title: DEN1 deneddylates non-cullin proteins in vivo.
abstract: 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.
authors.affiliation: Institute of Molecular Biology, Academia Sinica, 128 Sec No. 2 Academia Road, Taipei 115, Taiwan.
authors.forename: Yaru
authors.initials: Y
authors.lastname: Chan
authors.forename: Jeongsook
authors.initials: J
authors.lastname: Yoon
authors.forename: June-Tai
authors.initials: JT
authors.lastname: Wu
authors.forename: Hyung-Jun
authors.initials: HJ
authors.lastname: Kim
authors.forename: Kuan-Ting
authors.initials: KT
authors.lastname: Pan
authors.forename: Jeongbin
authors.initials: J
authors.lastname: Yim
authors.forename: Cheng-Ting
authors.initials: CT
authors.lastname: Chien
mesh_terms: 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*
chemical_list: 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