Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2012 Nov;1823(11):2087-93.
doi: 10.1016/j.bbamcr.2012.06.016. Epub 2012 Jun 19.

Proteasome protease mediated regulation of cytokine induction and inflammation

Affiliations
Review

Proteasome protease mediated regulation of cytokine induction and inflammation

Nilofer Qureshi et al. Biochim Biophys Acta. 2012 Nov.

Abstract

We have previously demonstrated that proteasome serves as a central regulator of inflammation and macrophage function. Until recently, proteasomes have generally been considered to play a relatively passive role in the regulation of cellular activity, i.e., any ubiquitinated protein was considered to be in discriminatively targeted for degradation by the proteasome. We have demonstrated, however, by using specific proteasome protease inhibitors and knockout mice lacking specific components of immunoproteasomes, that proteasomes (containing X, Y, and Z protease subunits) and immunoproteasomes (containing LMP7, LMP2, and LMP10 protease subunits) have well-defined functions in cytokine induction and inflammation based on their individual protease activities. We have also shown that LPS-TLR mediated signaling in the murine RAW 264.7 macrophage cell line results in the replacement of macrophage immunoproteasomal subunits. Such modifications serve as pivotal regulators of LPS-induced inflammation. Our findings support the relatively novel concept that defects in structure/function of proteasome protease subunits caused by genetic disorders, aging, diet, or drugs may well have the potential to contribute to modulation of proteasome activity. Of particular relevance, we have identified quercetin and resveratrol, significant constituents present in berries and in red wine respectively, as two novel proteasome inhibitors that have been previously implicated as disease-modifying natural products. We posit that natural proteasome inhibitors/activators can potentially be used as therapeutic response modifiers to prevent/treat diseases through pathways involving the ubiquitin-proteasome pathway (UP-pathway), which likely functions as a master regulator involved in control of overall inflammatory responses. This article is part of a Special Issue entitled: Ubiquitin Drug Discovery and Diagnostics.

PubMed Disclaimer

Figures

Fig. 1
Fig. 1. LPS-induced signaling pathways in macrophages
Pathways 1 and 3 utilize MyD88/MAL as the adaptor molecules, while pathways 2a and 2b utilize the TRIF/TRAM adaptor molecules.
Fig. 2
Fig. 2. A. The six proteases of the proteasome
Subunits X, LMP7 have the chymotrypsin-like activity, Y, LMP2 have the post-acidic and Z, LMP10 have the trypsin-like activity. B. LPS treated RAW 264.7 cells manifest altered XYZ/LMP subunits and proteolytic activities of the proteasome. The ratio of chymotrypsin-like/post-acidic activity increases when the proteasomes contain LMP subunits upon LPS treatment. After use, the subunits of the proteasomes are ubiquitinated and degraded by the proteasome.

Similar articles

Cited by

References

    1. Qureshi N, Vogel SN, Van Way C, III, Papasian CJ, Qureshi AA, Morrison DC. The proteasome. A central regulator of Inflammation and macrophage function. Immunol Res. 2005;31:243–260. - PubMed
    1. Qureshi N, Perera P-Y, Splitter G, Morrison DC, Vogel SN. The Proteasome as a LPS-binding protein in macrophages. Toxic lipopolysaccharide activates the proteasome complex. J Immunol. 2003;171:1515–1525. - PubMed
    1. Shen J, Reis J, Morrison DC, Papasian C, Raghavaikaimal S, Kolbert C, Qureshi AA, Vogel SN, Qureshi N. Key inflammatory signaling pathways are regulated by the proteasome. Shock. 2006;25:472–484. - PubMed
    1. Shen J, Gao JJ, Zhang G, Tan X, Morrison DC, Papasian CJ, Vogel SN, Qureshi N. Proteasome inhibitor, lactacystin blocks CpG DNA- and peptidoglycan induced inflammatory genes, cytokines and mitogen-activated protein kinases in macrophages. Shock. 2006;25:594–599. - PubMed
    1. Gao JJ, Shen J, Kolbert C, Raghavakaimal S, Papasian CJ, Qureshi N, Vogel SN, Morrison DC, Qureshi N. The proteasome regulates bacterial CpG DNA-induced signaling pathways in murine macrophages. Shock. 2010;34:390–401. - PMC - PubMed