Identification of phosphatidylinositol 3,4,5-trisphosphate in pancreatic islets and insulin-secreting beta-cells.
Publication/Presentation Date
3-8-1995
Abstract
The signal transduction mechanisms involved in insulin secretion by the beta-cell are poorly understood. Glucose, the main physiological secretagogue, needs to be metabolized, but the identity of the intracellular messengers which couple glucose metabolism and insulin exocytosis is controversial. We now report the identification of phosphatidylinositol 3,4,5-triphosphate (PtdIns(3,4,5)P3), the end-product of phosphatidylinositol 3-kinase phosphorylation of polyphosphoinositides, in islets and in an insulin-secreting clonal beta-cell line, RINm5F, using a combination of thin layer chromatography and high performance liquid chromatography analyses and by demonstrating that sequential deacylation and deglyceration of PtdIns(3,4,5)P3 yields inositol 1,3,4,5-tetrakisphosphate. Unlike other cell types, significant levels of PtdIns(3,4,5)P3 were detected in beta-cells under non-stimulatory conditions. Insulin secretagogues (28 mM glucose + 0.5 mM carbachol) caused a rapid and transient increase in PtdIns(3,4,5)P3 levels which peaked at 2-5 min, corresponding to peak early phase insulin release.
Volume
208
Issue
1
First Page
190
Last Page
197
ISSN
0006-291X
Published In/Presented At
Alter, C. A., & Wolf, B. A. (1995). Identification of phosphatidylinositol 3,4,5-trisphosphate in pancreatic islets and insulin-secreting beta-cells. Biochemical and biophysical research communications, 208(1), 190–197. https://doi.org/10.1006/bbrc.1995.1322
Disciplines
Medicine and Health Sciences | Pediatrics
PubMedID
7887929
Department(s)
Department of Pediatrics
Document Type
Article