Atg37 is required for pexophagy at the stage of phagophore formation. (A) Atg37 is expressed strictly under peroxisome proliferation conditions. Glc, glucose medium; Eth, ethanol medium; Mth, methanol medium; Ole, oleate medium; F1β, loading control. (B and C) Atg37 is dispensable for peroxisome biogenesis. Peroxisome biogenesis was assessed by the growth of strains in methanol (B) and oleate (C) media. The data shown are from a single representative experiment out of two repeats. (D and E) Atg37 is required for micropexophagy (D) and macropexophagy (E). Cells were replica plated from methanol to glucose and ethanol plates, respectively. The residual activity of AOX was used to assess pexophagy. (F and G) Atg37 is needed for the delivery of peroxisomes to the vacuole during micropexophagy (F) and macropexophagy (G). Methanol-grown cells were adapted to glucose and ethanol media, respectively. FM 4-64 labeled vacuolar membranes. Arrows point to the WT vacuoles with the peroxisome-associated GFP-SKL. Bars, 5 µm. (H and I) Atg37 is essential for MIPA (H) and pexophagosome (I) formation during micropexophagy and macropexophagy, respectively. Methanol-grown cells were adapted to glucose and ethanol media. Arrows point to MIPA (H) and pexophagosome (I) in the WT cells. Bars, 5 µm.