Ubp2 regulates Rsp5 ubiquitination activity in vivo and in vitro.
The yeast HECT-family E3 ubiquitin ligase Rsp5 has been implicated in diverse cell functions. Previously, we and others [1], [2] reported the physical and functional interaction of Rsp5 with the deubiquitinating enzyme Ubp2, and the ubiquitin associated (UBA) domain-containing cofactor Rup1. To investigate the mechanism and significance of the Rsp5-Rup1-Ubp2 complex, we examined Rsp5 ubiquitination status in the presence or absence of these cofactors. We found that, similar to its mammalian homologues, Rsp5 is auto-ubiquitinated in vivo. Association with a substrate or Rup1 increased Rsp5 self-ubiquitination, whereas Ubp2 efficiently deubiquitinates Rsp5 in vivo and in vitro. The data reported here imply an auto-modulatory mechanism of Rsp5 regulation common to other E3 ligases.
Banting and Best Department of Medical Research, Donnelly Centre for Cellular and Biomolecular Research, Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada.
Mandy H Y
MH
Lam
Andrew
A
Emili
D002384:Catalysis; D010450:Endopeptidases / Q000378:metabolism*; D056827:Endosomal Sorting Complexes Required for Transport; D005656:Fungal Proteins / Q000378:metabolism*; D011485:Protein Binding; D013379:Substrate Specificity; D043743:Ubiquitin-Protein Ligase Complexes / Q000378:metabolism*; D054875:Ubiquitination
D056827:Endosomal Sorting Complexes Required for Transport; D005656:Fungal Proteins; D043743:Ubiquitin-Protein Ligase Complexes; D010450:Endopeptidases; C059237:ubiquitin-Nalpha-protein hydrolase