Lysine 63-linked polyubiquitin chain may serve as a targeting signal for the 26S proteasome
Yasushi Saeki,Tai Kudo,Takayuki Sone,Yoshiko Kikuchi,Hideyoshi Yokosawa,Akio Toh-e,Keiji Tanaka +6 more
Reads0
Chats0
TLDR
Using mass spectrometry, it is found that Rsp5, a ubiquitin‐ligase in budding yeast, catalyzes the formation of Lys63‐linked Ubiquitin chains in vitro, raising the possibility that Lys63-linked ubiquit in chain also serves as a targeting signal for the 26S proteaseome in vivo.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.read more
Citations
More filters
Journal ArticleDOI
The Ubiquitin Code
David Komander,Michael Rape +1 more
TL;DR: The structure, assembly, and function of the posttranslational modification with ubiquitin, a process referred to as ubiquitylation, controls almost every process in cells.
Journal ArticleDOI
Recognition and Processing of Ubiquitin-Protein Conjugates by the Proteasome
TL;DR: The proteasome contains deubiquitinating enzymes (DUBs) that can remove ubiquitin before substrate degradation initiates, thus allowing some substrates to dissociate from the proteasomes and escape degradation.
Journal ArticleDOI
Ubiquitin-binding domains — from structures to functions
TL;DR: New structure-based insights provide strategies for controlling cellular processes by targeting ubiquitin–UBD interfaces with implications for drug design and cell reprograming.
Journal ArticleDOI
The emerging complexity of protein ubiquitination
TL;DR: The present review focuses on the emerging complexity of the ubiquitin system, and reviews what is known about individual chain types, and highlights recent advances that explain how the ubiqu itin system achieves its intrinsic specificity.
Journal ArticleDOI
The increasing complexity of the ubiquitin code
Richard G. Yau,Michael Rape +1 more
TL;DR: How the increasing complexity of ubiquitylation is employed to ensure robust and faithful signal transduction in eukaryotic cells is discussed.
References
More filters
Journal ArticleDOI
The Ubiquitin System
Avram Hershko,Aaron Ciechanover +1 more
TL;DR: This review discusses recent information on functions and mechanisms of the ubiquitin system and focuses on what the authors know, and would like to know, about the mode of action of ubi...
Journal Article
A system of shuttle vectors and yeast host strains designed for efficient manipulation of DNA in Saccharomyces cerevisiae.
Journal ArticleDOI
Global analysis of protein expression in yeast
Sina Ghaemmaghami,Won-Ki Huh,Kiowa Bower,Russell W. Howson,Archana Belle,Noah Dephoure,Erin K. O'Shea,Jonathan S. Weissman +7 more
TL;DR: A Saccharomyces cerevisiae fusion library is created where each open reading frame is tagged with a high-affinity epitope and expressed from its natural chromosomal location, and it is found that about 80% of the proteome is expressed during normal growth conditions.
Book ChapterDOI
Getting started with yeast.
TL;DR: The yeast Saccharomyces cerevisiae is now recognized as a model system representing a simple eukaryote whose genome can be easily manipulated and made particularly accessible to gene cloning and genetic engineering techniques.
Journal ArticleDOI
Recognition of the polyubiquitin proteolytic signal.
TL;DR: The properties of the substrates studied here implicate substrate unfolding as a kinetically dominant step in the proteolysis of properly folded proteins, and suggest that extraproteasomal chaperones are required for efficient degradation of certain proteasome substrates.