UBR1

E3 ubiquitin-protein ligase which is a component of the N-end rule pathway. Recognizes and binds proteins bearing specific N-terminal residues that are destabilizing according to the N-end rule, leading to their ubiquitination and subsequent degradation. Recognizes both type-1 and type-2 N-degrons, containing positively charged amino acids (Arg, Lys and His) and bulky and hydrophobic amino acids, respectively. Does not ubiquitinate proteins that are acetylated at the N-terminus. In contrast, it strongly binds methylated N-degrons. Binds leucine and is a negative regulator of the leucine-mTOR signaling pathway, thereby controlling cell growth..

Function from UniProtKB (Q8IWV7), read 2026-09-23. CC BY 4.0.