Skip to Main content Skip to Navigation
Journal articles

Retrograde regulation of store-operated calcium channels by the ryanodine receptor-associated protein triadin 95 in rat skeletal myotubes.

Abstract : The 95kDa triadin (or T95), the main skeletal muscle triadin isoform, negatively regulates the mechanism of excitation-contraction coupling. T95 is a ryanodine receptor (RyR)-interacting protein but it also possesses a calsequestrin-interacting domain. RyR and calsequestrin are involved in Ca2+ signalling and, for instance, influence the activity of store-dependent Ca2+ channels (SOC). This work was undertaken to determine whether T95 was able to modulate the entry of Ca2+ through SOC. The experiments were carried out on differentiated rat myotubes over-expressing T95 or DsRed (control cells) by means of an adenovirus infection. Intracellular Ca2+ signals were analyzed using the Ca2+ indicator Fluo-4. The sarco-endoplasmic reticulum Ca2+-ATPase inhibitor thapsigargin was used to deplete intracellular Ca2+ stores. When applied in the presence of a Ca2+-free medium, thapsigargin elicited transient but long-lasting Fluo-4 responses by elevating the cytoplasmic concentration of Ca2+ ([Ca2+]i). The over-expression of T95 reduced the thapsigargin-dependent [Ca2+]i increase, with respect to control myotubes. Addition of extracellular Ca2+after the depletion of this Ca2+ pool was accompanied by a [Ca2+]i increase that was sensitive to the SOC blockers 2-APB, SKF-96365 and La3+. The over-expression of T95 reduced this Ca2+ influx, without changing its pharmacological properties, showing that T95 over-expression did not alter the properties of the SOC. In conclusion, the RyR-interacting molecule T95, recently shown to inhibit the excitation-contraction coupling, has also the ability to interfere with the skeletal muscle Ca2+ signalling by depressing thapsigargin-dependent Ca2+ release and influx.
Document type :
Journal articles
Complete list of metadatas

Cited literature [24 references]  Display  Hide  Download

https://www.hal.inserm.fr/inserm-00380044
Contributor : Nathalie Roux-Buisson <>
Submitted on : Wednesday, July 13, 2011 - 3:26:14 PM
Last modification on : Saturday, May 30, 2020 - 12:28:04 AM
Long-term archiving on: : Friday, December 2, 2016 - 2:55:37 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

CNRS | CEA | U836 | UGA

Citation

Stéphane Vassilopoulos, Julie Brocard, Luis Garcia, Isabelle Marty, Alexandre Bouron. Retrograde regulation of store-operated calcium channels by the ryanodine receptor-associated protein triadin 95 in rat skeletal myotubes.. Cell Calcium, Elsevier, 2007, 41 (2), pp.179-85. ⟨10.1016/j.ceca.2006.06.003⟩. ⟨inserm-00380044⟩

Share

Metrics

Record views

188