|3kmr, resolution 1.80Å ()|
|Gene:||NR1B1, RARA (Homo sapiens)|
Crystal structure of RARalpha ligand binding domain in complex with an agonist ligand (Am580) and a coactivator fragment
In the absence of ligand, some nuclear receptors, including retinoic acid receptor (RAR), act as transcriptional repressors by recruiting corepressor complexes to target genes. This constitutive repression is crucial in metazoan reproduction, development and homeostasis. However, its specific molecular determinants had remained obscure. Using structural, biochemical and cell-based assays, we show that the basal repressive activity of RAR is conferred by an extended beta-strand that forms an antiparallel beta-sheet with specific corepressor residues. Agonist binding induces a beta-strand-to-alpha-helix transition that allows for helix H11 formation, which in turn provokes corepressor release, repositioning of helix H12 and coactivator recruitment. Several lines of evidence suggest that this structural switch could be implicated in the intrinsic repressor function of other nuclear receptors. Finally, we report on the molecular mechanism by which inverse agonists strengthen corepressor interaction and enhance gene silencing by RAR.
A unique secondary-structure switch controls constitutive gene repression by retinoic acid receptor., le Maire A, Teyssier C, Erb C, Grimaldi M, Alvarez S, de Lera AR, Balaguer P, Gronemeyer H, Royer CA, Germain P, Bourguet W, Nat Struct Mol Biol. 2010 Jul;17(7):801-7. Epub 2010 Jun 13. PMID:20543827
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
[RARA_HUMAN] Note=Chromosomal aberrations involving RARA are commonly found in acute promyelocytic leukemia. Translocation t(11;17)(q32;q21) with ZBTB16/PLZF; translocation t(15;17)(q21;q21) with PML; translocation t(5;17)(q32;q11) with NPM. The PML-RARA oncoprotein requires both the PML ring structure and coiled-coil domain for both interaction with UBE2I, nuclear microspeckle location and sumoylation. In addition, the coiled-coil domain functions in blocking RA-mediated transactivation and cell differentiation. [NCOA1_HUMAN] Note=A chromosomal aberration involving NCOA1 is a cause of rhabdomyosarcoma. Translocation t(2;2)(q35;p23) with PAX3 generates the NCOA1-PAX3 oncogene consisting of the N-terminus part of PAX3 and the C-terminus part of NCOA1. The fusion protein acts as a transcriptional activator. Rhabdomyosarcoma is the most common soft tissue carcinoma in childhood, representing 5-8% of all malignancies in children.
[RARA_HUMAN] Receptor for retinoic acid. Retinoic acid receptors bind as heterodimers to their target response elements in response to their ligands, all-trans or 9-cis retinoic acid, and regulate gene expression in various biological processes. The RXR/RAR heterodimers bind to the retinoic acid response elements (RARE) composed of tandem 5'-AGGTCA-3' sites known as DR1-DR5. In the absence of ligand, the RXR-RAR heterodimers associate with a multiprotein complex containing transcription corepressors that induce histone acetylation, chromatin condensation and transcriptional suppression. On ligand binding, the corepressors dissociate from the receptors and associate with the coactivators leading to transcriptional activation. RARA plays an essential role in the regulation of retinoic acid-induced germ cell development during spermatogenesis. Has a role in the survival of early spermatocytes at the beginning prophase of meiosis. In Sertoli cells, may promote the survival and development of early meiotic prophase spermatocytes. In concert with RARG, required for skeletal growth, matrix homeostasis and growth plate function (By similarity). Regulates expression of target genes in a ligand-dependent manner by recruiting chromatin complexes containing MLL5. Mediates retinoic acid-induced granulopoiesis. [NCOA1_HUMAN] Nuclear receptor coactivator that directly binds nuclear receptors and stimulates the transcriptional activities in a hormone-dependent fashion. Involved in the coactivation of different nuclear receptors, such as for steroids (PGR, GR and ER), retinoids (RXRs), thyroid hormone (TRs) and prostanoids (PPARs). Also involved in coactivation mediated by STAT3, STAT5A, STAT5B and STAT6 transcription factors. Displays histone acetyltransferase activity toward H3 and H4; the relevance of such activity remains however unclear. Plays a central role in creating multisubunit coactivator complexes that act via remodeling of chromatin, and possibly acts by participating in both chromatin remodeling and recruitment of general transcription factors. Required with NCOA2 to control energy balance between white and brown adipose tissues. Required for mediating steroid hormone response. Isoform 2 has a higher thyroid hormone-dependent transactivation activity than isoform 1 and isoform 3.
