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Agonist-activated Ca2+ influx occurs at stable plasma membrane and endoplasmic reticulum junctions

Treves, Susan and Vukcevic, Mirko and Griesser, Johanna and Franzini-Armstrong, Clara and Zhu, Michael X. and Zorzato, Francesco. (2010) Agonist-activated Ca2+ influx occurs at stable plasma membrane and endoplasmic reticulum junctions. Journal of Cell Science, 123. pp. 4170-4181.

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Official URL: http://edoc.unibas.ch/dok/A6174399

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Abstract

Junctate is a 33 kDa integral protein of sarco(endo)plasmic reticulum membranes that forms a macromolecular complex with inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] receptors and TRPC3 channels. TIRF microscopy shows that junctate enhances the number of fluorescent puncta on the plasma membrane. The size and distribution of these puncta are not affected by the addition of agonists that mobilize Ca2+ from Ins(1,4,5)P3-sensitive stores. Puncta are associated with a significantly larger number of peripheral junctions between endoplasmic reticulum and plasma membrane, which are further enhanced upon stable co-expression of junctate and TRPC3. The gap between the membranes of peripheral junctions is bridged by regularly spaced electron-dense structures of 10 nm. Ins(1,4,5)P3 inhibits the interaction of the cytoplasmic N-terminus of junctate with the ligand-binding domain of the Ins(1,4,5)P3 receptor. Furthermore, Ca2+ influx evoked by activation of Ins(1,4,5)P3 receptors is increased where puncta are located. We conclude that stable peripheral junctions between the plasma membrane and endoplasmic reticulum are the anatomical sites of agonist-activated Ca2+ entry.
Faculties and Departments:03 Faculty of Medicine > Departement Biomedizin
03 Faculty of Medicine > Departement Biomedizin > Department of Biomedicine, University Hospital Basel > Perioperative Patient Safety (Girard/Treves)
UniBasel Contributors:Treves, Susan and Zorzato, Francesco and Vukcevic, Mirko
Item Type:Article, refereed
Article Subtype:Research Article
Publisher:Company of Biologists
ISSN:0021-9533
e-ISSN:1477-9137
Note:Publication type according to Uni Basel Research Database: Journal article
Language:English
Identification Number:
Last Modified:05 Oct 2017 12:35
Deposited On:25 Oct 2013 08:33

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