Acts as an effector of RABF2A and RABF2B. Involved in vacuolar transport of storage proteins. Regulates membrane trafficking to protein storage vacuoles (PSVs). Binds specifically to phosphatidylinositol 3-monophosphate (PtdIns3P).
The endosomal localization depends on the active state of RABF2B. Binding of phosphatidylinositol 3-monophosphate via the PX domain is required for the endosomal localization.