title: Sequential ubiquitination and deubiquitination enzymes synchronize the dual sensor and effector functions of TRIM21.
abstract: Tripartite motif (TRIM) 21 is a cytosolic antibody receptor that neutralizes antibody-coated viruses that penetrate the cell and simultaneously activates innate immunity. Here we show that the conjugation of TRIM21 with K63-linked ubiquitin (Ub-(63)Ub) catalyzed by the sequential activity of nonredundant E2 Ub enzymes is required for its dual antiviral functions. TRIM21 is first labeled with monoubiquitin (monoUb) by the E2 Ube2W. The monoUb is a substrate for the heterodimeric E2 Ube2N/Ube2V2, resulting in TRIM21-anchored Ub-(63)Ub. Depletion of either E2 abolishes Ub-(63)Ub and Ub-(48)Ub conjugation of TRIM21, NF-κB signaling, and virus neutralization. The formation of TRIM21-Ub-(63)Ub precedes proteasome recruitment, and we identify an essential role for the 19S-resident and degradation-coupled deubiquitinase Poh1 in TRIM21 neutralization, signaling, and cytokine induction. This study elucidates a complex mechanism of step-wise ubiquitination and deubiquitination activities that allows contemporaneous innate immune signaling and neutralization by TRIM21.
authors.affiliation: Division of Protein and Nucleic Acid Chemistry, Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom fletcher@mrc-lmb.cam.ac.uk lcj@mrc-lmb.cam.ac.uk.
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Fletcher
authors.affiliation: Division of Protein and Nucleic Acid Chemistry, Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom.
authors.forename: Donna L
authors.initials: DL
authors.lastname: Mallery
authors.affiliation: Division of Protein and Nucleic Acid Chemistry, Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom.
authors.forename: Ruth E
authors.initials: RE
authors.lastname: Watkinson
authors.affiliation: Division of Protein and Nucleic Acid Chemistry, Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom.
authors.forename: Claire F
authors.initials: CF
authors.lastname: Dickson
authors.affiliation: Division of Protein and Nucleic Acid Chemistry, Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom fletcher@mrc-lmb.cam.ac.uk lcj@mrc-lmb.cam.ac.uk.
authors.forename: Leo C
authors.initials: LC
authors.lastname: James
mesh_terms: D000818:Animals; D002460:Cell Line; D016207:Cytokines / Q000235:genetics; D006801:Humans; D008239:Lysine / Q000378:metabolism; D051379:Mice; D008954:Models, Biological; D016328:NF-kappa B / Q000378:metabolism; D009500:Neutralization Tests; D025821:Polyubiquitin / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D012261:Ribonucleoproteins / Q000378:metabolism*; D015398:Signal Transduction; D013379:Substrate Specificity; D015534:Trans-Activators / Q000378:metabolism; D014158:Transcription, Genetic; D044763:Ubiquitin-Conjugating Enzymes / Q000378:metabolism; D054875:Ubiquitination; D000099207:SS-A Antigen
chemical_list: D016207:Cytokines; D008239:Lysine; D016328:NF-kappa B; D025821:Polyubiquitin; D046988:Proteasome Endopeptidase Complex; D012261:Ribonucleoproteins; D015534:Trans-Activators; D044763:Ubiquitin-Conjugating Enzymes; D000099207:SS-A Antigen; C109285:PSMD14 protein, human; C471607:UBE2N protein, human; C510626:UBE2W protein, human
keywords: NF-kB; Poh1; TRIM21; Ube2N/Ube2V2; Ube2W