The deubiquitinase USP7 uses a distinct ubiquitin-like domain to deubiquitinate NF-ĸB subunits

Mitxitorena, I., Somma, D. , Mitchell, J. P., Lepistö, M., Tyrchan, C., Smith, E. L., Kiely, P. A., Walden, H. , Keeshan, K. and Carmody, R. J. (2020) The deubiquitinase USP7 uses a distinct ubiquitin-like domain to deubiquitinate NF-ĸB subunits. Journal of Biological Chemistry, 295(33), pp. 11754-11763. (doi: 10.1074/jbc.RA120.014113) (PMID:32587091) (PMCID:PMC7450122)

Abstract

The transcription factor NF-ĸB is a master regulator of the innate immune response and plays a central role in inflammatory diseases by mediating the expression of pro-inflammatory cytokines. Ubiquitination-triggered proteasomal degradation of DNA-bound NF-ĸB strongly limits the expression of its target genes. Conversely, the deubiquitinase ubiquitin-specific peptidase 7 (USP7) opposes the activities of E3 ligases, stabilizes DNA-bound NF-ĸB, and thereby promotes NF-ĸB–mediated transcription. Using gene expression and synthetic peptide arrays on membrane support (SPOT) synthesis of peptides and overlay analyses, we found here that inhibiting USP7 increases NF-ĸB ubiquitination and degradation, prevents Toll-like receptor–induced pro-inflammatory cytokine expression, and represents an effective strategy for controlling inflammation. However, the broad regulatory roles of USP7 in cell death pathways, chromatin, and DNA damage responses limits the use of catalytic inhibitors of USP7 as anti-inflammatory agents. To this end, we identified an NF-ĸB–binding site in USP7, ubiquitin-like domain 2, that selectively mediates interactions of USP7 with NF-ĸB subunits, but is dispensable for interactions with other proteins. Moreover, we found that the amino acids 757LDEL760 in USP7 critically contribute to the interaction with the p65 subunit of NF-ĸB. Our findings support the notion that USP7 activity could be potentially targeted in a substrate-selective manner through the development of non-catalytic inhibitors of this deubiquitinase to abrogate NF-ĸB activity.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: MITCHELL, JENNIFER and Carmody, Dr Ruaidhri and Keeshan, Dr Karen and Mitxitorena, Izaskun and Walden, Professor Helen and Somma, Domenico
• Authors: Mitxitorena, I., Somma, D., Mitchell, J. P., Lepistö, M., Tyrchan, C., Smith, E. L., Kiely, P. A., Walden, H., Keeshan, K., and Carmody, R. J.
• College/School: College of Medical Veterinary and Life Sciences > School of Cancer Sciences; College of Medical Veterinary and Life Sciences > School of Infection & Immunity; College of Medical Veterinary and Life Sciences > School of Molecular Biosciences
• Research Centre: College of Medical Veterinary and Life Sciences > School of Infection & Immunity > Centre for Immunobiology
• Journal Name: Journal of Biological Chemistry
• Publisher: American Society for Biochemistry and Molecular Biology
• ISSN: 0021-9258
• ISSN (Online): 1083-351X
• Published Online: 25 June 2020
• Copyright Holders: Copyright © 2020 Mitxitorena et al.
• First Published: First published in Journal of Biological Chemistry 2020
• Publisher Policy: Reproduced under a Creative Commons License

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
190848		Investigating NF-kB p50 phosphorylation and the regulation of transcription	Ruaidhri Carmody	Medical Research Council (MRC)	MR/M010694/1	III - Immunology
190815		Dissecting the function of Bcl-3 in NF-kappaB signaling in B cells	Ruaidhri Carmody	Biotechnology and Biological Sciences Research Council (BBSRC)	BB/M003671/1	III - Immunology
171868		The basis of agonist and antagonist function at Free Fatty Acid receptor 2	Graeme Milligan	Biotechnology and Biological Sciences Research Council (BBSRC)	BB/J013854/1	MCSB - Molecular Pharmacology