Extensive research has focused on understanding developmental mechanisms for regenerating damaged salivary glands. However, while most studies have investigated early branching morphogenesis, the process of forming acinar cells—which completes morphogenesis after birth—remains poorly understood. In this study, we examined the role of Cdc42, a member of the Rho GTPase family, in the acinar cell formation.
By knocking out Cdc42 during acinar cell formation, we observed suppression in the formation of the luminal membrane. Remarkably, GFP, a protein with a targeting signal for plasma membrane trafficking, was detected on vesicles that had gathered near the plasma membrane. Through immunostaining aquaporin 5, a marker for the luminal membrane, we revealed its co-localization with these GFP-containing vesicles. Furthermore, we examined Rab11a, a marker protein indicating vesicles that create the luminal surface membrane within cultured epithelial cells. As a result, we observed a co-localization between Rab11a and the GFP vesicles.
In summary, these findings suggest a model in which apical membrane proteins within salivary glands are transported to the apical membrane through vesicles associated with Rab11a. Additionally, our findings suggest that Cdc42 potentially plays a role in promoting the formation of the apical membrane by regulating the targeted transport of newly synthesized apical membrane proteins.