(d) Wild-type and pep4Δ cells expressing RPL25-GFP were analysed as in b; 0.1 mM of PMSF was added to pep4Δ cells at the time of starvation to block all vacuolar proteases completely. The LI-COR imaging system was used to quantify the ratio between cleaved GFP and full-length protein as described in Methods. The last time point of wild-type cells containing RPL25-GFP was set to 1 arbitrary unit (a.u.). One of two independent experiments is shown. 