Retinoic acid receptor beta

Retinoic acid receptor beta (RAR-beta), also known as NR1B2 (nuclear receptor subfamily 1, group B, member 2), is a nuclear receptor that in humans is encoded by the RAR-beta gene.

Function

Retinoic acid receptor beta is a receptor for retinoic acid. This receptor is a member of the nuclear receptor family, a group of transcription factors that are activated by the binding of their ligands. The retinoic acid receptors (RARs) are ligand-dependent, DNA-binding proteins that regulate gene expression by binding to retinoic acid response elements (RAREs) in the promoters of target genes.

Structure

The RAR-beta protein has a modular structure and is composed of several domains. The A/B domain is located at the N-terminus and is responsible for ligand-independent activation. The C domain, also known as the DNA-binding domain (DBD), binds to specific sequences of DNA. The D domain, or hinge region, connects the DBD to the E/F domain. The E/F domain, also known as the ligand-binding domain (LBD), binds to retinoic acid and is responsible for ligand-dependent activation.

Clinical significance

Alterations in the expression of this receptor are associated with acute promyelocytic leukemia, squamous cell carcinoma of the head and neck, and lung cancer. In addition, lower levels of RAR-beta expression have been linked to a poorer prognosis in several types of cancer.

See also

• Retinoic acid receptor
• Retinoic acid
• Nuclear receptor