Exo- and endoribonucleolytic activities of yeast cytoplasmic and nuclear RNA exosomes are dependent on the noncatalytic core and central channel Journal Article


Authors: Wasmuth, E. V.; Lima, C. D.
Article Title: Exo- and endoribonucleolytic activities of yeast cytoplasmic and nuclear RNA exosomes are dependent on the noncatalytic core and central channel
Abstract: The RNA exosome is an essential multisubunit ribonuclease (RNase) that contributes to cytoplasmic and nuclear RNA decay and quality control. The 9-subunit exosome core (Exo9) features a prominent central channel formed by stacked asymmetric rings of six RNase PH-like proteins and three S1/KH domain proteins. Exo9 is catalytically inert but associates with Rrp44, an endoribonuclease and processive 3'→5' exoribonuclease, and Rrp6, a distributive 3'→5' exoribonuclease. We show that Exo9 and its central channel modulate all three yeast exosome RNase activities because channel occlusion attenuates RNA binding and RNase activities in vitro and fails to complement exosome functions in vivo. We find that Rrp6 stimulates Rrp44 RNase activities and that Rrp6 is inhibited by a mutation in the Rrp44 exoribonuclease active site in 11-subunit nuclear exosomes. These results suggest the exosome core and central channel is essential because it modulates each of the known RNase activities of the yeast RNA exosome. © 2012 Elsevier Inc.
Keywords: unclassified drug; mutation; nonhuman; protein function; enzyme activation; enzyme activity; enzyme regulation; saccharomyces cerevisiae; recombinant proteins; cytoplasm; models, molecular; cell nucleus; yeast; saccharomyces cerevisiae proteins; protein subunits; catalytic domain; rna, fungal; endoribonucleases; ribonuclease; exosome; nuclear rna; exoribonuclease; exoribonucleases; endoribonuclease rrp44; exoribonuclease rrp6; rna exosome core exo9; exosome multienzyme ribonuclease complex
Journal Title: Molecular Cell
Volume: 48
Issue: 1
ISSN: 1097-2765
Publisher: Cell Press  
Date Published: 2012-10-12
Start Page: 133
End Page: 144
Language: English
DOI: 10.1016/j.molcel.2012.07.012
PROVIDER: scopus
PMCID: PMC3472098
PUBMED: 22902556
DOI/URL:
Notes: --- - "Cited By (since 1996): 1" - "Export Date: 2 November 2012" - "CODEN: MOCEF" - "Source: Scopus"
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MSK Authors
  1. Christopher D Lima
    95 Lima
  2. Elizabeth Wasmuth
    10 Wasmuth