DEN1 deneddylates non-cullin proteins in vivo.
The ubiquitin-like protein Nedd8/Rub1 covalently modifies and activates cullin ubiquitin ligases. However, the repertoire of Nedd8-modified proteins and the regulation of protein neddylation status are not clear. The cysteine protease DEN1/NEDP1 specifically processes the Nedd8 precursor and has been suggested to deconjugate Nedd8 from cullin proteins. By characterizing the Drosophila DEN1 protein and DEN1 null (DEN1(null)) mutants, we provide in vitro and in vivo evidence that DEN1, in addition to processing Nedd8, deneddylates many cellular proteins. Although purified DEN1 protein efficiently deneddylates the Nedd8-conjugated cullin proteins Cul1 and Cul3, neddylated Cul1 and Cul3 protein levels are not enhanced in DEN1(null). Strikingly, many cellular proteins are highly neddylated in DEN1 mutants and are deneddylated by purified DEN1 protein. DEN1 deneddylation activity is distinct from that of the cullin-deneddylating CSN. Genetic analyses indicate that a balance between neddylation and deneddylation maintained by DEN1 is crucial for animal viability.
Chan
Yaru
Y
Institute of Molecular Biology, Academia Sinica, 128 Sec No. 2 Academia Road, Taipei 115, Taiwan.
Yoon
Jeongsook
J
Wu
June-Tai
JT
Kim
Hyung-Jun
HJ
Pan
Kuan-Ting
KT
Yim
Jeongbin
J
Chien
Cheng-Ting
CT
D000818:Animals; D044842:Cullin Proteins / Q000378:metabolism*; D029721:Drosophila Proteins / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000378:metabolism*; D010450:Endopeptidases / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D000075687:NEDD8 Protein; D011499:Protein Processing, Post-Translational; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D014452:Ubiquitins / Q000378:metabolism*
D044842:Cullin Proteins; C485182:Cyan Fluorescent Protein; D029721:Drosophila Proteins; D000075687:NEDD8 Protein; C513173:Nedd8 protein, Drosophila; D011993:Recombinant Fusion Proteins; D014452:Ubiquitins; D049452:Green Fluorescent Proteins; C000620846:DEN1 protein, Drosophila; D010450:Endopeptidases