RRC ID 35688
Author Shibukawa Y, Yamazaki N, Daimon E, Wada Y.
Title Rock-dependent calponin 3 phosphorylation regulates myoblast fusion.
Journal Exp. Cell Res.
Abstract Myogenesis occurs during embryonic development as well as regeneration following postnatal muscle fiber damage. Herein, we show that acidic calponin or calponin 3 (CNN3) regulates both myoblast cell fusion and muscle-specific gene expressions. Overexpression of CNN3 impaired C2C12 cell fusion, whereas CNN3 gene knockdown promoted skeletal myosin expression and fusion. CNN3 was phosphorylated at Ser293/296 in the C-terminal region. The basal inhibitory property of CNN3 against myoblast differentiation was enhanced by Ser293/296Ala mutation or deletion of the C-terminal region, and this inhibition was reversed by Ser293/296Asp mutation. Ser293/296 phosphorylation was required for CNN3 to bind actin and was dependent on Rho-associated kinases 1/2 (ROCK 1/2). Gene knockdown of ROCK1/2 suppressed CNN3 phosphorylation and impaired myoblast fusion, and these effects were partially attenuated by additional CNN3 overexpression of Ser293/296Asp CNN3. These findings indicated that CNN3 phosphorylation by ROCK blunts CNN3's inhibitory effects on muscle cell differentiation and fusion. In muscle tissues, satellite cells, but not mature myofibrils, expressed CNN3. CNN3 was also expressed and phosphorylated during myotube induction in isolated muscle satellite cells. Taken together, these results indicate that CNN3 is a downstream regulator of the ROCK signaling pathway for myogenesis.
Volume 319(5)
Pages 633-48
Published 2013-3-10
DOI 10.1016/j.yexcr.2012.12.022
PII S0014-4827(12)00499-5
PMID 23276748
MeSH Actins / metabolism Animals Blotting, Western Calcium-Binding Proteins / antagonists & inhibitors Calcium-Binding Proteins / genetics Calcium-Binding Proteins / metabolism* Cell Communication Cell Fusion Cytoskeleton / metabolism Electrophoresis, Gel, Two-Dimensional Immunoenzyme Techniques Mice Microfilament Proteins / antagonists & inhibitors Microfilament Proteins / genetics Microfilament Proteins / metabolism* Muscle Development / physiology* Myoblasts / cytology* Myoblasts / metabolism Phosphorylation RNA, Small Interfering / genetics rho-Associated Kinases / metabolism*
IF 3.329
Times Cited 8
DNA material pCAG-HIVgp (RDB04394) pCMV-VSV-G-RSV-Rev (RDB04393)