title: Transcription factor YY1 promotes adipogenesis via inhibiting CHOP-10 expression.
abstract: CHOP-10, a dominant-negative member of the C/EBP family of transcription factors, is initially expressed by growth-arrested preadipocytes and sequesters/inactivates C/EBPbeta through heterodimerization with its leucine zipper during 3T3-L1 preadipocyte differentiation. Our previous studies indicated that, FBS leads to the down-regulation of CHOP-10 expression after induction, and releasing C/EBPbeta from inhibitory constraint, allowing the transactivation of C/EBPalpha and PPARgamma genes, transcription factors required for terminal adipocyte differentiation. In the present study, we reported that FBS induced the expression of YY1, which bound to CHOP-10 promoter via two adjacent YY1-binding sites, suppressing its expression. The knock-down of YY1 expression with YY1 siRNA increased the expression of CHOP-10, inhibiting adipocyte differentiation. IGF-1, a growth factor present in greater concentration in FBS, independently induced the expression of YY1, and contributed to the down-regulation of CHOP-10 during the adipocyte differentiation program. Our studies suggested that YY1 can be a new adipocyte differentiation stimulator.
authors.affiliation: Key Laboratory of Molecular Medicine, The Ministry of Education, Shanghai Medical School, Fudan University, Shanghai 200032, PR China.
authors.forename: Hai-Yan
authors.initials: HY
authors.lastname: Huang
authors.forename: Xi
authors.initials: X
authors.lastname: Li
authors.forename: Mei
authors.initials: M
authors.lastname: Liu
authors.forename: Tan-Jing
authors.initials: TJ
authors.lastname: Song
authors.forename: Qun
authors.initials: Q
authors.lastname: He
authors.forename: Chun-Gu
authors.initials: CG
authors.lastname: Ma
authors.forename: Qi-Qun
authors.initials: QQ
authors.lastname: Tang
mesh_terms: D041721:3T3-L1 Cells; D050156:Adipogenesis / Q000235:genetics*; D000818:Animals; D002417:Cattle; D005786:Gene Expression Regulation; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D051379:Mice; D011401:Promoter Regions, Genetic; D034741:RNA, Small Interfering / Q000235:genetics; D044967:Serum / Q000378:metabolism; D051742:Transcription Factor CHOP / Q000037:antagonists & inhibitors / Q000235:genetics*; D050986:YY1 Transcription Factor / Q000235:genetics / Q000378:metabolism*
chemical_list: C497250:Ddit3 protein, mouse; D034741:RNA, Small Interfering; D050986:YY1 Transcription Factor; C494699:Yy1 protein, mouse; D051742:Transcription Factor CHOP; D007334:Insulin-Like Growth Factor I