DIRECT ASSOCIATION OF YY-1 WITH C-MYC AND THE E-BOX BINDING-PROTEIN IN REGULATION OF GLYCOPHORIN GENE-EXPRESSION

We previously reported that YY-1, a versatile transcription factor, re gulates expression of glycophorin gene by binding to its locus control region-like region (Gp-LCR) in combination with E-box binding protein during murine erythroleukemia (MEL) cell differentiation. In the pres ent work, we demonstrated that YY-I and c-Myc, a nuclear oncoprotein, were physically associated ill vivo and that down regulation of c-Myc liberated free W-l from its complex, resulting in the functional bindi ng of W-l to the Gp-LCR. We also showed that the E-box binding protein (EBP) which bound to E-box was physically associated with YY-1, facil itated binding of YY-I to the neighboring site and their combinatorial binding may stimulate the Gp-LCR mediated enhancement of erythroid-sp ecific transcription of glycophorin gene in MEL cells.