Referenced in: none

Automatically associated channels: TRP , TRPC , TRPC3 , TRPC4

Title: Interaction between mitsugumin 29 and TRPC3 participates in regulating Ca(2+) transients in skeletal muscle.

Authors: Jin Seok Woo, Ji-Hye Hwang, Mei Huang, Mi Kyoung Ahn, Chung-Hyun Cho, Jianjie Ma, Eun Hui Lee

Journal, date & volume: Biochem. Biophys. Res. Commun., 2015 Aug 14 , 464, 133-9

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/26141232

Abstract
Mitsugumin 29 (MG29) is related to the fatigue and aging processes of skeletal muscle. To examine the roles of MG29 in conjunction with its binding protein, the canonical-type transient receptor potential cation channel 3 (TRPC3), in skeletal muscle, the binding region of MG29 to TRPC3 was studied along with the functional relevance of the binding in mouse primary skeletal myotubes using co-immunoprecipitation assays and Ca(2+) imaging experiments. The N-terminus and the I-II loop of MG29 constitute the binding region for TRPC3. The myotubes that expressed the MG29 mutant missing the entire TRPC3-binding region showed a disrupted binding between endogenous MG29 and TRPC3 and a reduction in Ca(2+) transients in response to membrane depolarization without affecting ryanodine receptor 1 activity, the resting cytosolic Ca(2+) level, and the amount of releasable Ca(2+) from the sarcoplasmic reticulum. Among the proteins mediating Ca(2+) movements in skeletal muscle, TRPC4 expression was significantly decreased by the MG29 mutant. Therefore, MG29 could be a new factor for regulating Ca(2+) transients during skeletal muscle contraction possibly via a correlation with TRPC3 and TRPC4.