Linked Life Data

7961732

Source:http://linkedlifedata.com/resource/pubmed/id/7961732

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
45
pubmed:dateCreated
1994-12-16
pubmed:abstractText
A key protein involved in the regulated exocytotic mechanism in neuroendocrine cells is the GTP-binding protein, Rab3A. Rab3A is thought to mediate exocytosis by an interaction of its effector domain with a putative effector protein. We demonstrate here that Rab3A effector domain peptides specifically stimulated insulin exocytosis in electroporated insulin-secreting cells (K0.5 activation, 6-8 microM) in a Ca(2+)-independent manner, although in the presence of Ca2+ insulin exocytosis was further potentiated. By using a 125I-radiolabeled photoactivated cross-linking Rab3A effector domain peptide, we identified a cytosolic protein doublet (REEP-1 and REEP-2), which specifically interacted with the Rab3A effector domain. Competitive inhibition studies revealed this protein-protein interaction to be at a concentration equivalent to that required for Rab3A effector domain peptides to trigger insulin exocytosis (Ki, 6-8 microM). Furthermore, under basal secretory conditions REEP-1 and -2 were membrane-associated, but upon stimulation of exocytosis they were released into a cytosolic fraction. Our results suggest that REEP-1 and -2 are part of the regulated exocytotic machinery, and their dissociation upon stimulation of hormone release (likely from a protein complex) may be essential to the mechanism that triggers regulated exocytosis in pancreatic beta-cells.
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
11
pubmed:volume
269
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
27987-91
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Rab3A effector domain peptides induce insulin exocytosis via a specific interaction with a cytosolic protein doublet.
pubmed:affiliation
E. P. Joslin Research Laboratory, Joslin Diabetes Center, Brigham and Women's Hospital, Boston, Massachusetts 02215.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.