A lysine-to-arginine mutation on NEDD8 markedly reduces the activity of cullin RING E3 ligase through the impairment of neddylation cascades.
Neural-precursor-cell-expressed developmentally down-regulated 8 (NEDD8) is a ubiquitin-like modifier, which forms covalent conjugates on lysines of its substrates. This post-translational modification, neddylation, plays important roles in tumor cell proliferation and viability. Ubiquitin can form diverse polyubiquitin chains, on its seven lysines, which play important functions in various biological processes. However, the roles of lysines in NEDD8 have not been explored. Here, we generated nine NEDD8 point mutants, each with one lysine replaced by an arginine, to study the putative function of lysines in NEDD8. Our experiments discover that Lys27 in NEDD8 is a critical residue for protein neddylation. Replacement of this residue with arginine almost completely eliminates the conjugation of NEDD8 to its substrates. Furthermore, we find that the K27R mutant impairs NEDD8 conjugation to the E2 enzyme, which normally forms thioester bonds for further transferring NEDD8 to its ligases and substrates. Therefore, this mutation completely inhibits global protein neddylation, including neddylation of cullin family proteins, resulting in decreased activity of cullin-RING E3 ligases. This work sheds new light on the roles of NEDD8 lysines on neddylation cascades and provides a dominant negative mutant for the study of neddylation and its biological functions.
Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences, Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases, Soochow University, Suzhou, Jiangsu 215123, China.
Yiyan
Y
Sui
Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences, Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases, Soochow University, Suzhou, Jiangsu 215123, China.
Yaobin
Y
Liu
Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences, Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases, Soochow University, Suzhou, Jiangsu 215123, China. Electronic address: gux2002@suda.edu.cn.
Guoqiang
G
Xu
D001120:Arginine / Q000737:chemistry / Q000378:metabolism*; D004789:Enzyme Activation; D057809:HEK293 Cells; D006801:Humans; D008239:Lysine / Q000737:chemistry / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D000075687:NEDD8 Protein; D013329:Structure-Activity Relationship; D025801:Ubiquitin / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism*; D014452:Ubiquitins / Q000378:metabolism*
D000075687:NEDD8 Protein; C082860:NEDD8 protein, human; D025801:Ubiquitin; D014452:Ubiquitins; D001120:Arginine; C584471:CULL-RING ligase, human; D044767:Ubiquitin-Protein Ligases; D008239:Lysine
Cullin-RING E3 ligases; Cullins; NEDD8; Neddylation; Ubiquitination