Atypical Ubiquitylation in Yeast Targets Lysine-less Asi2 for Proteasomal Degradation

作者:Boban Mirta; Ljungdahl Per O; Foisner Roland*
来源:JOURNAL OF BIOLOGICAL CHEMISTRY, 2015, 290(4): 2489-2495.
DOI:10.1074/jbc.M114.600593

摘要

Proteins are typically targeted for proteasomal degradation by the attachment of a polyubiquitin chain to epsilon-amino groups of lysine residues. Non-lysine ubiquitylation of proteasomal substrates has been considered an atypical and rare event limited to complex eukaryotes. Here we report that a fully functional lysine-less mutant of an inner nuclear membrane protein in yeast, Asi2, is polyubiquitylated and targeted for proteasomal degradation. Efficient degradation of lysine-free Asi2 requires E3-ligase Doa10 and E2 enzymes Ubc6 and Ubc7, components of the endoplasmic reticulum-associated degradation pathway. Together, our data suggest that non-lysine ubiquitylation may be more prevalent than currently considered.

  • 出版日期2015-1-23