Plays a regulatory role in autophagic activity. In complex with BCAS3, associates with the autophagosome formation site during both non-selective and selective autophagy. Interacts with BCAS3; the interaction is requrired for the association with the phagophore. The BCAS3:PHAF1 complex is recruited to the preautophagosomal structures adjacent to the damaged mitochondria upon mitophagy in a PRKN-PINK1 dependent manner. Belongs to the PHAF1 family. Was originally (Ref.1) thought to be a lin-10 homolog.