title: Identification of a DNA binding protein cooperating with estrogen receptor as RIZ (retinoblastoma interacting zinc finger protein).
abstract: Double-stranded DNA fragments were selected from a random pool by repeated cycles of estrogen receptor-specific immunoprecipitation in the presence of a nuclear extract and PCR amplification (cyclic amplification and selection of target, CAST, for multiple elements). Fragments were cloned and sequence analysis indicated the 5-nucleotide word TTGGC was the most recurrent sequence unrelated to the known estrogen responsive element. Screening a HeLa cell expression library with a probe designed with multiple repeats of this sequence resulted in the identification of a 1700-aa protein showing a complete homology with the product of the human retinoblastoma-interacting zinc-finger gene RIZ. In transfection experiments, RIZ protein was able to bestow estrogen inducibility to a promoter containing an incomplete estrogen responsive element and a TTGGC motif. RIZ protein present in MCF-7 cell nuclear extract retarded the TTGGC-containing probe in an EMSA. Estrogen receptor was co-immunoprecipitated from MCF-7 cell extract by antibodies to RIZ protein and vice versa, thus indicating an existing interaction between these two proteins.
authors.affiliation: Facoltà di Medicina e Chirurgia, Seconda Università degli studi di Napoli, Larghetto Sant' Aniello a Caponapoli, 2, Naples, I-80138, Italy.
authors.forename: N
authors.initials: N
authors.lastname: Medici
authors.forename: C
authors.initials: C
authors.lastname: Abbondanza
authors.forename: V
authors.initials: V
authors.lastname: Nigro
authors.forename: V
authors.initials: V
authors.lastname: Rossi
authors.forename: G
authors.initials: G
authors.lastname: Piluso
authors.forename: A
authors.initials: A
authors.lastname: Belsito
authors.forename: L
authors.initials: L
authors.lastname: Gallo
authors.forename: A
authors.initials: A
authors.lastname: Roscigno
authors.forename: P
authors.initials: P
authors.lastname: Bontempo
authors.forename: A A
authors.initials: AA
authors.lastname: Puca
authors.forename: A M
authors.initials: AM
authors.lastname: Molinari
authors.forename: B
authors.initials: B
authors.lastname: Moncharmont
authors.forename: G A
authors.initials: GA
authors.lastname: Puca
mesh_terms: D001483:Base Sequence; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D006367:HeLa Cells; D011495:Histone-Lysine N-Methyltransferase; D006801:Humans; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D011960:Receptors, Estrogen / Q000235:genetics* / Q000378:metabolism; D017421:Sequence Analysis; D014157:Transcription Factors; D014162:Transfection; D016335:Zinc Fingers
chemical_list: D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D011960:Receptors, Estrogen; D014157:Transcription Factors; D011495:Histone-Lysine N-Methyltransferase; C093563:PRDM2 protein, human