Linked Life Data

7592854

Source:http://linkedlifedata.com/resource/pubmed/id/7592854

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
44
pubmed:dateCreated
1995-12-21
pubmed:abstractText
We investigated the degradation of the gap junction protein connexin43 in E36 Chinese hamster ovary cells and rat cardiomyocyte-derived BWEM cells. Treatment of E36 cells with the lysosomotropic amine, primaquine, for 16 h doubled the amount of connexin43 detected by immunoblotting and modestly increased the half-life of connexin43 in pulse-chase studies, suggesting that the lysosome played a minor role in connexin43 proteolysis. In contrast, treatment with the proteasomal inhibitor N-acetyl-L-leucyl-L-leucinyl-norleucinal led to a 6-fold accumulation of connexin43 and increased the half-life of connexin43 to approximately 9 h. The role of ubiquitin in connexin43 degradation was examined in an E36-derived mutant, ts20, which contains a thermolabile ubiquitin-activating enzyme, E1. E36 and ts20 cells grown at the permissive temperature contained similar amounts of connexin43 detectable by immunoblotting. Heat treatment dramatically reduced the amount of connexin43 detected in E36 cells, while connexin43 levels in heat-treated ts20 cells did not change. E36 cells that were heat-treated in the presence of N-acetyl-L-leucyl-L-leucinyl-norleucinal did not lose their connexin43. Pulse-chase experiments showed the reversibility of the block to connexin43 degradation in ts20 cells that were returned to the permissive temperature. Finally, sequential immunoprecipitation using anti-connexin43 and anti-ubiquitin antibodies demonstrated polyubiquitination of connexin43. These results indicate that ubiquitin-mediated proteasomal proteolysis may be the major mechanism of degradation of connexin43.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
3
pubmed:volume
270
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
26399-403
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
The gap junction protein connexin43 is degraded via the ubiquitin proteasome pathway.
pubmed:affiliation
Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't