| First Author | Lazaro JB | Year | 2002 |
| Journal | Genes Dev | Volume | 16 |
| Issue | 14 | Pages | 1792-805 |
| PubMed ID | 12130539 | Mgi Jnum | J:77997 |
| Mgi Id | MGI:2183076 | Doi | 10.1101/gad.U-9988R |
| Citation | Lazaro JB, et al. (2002) Cyclin D-cdk4 activity modulates the subnuclear localization and interaction of MEF2 with SRC-family coactivators during skeletal muscle differentiation. Genes Dev 16(14):1792-805 |
| abstractText | Prior work has indicated that D-type cyclin-cdk4 complexes, which are only active in proliferating cells, can suppress the skeletal muscle differentiation program in proliferating myoblasts. In this study, we show that cyclin D-cdk activity can block the activity of the MEF2 family of transcriptional regulators, which are crucial regulators of skeletal muscle gene expression. We have found that cyclin D-cdk activity blocks the association of MEF2C with the coactivator protein GRIP-1 and thereby inhibits the activity of MEF2. During skeletal muscle differentiation, GRIP-1 is localized to punctate nuclear structures and can apparently tether MEF2 to such structures. Cotransfection of GRIP-1 can both potentiate the transcriptional activity of a Gal4-MEF2C construct and induce MEF2C localization to punctate nuclear structures. Consistent with the absence of punctate nuclear GRIP-1 in proliferating myoblasts, we have found that ectopic cyclin D-cdk4 expression disrupts the localization of both GRIP-1 and MEF2C to these punctate subnuclear structures. Our findings indicate that cyclin D-cdk4 activity represses skeletal muscle differentiation in proliferating cells by blocking the association of MEF2 with the coactivator GRIP-1 and concomitantly disrupts the association of these factors with punctate nuclear subdomains within the cell. |
