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Updated: Jul 1, 2025

Isolation of Human Myoblasts, Assessment of Myogenic Differentiation, and Store-operated Calcium Entry Measurement
Published on: July 26, 2017
Lmod2 is necessary for effective skeletal muscle contraction
Tania M Larrinaga1, Gerrie P Farman1, Rachel M Mayfield1
1Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, AZ 85724, USA.
Abstract:
Muscle contraction is a regulated process driven by the sliding of actin-thin filaments over myosin-thick filaments. Lmod2 is an actin filament length regulator and essential for life since human mutations and complete loss of Lmod2 in mice lead to dilated cardiomyopathy and death. To study the little-known role of Lmod2 in skeletal muscle, we created a mouse model with Lmod2 expressed exclusively in the heart but absent in skeletal muscle. Loss of Lmod2 in skeletal muscle results in decreased force production in fast- and slow-twitch muscles. Soleus muscle from rescued Lmod2 knockout mice have shorter thin filaments, increased Lmod3 levels, and present with a myosin fiber type switch from fast myosin heavy chain (MHC) IIA to the slower MHC I isoform. Since Lmod2 regulates thin-filament length in slow-twitch but not fast-twitch skeletal muscle and force deficits were observed in both muscle types, this work demonstrates that Lmod2 regulates skeletal muscle contraction, independent of its role in thin-filament length regulation.
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