Rab proteins are small GTPases that are essential components involved in the control of eukaryotic intracellular membrane trafficking. Previously, we investigated whether Rab proteins are involved in the exocytosis of amylase-containing granules in rat parotid acinar cells.HighlightRab27 and its effectors regulate amylase release from parotid acinar cells.ConclusionExocytosis occurs via a Rab27 GDP/GTP cycling mechanism in parotid acinar cells.