The role of Bug1, autophagy-related proteins, and the ESCRT machinery in CUPS formation. (A and B) Wild-type yeast, yeast strains deleted for BUG1, VPS34, ATG1, 5, 7, 8, 9, 11, 14, 17, 18, and 11/17 (A) or yeast cells deleted for components of the ESCRT machinery (VPS27, HSE1, VPS23, VPS28, MVB12, VPS36, VPS25, VPS20, VPS2, and VPS4; B) expressing Grh1-GFP were cultured in growth medium or starved for 4 h, and the formation of CUPS was visualized by fluorescence microscopy. Bar, 2 µm.