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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2007-2-27
pubmed:abstractText
Previously we reported that the G-protein Galphai3 localized in pancreatic zymogen granule (ZG) membrane participates in vesicular fusion at the cell plasma membrane (PM). In the present study, the presence of cytosolic phosholipase A2 (cPLA2) in rat ZGs was demonstrated and its potential role in G-protein-mediated ZG-PM fusion was investigated. In vitro fusion assays utilizing both enzymatic and fluorimetric techniques demonstrate that ZGs fuse with PM with a greater potency in the presence of GTP. Arachidonyl trifluoromethyl ketone (AACOCF3) at 40 microM reduces GTP-induced ZG-PM fusion by 25-50%. Anti-cPLA2 antibody reduces ZG-PM fusion in a dose-dependent manner and a 50% reduction of the fusion takes place in the range of 0.48-0.64 ratios of cPLA2 antibody to ZG proteins. PLAP, a cPLA2 activator synthetic peptide increases ZG-PM fusion in a limited dose-dependent manner and tends to inhibit at higher concentrations. Exogenous arachidonic acid inhibits GTP-induced ZG-PM fusion in a dose-dependent manner. Furthermore, a non-hydrolysable GTP analogue, Gpp(NH)p, reduces PLAP effect in ZG-PM fusion; and the net effect of Gpp(NH)p and PLAP differs significantly from the net effect of GTP and PLAP on ZG-PM fusion suggesting that cPLA2 is involved in G-protein-mediated secretory vesicle fusion.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-924X
pubmed:author
pubmed:issnType
Print
pubmed:volume
141
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
77-84
pubmed:dateRevised
2007-12-19
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Cytosolic PLA2 in zymogen granule fusion and amylase release: inhibition of GTP-induced fusion by arachidonyl trifluoromethyl ketone points to cPLA2 in G-protein-mediated secretory vesicle fusion.
pubmed:affiliation
Division of Endocrinology, Department of Internal Medicine, Wayne State University School of Medicine, 421 East Canfield Avenue, Detroit, Michigan 48201, USA. asattar@med.wayne.edu
pubmed:publicationType
Journal Article