DEN1 is a dual function protease capable of processing the C terminus of Nedd8 and deconjugating hyper-neddylated CUL1.
Nedd8 activates ubiquitination by increasing the efficiency of polyubiquitin chain assembly through its covalent conjugation to cullin molecules. Here we report the isolation, cloning, and characterization of a novel human Nedd8-specific protease called DEN1. Human DEN1 is encoded by AAH31411.1, a previously uncharacterized protein of 212 amino acids that shares homology with the Ulp1 cysteinyl SUMO deconjugating enzyme family. Recombinant human DEN1, purified from bacteria, selectively binds to Nedd8 and hydrolyzes C-terminal derivatives of Nedd8. Interestingly, DEN1 deconjugates cullin 1 (CUL1)-Nedd8 in a concentration-dependent manner. At a low concentration, DEN1 processes hyper-neddylated CUL1 to yield a mononeddylated form, which presumably contains the Lys-720CUL1-Nedd8 linkage. At elevated concentrations, DEN1 is able to complete the removal of Nedd8 from CUL1. These activities distinguish DEN1 from the COP9 signalosome, which is capable of efficiently cleaving the Lys-720CUL1-Nedd8 conjugate, but lacks Nedd8 C-terminal hydrolytic activity and poorly processes hyperneddylated CUL1. These results suggest a unique role for DEN1 in regulating the modification of cullins by Nedd8.
Wu
Kenneth
K
Derald H. Ruttenberg Cancer Center and Department of Human Genetics, The Mount Sinai School of Medicine, New York, New York 10029-6574, USA.
Yamoah
Kosj
K
Dolios
Georgia
G
Gan-Erdene
Tudeviin
T
Tan
Peilin
P
Chen
Angus
A
Lee
Chee-Gun
CG
Wei
Ning
N
Wilkinson
Keith D
KD
Wang
Rong
R
Pan
Zhen-Qiang
ZQ
D000595:Amino Acid Sequence; D018797:Cell Cycle Proteins / Q000378:metabolism*; D044842:Cullin Proteins; D004591:Electrophoresis, Polyacrylamide Gel; D010450:Endopeptidases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D000075687:NEDD8 Protein; D011994:Recombinant Proteins / Q000378:metabolism; D025801:Ubiquitin / Q000378:metabolism; D014452:Ubiquitins / Q000378:metabolism*
D018797:Cell Cycle Proteins; C100318:Cullin 1; D044842:Cullin Proteins; D000075687:NEDD8 Protein; C082860:NEDD8 protein, human; D011994:Recombinant Proteins; D025801:Ubiquitin; D014452:Ubiquitins; D010450:Endopeptidases; C477008:SENP8 protein, human