The class III phosphatidylinositol 3-kinase( Pi( 3) KC3) is part of a key complex regulating autophagy. How this complex mechanistically contributes to autophagosome formation remains largely unknown. The BaR-domain- containing protein Bif-1/ endophilin B1, commonly associated with the control of membrane curvature, has been identified as a new interacting partner for Pi( 3) KC3, suggesting the complex plays an active part in the regulation of membrane dynamics during autophagy.