Linked Life Data

18171678

Source:http://linkedlifedata.com/resource/pubmed/id/18171678

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
2008-3-3
pubmed:abstractText
Skeletal muscle excitation-contraction coupling involves activation of homotetrameric ryanodine receptor ion channels (RyR1s), resulting in the rapid release of Ca(2+) from the sarcoplasmic reticulum. Previous work has shown that Ca(2+) release is impaired by mutations in RyR1 linked to Central Core Disease and Multiple Minicore Disease. We studied the consequences of these mutations on RyR1 function, following their expression in human embryonic kidney 293 cells and incorporation in lipid bilayers. RyR1-G4898E, -G4898R, and -DeltaV4926/I4927 mutants in the C-terminal pore region of RyR1 and N-terminal RyR1-R110W/L486V mutant all showed negligible Ca(2+) permeation and loss of Ca(2+)-dependent channel activity but maintained reduced K(+) conductances. Co-expression of wild type and mutant RyR1s resulted in Ca(2+)-dependent channel activities that exhibited intermediate Ca(2+) selectivities compared with K(+), which suggested the presence of tetrameric RyR1 complexes composed of wild type and mutant subunits. The number of wild-type subunits to maintain a functional heterotetrameric channel differed among the four RyR1 mutants. The results indicate that homozygous RyR1 mutations associated with core myopathies abolish or greatly reduce sarcoplasmic reticulum Ca(2+) release during excitation-contraction coupling. They further suggest that in individuals, expressing wild type and mutant alleles, a substantial portion of RyR1 channels is able to release Ca(2+) from sarcoplasmic reticulum.
pubmed:grant
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
7
pubmed:volume
283
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6321-9
pubmed:dateRevised
2011-5-5
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Single channel properties of heterotetrameric mutant RyR1 ion channels linked to core myopathies.
pubmed:affiliation
Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599-7260, USA.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural