THE KRÜPPEL-LIKE ZINC-FINGER PROTEIN ZNF224 REPRESSES ALDOLASE A GENE TRANSCRIPTION BY INTERACTING WITH THE KAP1 COREPRESSOR PROTEIN

Transcription ranscription factors belonging to the Kru ¨ ppel-like zinc finger family of proteins participate in the regulation of cell differentiation and development. Although many of these proteins have been identified, little is known about their structure and function. We recently purified ZNF224, a new Kru ¨ ppel-like zinc finger protein, that contains a Kru ¨ ppel-associated box (KRAB) domain at the NH NH2 terminus, and 19 Cys2- His2 zinc-finger domains at the COOH terminus. Using chromatin immunoprecipitation and transient transfection assays, we demonstrate that ZNF224 binds in vivo to the distal promoter of the aldolase A gene and represses its transcription. The results of transient co-transfection experiments show that ZNF224-mediated transcription repression requires the 45-amino acid long KRAB A domain. The ability of KRAB- KRABcontaining containing ZNF224 protein to repress transcription depends on specific interaction with the KAP-1 co-repressor molecule. Finally Finally, using selective treatment with the HDAC1 inhibitor trichostatin A, we demonstrate that ZNF224-mediated repression requires histone deacetylases. D 2005 Elsevier B.V V. All rights reserved.