Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
1993-4-22
pubmed:abstractText
F-actin and tropomyosin inhibited the phosphorylation of calponin by protein kinase C, and the phosphorylation reduced the binding of calponin to F-actin and tropomyosin. Labeled phosphate from [gamma-32P]ATP was retained both on the chymotryptic NH2-terminal 22-kDa fragment, which contains the actin-, tropomyosin-, and calmodulin-binding regions, and on the COOH-terminal 12-kDa fragment. Fractionation of tryptic 32P-labeled peptides by high performance liquid chromatography allowed isolation of three phosphopeptides (designated T1, T2, and T3), each of which was located in three repeating amino acid motifs of calponin. Both the relative initial rates and extent of phosphorylation decreased in the order T2 > T3 > T1. Both serine and threonine residues were phosphorylated in T1 (GASQAGMTAPGTK), and only a threonine residue was phosphorylated in T2 (FASQQGMTAYGTR) and in T3 (GASQQGMTVYGLPR). As the 22-kDa fragment contained only T2, the phosphorylation site in T2 appeared to regulate the binding of calponin to F-actin and tropomyosin. The amino acid sequence of T2 indicates that protein kinase C phosphorylates Thr184. Thus Thr184 is the preferred site of phosphorylation and is functionally the most important of the sites phosphorylated by protein kinase C in smooth muscle calponin.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
268
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6194-201
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed-meshheading:8454594-Actins, pubmed-meshheading:8454594-Amino Acid Sequence, pubmed-meshheading:8454594-Animals, pubmed-meshheading:8454594-Binding Sites, pubmed-meshheading:8454594-Calcium-Binding Proteins, pubmed-meshheading:8454594-Calmodulin, pubmed-meshheading:8454594-Cattle, pubmed-meshheading:8454594-Chickens, pubmed-meshheading:8454594-Chromatography, High Pressure Liquid, pubmed-meshheading:8454594-Electrophoresis, Polyacrylamide Gel, pubmed-meshheading:8454594-Kinetics, pubmed-meshheading:8454594-Microfilament Proteins, pubmed-meshheading:8454594-Molecular Sequence Data, pubmed-meshheading:8454594-Muscle, Smooth, pubmed-meshheading:8454594-Peptide Fragments, pubmed-meshheading:8454594-Phosphorylation, pubmed-meshheading:8454594-Protein Kinase C, pubmed-meshheading:8454594-Rats, pubmed-meshheading:8454594-Tropomyosin
pubmed:year
1993
pubmed:articleTitle
Identification of the regulatory site in smooth muscle calponin that is phosphorylated by protein kinase C.
pubmed:affiliation
Department of Molecular and Cellular Pharmacology, Mie University School of Medicine, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't