title: Biochemical characterization of the zinc-finger protein 217 transcriptional repressor complex: identification of a ZNF217 consensus recognition sequence.
abstract: Zinc-finger protein 217 (ZNF217) is a Kruppel-like zinc-finger protein located at 20q13.2, within a region of recurrent maximal amplification. Here, we demonstrate that ZNF217 is a transcriptional repressor protein and report the purification and characterization of a ZNF217 complex. The purified ZNF217 complex consists of approximately six proteins and contains the transcriptional co-repressors CoREST, BHC110/LSD1, histone deacetylase (HDAC) 2 and C-terminal binding protein (CtBP1). The purified ZNF217 complex possesses deacetylase activity as well as lysine 4 histone H3-specific demethylase activity that is most likely mediated by the BHC110/LSD1 component. To determine if ZNF217 is a sequence-specific binding protein, we have made use of cyclic amplification and selection of targets (CAST) assay and identify for the first time a ZNF217 DNA consensus recognition sequence (CRS) that is highly conserved in the human E-cadherin promoter. Chromatin immunoprecipitation (ChIP) experiments demonstrate that ZNF217, as well as the other components of the ZNF217 complex, are found on the region of the proximal E-cadherin promoter that contains the identified ZNF217 CRS in vivo. Using a combination of transient transfections and small interfering RNA, we demonstrate that ZNF217 represses the E-cadherin promoter. Collectively, our results implicate ZNF217 and its associated proteins in a novel pathway that may have profound effects on cancer progression.
authors.affiliation: Department of Oncology, London Regional Cancer Program, The University of Western Ontario, London, Ontario, Canada.
authors.forename: J J M
authors.initials: JJ
authors.lastname: Cowger
authors.forename: Q
authors.initials: Q
authors.lastname: Zhao
authors.forename: M
authors.initials: M
authors.lastname: Isovic
authors.forename: J
authors.initials: J
authors.lastname: Torchia
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D015820:Cadherins / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D016384:Consensus Sequence; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D015536:Down-Regulation; D006801:Humans; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D016415:Sequence Alignment; D015534:Trans-Activators / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D014158:Transcription, Genetic / Q000235:genetics
chemical_list: D015820:Cadherins; D004268:DNA-Binding Proteins; D015534:Trans-Activators; C113698:ZNF217 protein, human; D004247:DNA