Linked Life Data

7775466

Source:http://linkedlifedata.com/resource/pubmed/id/7775466

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
23
pubmed:dateCreated
1995-7-10
pubmed:abstractText
Previous studies with synthetic peptides indicate that residues 290-309, corresponding to the calmodulin (CaM)-binding domain of Ca2+/CaM-dependent protein kinase II interact with the catalytic core of the enzyme as a pseudosubstrate (Colbran, R. J., Smith, M. K., Schworer, C. M., Fong, Y. L., and Soderling, T. R. (1989) J. Biol. Chem. 264, 4800-4804). In the present study, we attempted to locate the pseudosubstrate motif by generation or removal of potential substrate recognition sequences (RXXS/T) at selected positions using site-directed mutagenesis. Based on previous results, Arg297, Thr305/306, and Ser314 were selected as key residues. Single mutations such as N294S, K300S, A302R, A309R, and R311A were expressed, purified, and characterized. Several of the mutants exhibited decreased binding of and activation by CaM, not surprising since the mutations were within the CaM-binding domain. None of the mutants exhibited enhanced Ca(2+)-independent kinase activity toward exogenous substrate, but the K300S and N294S mutants showed a significant enhancement in the rate and stoichiometry of 32P incorporation during Ca(2+)-independent autophosphorylation. Using two-dimensional peptide mapping and phosphoamino acid analyses, enhanced phosphorylation of the introduced Ser residue was demonstrated in the K300S mutant but not in the N294S mutant. This specific Ca(2+)-independent autophosphorylation of Ser300 is consistent with the hypothesis that Arg297 may occupy the P (-3) position in a pseudosubstrate autoinhibitory interaction with the catalytic core in the nonactivated state of the kinase.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
9
pubmed:volume
270
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
14062-7
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Mutational analysis of Ca(2+)-independent autophosphorylation of calcium/calmodulin-dependent protein kinase II.
pubmed:affiliation
Vollum Institute, Oregon Health Sciences University, Portland 97201, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.