A variety of RNA polymerases II and III-dependent promoter classes is repressed by factors containing the Krüppel-associated/finger preceding box of zinc finger proteins.
KRAB/FPB (Krüppel-associated/finger preceding box) domains are small, portable transcriptional repression motifs, encoded by hundreds of vertebrates C2-H2-type zinc finger genes. We report that KRAB/FPB domains feature an unprecedented, highly promiscuous DNA-binding dependent transcriptional repressing activity. Indeed, template bound chimeric factors containing KRAB/FPB modules actively repress in vivo the transcription of distinct promoter classes that depend on different core elements, recruit distinct basal transcriptional apparatuses and are transcribed either by RNA polymerase II or III. The promoter types repressed in transient assays in a dose- and DNA-binding dependent, but position- and orientation-independent manner, by GAL4-KRAB/FPB fusions include an RNA polymerase II-dependent small nuclear RNA promoter (U1) as well as RNA polymerase III-dependent class 2 (adenovirus VA1), class 3 (human U6) and atypical (human 7SL) promoters. Down-modulation of all of these templates depended on factors containing the A module of the KRAB/FPB domain. Data provide further insights into the properties and mode of action of this widespread repression motif, and support the notion that genes belonging to distinct classes may be repressed in vivo by KRAB/FPB containing zinc finger proteins. The exquisitely DNA-binding dependent transcriptional promiscuity exhibited by KRAB/FPB domains may provide a unique model system for studying the mechanism by which a promoter recruited repression motif can down-modulate a large variety of promoter types.
International Institute of Genetics and Biophysics, CNR, Via Marconi 10, Naples, Italy.
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Senatore
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Cafieri
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Di Marino
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Rosati
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Di Nocera
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Grimaldi
D000818:Animals; D001665:Binding Sites; D019556:COS Cells; D004268:DNA-Binding Proteins / Q000502:physiology*; D005656:Fungal Proteins / Q000235:genetics / Q000502:physiology; D005786:Gene Expression Regulation; D006367:HeLa Cells; D006801:Humans; D051741:Kruppel-Like Transcription Factors; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012313:RNA / Q000235:genetics; D012319:RNA Polymerase II / Q000502:physiology*; D012320:RNA Polymerase III / Q000502:physiology*; D020733:RNA, Small Cytoplasmic; D012342:RNA, Small Nuclear / Q000235:genetics; D012367:RNA, Viral / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000502:physiology; D012097:Repressor Proteins / Q000502:physiology; D017414:Ribonucleoprotein, U4-U6 Small Nuclear / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*; D014158:Transcription, Genetic; D016335:Zinc Fingers
D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C052130:GAL4 protein, S cerevisiae; D051741:Kruppel-Like Transcription Factors; D020733:RNA, Small Cytoplasmic; D012342:RNA, Small Nuclear; D012367:RNA, Viral; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D017414:Ribonucleoprotein, U4-U6 Small Nuclear; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; C052835:adenovirus associated RNA; D012313:RNA; D012319:RNA Polymerase II; D012320:RNA Polymerase III