Interaction of Estrogen Receptor Associated Protein (ERAP) 140 with ER beta decreases but its expression increases in aging mouse cerebral cortex.

Following binding to cognate ligand, estrogen receptor (ER) beta interacts with specific responsive elements of the target genes and recruits a host of nuclear proteins for hormone dependent gene regulation. However, it is poorly known which proteins interact with ER beta in mouse brain and whether their interaction and expression change with age. In this report, we have used his-tag mouse ER beta for interaction with nuclear proteins of cerebral cortex of young (6 +/- 1 weeks), adult (25 +/- 2 weeks), and old (70 +/- 5 weeks) female mice. We have identified estrogen receptor-associated protein (ERAP) 140 as one of the interacting proteins and studied its interaction by pull down immunoblotting, far-Western blotting and immunoprecipitation, and expression by western blotting. The data show that ERAP 140 interacts with ER beta and its interaction decreases but its expression increases with age in mouse cerebral cortex, suggesting its role in estrogen-mediated brain functions during aging.