An understanding of de novo organelle construction comes one step closer thanks to He et al. (page 925), who find that Atg11 leads Atg9 to the preautophagosomal structure (PAS).
The PAS is intriguing because it is the site where fragments of membrane coalesce to form a new organelle: the autophagosome. In yeast, two flavors of this process exist. Bulk autophagy is induced by starvation and is essentially a cell nondiscriminately eating itself. The cytoplasm-to-vacuole targeting (Cvt) pathway, however, is constitutive and picks selected cargoes for delivery to the vacuole (the yeast equivalent of the lysosome).
Nobody knows what protein gets to the PAS first, but Atg9, as the first characterized transmembrane protein required for both pathways, is a good starting point. It cycles between the PAS and other sites, including mitochondria, probably as a way of collecting membrane fragments to build an autophagosome. It...
