A novel TBP-interacting zinc finger protein represses transcription by inhibiting the recruitment of TFIIA and TFIIB.
We isolated a novel gene encoding a zinc finger protein from Xenopus laevis, designated NZFP that interacts with the TATA-binding protein (TBP). NZFP contains a highly conserved sequence designated finger associated box (FAX) and SUMO-1 consensus-binding motifs at the N-terminal half and 10 C2H2 type zinc finger motifs at the C-terminal half, respectively. Deletion mutants of NZFP fused with the Gal4 DNA binding domain were used to determine the function of NZFP during gene transcription by transfecting them into a Xenopus kidney cell line. Both full-length NZFP and the FAX domain repressed transcription activity by 3-5-fold. Moreover, an in vitro pull-down assay showed that the C-terminal core domain of TBP makes direct contact with the N-terminal portion of NZFP. We also found through chromatin immunoprecipitation experiments that the interaction between NZFP and TBP inhibits binding of TFIIA and TFIIB. These data strongly suggest that the repression by NZFP occurs through its binding to both DNA and TBP and the resulting NZFP-TBP-promoter complex inhibits preinitiation complex assembly by preventing binding of TFIIA and TFIIB.
Kim
Mijin
M
Laboratory of Molecular Genetics, School of Biological Sciences, Seoul National University, 151-742, Seoul, South Korea.
Park
Chan Ho
CH
Lee
Myoung Sook
MS
Carlson
Bradley A
BA
Hatfield
Dolph L
DL
Lee
Byeong Jae
BJ
D000595:Amino Acid Sequence; D000818:Animals; D019843:Archaeal Proteins; D001483:Base Sequence; D018076:DNA, Complementary / Q000235:genetics / Q000302:isolation & purification; D066298:In Vitro Techniques; D008954:Models, Biological; D008969:Molecular Sequence Data; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D035181:TATA-Box Binding Protein / Q000378:metabolism*; D035561:Transcription Factor TFIIA / Q000378:metabolism*; D035581:Transcription Factor TFIIB / Q000378:metabolism*; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D014158:Transcription, Genetic; D014982:Xenopus laevis; D016335:Zinc Fingers
D019843:Archaeal Proteins; D018076:DNA, Complementary; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D035181:TATA-Box Binding Protein; C121585:TIP protein, Pyrococcus kodakaraensis; D035561:Transcription Factor TFIIA; D035581:Transcription Factor TFIIB; D014157:Transcription Factors