Linked Life Data

17709608

Source:http://linkedlifedata.com/resource/pubmed/id/17709608

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2008-1-1
pubmed:abstractText
Synaptotagmins (SYT) are calcium-binding proteins that participate in regulated exocytosis. Although SYTI to IX isoforms are expressed in insulin-producing cell lines, hitherto only SYTIX has been associated with native beta-cell insulin granules and implicated in exocytosis. SYTVII was also proposed to regulate insulin exocytosis, but its subcellular location and number of alternative splice variants produced remain controversial. Only transcripts of SYTVII alpha, beta, and a novel splice variant delta are expressed in beta-cells and INS-1E cells. Western blotting revealed that INS-1E cells predominantly produced SYTVII alpha and low levels of SYTVII beta, whereas SYTVII delta was undetectable. The protein colocalized with insulin granules but not with synaptic-like microvesicles. Overexpression of SYTVII alpha resulted in decreased insulin granule content with a concomitant translocation of the variant to the plasma membrane, while SYTVII beta retained largely a granular pattern. Overexpressed SYTVII delta exhibited a distribution different to that of insulin granules and inhibited exocytosis when assessed by whole cell patch clamp capacitance recording. Silencing of SYTVII alpha by targeted RNA interference suppressed secretion, while repression of beta slightly increased release. Our results demonstrate that SYTVII is expressed on insulin granules and that only SYTVII alpha is implicated in exocytosis under physiological conditions.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
1530-6860
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
22
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
194-206
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Synaptotagmin VII splice variants alpha, beta, and delta are expressed in pancreatic beta-cells and regulate insulin exocytosis.
pubmed:affiliation
Department of Cell Physiology and Metabolism, University Medical Center, 1211 Geneva 4, Switzerland. benoit.gauthier@medecine.unige.ch
pubmed:publicationType
Journal Article