title: The polycystic kidney disease-1 gene is a target for p53-mediated transcriptional repression.
abstract: This study provides evidence that the tumor suppressor protein, p53, is a transcriptional repressor of PKD1. Kidneys of p53-null mice expressed higher Pkd1 mRNA levels than wild-type littermates; gamma-irradiation suppressed PKD1 gene expression in p53+/+ but not p53-/- cells; and chromatin immunoprecipitation assays demonstrated the binding of p53 to the PKD1 promoter in vivo. In transient transfection assays, p53 repressed PKD1 promoter activity independently of endogenous p21. Deletion analysis mapped p53-mediated repression to the proximal promoter region of PKD1. Mutations of the DNA binding or C-terminal minimal repression domains of p53 abolished its ability to repress PKD1. Moreover, trichostatin A, an inhibitor of histone deacetylase activity, attenuated p53-induced repression of the PKD1 promoter. These findings, together with previous reports showing that dedifferentiated Pkd1-deficient cells express lower p53 and p21 levels, suggest a model whereby PKD1 signaling activates the p53-p21 differentiation pathway. In turn, p53 cooperates with histone deacetylases to repress PKD1 gene transcription. Loss of a p53-mediated negative feedback loop in PKD1 mutant cells may therefore contribute to deregulated PKD1 expression and cystogenesis.
authors.affiliation: Department of Pediatrics, Section of Pediatric Nephrology, Tulane University Health Sciences Center, New Orleans, Louisiana 70112, USA.
authors.forename: Diederik
authors.initials: D
authors.lastname: Van Bodegom
authors.forename: Zubaida
authors.initials: Z
authors.lastname: Saifudeen
authors.forename: Susana
authors.initials: S
authors.lastname: Dipp
authors.forename: Sanjeev
authors.initials: S
authors.lastname: Puri
authors.forename: Brenda S
authors.initials: BS
authors.lastname: Magenheimer
authors.forename: James P
authors.initials: JP
authors.lastname: Calvet
authors.forename: Samir S
authors.initials: SS
authors.lastname: El-Dahr
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D005786:Gene Expression Regulation; D016158:Genes, p53; D007668:Kidney / Q000378:metabolism; D051379:Mice; D011401:Promoter Regions, Genetic; D016283:Proto-Oncogene Proteins p21(ras) / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D015398:Signal Transduction; D050396:TRPP Cation Channels / Q000378:metabolism*; D014158:Transcription, Genetic; D016159:Tumor Suppressor Protein p53 / Q000502:physiology*
chemical_list: D016283:Proto-Oncogene Proteins p21(ras); D012333:RNA, Messenger; D050396:TRPP Cation Channels; D016159:Tumor Suppressor Protein p53