RST1 and RIPR connect the cytosolic RNA exosome to the Ski complex in Arabidopsis

Nat Commun. 2019 Aug 27;10(1):3871. doi: 10.1038/s41467-019-11807-4.


The RNA exosome is a key 3'-5' exoribonuclease with an evolutionarily conserved structure and function. Its cytosolic functions require the co-factors SKI7 and the Ski complex. Here we demonstrate by co-purification experiments that the ARM-repeat protein RESURRECTION1 (RST1) and RST1 INTERACTING PROTEIN (RIPR) connect the cytosolic Arabidopsis RNA exosome to the Ski complex. rst1 and ripr mutants accumulate RNA quality control siRNAs (rqc-siRNAs) produced by the post-transcriptional gene silencing (PTGS) machinery when mRNA degradation is compromised. The small RNA populations observed in rst1 and ripr mutants are also detected in mutants lacking the RRP45B/CER7 core exosome subunit. Thus, molecular and genetic evidence supports a physical and functional link between RST1, RIPR and the RNA exosome. Our data reveal the existence of additional cytosolic exosome co-factors besides the known Ski subunits. RST1 is not restricted to plants, as homologues with a similar domain architecture but unknown function exist in animals, including humans.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / physiology*
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Carbon-Carbon Lyases / genetics
  • Cytosol / metabolism
  • Exosome Multienzyme Ribonuclease Complex / metabolism*
  • Exosomes / metabolism
  • Intracellular Signaling Peptides and Proteins / genetics
  • Intracellular Signaling Peptides and Proteins / metabolism*
  • Mass Spectrometry
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Plants, Genetically Modified
  • Protein Binding / physiology
  • RNA Interference / physiology*
  • RNA Stability / physiology
  • RNA, Messenger / metabolism
  • RNA, Small Interfering / metabolism


  • AT5G44150 protein, Arabidopsis
  • Arabidopsis Proteins
  • Intracellular Signaling Peptides and Proteins
  • Membrane Proteins
  • RNA, Messenger
  • RNA, Small Interfering
  • RST1 protein, Arabidopsis
  • Exosome Multienzyme Ribonuclease Complex
  • CER3 protein, Arabidopsis
  • Carbon-Carbon Lyases