title: Promyelocytic leukemia protein PML inhibits Nur77-mediated transcription through specific functional interactions.
abstract: The promyelocytic leukemia protein PML is a tumor and growth suppressor and plays an important role in a multiple pathways of apoptosis and regulation of cell cycle progression. Our previous studies and others also documented a role of PML in transcriptional regulation through its association with transcription coactivator CBP and transcription corepressor HDAC. Here, we showed that PML is a potent transcriptional repressor of Nur77, an orphan receptor and a member of the steroid receptor superfamily of proteins. We found that PML represses Nur77-mediated transactivation through a physical and functional interaction between the two proteins. PML interacts with Nur-77 in vitro in a GST-pull down assay and in vivo by coimmunoprecipitation assay. PML/Nur77 colocalized in vivo in a double immunofluorescent staining and confocal microscopic analysis. Our study further showed that the coiled-coil domain of PML interacts with the DNA-binding domain of Nur77 (amino acids 267-332). Electrophoretic mobility shift assay demonstrated that PML interferes with Nur77 DNA binding in a dose-dependent manner. This study indicates that PML interacts with the DNA-binding domain of Nur77 and represses transcription by preventing it from binding to the target promoter. This study supports a role of PML/Nur77 interaction in regulating cell growth and apoptosis.
authors.affiliation: Department of Molecular Pathology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA.
authors.forename: Wen-Shu
authors.initials: WS
authors.lastname: Wu
authors.forename: Zhi-Xiang
authors.initials: ZX
authors.lastname: Xu
authors.forename: Ruixiang
authors.initials: R
authors.lastname: Ran
authors.forename: Feng
authors.initials: F
authors.lastname: Meng
authors.forename: Kun-Sang
authors.initials: KS
authors.lastname: Chang
mesh_terms: D017209:Apoptosis; D002455:Cell Division; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D015972:Gene Expression Regulation, Neoplastic; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D008156:Luciferases / Q000378:metabolism; D008856:Microscopy, Fluorescence; D009363:Neoplasm Proteins / Q000378:metabolism*; D009687:Nuclear Proteins; D057105:Nuclear Receptor Subfamily 4, Group A, Member 1; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D000071156:Promyelocytic Leukemia Protein; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D018160:Receptors, Cytoplasmic and Nuclear; D011987:Receptors, Steroid; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014407:Tumor Cells, Cultured; D025521:Tumor Suppressor Proteins
chemical_list: D018076:DNA, Complementary; D004268:DNA-Binding Proteins; C539821:NR4A1 protein, human; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D057105:Nuclear Receptor Subfamily 4, Group A, Member 1; D000071156:Promyelocytic Leukemia Protein; D018160:Receptors, Cytoplasmic and Nuclear; D011987:Receptors, Steroid; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins; C070576:PML protein, human; D008156:Luciferases; D005982:Glutathione Transferase