Ubiquitin Protein Ligase E3 Component N-Recognin 2 (UBR2)

Proteolysis by the ubiquitin-proteasome system controls the concentration of many regulatory proteins. The selectivity of ubiquitylation is determined by ubiquitin E3 ligases, which recognize the substrate's destabilization signal, or degron. The E3 ligase UBR2 participates in the N-end rule pathway, which targets proteins bearing an N-terminal degron, or N-degron. The deduced 1,275-amino acid protein shares 19.9% identity over 710 amino acids with an S. cerevisiae N-end-recognizing protein. RT-PCR of several tissues detected UBR2 expression only in testis.mouse Ubr2 bound to type-1 (arg) and type-2 (leu or phe) destabilizing N-terminal residues of a test substrate or a 12-residue peptide. It did not bind to stabilizing (met or gly), secondary destabilizing (asp), or type-3 destabilizing (ser, thr, or ala) residues.