Ubiquitylation plays multiple roles not only in proteasome-mediated protein degradation but
also in various other cellular processes including DNA repair, signal transduction, and
endocytosis. Ubiquitylation is mediated by ubiquitin ligases, which are predicted to be
encoded by more than 600 genes in humans. RING finger (RNF) proteins form the majority
of these ubiquitin ligases. It has also been predicted that there are 49 RNF proteins
containing transmembrane regions in humans, several of which are specifically localized to …