title: Isoform-specific interaction of HP1 with human TAFII130.
abstract: The general transcription factor TFIID facilitates recruitment of the transcription machinery to gene promoters and regulates initiation of transcription by RNA polymerase II. hTAF(II)130, a component of TFIID, interacts with and serves as a coactivator for multiple transcriptional regulatory proteins, including Sp1 and CREB. A yeast two-hybrid screen has identified an interaction between hTAF(II)130 and heterochromatin protein 1 (HP1), a chromatin-associated protein whose function has been implicated in gene silencing. We find that hTAF(II)130 associates with HP1 in an isoform-specific manner: HP1alpha and HP1gamma bind to hTAF(II)130, but not HP1beta. In addition, we show that endogenous hTAF(II)130 and components of TFIID in HeLa nuclear extracts associate with glutathione S-transferase-HP1alpha and -HP1gamma. hTAF(II)130 possesses a pentapeptide HP1-binding motif, and mutation of the hTAF(II)130 HP1 box compromises the interaction of hTAF(II)130 with HP1. We demonstrate that Gal4-HP1 proteins interfere with hTAF(II)130-mediated activation of transcription. Our results suggest that HP1alpha and HP1gamma associate with hTAF(II)130 to mediate repression of transcription, supporting a new model of transcriptional repression involving a specific interaction between a component of TFIID and chromatin.
authors.affiliation: Department of Microbiology and Kaplan Comprehensive Cancer Center, New York University School of Medicine, New York, NY 10016, USA.
authors.forename: Milo F
authors.initials: MF
authors.lastname: Vassallo
authors.forename: Naoko
authors.initials: N
authors.lastname: Tanese
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D002467:Cell Nucleus / Q000378:metabolism; D000090266:Chromobox Protein Homolog 5; D002868:Chromosomal Proteins, Non-Histone / Q000737:chemistry* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry; D010957:Plasmids / Q000378:metabolism; D011485:Protein Binding; D020033:Protein Isoforms; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D035381:TATA-Binding Protein Associated Factors; D035362:Transcription Factor TFIID; D014157:Transcription Factors / Q000737:chemistry* / Q000378:metabolism; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014162:Transfection; D020798:Two-Hybrid System Techniques
chemical_list: C000715593:CBX1 protein, human; C000715594:CBX5 protein, human; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D010455:Peptides; D020033:Protein Isoforms; D011993:Recombinant Fusion Proteins; C101882:TAF4 protein, human; D035381:TATA-Binding Protein Associated Factors; D035362:Transcription Factor TFIID; D014157:Transcription Factors; D000090266:Chromobox Protein Homolog 5; D005982:Glutathione Transferase