Mutation of the E box abolished USF/c-Myc -mediated up-regulation of CXCR4 promoter activity , and mutation of the YY1 binding site was associated with unresponsiveness to YY1 -mediated inhibition .
mutation of the e box abolished usf/c-myc -mediated up-regulation of cxcr4 promoter activity , and mutation of the yy1 binding site was associated with unresponsiveness to yy1 -mediated inhibition .
O O O B-DNA_domain_or_region I-DNA_domain_or_region O B-protein_molecule O O O B-protein_molecule B-other_name I-other_name O O O O O B-protein_molecule O O O O O O O B-protein_molecule O O O