Intercellular communication via tagB may mediate integration of cellular differentiation with morphogenesis. Null mutations in either tagB or tagC lead to a cell autonomous defect in prestalk differentiation and a 5-fold reduction in the expression of the prestalk gene ecmA. Disruption of regA in a tagB null or in a tagC null background results in higher levels of sporulation. In the C-terminal section; belongs to the ABC transporter superfamily. ABCB family. Multidrug resistance exporter (TC 3.A.1.201) subfamily. In the N-terminal section; belongs to the peptidase S8 family.