RSK2 mediates muscle cell differentiation through regulation of NFAT3.
Article Details
- CitationCopy to clipboard
Cho YY, Yao K, Bode AM, Bergen HR 3rd, Madden BJ, Oh SM, Ermakova S, Kang BS, Choi HS, Shim JH, Dong Z
RSK2 mediates muscle cell differentiation through regulation of NFAT3.
J Biol Chem. 2007 Mar 16;282(11):8380-92. Epub 2007 Jan 9.
- PubMed ID
- 17213202 [ View in PubMed]
- Abstract
RSK2, an ERK downstream kinase, is a novel mediator of skeletal muscle cell differentiation through its regulation of NFAT3 activity. We found that the N-terminal (amino acids (aa) 1-68) and C-terminal (aa 416-674) kinase domains of RSK2 directly interacted with nuclear localization signal 1, the Ser/Pro repeat, and the polyproline domains (aa 261-365) of NFAT3. Upon A23187 stimulation, RSK2 induced nuclear localization of NFAT3. RSK2 phosphorylated NFAT3 in vitro (Km=3.559 microM), and activation of NFAT3 by RSK2 enhanced the promoter activity of NFAT3 downstream target genes in vivo. Furthermore, nuclear accumulation of NFAT3 was attenuated markedly in RSK2-/- cells compared with wild-type RSK2+/+ cells. Notably, RSK2 and NFAT3 induced a significant differentiation of C2C12 myoblasts to multinucleated myotubes. Multinucleated myotube differentiation was inhibited by small interfering RNA against RSK2, ERK1/2, or NFAT3. These results demonstrate that RSK2 is an important kinase for NFAT3 in mediating myotube differentiation.