Functional coordination of BET family proteins

Bromodomain and extraterminal proteins (BET) are epigenetic adaptors that play critical roles in gene regulation. This protein family contains two conserved bromodomains which can mediate the interaction with acetylated histone lysine residues and/or other acetylated proteins, and one extraterminal (ET) domain. BET protein inhibition has been recognized as a promising therapeutic strategy for several diseases, including acute myeloid leukaemia, castration resistant prostate cancer, and triple negative breast cancer. BET inhibition by a specific inhibitor JQ1 caused an impairment in various brain functions but the underlying molecular mechanisms are not well understood. Among BET family members, BRD4 has been recognized for its prominent role in epigenetic regulation of gene expression. However, we have found an extensive functional redundancy and coordination among all three major BET family members (BRD2/3/4) during the activity-dependent gene induction in neurons, which is also reflected in learning and memory behavior. Our study further revealed the molecular hierarchy in the coordination of BET family proteins dissecting their distinctive functions during gene induction required for proper brain function and plasticity. Understanding the functional coordination of BET family proteins at the molecular level would be beneficial to the development of more selective interventions for various diseases that are caused by dysregulated epigenetic pathways. mRNA-, nascent RNA-, or ChIP-seq profiles were generated from primary mouse cortical neurons at DIV7, comparing untreated neurons to neurons treated with different stimuli for different length of time or from Fmr1 KO with littermate control in duplicate