Linked Life Data

11739385

Source:http://linkedlifedata.com/resource/pubmed/id/11739385

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2002-2-4
pubmed:abstractText
Both extracellular and intracellular proteases can activate epithelial Na(+) channels (ENaC). The mechanism by which serine proteases activate ENaC is unknown. We investigated the effect of the serine protease trypsin on in vitro translated and immunopurified alpha-, beta-, and gamma-rENaC subunits. Immunopurified subunit proteins were exposed to increasing concentrations of trypsin ranging from 0.002 to 2 microg/ml in Tris-buffered saline buffer for 2 h. The proteolytic mixture was subjected to SDS-PAGE and analyzed by autoradiography. Our results demonstrate that the beta- and gamma-subunits of ENaC were most susceptible to trypsin proteolysis, and exposure to as little as 0.002 microg/ml trypsin resulted in a reduction in the size of the beta- and gamma-transcripts by 7-8 kDa. By using N- and C-terminally truncated beta- and gamma-subunits, we determined that trypsin cleaved the C termini of both subunits, resulting in a channel structure resembling that seen in Liddle's disease. Exposure to 2 microg/ml trypsin completely digested all three subunits. Our results suggest different susceptibilities of proteolytic sites of ENaC subunits to trypsin. Thus, we propose that limited intracellular proteolysis may be one of the potential physiological mechanisms of sodium channel regulation.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
8
pubmed:volume
277
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4134-40
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
The serine protease trypsin cleaves C termini of beta- and gamma-subunits of epithelial Na+ channels.
pubmed:affiliation
Department of Physiology and Biophysics, University of Alabama at Birmingham, Birmingham, Alabama 35294-0005, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.