title: Transcription elongation factors repress transcription initiation from cryptic sites.
abstract: Previous studies have suggested that transcription elongation results in changes in chromatin structure. Here we present studies of Saccharomyces cerevisiae Spt6, a conserved protein implicated in both transcription elongation and chromatin structure. Our results show that, surprisingly, an spt6 mutant permits aberrant transcription initiation from within coding regions. Furthermore, transcribed chromatin in the spt6 mutant is hypersensitive to micrococcal nuclease, and this hypersensitivity is suppressed by mutational inactivation of RNA polymerase II. These results suggest that Spt6 plays a critical role in maintaining normal chromatin structure during transcription elongation, thereby repressing transcription initiation from cryptic promoters. Other elongation and chromatin factors, including Spt16 and histone H3, appear to contribute to this control.
authors.affiliation: Department of Genetics, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, USA.
authors.forename: Craig D
authors.initials: CD
authors.lastname: Kaplan
authors.forename: Lisa
authors.initials: L
authors.lastname: Laprade
authors.forename: Fred
authors.initials: F
authors.lastname: Winston
mesh_terms: D002843:Chromatin / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D056488:Histone Chaperones; D006657:Histones / Q000378:metabolism; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D009707:Nucleosomes / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D011401:Promoter Regions, Genetic; D012319:RNA Polymerase II / Q000378:metabolism; D012331:RNA, Fungal / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D035181:TATA-Box Binding Protein / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics; D014158:Transcription, Genetic; D035602:Transcriptional Elongation Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D002843:Chromatin; C100940:FLO8 protein, S cerevisaie; D056488:Histone Chaperones; D006657:Histones; D009687:Nuclear Proteins; D009707:Nucleosomes; D012331:RNA, Fungal; D012333:RNA, Messenger; C065456:SPT6 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D035181:TATA-Box Binding Protein; D015534:Trans-Activators; D035602:Transcriptional Elongation Factors; D012319:RNA Polymerase II