This entry represents the RZ type zinc finger domain, found in NFX1-type zinc finger-containing protein 1 (ZNFX1) and E3 ubiquitin-protein ligase RNF213 from humans. It contains two conserved histidine residues and four conserved cysteine residues in a CHC3H motif. It can bind divalent transition metals, with a preference for Zn2+. ZNFX1 is an RNA-binding protein that initiates the antiviral response and is required to restrict the replication of RNA viruses [1,2]. RNF213 is a giant E3 ubiquitin ligase that can catalyse ubiquitination of both proteins and lipids, which is involved in various processes, such as lipid metabolism, angiogenesis and cell-autonomous immunity. It functions as a key immune sensor by catalysing ubiquitination of the lipid A moiety of bacterial LPS via its RZ-type zinc-finger and restricts the proliferation of cytosolic bacteria [3,4]. RNF213 is a major susceptibility factor of Moyamoya disease [5].

1: Mitochondria-localised ZNFX1 functions as a dsRNA sensor to initiate antiviral responses through MAVS. Wang Y, Yuan S, Jia X, Ge Y, Ling T, Nie M, Lan X, Chen S, Xu A; Nat Cell Biol. 2019;21:1346-1356. PMID:31685995

2: Multisystem inflammation and susceptibility to viral infections in human ZNFX1 deficiency. Vavassori S, Chou J, Faletti LE, Haunerdinger V, Opitz L, Joset P, Fraser CJ, Prader S, Gao X, Schuch LA, Wagner M, Hoefele J, Maccari ME, Zhu Y, Elakis G, Gabbett MT, Forstner M, Omran H, Kaiser T, Kessler C, Olbrich H, Frosk P, Almutairi A, Platt CD, Elkins M, Weeks S, Rubin T, Planas R, Marchetti T, Koovely D, Klambt V, Soliman NA, von Hardenberg S, Klemann C, Baumann U, Lenz D, Klein-Franke A, Schwemmle M, Huber M, Sturm E, Hartleif S, Haffner K, Gimpel C, Brotschi B, Laube G, Gungor T, Buckley MF, Kottke R, Staufner C, Hildebrandt F, Reu-Hofer S, Moll S, Weber A, Kaur H, Ehl S, Hiller S, Geha R, Roscioli T, Griese M, Pachlopnik Schmid J; J Allergy Clin Immunol. 2021;148:381-393. PMID:33872655

3: UBC13 is an RNF213-associated E2 ubiquitin-conjugating enzyme, and Lysine 63-linked ubiquitination by the RNF213-UBC13 axis is responsible for angiogenic activity. Habu T, Harada KH; FASEB Bioadv. 2021;3:243-258. PMID:33842849

4: Ubiquitylation of lipopolysaccharide by RNF213 during bacterial infection. Otten EG, Werner E, Crespillo-Casado A, Boyle KB, Dharamdasani V, Pathe C, Santhanam B, Randow F; Nature. 2021;594:111-116. PMID:34012115

5: Moyamoya disease patient mutations in the RING domain of RNF213 reduce its ubiquitin ligase activity and enhance NFkappaB activation and apoptosis in an AAA+ domain-dependent manner. Takeda M, Tezuka T, Kim M, Choi J, Oichi Y, Kobayashi H, Harada KH, Mizushima T, Taketani S, Koizumi A, Youssefian S; Biochem Biophys Res Commun. 2020;525:668-674. PMID:32139119