As component of the WDR11 complex acts together with TBC1D23 to facilitate the golgin-mediated capture of vesicles generated using AP-1. Component of the complex WDR11 composed of C17orf75, FAM91A1 and WDR11; FAM91A1 and WDR11 are required for proper location of the complex (By similarity). Interacts with golgins GOLGA1 and GOLGA4 and with TBC1D23; interaction with golgins may be mediated by TBC1D23 and interaction with TBC1D23 recruits TBC1D23 to AP-1-derived vesicles (PubMed:29084197). Recruitment to the TGN requires the presence of GOLGA1, GOLGA4 and TBC1D23. Belongs to the FAM91 family. Truncated N-terminus. Extended N-terminus.