Tropomodulin capping of actin filaments in striated muscle development and physiology.
Efficient striated muscle contraction requires precise assembly and regulation of diverse actin filament systems, most notably the sarcomeric thin filaments of the contractile apparatus. By capping the pointed ends of actin filaments, tropomodulins (Tmods) regulate actin filament assembly, lengths, and stability. Here, we explore the current understanding of the expression patterns, localizations, and functions of Tmods in both cardiac and skeletal muscle. We first describe the mechanisms by which Tmods regulate myofibril assembly and thin filament lengths, as well as the roles of closely related Tmod family variants, the leiomodins (Lmods), in these processes. We also discuss emerging functions for Tmods in the sarcoplasmic reticulum. This paper provides abundant evidence that Tmods are key structural regulators of striated muscle cytoarchitecture and physiology.
Department of Cell Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
David S
DS
Gokhin
Velia M
VM
Fowler
D008841:Actin Cytoskeleton / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D006801:Humans; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism*; D024510:Muscle Development / Q000235:genetics / Q000502:physiology*; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000378:metabolism / Q000502:physiology; D054792:Muscle, Striated / Q000378:metabolism / Q000502:physiology; D009206:Myocardium / Q000378:metabolism; D017434:Protein Structure, Tertiary / Q000235:genetics; D012518:Sarcomeres / Q000378:metabolism* / Q000648:ultrastructure; D051348:Tropomodulin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
C528309:LMOD2 protein, human; D008840:Microfilament Proteins; D009124:Muscle Proteins; D051348:Tropomodulin