title: H2B ubiquitylation is part of chromatin architecture that marks exon-intron structure in budding yeast.
abstract: BACKGROUND
  The packaging of DNA into chromatin regulates transcription from initiation through 3' end processing. One aspect of transcription in which chromatin plays a poorly understood role is the co-transcriptional splicing of pre-mRNA.
  
  
  RESULTS
  Here we provide evidence that H2B monoubiquitylation (H2BK123ub1) marks introns in Saccharomyces cerevisiae. A genome-wide map of H2BK123ub1 in this organism reveals that this modification is enriched in coding regions and that its levels peak at the transcribed regions of two characteristic subgroups of genes. First, long genes are more likely to have higher levels of H2BK123ub1, correlating with the postulated role of this modification in preventing cryptic transcription initiation in ORFs. Second, genes that are highly transcribed also have high levels of H2BK123ub1, including the ribosomal protein genes, which comprise the majority of intron-containing genes in yeast. H2BK123ub1 is also a feature of introns in the yeast genome, and the disruption of this modification alters the intragenic distribution of H3 trimethylation on lysine 36 (H3K36me3), which functionally correlates with alternative RNA splicing in humans. In addition, the deletion of genes encoding the U2 snRNP subunits, Lea1 or Msl1, in combination with an htb-K123R mutation, leads to synthetic lethality.
  
  
  CONCLUSIONS
  These data suggest that H2BK123ub1 facilitates cross talk between chromatin and pre-mRNA splicing by modulating the distribution of intronic and exonic histone modifications.
authors.affiliation: Institute of Statistical Sciences, Academia Sinica, Academia Road, Nankang, Taipei 115, Taiwan.
authors.forename: Grace S
authors.initials: GS
authors.lastname: Shieh
authors.forename: Chin-Hua
authors.initials: CH
authors.lastname: Pan
authors.forename: Jia-Hong
authors.initials: JH
authors.lastname: Wu
authors.forename: Yun-Ju
authors.initials: YJ
authors.lastname: Sun
authors.forename: Chia-Chang
authors.initials: CC
authors.lastname: Wang
authors.forename: Wei-Chun
authors.initials: WC
authors.lastname: Hsiao
authors.forename: Chia-Yeh
authors.initials: CY
authors.lastname: Lin
authors.forename: Luh
authors.initials: L
authors.lastname: Tung
authors.forename: Tien-Hsien
authors.initials: TH
authors.lastname: Chang
authors.forename: Alastair B
authors.initials: AB
authors.lastname: Fleming
authors.forename: Cory
authors.initials: C
authors.lastname: Hillyer
authors.forename: Yi-Chen
authors.initials: YC
authors.lastname: Lo
authors.forename: Shelley L
authors.initials: SL
authors.lastname: Berger
authors.forename: Mary Ann
authors.initials: MA
authors.lastname: Osley
authors.forename: Cheng-Fu
authors.initials: CF
authors.lastname: Kao
mesh_terms: D005091:Exons; D006657:Histones / Q000378:metabolism*; D007438:Introns; D008745:Methylation; D016366:Open Reading Frames; D012323:RNA Processing, Post-Transcriptional; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D054875:Ubiquitination
chemical_list: D006657:Histones