RXR and RAR are nuclear receptors that bind either all trans retinoic (tRA) or 9cis retinoic acid (9cisRA). In the absence of ligand corepressors with histone deacetylase activity are bound to the RAR/RXR hetrodimer and suppress transcription. Once they bind retinoic acid a conformational change in the receptors cause the dissociation of the corepressors and the binding of coactivators with histone acetylase activity (1). Following ligand binding by the hetrodimer the receptors and proteins in the basal transcription machinery (like TBP and TAF135) are degraded by the proteasome (2).
Contributor: Kopf Eliezer, PhD.
REFERENCES: Coordinate regulation of RARgamma2, TBP, and TAFII135 by targeted proteolysis during retinoic acid-induced differentiation of F9 embryonal carcinoma cells. Perletti L, Kopf E, Carre L, Davidson I. BMC Mol Biol. 2001;2(1):4. Nuclear receptors coordinate the activities of chromatin remodeling complexes and coactivators to facilitate initiation of transcription. Dilworth FJ, Chambon P. Oncogene. 2001 May 28;20(24):3047-54. Review.
首页
