Structural highlightsDisease[PPARG_HUMAN] Note=Defects in PPARG can lead to type 2 insulin-resistant diabetes and hyptertension. PPARG mutations may be associated with colon cancer. Defects in PPARG may be associated with susceptibility to obesity (OBESITY) [MIM:601665]. It is a condition characterized by an increase of body weight beyond the limitation of skeletal and physical requirements, as the result of excessive accumulation of body fat.[1] Defects in PPARG are the cause of familial partial lipodystrophy type 3 (FPLD3) [MIM:604367]. Familial partial lipodystrophies (FPLD) are a heterogeneous group of genetic disorders characterized by marked loss of subcutaneous (sc) fat from the extremities. Affected individuals show an increased preponderance of insulin resistance, diabetes mellitus and dyslipidemia.[2] [3] Genetic variations in PPARG can be associated with susceptibility to glioma type 1 (GLM1) [MIM:137800]. Gliomas are central nervous system neoplasms derived from glial cells and comprise astrocytomas, glioblastoma multiforme, oligodendrogliomas, and ependymomas. Note=Polymorphic PPARG alleles have been found to be significantly over-represented among a cohort of American patients with sporadic glioblastoma multiforme suggesting a possible contribution to disease susceptibility.
Function[PPARG_HUMAN] Receptor that binds peroxisome proliferators such as hypolipidemic drugs and fatty acids. Once activated by a ligand, the receptor binds to a promoter element in the gene for acyl-CoA oxidase and activates its transcription. It therefore controls the peroxisomal beta-oxidation pathway of fatty acids. Key regulator of adipocyte differentiation and glucose homeostasis. Acts as a critical regulator of gut homeostasis by suppressing NF-kappa-B-mediated proinflammatory responses.[4] [5] [6] [MED1_HUMAN] Component of the Mediator complex, a coactivator involved in the regulated transcription of nearly all RNA polymerase II-dependent genes. Mediator functions as a bridge to convey information from gene-specific regulatory proteins to the basal RNA polymerase II transcription machinery. Mediator is recruited to promoters by direct interactions with regulatory proteins and serves as a scaffold for the assembly of a functional preinitiation complex with RNA polymerase II and the general transcription factors.[7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17]
References
- ↑ Ristow M, Muller-Wieland D, Pfeiffer A, Krone W, Kahn CR. Obesity associated with a mutation in a genetic regulator of adipocyte differentiation. N Engl J Med. 1998 Oct 1;339(14):953-9. PMID:9753710 doi:10.1056/NEJM199810013391403
- ↑ Hegele RA, Cao H, Frankowski C, Mathews ST, Leff T. PPARG F388L, a transactivation-deficient mutant, in familial partial lipodystrophy. Diabetes. 2002 Dec;51(12):3586-90. PMID:12453919
- ↑ Agarwal AK, Garg A. A novel heterozygous mutation in peroxisome proliferator-activated receptor-gamma gene in a patient with familial partial lipodystrophy. J Clin Endocrinol Metab. 2002 Jan;87(1):408-11. PMID:11788685
- ↑ Mukherjee R, Jow L, Croston GE, Paterniti JR Jr. Identification, characterization, and tissue distribution of human peroxisome proliferator-activated receptor (PPAR) isoforms PPARgamma2 versus PPARgamma1 and activation with retinoid X receptor agonists and antagonists. J Biol Chem. 1997 Mar 21;272(12):8071-6. PMID:9065481
- ↑ Yin Y, Yuan H, Wang C, Pattabiraman N, Rao M, Pestell RG, Glazer RI. 3-phosphoinositide-dependent protein kinase-1 activates the peroxisome proliferator-activated receptor-gamma and promotes adipocyte differentiation. Mol Endocrinol. 2006 Feb;20(2):268-78. Epub 2005 Sep 8. PMID:16150867 doi:10.1210/me.2005-0197
- ↑ Park SH, Choi HJ, Yang H, Do KH, Kim J, Lee DW, Moon Y. Endoplasmic reticulum stress-activated C/EBP homologous protein enhances nuclear factor-kappaB signals via repression of peroxisome proliferator-activated receptor gamma. J Biol Chem. 2010 Nov 12;285(46):35330-9. doi: 10.1074/jbc.M110.136259. Epub 2010, Sep 9. PMID:20829347 doi:10.1074/jbc.M110.136259
- ↑ Yuan CX, Ito M, Fondell JD, Fu ZY, Roeder RG. The TRAP220 component of a thyroid hormone receptor- associated protein (TRAP) coactivator complex interacts directly with nuclear receptors in a ligand-dependent fashion. Proc Natl Acad Sci U S A. 1998 Jul 7;95(14):7939-44. PMID:9653119
- ↑ Zhang J, Fondell JD. Identification of mouse TRAP100: a transcriptional coregulatory factor for thyroid hormone and vitamin D receptors. Mol Endocrinol. 1999 Jul;13(7):1130-40. PMID:10406464
- ↑ Wang Q, Sharma D, Ren Y, Fondell JD. A coregulatory role for the TRAP-mediator complex in androgen receptor-mediated gene expression. J Biol Chem. 2002 Nov 8;277(45):42852-8. Epub 2002 Sep 5. PMID:12218053 doi:10.1074/jbc.M206061200
- ↑ Ge K, Guermah M, Yuan CX, Ito M, Wallberg AE, Spiegelman BM, Roeder RG. Transcription coactivator TRAP220 is required for PPAR gamma 2-stimulated adipogenesis. Nature. 2002 May 30;417(6888):563-7. PMID:12037571 doi:10.1038/417563a
- ↑ Kang YK, Guermah M, Yuan CX, Roeder RG. The TRAP/Mediator coactivator complex interacts directly with estrogen receptors alpha and beta through the TRAP220 subunit and directly enhances estrogen receptor function in vitro. Proc Natl Acad Sci U S A. 2002 Mar 5;99(5):2642-7. Epub 2002 Feb 26. PMID:11867769 doi:10.1073/pnas.261715899
- ↑ Coulthard VH, Matsuda S, Heery DM. An extended LXXLL motif sequence determines the nuclear receptor binding specificity of TRAP220. J Biol Chem. 2003 Mar 28;278(13):10942-51. Epub 2003 Jan 29. PMID:12556447 doi:10.1074/jbc.M212950200
- ↑ Wallberg AE, Yamamura S, Malik S, Spiegelman BM, Roeder RG. Coordination of p300-mediated chromatin remodeling and TRAP/mediator function through coactivator PGC-1alpha. Mol Cell. 2003 Nov;12(5):1137-49. PMID:14636573
- ↑ Wu Q, Burghardt R, Safe S. Vitamin D-interacting protein 205 (DRIP205) coactivation of estrogen receptor alpha (ERalpha) involves multiple domains of both proteins. J Biol Chem. 2004 Dec 17;279(51):53602-12. Epub 2004 Oct 5. PMID:15471764 doi:10.1074/jbc.M409778200
- ↑ Malik S, Guermah M, Yuan CX, Wu W, Yamamura S, Roeder RG. Structural and functional organization of TRAP220, the TRAP/mediator subunit that is targeted by nuclear receptors. Mol Cell Biol. 2004 Sep;24(18):8244-54. PMID:15340084 doi:10.1128/MCB.24.18.8244-8254.2004
- ↑ Zhang X, Krutchinsky A, Fukuda A, Chen W, Yamamura S, Chait BT, Roeder RG. MED1/TRAP220 exists predominantly in a TRAP/ Mediator subpopulation enriched in RNA polymerase II and is required for ER-mediated transcription. Mol Cell. 2005 Jul 1;19(1):89-100. PMID:15989967 doi:10.1016/j.molcel.2005.05.015
- ↑ Udayakumar TS, Belakavadi M, Choi KH, Pandey PK, Fondell JD. Regulation of Aurora-A kinase gene expression via GABP recruitment of TRAP220/MED1. J Biol Chem. 2006 May 26;281(21):14691-9. Epub 2006 Mar 30. PMID:16574658 doi:M600163200
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