Uloga retinoične kiseline u regulaciji transkripcije gena

Retinoids, including retinoic acid, are compounds responsible for normal biological processes such as embrionic development, cell differentiation, metabolism, reproduction, vision. All-trans retinoic acid (aTRA) as the main signal molecule and ligand regulates gene transcription by binding retinoid receptors (RAR and RXR) within cell nucleus. Binding of the ligand induces conformational change of receptor, corepressor proteins are then dissociated enabling coactivators to recruit. Consequently, receptor binds to so called retinoic acid response element (RARE) located in the promoter region of target genes and thus up-regulates or down-regulates transcription, respectively. Phosphorylation and ubiquitin-proteasome system are also involved as further processes in regulation of transcription. By identifying genes containing RARE in its promoter and analysing functions of encoded proteins, it has been found that majority is involved in cell diferentiation and metabolism. Still, further studies are needed to describe other roles of retinoids in cell metabolism which are apparently present.