E3 ubiquitin-protein ligase which mediates ubiquitination and subsequent proteasomal degradation of target proteins. Involved in chromosome segregation and cell cycle regulation (PubMed:28087737). May play a role in the acrosome reaction and fertilization. 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. Interacts with CENPH. Found in the acrosomal region of elongated spermatids and mature sperm. Highly expressed in testis, prostate and brain (PubMed:15145053). Weakly expressed in kidney, lung and heart (PubMed:15145053). Expressed in fetal tissues (PubMed:28087737). The disease is caused by variants affecting the gene represented in this entry. Belongs to the TRIM/RBCC family.