Synthetic Uncleavable Ubiquitinated Proteins Dissect Proteasome Deubiquitination and Degradation, and Highlight Distinctive Fate of Tetraubiquitin
| Autor: | Sumeet K. Singh, Ashraf Brik, Michael H. Glickman, Oded Kleifeld, Sachitanand M. Mali, Hosahalli P. Hemantha, Indrajit Sahu |
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| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
chemistry.chemical_classification Proteasome Endopeptidase Complex Isopeptide bond Deubiquitinating Enzymes Molecular Structure Ubiquitin Chemistry Substrate (chemistry) General Chemistry Cleavage (embryo) Ubiquitinated Proteins Biochemistry Catalysis Cell biology 03 medical and health sciences Chain length 030104 developmental biology Colloid and Surface Chemistry Proteasome Humans Degradation (geology) Deubiquitination |
| Zdroj: | Journal of the American Chemical Society. 138:16004-16015 |
| ISSN: | 1520-5126 0002-7863 |
| Popis: | Various hypotheses have been proposed regarding how chain length, linkage type, position on substrate, and susceptibility to deubiquitinases (DUBs) affect processing of different substrates by proteasome. Here we report a new strategy for the chemical synthesis of ubiquitinated proteins to generate a set of well-defined conjugates bearing an oxime bond between the chain and the substrate. We confirmed that this isopeptide replacement is resistant to DUBs and to shaving by proteasome. Analyzing products generated by proteasomes ranked how chain length governed degradation outcome. Our results support that (1) the cleavage of the proximal isopeptide bond is not a prerequisite for proteasomal degradation, (2) by overcoming trimming at the proteasome, tetraUb is a fundamentally different signal than shorter chains, and (3) the tetra-ubiquitin chain can be degraded with the substrate. Together these results highlight the usefulness of chemistry to dissect the contribution of proteasome-associated DUBs and the complexity of the degradation process. |
| Databáze: | OpenAIRE |
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