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Related to Ubiquitin proteasome system: Ubiquitin proteasome pathway, Ubiquitylation, Immunoproteasome


Cytoplasmic organelle, composed of a cylindric core particle bound by two regulatory particles at each end, responsible for degrading endogenous proteins. Proteins to be destroyed are recognized by proteasomes because of the presence of ubiquitin conjugated to the targeted protein's lysine residue.
See also: ubiquitin-protease pathway.
[protease + -some ]


A cellular protein complex consisting of proteolytic enzymes that degrade endogenous proteins, especially those that are damaged, pathogenic, or no longer of use.


, proteosome (prō′tē-ă-sōm″)
An enzymatic (protease) cell organelle that degrades misfolded or damaged proteins and modulates the quantity of regulatory proteins in the cell. The breakdown of proteins by proteasomes (proteolysis) is triggered when damaged proteins are tagged by ubiquitin.


A large, cylindrical protein complex of several sub-units, present in the cytoplasm and nucleus of all cells and an essential component in cell metabolism. The function of the proteasome is to act as a kind of shredder, degrading unwanted proteins that have been tagged for destruction with UBIQUITIN chains. It strips proteins of their ubiquitin, unfolds them and catalyzed them to peptides. Proteasomes have aroused much interest as therapeutic trargets in cancer. The proteasome 26S is involved both in the induction and repression of APOPTOSIS. See also POLYUBIQUITINATION.
References in periodicals archive ?
To evaluate the effect of parthenolide on the proinflammatory cytokine and the downstream proteolytic ubiquitin proteasome system, we first measured the levels of IL-6 and TNF-[alpha].
We next used the proteasome inhibitors MG132 (20 [micro]M for 4h) to determine whether the OGDR-mediated increase in Drp1 protein expression was due to inhibition of ubiquitin proteasome system (UPS).
Mutations in parkin would result in ubiquitin proteasome system (UPS) dysfunction [21].
The regulated protein level of Drp1 after OGDR insult is mediated by parkin through the ubiquitin proteasome system.
Of the two systems of intracellular proteolysis, the lysosomal system plays an important role in the degradation of membrane-bound proteins while the ubiquitin proteasome system (UPS) is widely recognized as the main system for degradation of cytosolic proteins [27,28].
Abbreviations ALT: Alanine aminotransferase AOPP: Advanced oxidation protein products GSH: Reduced glutathione GSH-R: Glutathione reductase GSSG: Oxidized glutathione HNE: 4-Hydroxynonenal IPRL: Isolated perfused rat livers MDA: Malondialdehyde NO: Nitric oxide TBARS: Thiobarbituric reactive substances UPS: Ubiquitin proteasome system.
Rolfe has extensive experience discovering kinase inhibitors, inhibitors of the ubiquitin proteasome system and novel cancer antibodies.

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