About this Structure
- le Maire A, Teyssier C, Erb C, Grimaldi M, Alvarez S, de Lera AR, Balaguer P, Gronemeyer H, Royer CA, Germain P, Bourguet W. A unique secondary-structure switch controls constitutive gene repression by retinoic acid receptor. Nat Struct Mol Biol. 2010 Jul;17(7):801-7. Epub 2010 Jun 13. PMID:20543827 doi:10.1038/nsmb.1855
- ↑ Srinivas H, Xia D, Moore NL, Uray IP, Kim H, Ma L, Weigel NL, Brown PH, Kurie JM. Akt phosphorylates and suppresses the transactivation of retinoic acid receptor alpha. Biochem J. 2006 May 1;395(3):653-62. PMID:16417524 doi:10.1042/BJ20051794
- ↑ Zhu L, Santos NC, Kim KH. Small ubiquitin-like modifier-2 modification of retinoic acid receptor-alpha regulates its subcellular localization and transcriptional activity. Endocrinology. 2009 Dec;150(12):5586-95. doi: 10.1210/en.2009-0868. Epub 2009 Oct, 22. PMID:19850744 doi:10.1210/en.2009-0868
- ↑ Fujiki R, Chikanishi T, Hashiba W, Ito H, Takada I, Roeder RG, Kitagawa H, Kato S. GlcNAcylation of a histone methyltransferase in retinoic-acid-induced granulopoiesis. Nature. 2009 May 21;459(7245):455-9. Epub 2009 Apr 19. PMID:19377461 doi:nature07954
- ↑ Santos NC, Kim KH. Activity of retinoic acid receptor-alpha is directly regulated at its protein kinase A sites in response to follicle-stimulating hormone signaling. Endocrinology. 2010 May;151(5):2361-72. doi: 10.1210/en.2009-1338. Epub 2010 Mar , 9. PMID:20215566 doi:10.1210/en.2009-1338
- ↑ Kalkhoven E, Valentine JE, Heery DM, Parker MG. Isoforms of steroid receptor co-activator 1 differ in their ability to potentiate transcription by the oestrogen receptor. EMBO J. 1998 Jan 2;17(1):232-43. PMID:9427757 doi:10.1093/emboj/17.1.232
- ↑ Onate SA, Tsai SY, Tsai MJ, O'Malley BW. Sequence and characterization of a coactivator for the steroid hormone receptor superfamily. Science. 1995 Nov 24;270(5240):1354-7. PMID:7481822
- ↑ Hayashi Y, Ohmori S, Ito T, Seo H. A splicing variant of Steroid Receptor Coactivator-1 (SRC-1E): the major isoform of SRC-1 to mediate thyroid hormone action. Biochem Biophys Res Commun. 1997 Jul 9;236(1):83-7. PMID:9223431 doi:10.1006/bbrc.1997.6911
- ↑ Spencer TE, Jenster G, Burcin MM, Allis CD, Zhou J, Mizzen CA, McKenna NJ, Onate SA, Tsai SY, Tsai MJ, O'Malley BW. Steroid receptor coactivator-1 is a histone acetyltransferase. Nature. 1997 Sep 11;389(6647):194-8. PMID:9296499 doi:10.1038/38304
- ↑ Jenster G, Spencer TE, Burcin MM, Tsai SY, Tsai MJ, O'Malley BW. Steroid receptor induction of gene transcription: a two-step model. Proc Natl Acad Sci U S A. 1997 Jul 22;94(15):7879-84. PMID:9223281
- ↑ Liu Z, Wong J, Tsai SY, Tsai MJ, O'Malley BW. Steroid receptor coactivator-1 (SRC-1) enhances ligand-dependent and receptor-dependent cell-free transcription of chromatin. Proc Natl Acad Sci U S A. 1999 Aug 17;96(17):9485-90. PMID:10449719
- ↑ Litterst CM, Kliem S, Marilley D, Pfitzner E. NCoA-1/SRC-1 is an essential coactivator of STAT5 that binds to the FDL motif in the alpha-helical region of the STAT5 transactivation domain. J Biol Chem. 2003 Nov 14;278(46):45340-51. Epub 2003 Sep 3. PMID:12954634 doi:http://dx.doi.org/10.1074/jbc.M303644200