MuRF1 is a muscle fiber-type II associated factor and together with MuRF2 regulates type-II fiber trophicity and maintenance

Autor(es)

Moriscot, Anselmo S. ; Baptista, Igor L. ; Bogomolovas, Julius ; Witt, Christian ; Hirner, Stephanie ; Granzier, Henk ; Labeit, Siegfried

• Tipo de documento: Artigo Científico
• Fonte: Journal of Structural Biology; v. 170, n. 2, p. 10-pg., 2010-05-01.

Resumo

MuRF1 is a member of the RBCC (RING, B-box, coiled-coil) superfamily that has been proposed to act as an atrogin during muscle wasting. Here, we show that MuRF1 is preferentially induced in type-II muscle fibers after denervation. Fourteen days after denervation, MuRF1 protein was further elevated but remained preferentially expressed in type-II muscle fibers. Consistent with a fiber-type dependent function of MuRF1, the tibialis anterior muscle (rich in type-II muscle fibers) was considerably more protected in MuRF1-KO mice from muscle wasting when compared to soleus muscle with mixed fiber-types. We also determined fiber-type distributions in MuRF1/MuRF2 double-deficient KO (dKO) mice, because MuRF2 is a close homolog of MuRF1. MuRF1/MuRF2 dKO mice showed a profound loss of type-II fibers in soleus muscle. As a potential mechanism we identified the interaction of MuRF1/MuRF2 with myozenin-1, a calcineurin/NFAT regulator and a factor required for maintenance of type-II muscle fibers. MuRF1/MuRF2 dKO mice had lost myozenin-1 expression in tibialis anterior muscle, implicating MuRF1/MuRF2 as regulators of the calcineurin/NFAT pathway. In summary, our data suggest that expression of MuRF1 is required for remodeling of type-II fibers under pathophysiological stress states, whereas MuRF1 and MuRF2 together are required for maintenance of type-II fibers, possibly via the regulation of myozenin-1. (C) 2010 Elsevier Inc. All rights reserved. (AU)

• Processo FAPESP: 07/57613-3 - Efeitos celulares e moleculares da sobrecarga de leucina na atrofia muscular induzida pelo desuso
• Beneficiário: Igor Luchini Baptista
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto
• Processo FAPESP: 06/61523-7 - Aspectos celulares e moleculares da plasticidade muscular
• Beneficiário: Anselmo Sigari Moriscot
• Modalidade de apoio: Auxílio à Pesquisa - Temático