Submitted to: Federation of American Societies for Experimental Biology Conference
Publication Type: Abstract Only
Publication Acceptance Date: 3/1/2004
Publication Date: 4/1/2004
Citation: Fiorotto, M.L., Davis, T.A., Rosenberger, J., DeBurin, C., Donovan, M. 2002. Muscle-specific overexpression of Id-1 impairs the developmental accretion of myofibrillar proteins [abstract]. Federation of American Societies for Experimental Biology Journal, Part II. 16(5):A773. Interpretive Summary: Not Necessary for an Abstract
Technical Abstract: The onset of myofibrillar protein accretion in myotubes requires the activation of muscle-specific gene expression by bHLH muscle-specific transcription factors (MRFs). We wished to determine if variations in the relative abundance of MRFs influences the composition of proteins expressed during skeletal muscle maturation. The composition and in vivo synthesis rates of myofibrilar (MP) and sarcoplasmic (SP) proteins in fast-twitch hindlimb muscles are measured at 10, 20, and 35 d of age (n=5-7/genotype/age) in nontransgenic mice (wt) and transgenic littermates (tg) that overexpressed in skeletal muscle, Id-I, an inhibitor of MRF activity. Total protein accretion from 10 to 20 d of age was 40% lower in tg than wt mice; MP accretion rate in tg mice was decreased more (-48%) than for SP (-34%). From 20 to 35 d of age, the accretion rates of MP and SP in tg mice were both reduced by 40%. In tg mice, MP synthesis rates were decreased more (-43%) than those of SP (-32%) for both periods. Thus, transcriptional regulation of muscle-specific gene expression can influence both the composition and accretion rates of skeletal muscle proteins during the early postnatal period.