Linked Life Data

19635597

Source:http://linkedlifedata.com/resource/pubmed/id/19635597

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
2009-9-23
pubmed:abstractText
To understand the importance of selected regions of the regulatory light chain (RLC) for phosphorylation-dependent regulation of smooth muscle myosin (SMM), we expressed three heavy meromyosins (HMMs) containing the following RLC mutants; K12E in a critical region of the phosphorylation domain, GTDP(95-98)/AAAA in the central hinge, and R160C a putative binding residue for phosphorylated S19. Single-turnover actin-activated Mg(2+)-ATPase (V(max) and K(ATPase)) and in vitro actin-sliding velocities were examined for both unphosphorylated (up-) and phosphorylated (p-) states. Turnover rates for the up-state (0.007-0.030 s(-1)) and velocities (no motion) for all constructs were not significantly different from the up-wild type (WT) indicating that they were completely turned off. The apparent binding constants for actin in the presence of ATP (K(ATPase)) were too weak to measure as expected for fully regulated constructs. For p-HMM containing GTDP/AAAA, we found that both ATPase and motility were normal. The data suggest that the native sequence in the central hinge between the two lobes of the RLC is not required for turning the HMM off and on both kinetically and mechanically. For p-HMM containing R160C, all parameters were normal, suggesting that R160C is not involved in coordination of the phosphorylated S19. For p-HMM containing K12E, the V(max) was 64% and the actin-sliding velocity was approximately 50% of WT, suggesting that K12 is an important residue for the ability to sense or to promote the conformational changes required for kinetic and mechanical activation.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:volume
1794
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1599-605
pubmed:dateRevised
2011-5-16
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Kinetic and motor functions mediated by distinct regions of the regulatory light chain of smooth muscle myosin.
pubmed:affiliation
Department of Biochemistry and Molecular Biology, University of Nevada School of Medicine, Reno, NV 89557, USA.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural