1. RST1 and RIPR connect the cytosolic RNA exosome to the Ski complex in Arabidopsis.
- Author
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Lange H, Ndecky SYA, Gomez-Diaz C, Pflieger D, Butel N, Zumsteg J, Kuhn L, Piermaria C, Chicher J, Christie M, Karaaslan ES, Lang PLM, Weigel D, Vaucheret H, Hammann P, and Gagliardi D
- Subjects
- Arabidopsis Proteins genetics, Carbon-Carbon Lyases genetics, Cytosol metabolism, Exosomes metabolism, Intracellular Signaling Peptides and Proteins genetics, Mass Spectrometry, Membrane Proteins genetics, Plants, Genetically Modified, Protein Binding physiology, RNA Stability physiology, RNA, Messenger metabolism, RNA, Small Interfering metabolism, Arabidopsis physiology, Arabidopsis Proteins metabolism, Exosome Multienzyme Ribonuclease Complex metabolism, Intracellular Signaling Peptides and Proteins metabolism, Membrane Proteins metabolism, RNA Interference physiology
- Abstract
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.
- Published
- 2019
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