sentence: Yeast Atg6 / Vps30 facilitates two distinctive processes : autophagy and retrograde traffic from endosomes to the Golgi apparatus by two different phosphatidylinositol 3-kinase ( PI3-kinase ) complexes : class I ( Atg14 , Atg6 , Vps34 , Vps15 ) and class II ( Atg38 , Atg6 , Vps34 , Vps15 ) ( Kihara et al ., 2001b ) .