NMR spectroscopy uncovers direct interaction between BAF60A and p53.

Abstract The BRG1-associated factor 60A (BAF60A), an SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily D member 1, has been known to be important for transcriptional activation and inhibition through the alteration of the DNA nucleosome. Although the association between BAF60A and p53 plays a critical role in tumor suppression, the interaction mode is still unclear. Here, we report the detailed interactions between BAF60A and p53 by both NMR spectroscopy and pull-down analysis. Both N-terminal region (BAF60ANR) and the SWIB domain (BAF60ASWIB) of BAF60A directly interact with the tetramerization domain of p53 (p53TET). NMR data show that Ile315, Met366, Ala388, and Tyr390 of BAF60ASWIB are mostly involved in p53TET binding. The calculated dissociation constant (KD) value between BAF60ASWIB and p53TET revealed relatively weak binding affinity, at approximately 0.3 ± 0.065 mM. Our data will enhance detailed interaction mechanism to elucidate the molecular basis of p53-mediated integration via BAF60A interaction.