Together, Rpn10 and Dsk2 Can Serve as a Polyubiquitin Chain-Length Sensor
| Autor: | Yulia Matiuhin, Vered Bronner, Daoning Zhang, David Fushman, Michael H. Glickman, Tony Y. Chen, Rina Rosenzweig, Inbal Ziv |
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| Rok vydání: | 2009 |
| Předmět: |
Models
Molecular Proteasome Endopeptidase Complex Saccharomyces cerevisiae Proteins biology Cell Cycle Proteins Plasma protein binding Saccharomyces cerevisiae Cell Biology Ubiquitin-conjugating enzyme Article Ubiquitin ligase Protein Structure Tertiary Ubiquitins Protein structure Proteasome Ubiquitin Biochemistry biology.protein Biophysics Signal transduction Polyubiquitin Molecular Biology Protein Binding Signal Transduction |
| Zdroj: | Molecular Cell. 36(6):1018-1033 |
| ISSN: | 1097-2765 |
| DOI: | 10.1016/j.molcel.2009.11.012 |
| Popis: | As a signal for substrate targeting, polyubiquitin meets various layers of receptors upstream to the 26S proteasome. We obtained structural information on two receptors, Rpn10 and Dsk2, alone, and in complex with (poly)ubiquitin or with each other. A hierarchy of affinities emerges with Dsk2 binding monoubiquitin tighter than Rpn10 does, whereas Rpn10 prefers the ubiquitin-like domain of Dsk2 to monoubiquitin, with increasing affinities for longer polyubiquitin chains. We demonstrated the formation of ternary complexes of both receptors simultaneously with (poly)ubiquitin and found that, depending on the ubiquitin-chain length, the orientation of the resulting complex is entirely different, providing for alternate signals. Dynamic rearrangement provides a chain-length sensor, possibly explaining how accessibility of Dsk2 to the proteasome is limited unless it carries a properly-tagged cargo. We propose a mechanism for a malleable ubiquitin-signal that depends both on chain-length and combination of receptors to produce tetra-ubiquitin as an efficient signal threshold. |
| Databáze: | OpenAIRE |
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