Retinoic acid receptor alpha

Retinoic acid receptor alpha (RAR-alpha) is a type of nuclear receptor that is activated by both all-trans retinoic acid and 9-cis retinoic acid. It is encoded by the RAR-alpha gene in humans.

Function

RAR-alpha is a member of the retinoic acid receptors family, which is a subfamily of nuclear receptors. The receptors are transcription factors that regulate gene expression in response to retinoic acid, a metabolite of vitamin A.

RAR-alpha forms heterodimers with retinoid X receptors (RXRs), and these heterodimers bind to specific sequences in the DNA of target genes. The RXR-RAR dimer complex binds to retinoic acid response elements (RAREs) located in the promoter region of target genes. The dimer complex regulates gene transcription by recruiting an array of coregulators, which can either activate or repress transcription.

Clinical significance

Mutations in the RAR-alpha gene are associated with acute promyelocytic leukemia (APL). APL is a subtype of acute myeloid leukemia, a cancer of the white blood cells. In most cases of APL, the RAR-alpha gene on chromosome 17 is involved in a reciprocal translocation with the PML gene on chromosome 15. This translocation creates a fusion gene, PML-RAR-alpha, which encodes a fusion protein that contributes to the pathogenesis of APL.

See also

• Retinoic acid receptor
• Retinoid X receptor
• Acute promyelocytic leukemia