4g21
From Proteopedia
Structural basis for the accommodation of bis- and tris-aromatic derivatives in Vitamin D Nuclear Receptor
Structural highlights
Disease[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. Function[VDRA_DANRE] Nuclear hormone receptor. Transcription factor that mediates the action of vitamin D3 by controlling the expression of hormone sensitive genes. Regulates transcription of hormone sensitive genes via its association with the WINAC complex, a chromatin-remodeling complex. Plays a central role in calcium homeostasis.[1] [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.[2] [3] [4] [5] [6] [7] [8] Publication Abstract from PubMedActual use of the active form of vitamin D (calcitriol or 1alpha,25-dihydroxyvitamin D(3)) to treat hyperproliferative disorders is hampered by calcemic effects, hence the continuous development of chemically modified analogues with dissociated profiles. Structurally distinct nonsecosteroidal analogues have been developed to mimic calcitriol activity profiles with low calcium serum levels. Here, we report the crystallographic study of vitamin D nuclear receptor (VDR) ligand binding domain in complexes with six nonsecosteroidal analogues harboring two or three phenyl rings. These compounds induce a stimulated transcription in the nanomolar range, similar to calcitriol. Examination of the protein-ligand interactions reveals the mode of binding of these nonsecosteroidal compounds and highlights the role of the various chemical modifications of the ligands to VDR binding and activity, notably (de)solvation effects. The structures with the tris-aromatic ligands exhibit a rearrangement of a novel region of the VDR ligand binding pocket, helix H6. Structural Basis for the Accommodation of Bis- and Tris-Aromatic Derivatives in Vitamin D Nuclear Receptor.,Ciesielski F, Sato Y, Chebaro Y, Moras D, Dejaegere A, Rochel N J Med Chem. 2012 Sep 19. PMID:22957834[9] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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