May mediate microtubule plus end-directed vesicle transport. Can form homodimers. Interacts (via C-terminus) with MAP1LC3B. Interacts with RAB7A; the interaction with RAB7A induces FYCO1 recruitment to late endosomal/lysosomal compartments. Localizes to the external but not to the internal membrane of autophagosomes, and upon autophagosome/late endosome/lysosome fusion, it stays on the external surface of autolysosomes. Expressed in heart and testis. Expressed in the eye lens. Contaminating sequence. Potential poly-A sequence.