A Novel Member of the BTB/POZ Family, PATZ, Associates with the RNF4 RING Finger Protein and Acts as a Transcriptional Repressor

• Published in: The Journal of biological chemistry Vol. 275; no. 11; pp. 7894 - 7901
• Main Authors: Fedele, Monica, Benvenuto, Giovanna, Pero, Raffaela, Majello, Barbara, Battista, Sabrina, Lembo, Francesca, Vollono, Erminia, Day, Patricia M., Santoro, Massimo, Lania, Luigi, Bruni, Carmelo Bruno, Fusco, Alfredo, Chiariotti, Lorenzo
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 17.03.2000; American Society for Biochemistry and Molecular Biology
• Subjects: Amino Acid Sequence; Animals; DNA-Binding Proteins - metabolism; High Mobility Group Proteins - metabolism; HMGA1a Protein; Humans; Kruppel-Like Transcription Factors; Mice; Molecular Sequence Data; Neoplasm Proteins; Nuclear Proteins; PATZ protein; Protein Binding; Repressor Proteins - classification; Repressor Proteins - genetics; Repressor Proteins - metabolism; RING finger proteins; RNF4 protein; Sequence Homology, Amino Acid; Transcription Factors - metabolism; Transcription, Genetic; Two-Hybrid System Techniques; Ubiquitin-Protein Ligases; Zinc Fingers
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.275.11.7894

We have identified a novel human gene encoding a 59-kDa POZ-AT hook-zinc finger protein (PATZ) that interacts with RNF4, a mediator of androgen receptor activity, and acts as a transcriptional repressor. PATZ cDNA was isolated through a two-hybrid interaction screening using the RING finger protein RNF4 as a bait.In vitro and in vivo interaction between RNF4 and PATZ was demonstrated by protein-protein affinity chromatography and coimmunoprecipitation experiments. Such interaction occurred through a small region of PATZ containing an AT-hook DNA binding domain. Immunofluorescence staining and confocal microscopy showed that PATZ localizes in distinct punctate nuclear regions and colocalizes with RNF4. Functional analysis was performed by cotransfection assays: PATZ acted as a transcriptional repressor, whereas its partner RNF4 behaved as a transcriptional activator. When both proteins were overexpressed a strong repression of the basal transcription was observed, indicating that the association of PATZ with RNF4 switches activation to repression. In addition, RNF4 was also found to associate with HMGI(Y), a chromatin-modeling factor containing AT-hook domains.