CREBBP and Huntington disease: CREB binding protein (CBP), a histone acetyltransferase and CREB co-activator that helps regulate the expression of a number of plasticity-related genes, is a known wtHTT interactor and its transcriptional activity is disrupted in HD mouse models (Steffan et al., 2000; Cong et al., 2005; Jiang et al., 2006).