Nuclear receptor coactivator 5 (NCOA5)

Nuclear receptor coactivator 5 (NCOA5) is a nuclear protein that functions as a transcriptional coregulator for both alpha and beta estrogen receptors and for the orphan receptor NR1D2. It can act as both a coactivator and corepressor, depending on cellular context, and its function is independent of the AF-2 domain commonly required by other nuclear receptor coactivators. NCOA5 influences gene expression profiles tied to hormone signaling, cell proliferation, immune regulation, and metabolic homeostasis. Changes in NCOA5 expression or function contribute to susceptibility and progression of cancers, autoimmune diseases, and metabolic disorders such as nonalcoholic fatty liver disease and insulin resistance. There is no validated drug that specifically targets NCOA5, but its modulation is mechanistically important for estrogen receptor biology, with consequent relevance to hormonal therapies and possible biomarker roles. Its context-dependent effects in cancer mean therapeutic interventions must consider tissue type, disease stage, and wider impact on immune/metabolic functions.

Other names

NCOA5KIAA1637NCoA-5CIAbA465L10.6Coactivator independent of AF-2BA465L10.6

NCOA5 modulates transcriptional activity of nuclear receptors (mainly estrogen receptors) by acting as a coregulator; drugs acting via these receptors may indirectly alter NCOA5 function.