Different roles of the IGF-I Ec peptide (MGF) and mature IGF-I in myoblast proliferation and differentiation.
The physiological function of a recently cloned splice variant of insulin-like growth factor-I (IGF-I; mechano growth factor (MGF)) was studied using an in vitro cell model. Unlike mature IGF-I, the distinct E domain of MGF inhibits terminal differentiation whilst increasing myoblast proliferation. Blocking the IGF-I receptor with a specific antibody indicated that the function of MGF E domain is mediated via a different receptor. The results provide a basis for localized tissue adaptation and helps explain why loss of muscle mass occurs in the elderly and in dystrophic muscle in which MGF production is markedly affected.
Yang
Shi Yu
SY
Molecular Tissue Repair Unit, Department of Surgery, Royal Free and University College Medical School, University College London, Rowland Hill Street, UK.
Goldspink
Geoffrey
G
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D002454:Cell Differentiation; D002455:Cell Division; D002460:Cell Line; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D051379:Mice; D008969:Molecular Sequence Data; D018482:Muscle, Skeletal / Q000166:cytology*; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D017526:Receptor, IGF Type 1 / Q000378:metabolism
D020033:Protein Isoforms; D007334:Insulin-Like Growth Factor I; D017526:Receptor, IGF Type 1