PtdIns 3-Kinase Orchestrates Autophagosome Formation in Yeast

Figure 2

Mechanism by which the PtdIns 3-kinsase complexes are sorted into distinct processes. Vps34, a catalytic subunit, forms two distinct PtdIns 3-kinase complexes (complexes I and II). Complex I functions in autophagy, while complex II functions in the vacuolar protein sorting pathway. Atg14 is specifically integrated into complex I, while complex II contains Vps38 as a unique subunit. These specific subunits regulate the intracellular localization of these complexes, thereby determining their specific functions. Complex I localizes to the PAS in an Atg14-dependent manner, while complex II localizes to the endosome. *The endosomal localization of the complete complex II including Vps30/Atg6 depends on Vps38. However, Vps34 and Vps15 can localize to the endosome even in the absence of Vps38.