Description
PHB2 (Prohibitin 2), also called Repressor of Estrogen Receptor Activity (REA), is a protein that in humans is encoded by the PHB2 gene. The International Radiation Hybrid Mapping Consortium mapped the PHB2 gene to chromosome 12. Montano et al.(1999) showed that REA enhanced the potency of a dominant-negative ER-alpha mutant and antiestrogens as suppressors of ER-alpha activity in Chinese hamster ovary cells. When coexpressed with wildtype ER-alpha or ER-beta(ESR2), REA suppressed activation of a reporter gene in a dose-dependent manner. REA had no effect on reporter activity in the absence of liganded ER, and it had no effect on the transcriptional activities of other hormone receptors. Mutation analysis showed that an N-terminal domain and a central domain of REA were required for its repressor activity