Abnormal actomyosin assembly in proliferating and differentiating myoblasts upon expression of a cytosolic DMPK isoform

作者：Mulders Susan A M; van Horssen Remco; Gerrits Lieke; Bennink Miranda B; Pluk Helma; de Boer van Huizen Roelie T; Croes Huib J E; Wijers Mietske; van de Loo Fons A J; Fransen Jack; Wieringa Be; Wansink Derick G^*

来源：Biochimica et Biophysica Acta-Molecular Cell Research, 2011, 1813(5): 867-877.

DOI：10.1016/j.bbamcr.2011.01.024

• Stress fiber
• ROCK
• Rho kinase
• Myotonic dystrophy protein kinase
• Actomyosin cytoskeleton
• Myogenesis
• Alternative splicing

DMPK, the product of the mutated gene in myotonic dystrophy type 1, belongs to the subfamily of Rho-associated serine-threonine protein kinases, whose members play a role in actin-based cell morphodynamics. Not much is known about the physiological role of differentially localized individual DMPK splice isoforms. We report here that prominent stellar-shaped stress fibers are formed during early and late steps of differentiation in DMPK-deficient myoblast-myotubes upon complementation with the short cytosolic DMPK E isoform. Expression of DMPK E led to an increased phosphorylation status of MLC2. We found no such effects with vectors that encode a mutant DMPK E which was rendered enzymatically inactive or any of the long C-terminally anchored DMPK isoforms. Presence of stellar structures appears associated with changes in cell shape and motility and a delay in myogenesis. Our data strongly suggest that cytosolic DMPK participates in remodeling of the actomyosin cytoskeleton in developing skeletal muscle cells.

• 出版日期2011-5