Fraction of total capacity that a proteasome works in in unstressed cells
| Range | ~20 % |
|---|---|
| Organism | Unspecified |
| Reference | Yewdell JW, Reits E, Neefjes J. Making sense of mass destruction: quantitating MHC class I antigen presentation. Nat Rev Immunol. 2003 Dec3(12):952-61. DOI: 10.1038/nri1250 p.959 left column 2nd paragraphPubMed ID14647477 |
| Primary Source | [69] Dantuma, N. P., Lindsten, K., Glas, R., Jellne, M. & Masucci, M. G. Short-lived green fluorescent proteins for quantifying ubiquitin/proteasome-dependent proteolysis in living cells. Nature Biotechnol. 18, 538–543 (2000). DOI: 10.1038/75406 [70] Bence, N. F., Sampat, R. M. & Kopito, R. R. Impairment of the ubiquitin-proteasome system by protein aggregation. Science 292, 1552–1555 (2001). DOI: 10.1126/science.292.5521.1552PubMed ID10802622, 11375494 |
| Method | Primary source [69] abstract: "[Investigators] have developed a convenient reporter system by producing N-end rule and ubiquitin fusion degradation (UFD)-targeted green fluorescent proteins that allow quantification of ubiquitin/proteasome-dependent proteolysis in living cells." |
| Comments | P.959 left column 2nd paragraph: "While each ribosome is producing a protein every 90 seconds, each proteasome is degrading 2.25 substrates per minute. Proteasomes are probably not working at full capacity though. Two independent studies estimate that proteasomes are acting at ~20% of their total capacity in unstressed cells [primary sources] indicating a Vmax of 11 substrates per proteasome per minute, or five seconds per substrate, which is 20 times faster than the rate of protein synthesis (see table 2 BNID 113775 for kinetics)." |
| Entered by | Uri M |
| ID | 113792 |