E3 ubiquitin-protein ligase, which catalyzes ubiquitination of target proteins together with ubiquitin-conjugating enzyme E2 UBE2L3 (PubMed:15236971, PubMed:21532592, PubMed:24076655, PubMed:27565346, PubMed:23707686). Acts as an atypical E3 ubiquitin-protein ligase by working together with cullin-RING ubiquitin ligase (CRL) complexes and initiating ubiquitination of CRL substrates: associates with CRL complexes and specifically mediates addition of the first ubiquitin on CRLs targets (PubMed:27565346). The initial ubiquitin is then elongated by CDC34/UBE2R1 and UBE2R2 (PubMed:27565346). E3 ubiquitin-protein ligase activity is activated upon binding to neddylated cullin-RING ubiquitin ligase complexes (PubMed:24076655, PubMed:27565346). Plays a role in protein translation in response to DNA damage by mediating ubiquitination of EIF4E2, the consequences of EIF4E2 ubiquitination are however unclear (PubMed:25624349). According to a report, EIF4E2 ubiquitination leads to promote EIF4E2 cap-binding and protein translation arrest (PubMed:25624349). According to another report EIF4E2 ubiquitination leads to its subsequent degradation (PubMed:14623119). Acts as the ligase involved in ISGylation of EIF4E2 (PubMed:17289916). In vitro, controls the degradation of the LINC (LInker of Nucleoskeleton and Cytoskeleton) complex member SUN2 and may therefore have a role in the formation and localization of the LINC complex, and as a consequence, nuclear subcellular localization and nuclear morphology (PubMed:29689197). [E2 ubiquitin-conjugating enzyme]-S-ubiquitinyl-L-cysteine + [acceptor protein]-L-lysine = [E2 ubiquitin-conjugating enzyme]-L-cysteine + [acceptor protein]-N(6)-ubiquitinyl-L-lysine. Autoinhibited by the ariadne domain, which masks the second RING-type zinc finger that contains the active site and inhibits the E3 activity (PubMed:23707686). Inhibition is relieved upon binding to neddylated cullin-RING ubiquitin ligase complexes, which activate the E3 ligase activity of ARIH1 (PubMed:24076655, PubMed:27565346). Protein modification; protein ubiquitination. Interacts (via the first RING-type zinc finger) with UBE2L3 (PubMed:11278816, PubMed:21532592, PubMed:24076655, PubMed:23707686). Associates with cullin-RING ubiquitin ligase (CRL) complexes containing CUL1, CUL2 and CUL3 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL1 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL2 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL3 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL4A (PubMed:24076655). Mainly cytoplasmic (PubMed:11278816). Present in Lewy body (PubMed:21590270). Widely expressed. Up-regulated following DNA damage (PubMed:25624349). Members of the RBR family are atypical E3 ligases. They interact with the E2 conjugating enzyme UBE2L3 and function like HECT-type E3 enzymes: they bind E2s via the first RING-type zinc finger, but require an obligate trans-thiolation step during the ubiquitin transfer, requiring a conserved active site Cys residue in the second RING-type zinc finger (PubMed:21532592, PubMed:23707686). The active site probably forms a thioester intermediate with ubiquitin taken from the active-site cysteine of the E2 before ultimately transferring it to a Lys residue on the substrate (PubMed:21532592, PubMed:23707686). The Ariadne domain inhibits activity by masking the second RING-type zinc finger that contains the active site (PubMed:23707686). Defects in ARIH1 have been found in several individuals with thoracic aortic aneurysms and cerebrovascular disease. Belongs to the RBR family. Ariadne subfamily. The RING-type 2 zinc finger was initially reported to only bind 1 zinc ion instead of 2 compared to classical RING-types (PubMed:15236971). But it was later shown that it is not the case and binds 2 zinc ions (PubMed:24058416, PubMed:23707686).