23440512_title
title
Vitamin A and retinoid signaling: genomic and non-genomic effects.
23440512_abstract
abstract
Vitamin A or retinol is arguably the most multifunctional vitamin in the human body as it is essential from embryogenesis to adulthood. The pleiotropic effects of vitamin A are exerted mainly by one active metabolite, all-trans retinoic acid (atRA), which regulates the expression of a battery of target genes through several families of nuclear receptors (RARs, RXRs and PPARβ/δ), polymorphic retinoic acid (RA) response elements and multiple coregulators. It also involves extra nuclear and non-transcriptional effects such as the activation of kinase cascades, which are integrated in the nucleus via the phosphorylation of several actors of RA signaling. However, vitamin A itself proved recently to be active and RARs to be present in the cytosol to regulate translation and cell plasticity. All these new concepts expand the scope of the biologic functions of vitamin A and RA.