Component of the FTS/Hook/FHIP complex (FHF complex). The FHF complex may function to promote vesicle trafficking and/or fusion via the homotypic vesicular protein sorting complex (the HOPS complex). Contributes to the establishment and maintenance of centrosome function. May function in the positioning or formation of aggresomes, which are pericentriolar accumulations of misfolded proteins, proteasomes and chaperones. FHF complex promotes the distribution of AP-4 complex to the perinuclear area of the cell (PubMed:32073997). {ECO:0000269|PubMed:17140400, ECO:0000269|PubMed:17540036, ECO:0000269|PubMed:18799622, ECO:0000269|PubMed:32073997}. This is the function of HOOK2 (hook microtubule tethering protein 2, ENSG00000095066).