E3 ubiquitin-protein ligase, which catalyzes ubiquitination of target proteins together with ubiquitin-conjugating enzyme E2 UBE2L3. 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. The initial ubiquitin is then elongated by CDC34/UBE2R1 and UBE2R2. E3 ubiquitin-protein ligase activity is activated upon binding to neddylated cullin-RING ubiquitin ligase complexes. Plays a role in protein translation in response to DNA damage by mediating ubiquitination of EIF4E2, the consequences of EIF4E2 ubiquitination are however unclear. According to a report, EIF4E2 ubiquitination leads to promote EIF4E2 cap-binding and protein translation arrest. According to another report EIF4E2 ubiquitination leads to its subsequent degradation. Acts as the ligase involved in ISGylation of EIF4E2. 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, may act in nuclear subcellular localization and nuclear morphology. [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. Inhibition is relieved upon binding to neddylated cullin-RING ubiquitin ligase complexes, which activate the E3 ligase activity of ARIH1. Protein modification; protein ubiquitination. Interacts (via the first RING-type zinc finger) with UBE2L3. Associates with cullin-RING ubiquitin ligase (CRL) complexes containing CUL1, CUL2 and CUL3. Interacts with neddylated CUL1. Interacts with neddylated CUL2. Interacts with neddylated CUL3. Interacts with neddylated CUL4A. Mainly cytoplasmic. Present in Lewy body. 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. 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. The Ariadne domain inhibits activity by masking the second RING-type zinc finger that contains the active site. Belongs to the RBR family. Ariadne subfamily.