Over-expression of the transcription factor, ZBP-89, leads to enhancement of the C2C12 myogenic program.
Myogenesis involves the complex interplay between the down-regulation of non-muscle genes and the up-regulation of muscle-specific genes. This interplay is controlled by the myogenic regulatory factors Myf5, MRF4, MyoD and myogenin. To trigger the up-regulation of these muscle-specific factors, certain environmental cues, such as the removal of serum, signal C2C12 myoblast cells to withdraw from cell cycle, fuse and activate muscle-specific genes. Here, the level of ZBP-89 (zfp148), a Krüppel-like transcription factor, has been shown to increase during myogenesis. Over-expression of ZBP-89, via adenoviral infection, led to the enhancement of the myogenic program without requiring the removal of serum. Quantitative real-time PCR and ChIP assays documented that ZBP-89 promoted the down-regulation of Pax7 coupled with the up-regulation of MRF4 and MyoD to regulate C2C12 differentiation in vitro. In addition, ZBP-89 over-expression up-regulated p21 and Rb while promoting the down-regulation of cyclinA and cyclinD1. In converse, the diminution of ZBP-89 by siRNA promoted the retention of myogenic and cell cycle regulators at myoblast levels resulting in a concomitant delay of the myogenic program. From these studies we conclude that the transcription factor ZBP-89 plays an important role in the timing of the myogenic program.
Salmon
Morgan
M
Department of Biochemistry and Molecular Biology, Virginia Commonwealth University Medical Center, Richmond, VA 23298-0614, USA.
Owens
Gary K
GK
Zehner
Zendra E
ZE
D000818:Animals; D015153:Blotting, Western; D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000378:metabolism; D002454:Cell Differentiation; D049109:Cell Proliferation; D002478:Cells, Cultured; D047369:Chromatin Immunoprecipitation; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D024202:Electrophoretic Mobility Shift Assay; D047468:Immunoprecipitation; D008156:Luciferases / Q000378:metabolism; D051379:Mice; D032448:Myoblasts, Skeletal / Q000166:cytology / Q000378:metabolism*; D018006:Myogenic Regulatory Factors / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D014162:Transfection
D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D018006:Myogenic Regulatory Factors; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D014157:Transcription Factors; C491741:Zfp148 protein, mouse; D008156:Luciferases