The ubiquitin-protein ligases Nedd4 and Nedd4-2 show similar ubiquitin-conjugating enzyme specificities.
Nedd4 and Nedd4-2 are closely related HECT-type ubiquitin-protein ligases (E3) implicated in the regulation of a number of proteins and pathways. Given the close homology between these E3 enzymes it would be predicted that a conserved ubiquitin-conjugating enzyme (E2) specificity exists between the two proteins. However, E2 specificities for Nedd4 and Nedd4-2 are not well established. In the present studies we aimed at clarifying the E2-specificities of Nedd4 and Nedd4-2 using in vitro ubiquitination assays. We demonstrate strong substrate ubiquitination in the presence of UbcH5b by both Nedd4 and Nedd4-2. We also found that Ube2e3, an E2 previously shown to be used by Nedd4-2, is used less efficiently than UbcH5b. Our results suggest that for optimal ubiquitination Nedd4 and Nedd4-2 require the same E2 enzymes.
Fotia
Andrew B
AB
Hanson Institute, IMVS, Frome Road, P.O. Box 14, Rundle Mall, Adelaide, SA 5000, Australia.
Cook
David I
DI
Kumar
Sharad
S
D000595:Amino Acid Sequence; D000818:Animals; D056827:Endosomal Sorting Complexes Required for Transport; D008969:Molecular Sequence Data; D000075702:Nedd4 Ubiquitin Protein Ligases; D016415:Sequence Alignment; D013379:Substrate Specificity; D025801:Ubiquitin / Q000378:metabolism*; D044763:Ubiquitin-Conjugating Enzymes / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000378:metabolism*
D056827:Endosomal Sorting Complexes Required for Transport; D025801:Ubiquitin; D044763:Ubiquitin-Conjugating Enzymes; D000075702:Nedd4 Ubiquitin Protein Ligases; D044767:Ubiquitin-Protein Ligases