First Author | Hanft LM | Year | 2006 |
Journal | Proc Natl Acad Sci U S A | Volume | 103 |
Issue | 14 | Pages | 5385-90 |
PubMed ID | 16565216 | Mgi Jnum | J:108299 |
Mgi Id | MGI:3623662 | Doi | 10.1073/pnas.0600980103 |
Citation | Hanft LM, et al. (2006) Cytoplasmic gamma-actin contributes to a compensatory remodeling response in dystrophin-deficient muscle. Proc Natl Acad Sci U S A 103(14):5385-90 |
abstractText | Dystrophin mechanically links the costameric cytoskeleton and sarcolemma, yet dystrophin-deficient muscle exhibits abnormalities in cell signaling, gene expression, and contractile function that are not clearly understood. We generated new antibodies specific for cytoplasmic gamma-actin and confirmed that gamma-actin most predominantly localized to the sarcolemma and in a faint reticular lattice within normal muscle cells. However, we observed that gamma-actin levels were increased 10-fold at the sarcolemma and within the cytoplasm of striated muscle cells from dystrophin-deficient mdx mice. Transgenic overexpression of the dystrophin homologue utrophin, or functional dystrophin constructs in mdx muscle, restored gamma-actin to normal levels, whereas gamma-actin remained elevated in mdx muscle expressing nonfunctional dystrophin constructs. We conclude that increased cytoplasmic gamma-actin in dystrophin-deficient muscle may be a compensatory response to fortify the weakened costameric lattice through recruitment of parallel mechanical linkages. However, the presence of excessive myoplasmic gamma-actin may also contribute to altered cell signaling or gene expression in dystrophin-deficient muscle. |