Abstract
In response to physiological stimuli, skeletal muscle alters its myofiber composition to significantly affect muscle performance and metabolism. This process requires concerted regulation of myofiber-specific isoforms of sarcomeric and calcium regulatory proteins that couple action potentials to the generation of contractile force. Here, we identify Sox6 as a fast myofiber-enriched repressor of slow muscle gene expression in vivo. Mice lacking Sox6 specifically in skeletal muscle have an increased number of slow myofibers, elevated mitochondrial activity, and exhibit down-regulation of the fast myofiber gene program, resulting in enhanced muscular endurance. In addition, microarray profiling of Sox6 knockout muscle revealed extensive muscle fiber-type remodeling, and identified numerous genes that display distinctive fiber-type enrichment. Sox6 directly represses the transcription of slow myofiber-enriched genes by binding to conserved cis-regulatory elements. These results identify Sox6 as a robust regulator of muscle contractile phenotype and metabolism, and elucidate a mechanism by which functionally related muscle fiber-type specific gene isoforms are collectively controlled.
Original language | English (US) |
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Pages (from-to) | 10196-10201 |
Number of pages | 6 |
Journal | Proceedings of the National Academy of Sciences of the United States of America |
Volume | 108 |
Issue number | 25 |
DOIs | |
State | Published - Jun 21 2011 |
Keywords
- Calcium handling
- Myosin heavy-chain isoforms
- Slow-twitch fiber
ASJC Scopus subject areas
- General