Krüppel-associated box-mediated repression of RNA polymerase II promoters is influenced by the arrangement of basal promoter elements.
The evolutionarily conserved Krüppel-associated box (KRAB) is present in the N-terminal regions of more than one-third of all Krüppel-class zinc finger proteins. Recent experiments have demonstrated that the KRAB-A domain tethered to a promoter DNA by connecting to heterologous DNA-binding protein domain or targeted to a promoter-proximal RNA sequence acts as a transcriptional silencing of RNA polymerase II promoters. Here we show that expression of KRAB domain suppresses in vivo the activating function of various defined activating transcription factors, and we demonstrate that the KRAB domain specifically silences the activity of promoters whose initiation is dependent on the presence of a TATA box. Promoters whose accurate transcription initiation is directed by a pyrimidine-rich initiator element, however, are relatively unaffected. We also report in vitro transcription experiments indicating that the KRAB domain is able to repress both activated and basal promoter activity. Thus, the KRAB domain appears to repress the activity of certain promoters through direct communication with TATA box-dependent basal transcription machinery.
Pengue
G
G
Department of Genetics, Molecular and General Biology, University of Naples, Federico II, Italy.
Lania
L
L
D001483:Base Sequence; D015500:Chloramphenicol O-Acetyltransferase / Q000032:analysis / Q000096:biosynthesis; D017124:Conserved Sequence; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004794:Enzyme Repression; D016325:HIV Long Terminal Repeat; D006367:HeLa Cells; D006801:Humans; D051741:Kruppel-Like Transcription Factors; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D010957:Plasmids; D011401:Promoter Regions, Genetic; D012319:RNA Polymerase II / Q000096:biosynthesis* / Q000235:genetics*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism; D015183:Restriction Mapping; D016385:TATA Box; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic; D014162:Transfection
D004268:DNA-Binding Proteins; D051741:Kruppel-Like Transcription Factors; D009838:Oligodeoxyribonucleotides; D011994:Recombinant Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; D015500:Chloramphenicol O-Acetyltransferase; D012319:RNA Polymerase II