Skip to Main content Skip to Navigation
Journal articles

Trisk 32 regulates IP(3) receptors in rat skeletal myoblasts.

Abstract : To date, four isoforms of triadins have been identified in rat skeletal muscle. While the function of the 95-kDa isoform in excitation-contraction coupling has been studied in detail, the role of the 32-kDa isoform (Trisk 32) remains elusive. Here, Trisk 32 overexpression was carried out by stable transfection in L6.G8 myoblasts. Co-localization of Trisk 32 and IP(3) receptors (IP(3)R) was demonstrated by immunocytochemistry, and their association was shown by co-immunoprecipitation. Functional effects of Trisk 32 on IP(3)-mediated Ca(2+) release were assessed by measuring changes in [Ca(2+)](i) following the stimulation by bradykinin or vasopressin. The amplitude of the Ca(2+) transients evoked by 20 μM bradykinin was significantly higher in Trisk 32-overexpressing (p < 0.01; 426 ± 84 nM, n = 27) as compared to control cells (76 ± 12 nM, n = 23). The difference remained significant (p < 0.02; 217 ± 41 nM, n = 21, and 97 ± 29 nM, n = 31, respectively) in the absence of extracellular Ca(2+). Similar observations were made when 0.1 μM vasopressin was used to initiate Ca(2+) release. Possible involvement of the ryanodine receptors (RyR) in these processes was excluded, after functional and biochemical experiments. Furthermore, Trisk 32 overexpression had no effect on store-operated Ca(2+) entry, despite a decrease in the expression of STIM1. These results suggest that neither the increased activity of RyR, nor the amplification of SOCE, is responsible for the differences observed in bradykinin- or vasopressin-evoked Ca(2+) transients; rather, they were due to the enhanced activity of IP(3)R. Thus, Trisk 32 not only co-localizes with, but directly contributes to, the regulation of Ca(2+) release via IP(3)R.
Document type :
Journal articles
Complete list of metadatas

Cited literature [35 references]  Display  Hide  Download

https://www.hal.inserm.fr/inserm-00763318
Contributor : Nathalie Roux-Buisson <>
Submitted on : Monday, December 10, 2012 - 3:09:32 PM
Last modification on : Friday, November 6, 2020 - 3:52:07 AM
Long-term archiving on: : Saturday, December 17, 2016 - 11:31:23 PM

File

 Restricted access
To satisfy the distribution rights of the publisher, the document is embargoed until : jamais

Please log in to resquest access to the document

Identifiers

Collections

U836 | UGA

Citation

Tamás Oláh, János Fodor, Sarah Oddoux, Olga Ruzsnavszky, Isabelle Marty, et al.. Trisk 32 regulates IP(3) receptors in rat skeletal myoblasts.. Pflügers Archiv European Journal of Physiology, Springer Verlag, 2011, 462 (4), pp.599-610. ⟨10.1007/s00424-011-1001-y⟩. ⟨inserm-00763318⟩

Share

Metrics

Record views

177