MXD/MIZ1 transcription regulatory complexes activate the expression of MYC?repressed genes

MXDs are transcription repressors that antagonize MYC-mediated gene activation. MYC, when associated with MIZ1, acts also as a repressor of subset genes, including p15 and p21. A role for in regulation MYC-repressed genes is not known. We report activate p21 U2OS cells. This activation required DNA binding by their interaction MIZ1. MXD mutants deficient MIZ1 interacted the MYC-binding partner MAX were active MYC-activated but failed to genes. Mutant reduced DNA-binding affinity neither repressed nor activated transcription. Our data show MYC have reciprocally antagonistic potential regulate target