Probable E3 ubiquitin-protein ligase which mediates ubiquitination and subsequent proteasomal degradation of target proteins. Involved in the repression of endoreduplication process and the cell morphogenesis in the trichomes. S-ubiquitinyl-[E2 ubiquitin-conjugating enzyme]-L-cysteine + [acceptor protein]-L-lysine = [E2 ubiquitin-conjugating enzyme]-L-cysteine + N(6)-ubiquitinyl-[acceptor protein]-L-lysine. Protein modification; protein ubiquitination. A number of isoforms are produced. According to EST sequences. Widely expressed. Belongs to the UPL family. K-HECT subfamily. Was originally thought to correspond to two different genes At4g38600 and At4g38610. Was originally thought to correspond to two different genes At4g38600 and At4g38610. Was originally thought to correspond to two different genes At4g38600 and At4g38610. Was originally thought to correspond to two different genes At4g38600 and At4g38610.