title: Interaction between mitsugumin 29 and TRPC3 participates in regulating Ca(2+) transients in skeletal muscle.
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.
authors.affiliation: Department of Physiology, College of Medicine, The Catholic University of Korea, Banpo-daero 222, Seocho-gu, Seoul 137-701, Republic of Korea.
authors.forename: Jin Seok
authors.initials: JS
authors.lastname: Woo
authors.affiliation: Department of Physiology, College of Medicine, The Catholic University of Korea, Banpo-daero 222, Seocho-gu, Seoul 137-701, Republic of Korea.
authors.forename: Ji-Hye
authors.initials: JH
authors.lastname: Hwang
authors.affiliation: Department of Physiology, College of Medicine, The Catholic University of Korea, Banpo-daero 222, Seocho-gu, Seoul 137-701, Republic of Korea.
authors.forename: Mei
authors.initials: M
authors.lastname: Huang
authors.affiliation: Department of Physiology, College of Medicine, The Catholic University of Korea, Banpo-daero 222, Seocho-gu, Seoul 137-701, Republic of Korea.
authors.forename: Mi Kyoung
authors.initials: MK
authors.lastname: Ahn
authors.affiliation: Department of Pharmacology, College of Medicine, Seoul National University, Seoul 110-799, Republic of Korea.
authors.forename: Chung-Hyun
authors.initials: CH
authors.lastname: Cho
authors.affiliation: Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA.
authors.forename: Jianjie
authors.initials: J
authors.lastname: Ma
authors.affiliation: Department of Physiology, College of Medicine, The Catholic University of Korea, Banpo-daero 222, Seocho-gu, Seoul 137-701, Republic of Korea. Electronic address: ehui@catholic.ac.kr.
authors.forename: Eun Hui
authors.initials: EH
authors.lastname: Lee
mesh_terms: D000818:Animals; D001665:Binding Sites; D002118:Calcium / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D017136:Ion Transport; D051379:Mice; D057054:Molecular Imaging; D018485:Muscle Fibers, Skeletal / Q000166:cytology / Q000378:metabolism*; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D017433:Protein Structure, Secondary; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D019837:Ryanodine Receptor Calcium Release Channel / Q000235:genetics / Q000378:metabolism; D012519:Sarcoplasmic Reticulum / Q000378:metabolism*; D015398:Signal Transduction; D016708:Synaptophysin / Q000235:genetics / Q000378:metabolism*; D050052:TRPC Cation Channels / Q000235:genetics / Q000378:metabolism*
chemical_list: C111842:Mg29 protein, mouse; D009124:Muscle Proteins; D011993:Recombinant Fusion Proteins; D019837:Ryanodine Receptor Calcium Release Channel; D016708:Synaptophysin; D050052:TRPC Cation Channels; C104603:TRPC3 cation channel; C489571:TRPC4 ion channel; C000592747:ryanodine receptor 1, mouse; D002118:Calcium
keywords: Mitsugumin 29; Skeletal muscle; TRPC3; TRPC4