Figure 7: Removal of K63 chains by Ubp2 and 3 mainly promotes proteasome degradation after HS.

(a) Degradation of ³⁵S pulsed-labelled proteins in WT (grey) and ubp2Δ (green) cells at 25 °C (dotted lines) or 45 °C (straight lines) that expressed solely ubiquitin (light, square) or ubiquitin-K63R (dark, round). The portion of proteins degraded at the indicated times was measured and averaged for short-lived proteins in three independent experiments (with s.d.). (b) Representative fluorescent microscopy images of WT, ubp2Δ and ubp3Δ cells that expressed Can1^GFP or Mup1^GFP from their endogenous promoters and that were incubated at 25 or 40 °C for 2 h. Both the GFP and Hoechst (DNA staining) channels are shown. Scale bar, 2 μm. (c) Cells that expressed the indicated aggregation-prone proteins C-terminally tagged with GFP (from endogenous locus) were starved at 30 °C for the indicated times before western blots.