Plays a role in controlling biogenesis of secretory granules at the trans-Golgi network (PubMed:22981988). Mechanistically, binds ARF-GTP at the neck of a growing secretory granule precursor and forms a protective scaffold (PubMed:22981988, PubMed:9038142). Once the granule precursor has been completely loaded, active PRKD1 phosphorylates ARFIP1 and releases it from ARFs (PubMed:22981988). In turn, ARFs induce fission (PubMed:22981988). Through this mechanism, ensures proper secretory granule formation at the Golgi of pancreatic beta cells (PubMed:22981988).
