PMID- 28351837 OWN - NLM STAT- MEDLINE DCOM- 20170609 LR - 20210205 IS - 1083-351X (Electronic) IS - 0021-9258 (Print) IS - 0021-9258 (Linking) VI - 292 IP - 21 DP - 2017 May 26 TI - Cyclin C regulates adipogenesis by stimulating transcriptional activity of CCAAT/enhancer-binding protein alpha. PG - 8918-8932 LID - 10.1074/jbc.M117.776229 [doi] AB - Brown adipose tissue is important for maintaining energy homeostasis and adaptive thermogenesis in rodents and humans. As disorders arising from dysregulated energy metabolism, such as obesity and metabolic diseases, have increased, so has interest in the molecular mechanisms of adipocyte biology. Using a functional screen, we identified cyclin C (CycC), a conserved subunit of the Mediator complex, as a novel regulator for brown adipocyte formation. siRNA-mediated CycC knockdown (KD) in brown preadipocytes impaired the early transcriptional program of differentiation, and genetic KO of CycC completely blocked the differentiation process. RNA sequencing analyses of CycC-KD revealed a critical role of CycC in activating genes co-regulated by peroxisome proliferator activated receptor gamma (PPARgamma) and CCAAT/enhancer-binding protein alpha (C/EBPalpha). Overexpression of PPARgamma2 or addition of the PPARgamma ligand rosiglitazone rescued the defects in CycC-KO brown preadipocytes and efficiently activated the PPARgamma-responsive promoters in both WT and CycC-KO cells, suggesting that CycC is not essential for PPARgamma transcriptional activity. In contrast, CycC-KO significantly reduced C/EBPalpha-dependent gene expression. Unlike for PPARgamma, overexpression of C/EBPalpha could not induce C/EBPalpha target gene expression in CycC-KO cells or rescue the CycC-KO defects in brown adipogenesis, suggesting that CycC is essential for C/EBPalpha-mediated gene activation. CycC physically interacted with C/EBPalpha, and this interaction was required for C/EBPalpha transactivation domain activity. Consistent with the role of C/EBPalpha in white adipogenesis, CycC-KD also inhibited differentiation of 3T3-L1 cells into white adipocytes. Together, these data indicate that CycC activates adipogenesis in part by stimulating the transcriptional activity of C/EBPalpha. CI - (c) 2017 by The American Society for Biochemistry and Molecular Biology, Inc. FAU - Song, Ziyi AU - Song Z AD - From the Laboratory of Animal Fat Deposition and Muscle Development, Department of Animal Sciences, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi 712100, China. AD - the Department of Medicine, Division of Endocrinology and Diabetes Research Center, and. FAU - Xiaoli, Alus M AU - Xiaoli AM AD - the Department of Medicine, Division of Endocrinology and Diabetes Research Center, and. AD - Departments of Developmental and Molecular Biology. FAU - Zhang, Quanwei AU - Zhang Q AD - Genetics, and. FAU - Zhang, Yi AU - Zhang Y AD - the Department of Medicine, Division of Endocrinology and Diabetes Research Center, and. AD - Departments of Developmental and Molecular Biology. FAU - Yang, Ellen S T AU - Yang EST AD - the Department of Medicine, Division of Endocrinology and Diabetes Research Center, and. AD - Departments of Developmental and Molecular Biology. FAU - Wang, Sven AU - Wang S AD - the Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, and. FAU - Chang, Rui AU - Chang R AD - the Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, and. FAU - Zhang, Zhengdong D AU - Zhang ZD AD - Genetics, and. FAU - Yang, Gongshe AU - Yang G AD - From the Laboratory of Animal Fat Deposition and Muscle Development, Department of Animal Sciences, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi 712100, China, gsyang999@hotmail.com. FAU - Strich, Randy AU - Strich R AD - the Department of Molecular Biology, Rowan University School of Osteopathic Medicine, Stratford, New Jersey 08055. FAU - Pessin, Jeffrey E AU - Pessin JE AD - the Department of Medicine, Division of Endocrinology and Diabetes Research Center, and. AD - Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York 10461. FAU - Yang, Fajun AU - Yang F AD - the Department of Medicine, Division of Endocrinology and Diabetes Research Center, and fajun.yang@einstein.yu.edu. AD - Departments of Developmental and Molecular Biology. LA - eng GR - R01 DK093623/DK/NIDDK NIH HHS/United States GR - T32 AG023475/AG/NIA NIH HHS/United States GR - R01 DK098439/DK/NIDDK NIH HHS/United States GR - R01 DK110063/DK/NIDDK NIH HHS/United States GR - P30 DK020541/DK/NIDDK NIH HHS/United States PT - Journal Article PT - Research Support, N.I.H., Extramural PT - Research Support, Non-U.S. Gov't DEP - 20170328 PL - United States TA - J Biol Chem JT - The Journal of biological chemistry JID - 2985121R RN - 0 (CCAAT-Enhancer-Binding Proteins) RN - 0 (CEBPA protein, mouse) RN - 0 (Ccnc protein, mouse) RN - 0 (Cyclin C) RN - 0 (PPAR gamma) SB - IM MH - 3T3-L1 Cells MH - Adipocytes, Brown/*metabolism MH - *Adipogenesis MH - Animals MH - CCAAT-Enhancer-Binding Proteins/genetics/*metabolism MH - *Cell Differentiation MH - Cyclin C/genetics/*metabolism MH - Humans MH - Mice MH - Mice, Knockout MH - PPAR gamma/genetics/metabolism MH - *Transcriptional Activation PMC - PMC5448125 OTO - NOTNLM OT - C/EBPalpha OT - Mediator complex OT - PPARgamma OT - adipocyte OT - adipogenesis OT - brown adipocyte OT - cell differentiation OT - cyclin C OT - gene expression OT - transcription coregulator COIS- The authors declare that they have no conflicts of interest with the contents of this article EDAT- 2017/03/30 06:00 MHDA- 2017/06/10 06:00 PMCR- 2018/05/26 CRDT- 2017/03/30 06:00 PHST- 2017/01/10 00:00 [received] PHST- 2017/03/27 00:00 [revised] PHST- 2017/03/30 06:00 [pubmed] PHST- 2017/06/10 06:00 [medline] PHST- 2017/03/30 06:00 [entrez] PHST- 2018/05/26 00:00 [pmc-release] AID - S0021-9258(20)42785-1 [pii] AID - M117.776229 [pii] AID - 10.1074/jbc.M117.776229 [doi] PST - ppublish SO - J Biol Chem. 2017 May 26;292(21):8918-8932. doi: 10.1074/jbc.M117.776229. Epub 2017 Mar 28.