Might act as an E3 ubiquitin-protein ligase which accepts ubiquitin from specific E2 ubiquitin-conjugating enzymes and then transfers it to substrates, which could be nuclear proteins. Could play a role as a coactivator for androgen- and, to a lesser extent, progesterone-dependent transcription (By similarity). [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. Interacts with the ubiquitin-conjugating enzymes UBE2E1 and UBE2E2. Interacts with AR/androgen receptor; testosterone- and RNF6-regulated it promotes AR transcriptional activity. The N-terminal destruction box (D-box) could act as a recognition signal for degradation via the ubiquitin-proteasome pathway. The RING-type zinc finger is essential for the interaction with UBE2E2. 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 domain, but require an obligate trans-thiolation step during the ubiquitin transfer, requiring a conserved cysteine residue in the second RING domain. RING-type zinc finger-dependent and UBE2E2-dependent autoubiquitination. Belongs to the RBR family. RNF14 subfamily. Lacks the His residue in the RING-type domain 2 that is one of the conserved features of the family.