title: Inhibition of Wilms tumor 1 transactivation by bone marrow zinc finger 2, a novel transcriptional repressor.
abstract: The Wilms tumor suppressor gene, wt1, encodes a zinc finger transcription factor that has been implicated in the regulation of a number of genes. Protein-protein interactions are known to modulate the transcription regulatory functions of Wilms tumor (WT1) and have also implicated WT1 in splicing. In this report, we identify a novel WT1-interacting protein, bone marrow zinc finger 2 (BMZF2), by affinity chromatography utilizing immobilized WT1 protein. BMZF2 is a potential transcription factor with 18 zinc fingers. The BMZF2 mRNA is mainly expressed in fetal tissues, and the protein is predominantly nuclear. Co-immunoprecipitation experiments are consistent with an in vivo association between WT1 and BMZF2. Glutathione S-transferase pulldown assays and far Western blots revealed that zinc fingers VI-X (amino acids 231-370) are required for interaction with the zinc finger region of WT1. Functionally, BMZF2 inhibits transcriptional activation by WT1. Moreover, a chimeric protein generated by fusion of BMZF2 to the GAL4 DNA-binding domain significantly decreases promoter activity of a reporter containing GAL4 DNA-binding sites, suggesting the presence of an active repressor domain within BMZF2. Our results suggest that BMZF2 interferes with the transactivation potential of WT1.
authors.affiliation: Department of Biochemistry, McGill University, Montreal, Quebec H3G 1Y6, Canada.
authors.forename: Tae Ho
authors.initials: TH
authors.lastname: Lee
authors.forename: Shelly
authors.initials: S
authors.lastname: Lwu
authors.forename: Jungho
authors.initials: J
authors.lastname: Kim
authors.forename: Jerry
authors.initials: J
authors.lastname: Pelletier
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D001853:Bone Marrow / Q000737:chemistry* / Q000502:physiology; D002458:Cell Fractionation; D002460:Cell Line; D057137:DAX-1 Orphan Nuclear Receptor; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D005333:Fetus / Q000033:anatomy & histology / Q000502:physiology; D017930:Genes, Reporter; D006801:Humans; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D018168:Receptors, Retinoic Acid / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D015533:Transcriptional Activation; D025721:WT1 Proteins / Q000235:genetics / Q000378:metabolism*; D009396:Wilms Tumor / Q000235:genetics; D016335:Zinc Fingers
chemical_list: D057137:DAX-1 Orphan Nuclear Receptor; D004268:DNA-Binding Proteins; C539965:NR0B1 protein, human; D018168:Receptors, Retinoic Acid; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; D025721:WT1 Proteins; C470003:ZNF224 protein, human