RAR alpha
Retinoic acid receptor alpha, encoded by RARA, transduces signals from all-trans retinoic acid into transcriptional programs controlling differentiation and proliferation. It heterodimerizes with RXR partners and binds retinoic acid response elements in target promoters, switching from corepressor to coactivator complexes upon ligand binding. RAR alpha is expressed in most tissues with high levels in hematopoietic cells, and it is the receptor hijacked in acute promyelocytic leukemia, where the PML-RARA fusion protein blocks myeloid differentiation; treatment with ATRA and arsenic trioxide degrades the fusion and induces remission, a paradigm of differentiation therapy. RAR alpha also contributes to skin, immune and metabolic homeostasis, and recombinant RAR alpha is used in subtype-selectivity profiling of retinoids.
