RRC ID 46995
著者 Saeki Y, Kudo T, Sone T, Kikuchi Y, Yokosawa H, Toh-e A, Tanaka K.
タイトル Lysine 63-linked polyubiquitin chain may serve as a targeting signal for the 26S proteasome.
ジャーナル EMBO J
Abstract Recruitment of substrates to the 26S proteasome usually requires covalent attachment of the Lys48-linked polyubiquitin chain. In contrast, modifications with the Lys63-linked polyubiquitin chain and/or monomeric ubiquitin are generally thought to function in proteasome-independent cellular processes. Nevertheless, the ubiquitin chain-type specificity for the proteasomal targeting is still poorly understood, especially in vivo. Using mass spectrometry, we found that Rsp5, a ubiquitin-ligase in budding yeast, catalyzes the formation of Lys63-linked ubiquitin chains in vitro. Interestingly, the 26S proteasome degraded well the Lys63-linked ubiquitinated substrate in vitro. To examine whether Lys63-linked ubiquitination serves in degradation in vivo, we investigated the ubiquitination of Mga2-p120, a substrate of Rsp5. The polyubiquitinated p120 contained relatively high levels of Lys63-linkages, and the Lys63-linked chains were sufficient for the proteasome-binding and subsequent p120-processing. In addition, Lys63-linked chains as well as Lys48-linked chains were detected in the 26S proteasome-bound polyubiquitinated proteins. These results raise the possibility that Lys63-linked ubiquitin chain also serves as a targeting signal for the 26S proteaseome in vivo.
巻・号 28(4)
ページ 359-71
公開日 2009-2-18
DOI 10.1038/emboj.2008.305
PII emboj2008305
PMID 19153599
PMC PMC2646160
MeSH Cyclin-Dependent Kinase Inhibitor Proteins Endosomal Sorting Complexes Required for Transport Lysine / chemistry* Mass Spectrometry / methods Membrane Proteins Models, Biological Plasmids / metabolism Polyubiquitin / chemistry* Proteasome Endopeptidase Complex / metabolism* Saccharomyces cerevisiae / metabolism Saccharomyces cerevisiae Proteins / metabolism* Signal Transduction Trans-Activators / metabolism Transcription Factors Ubiquitin / chemistry Ubiquitin-Protein Ligase Complexes / metabolism* p120 GTPase Activating Protein / metabolism
IF 9.889
引用数 155
WOS 分野 BIOCHEMISTRY & MOLECULAR BIOLOGY CELL BIOLOGY
リソース情報
病原微生物