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. Self-associates (By similarity). Component of the FTS/Hook/FHIP complex (FHF complex), composed of AKTIP/FTS, FHIP1B, and one or more members of the Hook family of proteins HOOK1, HOOK2, and HOOK3 (By similarity). May interact directly with AKTIP/FTS, HOOK1 and HOOK3 (By similarity). Associates with several subunits of the homotypic vesicular sorting complex (the HOPS complex) including VPS16 and VPS41; these interactions may be indirect (By similarity). Interacts with CNTRL (By similarity). Interacts with microtubules (By similarity). Interacts with ZC3H14 (By similarity). Interacts with LRGUK (via guanylate kinase-like domain) (PubMed:25781171, PubMed:28003339). Interacts with CCDC181 (PubMed:28283191). Interacts with AP4M1; the interaction is direct, mediates the interaction between FTS-Hook-FHIP (FHF) complex and AP-4 and the perinuclear distribution of AP-4 (By similarity). Colocalizes with aggresomes, which are aggregates of misfolded proteins, at the centrosome. Also localizes to punctate cytoplasmic foci which do not appear to overlap with early or late endosomes, the endoplasmic reticulum, multivesicular bodies (MVBs), lysosome, or mitochondria (By similarity). Often found in close association with microtubules (By similarity). Localizes to the manchette in elongating spermatids (PubMed:28003339). Expressed in brain, cerebellum, kidney, liver and heart, with highest levels in heart and kidney (at protein level). Belongs to the hook family. Extended N-terminus.