Acts as an E3 ubiquitin-protein ligase, or as part of E3 complex, which accepts ubiquitin from specific E2 ubiquitin-conjugating enzymes and then transfers it to substrates (PubMed:24388521). Negative regulator of the abscisic acid (ABA) signaling pathway which targets PYL4 and PYR1 ABA receptors in plasma membrane to promote their FREE1/FYVE1-dependent trafficking and degradation upon ubiquitynation; this process involves clathrin-mediated endocytosis and trafficking through the ESCRT pathway (PubMed:25330042, PubMed:27495812). Involved in the maintenance of seed longevity (PubMed:24388521). May enhance gibberellins responses (PubMed:24388521). [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. Binds 4 Zn(2+) ions per subunit. Protein modification; protein ubiquitination. Interacts with the PYL4 and PYR1 ABA receptors at the plasma membrane. Localized transiently in the vacuole when in complex with PYL4 and PYR1. The RING-type zinc finger domains mediate binding to an E2 ubiquitin-conjugating enzyme. Enhanced sensitivity to abscisic acid (ABA) (PubMed:25330042). Decreased seed longevity (PubMed:24388521). Belongs to the RBR family.