# PubMed- Evaluation of ubiquitinated proteins by proteomics reveals the role of the ubiquitin proteasome system in the regulation of Grp75 and Grp78 ch



## VSsupport (Feb 12, 2008)

[TD]
*Evaluation of ubiquitinated proteins by proteomics reveals the role of the ubiquitin proteasome system in the regulation of Grp75 and Grp78 chaperone proteins during intestinal inflammation.*

Proteomics. 2013 Sep 9;

Authors: Bertrand J, Tennoune N, Marion-Letellier R, Goichon A, Chan P, Mbodji K, Vaudry D, Déchelotte P, Coëffier M

Abstract
The ubiquitin proteasome system (UPS) is the major pathway of intracellular protein degradation and may be involved in the pathophysiology of inflammatory bowel diseases or of irritable bowel syndrome. UPS specifically degrades proteins tagged with an ubiquitin chain. We aimed to identify polyubiquitinated proteins during inflammatory response in intestinal epithelial HCT-8 cells by a proteomic approach. HCT-8 cells were incubated with IL-1Î², TNFÎ± and IFNÎ³ for 2 hours. Total cellular protein extracts were separated by 2D gel electrophoresis and analyzed by an immunodetection using anti-ubiquitin antibody. Differentially ubiquitinated proteins were then identified by liquid chromatography-electrospray ionization MS/MS. Seven proteins were differentially ubiquitinated between control and inflammatory conditions. Three of them were chaperones: Grp75 and Hsc70 were more ubiquitinated (p<0,05) and Grp78 less ubiquitinated (p<0,05) under inflammatory conditions. The results for Grp75 and Grp78 were then confirmed in HCT-8 cells and in TNBS-induced colitis in rats mimicking Inflammatory Bowel Disease (IBD) by immunoprecipitation. No difference was observed in Irritable Bowel Syndrome (IBS)-like model. In conclusion, we showed that a proteomic approach is suitable to identify ubiquitinated proteins and that UPS-regulated expression of Grp75 and Grp78 may be involved in inflammatory response. Further studies should lead to the identification of ubiquitin-ligases responsible of Grp75 and Grp78 ubiquitination. This article is protected by copyright. All rights reserved.

PMID: 24030972 [PubMed - as supplied by publisher]

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