Linked Life Data

9887965

Source:http://linkedlifedata.com/resource/pubmed/id/9887965

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1999-4-7
pubmed:abstractText
Smooth muscle contraction is regulated primarily by the reversible phosphorylation of myosin triggered by an increase in sarcoplasmic free Ca2+ concentration ([Ca2+]i). Contraction can, however, be modulated by other signal transduction pathways, one of which involves the thin filament-associated protein calponin. The h1 (basic) isoform of calponin binds to actin with high affinity and is expressed specifically in smooth muscle at a molar ratio to actin of 1:7. Calponin inhibits (i) the actin-activated MgATPase activity of smooth muscle myosin (the cross-bridge cycling rate) via its interaction with actin, (ii) the movement of actin filaments over immobilized myosin in the in vitro motility assay, and (iii) force development or shortening velocity in permeabilized smooth muscle strips and single cells. These inhibitory effects of calponin can be alleviated by protein kinase C (PKC)-catalysed phosphorylation and restored following dephosphorylation by a type 2A phosphatase. Three physiological roles of calponin can be considered based on its in vitro functional properties: (i) maintenance of relaxation at resting [Ca2+]i, (ii) energy conservation during prolonged contractions, and (iii) Ca(2+)-independent contraction mediated by phosphorylation of calponin by PKC epsilon, a Ca(2+)-independent isoenzyme of PKC.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0001-6772
pubmed:author
pubmed:issnType
Print
pubmed:volume
164
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
415-26
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Regulation of smooth muscle actin-myosin interaction and force by calponin.
pubmed:affiliation
Smooth Muscle Research Group, University of Calgary, Alberta, Canada.
pubmed:publicationType
Journal Article, Review, Research Support, Non-U.S. Gov't