Mutant analysis allows for differentiation between vacuolar delivery by Cvt vesicles and autophagosomes. (A) SEY6210 (wild-type), cvt3, and cvt7 yeast were grown in SD to 1 OD600 U/ml and transferred to SD (-N). Aliquots were collected after 0 h (+) and 4 h (−) incubation and subjected to immunoblotting. The positions of precursor (pro) and mature (m) API are indicated. (B) cvt3 and cvt7 cells were pulse labeled for 10 min. After addition of cold cysteine and methionine, the cells were harvested, washed, and resuspended in either SD or SD(-N) and chased for the indicated times. API was recovered by immunoprecipitation, resolved on SDS polyacrylamide gels, and quantified using a phosphorimager (STORM; Molecular Dynamics, Sunnyvale, CA). 