%0 Journal Article
%T USP16 is an ISG15 cross-reactive deubiquitinase that targets pro-ISG15 and ISGylated proteins involved in metabolism.
%A Gan J
%A Pinto-Fernández A
%A Flierman D
%A Akkermans JJLL
%A O'Brien DP
%A Greenwood H
%A Scott HC
%A Fritz G
%A Knobeloch KP
%A Neefjes J
%A van Dam H
%A Ovaa H
%A Ploegh HL
%A Kessler BM
%A Geurink PP
%A Sapmaz A
%J Proc Natl Acad Sci U S A
%V 120
%N 50
%D 2023 Dec 12
%M 38055744
%F 12.779
%R 10.1073/pnas.2315163120
%X Interferon-induced ubiquitin (Ub)-like modifier ISG15 covalently modifies host and viral proteins to restrict viral infections. Its function is counteracted by the canonical deISGylase USP18 or Ub-specific protease 18. Notwithstanding indications for the existence of other ISG15 cross-reactive proteases, these remain to be identified. Here, we identify deubiquitinase USP16 as an ISG15 cross-reactive protease by means of ISG15 activity-based profiling. Recombinant USP16 cleaved pro-ISG15 and ISG15 isopeptide-linked model substrates in vitro, as well as ISGylated substrates from cell lysates. Moreover, interferon-induced stimulation of ISGylation was increased by depletion of USP16. The USP16-dependent ISG15 interactome indicated that the deISGylating function of USP16 may regulate metabolic pathways. Targeted enzymes include malate dehydrogenase, cytoplasmic superoxide dismutase 1, fructose-bisphosphate aldolase A, and cytoplasmic glutamic-oxaloacetic transaminase 1. USP16 may thus contribute to the regulation of a subset of metabolism-related proteins during type-I interferon responses.