Two distinct transcription termination modes dictated by promoters

Genes Dev. 2017 Sep 15;31(18):1870-1879. doi: 10.1101/gad.301093.117. Epub 2017 Oct 11.


Transcription termination determines the ends of transcriptional units and thereby ensures the integrity of the transcriptome and faithful gene regulation. Studies in yeast and human cells have identified the exoribonuclease XRN2 as a key termination factor for protein-coding genes. Here we performed a genome-wide investigation of RNA polymerase II (Pol II) transcription termination in XRN2-deficient Caenorhabditis elegans and observed two distinct modes of termination. Although a subset of genes requires XRN2, termination of other genes appears both independent of, and refractory to, XRN2. XRN2 independence is not merely a consequence of failure to recruit XRN2, since XRN2 is present on-and promotes Pol II accumulation near the polyadenylation sites of-both gene classes. Unexpectedly, promoters instruct the choice of termination mode, but XRN2-independent termination additionally requires a compatible region downstream from the 3' end cleavage site. Hence, different termination mechanisms may work with different configurations of Pol II complexes dictated by promoters.

Keywords: RNA polymerase II; XRN2, Caenorhabditis elegans; transcription termination.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Caenorhabditis elegans / genetics*
  • Caenorhabditis elegans / metabolism
  • Caenorhabditis elegans Proteins / genetics
  • Caenorhabditis elegans Proteins / metabolism*
  • Exoribonucleases / genetics
  • Exoribonucleases / metabolism*
  • Promoter Regions, Genetic*
  • RNA Interference
  • RNA Polymerase II / genetics
  • RNA Polymerase II / metabolism*
  • RNA, Messenger / genetics
  • Transcription Termination, Genetic / physiology*


  • Caenorhabditis elegans Proteins
  • RNA, Messenger
  • RNA Polymerase II
  • Exoribonucleases
  • XRN-2 protein, C elegans