The RNA helicases p68/p72 and the noncoding RNA SRA are coregulators of MyoD and skeletal muscle differentiation.
MyoD regulates skeletal myogenesis. Since proteins associated with MyoD exert regulatory functions, their identification is expected to contribute important insights into the mechanisms governing gene expression in skeletal muscle. We have found that the RNA helicases p68/p72 are MyoD-associated proteins and that the noncoding RNA SRA also immunoprecipitates with MyoD. In vitro and in vivo experiments indicated that both p68/p72 and SRA are coactivators of MyoD. RNA interference toward either p68/p72 or SRA prevented proper activation of muscle gene expression and cell differentiation. Unexpectedly, reducing the levels of p68/p72 proteins impaired recruitment of the TATA binding protein TBP; RNA polymerase II; and the catalytic subunit of the ATPase SWI/SNF complex, Brg-1, and hindered chromatin remodeling. These findings reveal that p68/p72 play a critical role in promoting the assembly of proteins required for the formation of the transcription initiation complex and chromatin remodeling.
Caretti
Giuseppina
G
Muscle Gene Expression Group, Laboratory of Muscle Biology, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland 20829, USA.
Schiltz
R Louis
RL
Dilworth
F Jeffrey
FJ
Di Padova
Monica
M
Zhao
Po
P
Ogryzko
Vasily
V
Fuller-Pace
Frances V
FV
Hoffman
Eric P
EP
Tapscott
Stephen J
SJ
Sartorelli
Vittorio
V
D000595:Amino Acid Sequence; D002454:Cell Differentiation / Q000502:physiology*; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D018482:Muscle, Skeletal / Q000166:cytology / Q000502:physiology*; D017570:MyoD Protein / Q000235:genetics / Q000378:metabolism*; D020365:RNA Helicases / Q000737:chemistry / Q000378:metabolism*; D022661:RNA, Untranslated / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid
D017570:MyoD Protein; D022661:RNA, Untranslated; D020365:RNA Helicases