Identification of a DNA binding protein cooperating with estrogen receptor as RIZ (retinoblastoma interacting zinc finger protein).
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.
Medici
N
N
Facoltà di Medicina e Chirurgia, Seconda Università degli studi di Napoli, Larghetto Sant' Aniello a Caponapoli, 2, Naples, I-80138, Italy.
Abbondanza
C
C
Nigro
V
V
Rossi
V
V
Piluso
G
G
Belsito
A
A
Gallo
L
L
Roscigno
A
A
Bontempo
P
P
Puca
A A
AA
Molinari
A M
AM
Moncharmont
B
B
Puca
G A
GA
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
D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D011960:Receptors, Estrogen; D014157:Transcription Factors; D011495:Histone-Lysine N-Methyltransferase; C093563:PRDM2 protein, human