BAF45D cooperates with SMAD signaling and promotes early neural differentiation in P19 and H9 cells

BAF45Dis a member of BAF complex,which may play a crucial role in neural development.PAX6 determines neuroectoderm formation,which is highly level sensitive.BAF45D is required for retinoic acid(RA)induced PAX6 expression.PAX6 expression is also regulated by TGF-beta/SMAD signaling.However,mechanism of such regulation remains elusive.We therefore sought to explore whether BAF45D regulates PAX6 expression through cooperating with TGF-beta/SMAD signaling.Here we identified BAF45D is required for expression of phosphorylated SMAD3 and PAX6 induced by RA.Genome-wide analysis revealed that during RA-induced early neural differentiation,BAF 45D knockdown failed to activate TGF-beta/SMAD signaling and induce expression of STAT3 and SMAD7,two negative regulators of TGF-beta/SMAD signaling.Moreover,in RA treated P19 and H9 cells,BAF45D interacts with BRG1 and phosphorylated SMAD3.