[Gene structure and transcriptional regulation of vitamin A, D binding proteins and nuclear receptors].
Vitamin A and D play an important role in many biological processes including cell differentiation, proliferation and bone metabolism. These effects are believed to be mediated by specific nuclear receptors such as retinoic acid receptors (RARs) or vitamin D receptor (VDR), that regulate the transcription of a particular set of target genes. Hetero-dimers of RAR or VDR to retinoid X receptors (RXRs) bind target enhancer elements in their gene promoters. The target enhancer elements are referred as RA response elements (RAREs) or vitamin D response elements (VDREs), and composed of two hexamer core motife. DNA-bound RAR/VDR control transcription in a ligand-binding dependent way in co-operation with a multiprotein complex containing RNA polymerase II and a series of auxiliary factors, TFIIA, B, D, E, F and H. During process of ligand-induced transactivation by nuclear receptors, nuclear coactivators interacting with the AF-2 including ligand binding domain (LBD) seems to be involved. Several transcriptional coactivators and corepressors have been recently identified, and their function is currently under investigation.
Takeyama
K
K
Institute of Molecular and Cellular Biosciences, University of Tokyo.
Kato
S
S
D005809:Genes, Regulator / Q000502:physiology*; D006801:Humans; D018167:Receptors, Calcitriol / Q000235:genetics* / Q000502:physiology*; D018168:Receptors, Retinoic Acid / Q000235:genetics* / Q000502:physiology*; D014801:Vitamin A / Q000378:metabolism; D014807:Vitamin D / Q000378:metabolism
D018167:Receptors, Calcitriol; D018168:Receptors, Retinoic Acid; D014801:Vitamin A; D014807:Vitamin D