Transcriptional regulation of selenoprotein W by MyoD during early skeletal muscle differentiation.
Selenoprotein W (SelW) is expressed in various tissues, but it is especially high in the skeletal muscle of mammals. Such tissue-specific protein expression implies regulation by a tissue-specific factor. In this study, we investigated SelW expression during myogenic C2C12 cell differentiation using RT-PCR, quantitative PCR, and Western blot analysis. Both the protein and mRNA levels of SelW were increased during C2C12 cell differentiation, particularly during the early stage. Sequence analysis of the SelW promoter revealed four putative E-boxes, E1, E2, E3, and E4, which are known binding sites for MyoD, a myogenic transcriptional factor. Luciferase reporter assay showed that E1 and E4 were crucial for MyoD-dependent promoter activity. Using EMSA analysis, we observed that MyoD bound directly to E1 but not to E4, even though E4 mutation reduced SelW promoter activity in the luciferase reporter assay. Binding of MyoD to E1 was further investigated by ChIP assay. These results suggest that the SelW gene was activated by the binding of MyoD to a specific E-box during early skeletal muscle differentiation.
Noh
Ok Jeong
OJ
Laboratory of Cellular and Molecular Biochemistry, School of Life Sciences and Biotechnology, Korea University, Anam-dong, Seongbuk-gu, Seoul 136-701, Korea.
Park
Yong Hwan
YH
Chung
Youn Wook
YW
Kim
Ick Young
IY
D000818:Animals; D002454:Cell Differentiation / Q000502:physiology*; D002460:Cell Line; D051379:Mice; D024510:Muscle Development / Q000502:physiology*; D018482:Muscle, Skeletal / Q000166:cytology / Q000378:metabolism*; D009154:Mutation; D017570:MyoD Protein / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D020218:Response Elements / Q000502:physiology*; D051151:Selenoprotein W / Q000096:biosynthesis* / Q000235:genetics
D017570:MyoD Protein; C057363:MyoD1 myogenic differentiation protein; D051151:Selenoprotein W