incubation with PKA in the presence of Ca(2+)/calmodulin but decreased in its absence, while the activity toward CaM-kinase IV is decreased by incubation with PKA in both the presence and absence of Ca(2+)/calmodulin. Six phosphorylation sites on CaM-kinase kinase alpha, Ser(24) for autophosphorylation, and Ser(52), Ser(74), Thr(108), Ser(458), and Ser(475) for phosphorylation by PKA, were identified by amino acid sequence analysis of the phosphopeptides purified from the tryptic digest of the phosphorylated enzymes. The presence of Ca(2+)/calmodulin suppresses phosphorylation on Ser(52), Ser(74), Thr(108), and Ser(458) by PKA, but accelerates phosphorylation on Ser(475). The changes in the activity of the enzyme upon phosphorylation appear to occur as a result of conformational changes induced by phosphorylation on several sites.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0021-924X
pubmed:author
pubmed:issnType
Print
pubmed:volume
130
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
503-13
pubmed:dateRevised
2007-12-19
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Regulation of Ca(2+)/calmodulin-dependent protein kinase kinase alpha by cAMP-dependent protein kinase: I. Biochemical analysis.
pubmed:affiliation
Department of Biochemistry, Asahikawa Medical College, Asahikawa 078-8510, Japan.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't