Figure 1.

The atg22Δ mutant displays normal autophagy. (A) Pho8Δ60 activity, a marker for nonspecific autophagy, indicates this process is normal in atg22Δ cells. The Pho8Δ60-dependent alkaline phosphatase activity was measured before and 2 or 4 h after shifting from YPD to SD-N medium. The error bars indicate the SD of two independent experiments. (B) GFP-Atg8 processing is normal in the atg22Δ mutant. The wild-type (WT, SEY6210), atg1Δ (WHY1), and atg22Δ (ZFY6) strains expressing GFP-Atg8 were grown in SMD to mid-log phase and shifted to SD-N to induce autophagy. At the indicated times, aliquots were removed and examined by immunoblot using anti-GFP antibody. The position of free GFP, indicating autophagy-dependent processing of GFP-Atg8, is indicated. The asterisk indicates a nonspecific band. (C) In the atg22Δ mutant autophagic delivery of prApe1 is normal in the Cvt pathway-defective vac8Δ background. The vac8Δ (YTS178), atg22Δ vac8Δ (ZFY8), and atg1Δ (WHY1) strains were cultured as described above. At the indicated times, aliquots were taken and checked by immunoblot using anti-Ape1 antiserum. The positions of precursor and mature Ape1 are indicated.