Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
2000-10-11
pubmed:abstractText
Rapsyn is a protein on the cytoplasmic face of the postsynaptic membrane of skeletal muscle that is essential for clustering acetylcholine receptors (AChR). Here we show that transfection of rapsyn cDNA can restore AChR clustering function to muscle cells cultured from rapsyn deficient (KORAP) mice. KORAP myotubes displayed no AChR aggregates before or after treatment with neural agrin. After transfection with rapsyn expression plasmid, some KORAP myotubes expressed rapsyn at physiological levels. These formed large AChR-rapsyn clusters in response to agrin, just like wild-type myotubes. KORAP myotubes that overexpressed rapsyn formed only scattered AChR-rapsyn microaggregates, irrespective of agrin treatment. KORAP cells were then transfected with mutant forms of rapsyn. A deletion mutant lacking residues 16-254 formed rapsyn microaggregates, but failed to aggregate AChRs. Substitution mutation to the C-terminal serine phosphorylation site of rapsyn (M43(D405,D406)) did not impair the response to agrin, showing that differential phosphorylation of this site is unlikely to mediate agrin-induced clustering. The results indicate that rapsyn expression is essential for agrin-induced AChR clustering but that its overexpression inhibits this pathway. The approach of using rapsyn-deficient muscle cells opens the way for defining the role of rapsyn in agrin-induced AChR clustering.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0300-4864
pubmed:author
pubmed:issnType
Print
pubmed:volume
28
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
763-75
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:10859577-Agrin, pubmed-meshheading:10859577-Animals, pubmed-meshheading:10859577-Cell Line, Transformed, pubmed-meshheading:10859577-Cytoskeletal Proteins, pubmed-meshheading:10859577-Female, pubmed-meshheading:10859577-Gene Deletion, pubmed-meshheading:10859577-Gene Expression, pubmed-meshheading:10859577-Male, pubmed-meshheading:10859577-Membrane Proteins, pubmed-meshheading:10859577-Mice, pubmed-meshheading:10859577-Mice, Mutant Strains, pubmed-meshheading:10859577-Muscle, Skeletal, pubmed-meshheading:10859577-Muscle Fibers, Skeletal, pubmed-meshheading:10859577-Muscle Proteins, pubmed-meshheading:10859577-Mutagenesis, pubmed-meshheading:10859577-Peptide Fragments, pubmed-meshheading:10859577-Phosphorylation, pubmed-meshheading:10859577-Receptors, Cholinergic, pubmed-meshheading:10859577-Serine, pubmed-meshheading:10859577-Transfection, pubmed-meshheading:10859577-Utrophin
pubmed:year
1999
pubmed:articleTitle
Overexpression of rapsyn inhibits agrin-induced acetylcholine receptor clustering in muscle cells.
pubmed:affiliation
Institute for Biomedical Research, Department of Physiology, University of Sydney, Sydney NSW, Australia.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't