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A two-segment model for thin filament architecture in skeletal muscle

Nature Reviews Molecular Cell Biology volume 14, pages 113–119 (2013)Cite this article

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Abstract

Correct specification of myofilament length is essential for efficient skeletal muscle contraction. The length of thin actin filaments can be explained by a novel 'two-segment' model, wherein the thin filaments consist of two concatenated segments, which are of either constant or variable length. This is in contrast to the classic 'nebulin ruler' model, which postulates that thin filaments are uniform structures, the lengths of which are dictated by nebulin. The two-segment model implicates position-specific microregulation of actin dynamics as a general principle underlying actin filament length and stability.

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Figure 1: The nebulin ruler model for thin filament length regulation in skeletal muscle.
Figure 2: A novel two-segment model for thin filament architecture in skeletal muscle.

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Acknowledgements

Work in the authors laboratory was supported by the US National Institutes of Health (NIH) grants R01-HL083464 and P30-AR061303 (to V.M.F.) and a development grant from the Muscular Dystrophy Association (to D.S.G.).

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  1. David S. Gokhin and Velia M. Fowler are at the Department of Cell Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, CB163, La Jolla, California 92037, USA.,

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Gokhin, D., Fowler, V. A two-segment model for thin filament architecture in skeletal muscle. Nat Rev Mol Cell Biol 14, 113–119 (2013). https://doi.org/10.1038/nrm3510

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