Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
41
pubmed:dateCreated
1999-11-9
pubmed:abstractText
Phosphorylation of the 20-kDa regulatory light chain of myosin catalyzed by a Ca(2+)/calmodulin-dependent myosin light chain kinase is important in the initiation of smooth muscle contraction and other contractile processes in non-muscle cells. It has been previously shown that residues 1-142 of smooth muscle myosin light chain kinase are necessary for high-affinity binding to actin-containing filaments in cells (1). To further localize the region of the kinase required for binding, a series of N-terminal deletion mutants as well as several N-terminal glutathione S-transferase fusion proteins were constructed. Cosedimentation assays showed that a peptide containing residues 1-75 binds to purified smooth muscle myofilaments. Furthermore, the N-terminal peptide was sufficient for high-affinity binding to actin stress fibers in smooth muscle cells in vivo. Alanine scanning mutagenesis in the fusion protein identified residues Asp-30, Phe-31, Arg-32, and Leu-35 as important for binding in vitro. There are two additional DFRXXL motifs located at residues 2-7 and 58-63. The DFR residues in these three motifs were individually replaced by alanine residues in the full-length kinase. Each of these mutations significantly decreased myosin light chain kinase binding to myofilaments in vitro, and each abolished high-affinity binding to actin-containing filaments in smooth muscle cells in vivo. These results identify a unique structural motif comprised of three repeat consensus sequences in the N terminus of myosin light chain kinase necessary for high-affinity binding to actin-containing filaments.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
8
pubmed:volume
274
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
29433-8
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Identification of a novel actin binding motif in smooth muscle myosin light chain kinase.
pubmed:affiliation
Department of Physiology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75235-9040, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.