Linked Life Data

18391941

Source:http://linkedlifedata.com/resource/pubmed/id/18391941

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2008-5-5
pubmed:abstractText
Eukaryotic cells use autophagy and the ubiquitin-proteasome system (UPS) as their major protein degradation pathways. Whereas the UPS is required for the rapid degradation of proteins when fast adaptation is needed, autophagy pathways selectively remove protein aggregates and damaged or excess organelles. However, little is known about the targets and mechanisms that provide specificity to this process. Here we show that mature ribosomes are rapidly degraded by autophagy upon nutrient starvation in Saccharomyces cerevisiae. Surprisingly, this degradation not only occurs by a non-selective mechanism, but also involves a novel type of selective autophagy, which we term 'ribophagy'. A genetic screen revealed that selective degradation of ribosomes requires catalytic activity of the Ubp3p/Bre5p ubiquitin protease. Although ubp3Delta and bre5Delta cells strongly accumulate 60S ribosomal particles upon starvation, they are proficient in starvation sensing and in general trafficking and autophagy pathways. Moreover, ubiquitination of several ribosomal subunits and/or ribosome-associated proteins was specifically enriched in ubp3Delta cells, suggesting that the regulation of ribophagy by ubiquitination may be direct. Interestingly, ubp3Delta cells are sensitive to rapamycin and nutrient starvation, implying that selective degradation of ribosomes is functionally important in vivo. Taken together, our results suggest a link between ubiquitination and the regulated degradation of mature ribosomes by autophagy.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/ATG8 protein, S cerevisiae, http://linkedlifedata.com/resource/pubmed/chemical/Aminopeptidases, http://linkedlifedata.com/resource/pubmed/chemical/Bre5 protein, S cerevisiae, http://linkedlifedata.com/resource/pubmed/chemical/Carrier Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Endopeptidases, http://linkedlifedata.com/resource/pubmed/chemical/LAP4 protein, S cerevisiae, http://linkedlifedata.com/resource/pubmed/chemical/Microtubule-Associated Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Nitrogen, http://linkedlifedata.com/resource/pubmed/chemical/Protein Subunits, http://linkedlifedata.com/resource/pubmed/chemical/Recombinant Fusion Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Saccharomyces cerevisiae Proteins, http://linkedlifedata.com/resource/pubmed/chemical/UBP3 protein, S cerevisiae, http://linkedlifedata.com/resource/pubmed/chemical/Ubiquitin
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1476-4679
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
10
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
602-10
pubmed:dateRevised
2008-10-28
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Mature ribosomes are selectively degraded upon starvation by an autophagy pathway requiring the Ubp3p/Bre5p ubiquitin protease.
pubmed:affiliation
Institute of Biochemistry, HPM, ETH Hönggerberg, 8093 Zürich, Switzerland. claudine.kraft@bc.biol.ethz.ch
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't