Regulation of the NEDD8 conjugation system by a splicing variant, NUB1L.
NEDD8 is a ubiquitin-like protein that controls vital biological events through its conjugation to target proteins. We previously identified a negative regulator of the NEDD8 conjugation system, NUB1, which works by recruiting NEDD8 and its conjugates to the proteasome for degradation. Recently, we found its splicing variant, NUB1L. It possesses an insertion of 14 amino acids that codes for a UBA domain. Structural study revealed that NUB1 has a NEDD8-binding site at the C terminus, whereas NUB1L has an additional site at the newly generated UBA domain. Interestingly, the sequence A(X4)L(X10)L(X3)L was conserved in these NEDD8-binding sites among human and other mammals. Mutational studies revealed that at least three Leu residues in the conserved sequence are required for binding with NEDD8. Functional study suggested that the NEDD8-binding ability at the C terminus of NUB1 and NUB1L is mainly involved in the down-regulation of NEDD8, but the NEDD8-binding ability at the UBA2 domain of NUB1L is minimally or not involved at all. The NEDD8-binding ability at the UBA2 domain might be required for an unknown function of NUB1L.
Tanaka
Tomoaki
T
Department of Cardiology, The University of Texas M. D. Anderson Cancer Center and Institute of Molecular Medicine, The University of Texas-Houston Health Science Center, Houston, Texas 77030, USA.
Kawashima
Hidenori
H
Yeh
Edward T H
ET
Kamitani
Tetsu
T
D048868:Adaptor Proteins, Signal Transducing; D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D015153:Blotting, Western; D019556:COS Cells; D003546:Cysteine Endopeptidases / Q000378:metabolism; D004252:DNA Mutational Analysis; D018076:DNA, Complementary / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005786:Gene Expression Regulation; D015723:Gene Library; D005822:Genetic Vectors; D005982:Glutathione Transferase / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D007150:Immunohistochemistry; D007930:Leucine / Q000737:chemistry; D051379:Mice; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000037:antagonists & inhibitors / Q000378:metabolism; D016297:Mutagenesis, Site-Directed; D000075687:NEDD8 Protein; D009693:Nucleic Acid Hybridization; D010957:Plasmids / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014018:Tissue Distribution; D014157:Transcription Factors / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology*; D014162:Transfection; D020798:Two-Hybrid System Techniques; D014452:Ubiquitins / Q000096:biosynthesis* / Q000235:genetics*
D048868:Adaptor Proteins, Signal Transducing; D018076:DNA, Complementary; D004791:Enzyme Inhibitors; D009097:Multienzyme Complexes; D000075687:NEDD8 Protein; C082860:NEDD8 protein, human; C430242:NUB1 protein, human; C513172:Nedd8 protein, mouse; C486597:Nub1 protein, mouse; D014157:Transcription Factors; D014452:Ubiquitins; D005982:Glutathione Transferase; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex; D007930:Leucine