De‐phosphorylation of MyoD is linking nerve‐evoked activity to fast myosin heavy chain expression in rodent adult skeletal muscle
Open Access
- 11 October 2007
- journal article
- research article
- Published by Wiley in The Journal of Physiology
- Vol. 584 (2), 637-650
- https://doi.org/10.1113/jphysiol.2007.141457
Abstract
Elucidating the molecular pathways linking electrical activity to gene expression is necessary for understanding the effects of exercise on muscle. Fast muscles express higher levels of MyoD and lower levels of myogenin than slow muscles, and we have previously linked myogenin to expression of oxidative enzymes. We here report that in slow muscles, compared with fast, 6 times as much of the MyoD is in an inactive form phosphorylated at T115. In fast muscles, 10 h of slow electrical stimulation had no effect on the total MyoD protein level, but the fraction of phosphorylated MyoD was increased 4‐fold. Longer stimulation also decreased the total level of MyoD mRNA and protein, while the level of myogenin protein was increased. Fast patterned stimulation did not have any of these effects. Overexpression of wild type MyoD had variable effects in active slow muscles, but increased expression of fast myosin heavy chain in denervated muscles. In normally active soleus muscles, MyoD mutated at T115 (but not at S200) increased the number of fibres containing fast myosin from 50% to 85% in mice and from 13% to 62% in rats. These data establish de‐phosphorylated active MyoD as a link between the pattern of electrical activity and fast fibre type in adult muscles.Keywords
This publication has 73 references indexed in Scilit:
- PPARδ expression is influenced by muscle activity and induces slow muscle properties in adult rat muscles after somatic gene transferThe Journal of Physiology, 2007
- Denervation produces different single fiber phenotypes in fast- and slow-twitch hindlimb muscles of the ratAmerican Journal of Physiology-Cell Physiology, 2006
- Regulation of Muscle Fiber Type and Running Endurance by PPARδPLoS Biology, 2004
- Coexpression after electroporation of plasmid mixtures into muscle in vivoActa Physiologica Scandinavica, 2004
- Myogenin induces higher oxidative capacity in pre-existing mouse muscle fibres after somatic DNA transferThe Journal of Physiology, 2003
- Circadian TranscriptionPublished by Elsevier BV ,2002
- Transcriptional co-activator PGC-1α drives the formation of slow-twitch muscle fibresNature, 2002
- Different Pathways Regulate Expression of the Skeletal Myosin Heavy Chain GenesJournal of Biological Chemistry, 2001
- A gene with homology to myogenin is expressed in developing myotomal musculature of the rainbow trout and in vitro during the conversion of myosatellite cells to myotubesFEBS Letters, 1995
- Three myosin heavy chain isoforms in type 2 skeletal muscle fibresJournal of Muscle Research and Cell Motility, 1989