May be directly involved in maturation and export of SDF-2. The exposure of the protease domain of tagC on the surface of the prestalk cells were it can convert acbA to SDF-2 is induced by GABA. Intercellular communication via tagC may mediate integration of cellular differentiation with morphogenesis. Found exclusively in prestalk cells. Cells in which tagC is disrupted do not form SDF-2. 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.