Gokhin David S, Fowler Velia M
Department of Cell Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
J Biomed Biotechnol. 2011;2011:103069. doi: 10.1155/2011/103069. Epub 2011 Oct 17.
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.
高效的横纹肌收缩需要精确组装和调节多种肌动蛋白丝系统，最显著的是收缩装置的肌节细肌丝。通过封闭肌动蛋白丝的尖端，原肌球蛋白（Tmods）调节肌动蛋白丝的组装、长度和稳定性。在这里，我们探讨了目前对Tmods在心肌和骨骼肌中的表达模式、定位和功能的理解。我们首先描述Tmods调节肌原纤维组装和细肌丝长度的机制，以及密切相关的Tmod家族变体，即平滑肌肌动蛋白结合蛋白（Lmods），在这些过程中的作用。我们还讨论了Tmods在肌浆网中的新功能。本文提供了大量证据表明Tmods是横纹肌细胞结构和生理学的关键结构调节因子。
