Store-operated Ca2+ Entry Mediated by Orai1 and TRPC1 Participates to Insulin Secretion in Rat β-Cells.

Details

Serval ID
serval:BIB_83FCF995331B
Type
Article: article from journal or magazin.
Collection
Publications
Title
Store-operated Ca2+ Entry Mediated by Orai1 and TRPC1 Participates to Insulin Secretion in Rat β-Cells.
Journal
Journal of Biological Chemistry
Author(s)
Sabourin J., Le Gal L., Saurwein L., Haefliger J.A., Raddatz E., Allagnat F.
ISSN
1083-351X (Electronic)
ISSN-L
0021-9258
Publication state
Published
Issued date
2015
Peer-reviewed
Oui
Volume
290
Number
51
Pages
30530-30539
Language
english
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't
Publication Status: ppublish
Abstract
Store-operated Ca(2+) channels (SOCs) are voltage-independent Ca(2+) channels activated upon depletion of the endoplasmic reticulum Ca(2+) stores. Early studies suggest the contribution of such channels to Ca(2+) homeostasis in insulin-secreting pancreatic β-cells. However, their composition and contribution to glucose-stimulated insulin secretion (GSIS) remains unclear. In this study, endoplasmic reticulum Ca(2+) depletion triggered by acetylcholine (ACh) or thapsigargin stimulated the formation of a ternary complex composed of Orai1, TRPC1, and STIM1, the key proteins involved in the formation of SOCs. Ca(2+) imaging further revealed that Orai1 and TRPC1 are required to form functional SOCs and that these channels are activated by STIM1 in response to thapsigargin or ACh. Pharmacological SOCs inhibition or dominant negative blockade of Orai1 or TRPC1 using the specific pore mutants Orai1-E106D and TRPC1-F562A impaired GSIS in rat β-cells and fully blocked the potentiating effect of ACh on secretion. In contrast, pharmacological or dominant negative blockade of TRPC3 had no effect on extracellular Ca(2+) entry and GSIS. Finally, we observed that prolonged exposure to supraphysiological glucose concentration impaired SOCs function without altering the expression levels of STIM1, Orai1, and TRPC1. We conclude that Orai1 and TRPC1, which form SOCs regulated by STIM1, play a key role in the effect of ACh on GSIS, a process that may be impaired in type 2 diabetes.
Keywords
Acetylcholine/pharmacology, Amino Acid Substitution, Animals, Calcium/metabolism, Calcium Channels/genetics, Calcium Channels/metabolism, Calcium Signaling, Cell Line, Tumor, Insulin/genetics, Insulin/secretion, Insulin-Secreting Cells/pathology, Insulin-Secreting Cells/secretion, Membrane Glycoproteins/genetics, Membrane Glycoproteins/metabolism, Mutation, Missense, Rats, TRPC Cation Channels/genetics, TRPC Cation Channels/metabolism, Thapsigargin/pharmacology
Pubmed
Web of science
Open Access
Yes
Create date
11/01/2016 18:23
Last modification date
20/08/2019 15:43
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