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