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Journal of Biomedicine and Biotechnology
Volume 2011 (2011), Article ID 103069, 16 pages
http://dx.doi.org/10.1155/2011/103069
Review Article

Tropomodulin Capping of Actin Filaments in Striated Muscle Development and Physiology

Department of Cell Biology, The Scripps Research Institute, La Jolla, CA 92037, USA

Received 30 June 2011; Accepted 18 August 2011

Academic Editor: Aikaterini Kontrogianni-Konstantopoulos

Copyright © 2011 David S. Gokhin and Velia M. Fowler. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

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.