Title |
The multiple roles of titin in muscle contraction and force production
|
---|---|
Published in |
Biophysical Reviews, January 2018
|
DOI | 10.1007/s12551-017-0395-y |
Pubmed ID | |
Authors |
Walter Herzog |
Abstract |
Titin is a filamentous protein spanning the half-sarcomere, with spring-like properties in the I-band region. Various structural, signaling, and mechanical functions have been associated with titin, but not all of these are fully elucidated and accepted in the scientific community. Here, I discuss the primary mechanical functions of titin, including its accepted role in passive force production, stabilization of half-sarcomeres and sarcomeres, and its controversial contribution to residual force enhancement, passive force enhancement, energetics, and work production in shortening muscle. Finally, I provide evidence that titin is a molecular spring whose stiffness changes with muscle activation and actin-myosin-based force production, suggesting a novel model of force production that, aside from actin and myosin, includes titin as a "third contractile" filament. Using this three-filament model of sarcomeres, the stability of (half-) sarcomeres, passive force enhancement, residual force enhancement, and the decrease in metabolic energy during and following eccentric contractions can be explained readily. |
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Other | 3 | 6% |
Unknown | 16 | 34% |
Demographic breakdown
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Scientists | 17 | 36% |
Unknown | 1 | 2% |
Mendeley readers
Geographical breakdown
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Student > Master | 32 | 15% |
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Researcher | 19 | 9% |
Professor | 12 | 6% |
Other | 35 | 16% |
Unknown | 55 | 25% |
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Agricultural and Biological Sciences | 14 | 6% |
Engineering | 14 | 6% |
Other | 24 | 11% |
Unknown | 68 | 31% |