Inhibition of Wilms tumor 1 transactivation by bone marrow zinc finger 2, a novel transcriptional repressor.
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.
Lee
Tae Ho
TH
Department of Biochemistry, McGill University, Montreal, Quebec H3G 1Y6, Canada.
Lwu
Shelly
S
Kim
Jungho
J
Pelletier
Jerry
J
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
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