Expression of chromatin remodeling factors during neural differentiation

The yeast SWI/SNF complex is involved in remodeling of chromatin structure during transcriptional modulation. One of the key subunits of this complex, called SWI2/SNF2, has a DNA-dependent ATPase activity. Two different types of mammalian homolog of yeast SWI2/SNF2, called BRM and BRG1, were recentl y identified. They are closely similar in structure but have distinct funct ions. We investigated the expression of BRM and BRG1 during differentiation of neural precursor cells (NPCs) cultured in vitro. The expression of BRM was very low in NPCs and was induced to a high level during differentiation to neurons and astrocytes, In contrast, BRG1 was constantly expressed thro ughout differentiation. These phenomena were also observed in differentiati on of P19 embryonal carcinoma cells to neural cells. Immunocytochemical ana lyses revealed that the expression of BRM started even in the undifferentia ted nestin-positive cells. These results indicate that BRM may have an impo rtant role in neural cell differentiation.