Establishing the Secretion Hierarchy

摘要

Type III protein secretion systems (T3SSs) are specialized complexes of molecules in Gram-negative bacteria that mediate the introduction of virulence proteins directly into eukaryotic host cells. These supramolecular structures span the bacterial membranes, cross the extracellular space, and penetrate host cell membranes. The proper function of these systems depends on sequential secretion of the needle components, the proteins that enable translocation across the host cell membrane (translocases), and the effector proteins that carry out virulence functions (/). How this hierarchical process is regulated, however, has been unclear.