title: Fad24, a Positive Regulator of Adipogenesis, Is Required for S Phase Re-entry of C2C12 Myoblasts Arrested in G0 Phase and Involved in p27(Kip1) Expression at the Protein Level.
abstract: Factor for adipocyte differentiation 24 (fad24) is a positive regulator of adipogenesis. We previously found that human fad24 is abundantly expressed in skeletal muscle. However, the function of fad24 in skeletal muscle remains largely unknown. Because skeletal muscle is a highly regenerative tissue, we focused on the function of fad24 in skeletal muscle regeneration. In this paper, we investigated the role of fad24 in the cell cycle re-entry of quiescent C2C12 myoblasts-mimicked satellite cells. The expression levels of fad24 and histone acetyltransferase binding to ORC1 (hbo1), a FAD24-interacting factor, were elevated at the early phase of the regeneration process in response to cardiotoxin-induced muscle injury. The knockdown of fad24 inhibited the proliferation of quiescent myoblasts, whereas fad24 knockdown did not affect differentiation. S phase entry following serum activation is abrogated by fad24 knockdown in quiescent cells. Furthermore, fad24 knockdown cells show a marked accumulation of p27(Kip1) protein. These results suggest that fad24 may have an important role in the S phase re-entry of quiescent C2C12 cells through the regulation of p27(Kip1) at the protein level.
authors.affiliation: Department of Molecular Biology, Graduate School of Pharmaceutical Sciences, Nagoya City University.
authors.forename: Natsuki
authors.initials: N
authors.lastname: Ochiai
authors.forename: Makoto
authors.initials: M
authors.lastname: Nishizuka
authors.forename: Shigehiro
authors.initials: S
authors.lastname: Osada
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Imagawa
mesh_terms: D050156:Adipogenesis / Q000502:physiology; D000818:Animals; D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics*; D018797:Cell Cycle Proteins; D002454:Cell Differentiation / Q000502:physiology; D002460:Cell Line; D050760:Cyclin-Dependent Kinase Inhibitor p27 / Q000378:metabolism*; D008810:Mice, Inbred C57BL; D018482:Muscle, Skeletal / Q000378:metabolism; D032446:Myoblasts / Q000378:metabolism* / Q000502:physiology; D009687:Nuclear Proteins / Q000235:genetics*; D051738:Origin Recognition Complex / Q000235:genetics; D016192:Resting Phase, Cell Cycle; D016196:S Phase
chemical_list: D050976:Basic-Leucine Zipper Transcription Factors; D018797:Cell Cycle Proteins; C502215:Noc3l protein, mouse; D009687:Nuclear Proteins; C497228:Orc1 protein, mouse; D051738:Origin Recognition Complex; D050760:Cyclin-Dependent Kinase Inhibitor p27