Polyadenylation site-induced decay of upstream transcripts enforces promoter directionality

Nat Struct Mol Biol. 2013 Aug;20(8):923-8. doi: 10.1038/nsmb.2640. Epub 2013 Jul 14.

Abstract

Active human promoters produce promoter-upstream transcripts (PROMPTs). Why these RNAs are coupled to decay, whereas their neighboring promoter-downstream mRNAs are not, is unknown. Here high-throughput sequencing demonstrates that PROMPTs generally initiate in the antisense direction closely upstream of the transcription start sites (TSSs) of their associated genes. PROMPT TSSs share features with mRNA-producing TSSs, including stalled RNA polymerase II (RNAPII) and the production of small TSS-associated RNAs. Notably, motif analyses around PROMPT 3' ends reveal polyadenylation (pA)-like signals. Mutagenesis studies demonstrate that PROMPT pA signals are functional but linked to RNA degradation. Moreover, pA signals are under-represented in promoter-downstream versus promoter-upstream regions, thus allowing for more efficient RNAPII progress in the sense direction from gene promoters. We conclude that asymmetric sequence distribution around human gene promoters serves to provide a directional RNA output from an otherwise bidirectional transcription process.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Blotting, Northern
  • HeLa Cells
  • High-Throughput Nucleotide Sequencing
  • Humans
  • Molecular Sequence Data
  • Oligonucleotides / genetics
  • Polyadenylation / genetics
  • Polyadenylation / physiology*
  • Promoter Regions, Genetic / genetics*
  • RNA Polymerase II / genetics
  • RNA Polymerase II / metabolism
  • RNA Stability / genetics
  • RNA Stability / physiology*
  • Transcription Initiation Site / physiology
  • Transcription, Genetic / genetics
  • Transcription, Genetic / physiology*

Substances

  • Oligonucleotides
  • RNA Polymerase II