The type 3 secretion system requires actin polymerization to open translocon pores

• DOI: 10.1371/journal.ppat.1009932
• Publication Date: 2021-09-09T18:21:19Z
• Authors: Brian C. Russo; Jeffrey K. Duncan...; Poyin Chen; Marcia B. Goldberg
• Keywords: 0303 health sciences; Virulence; QH301-705.5; RC581-607; Actins; Polymerization; Shigella flexneri; 03 medical and health sciences; Host-Pathogen Interactions; Type III Secretion Systems; Humans; Immunologic diseases. Allergy; Biology (General); Research Article; Dysentery, Bacillary; HeLa Cells

Many bacterial pathogens require a type 3 secretion system (T3SS) to establish niche. Host contact activates T3SS assembly of translocon pore in the host plasma membrane. Following formation, docks onto pore. Docking establishes continuous passage that enables translocation virulence proteins, effectors, into cytosol. Here we investigate contribution actin polymerization T3SS-mediated translocation. Using model organism Shigella flexneri , show is required for assembling an open conformation, thereby enabling effector Opening channel associated with conformational change pore, which dependent upon and coiled-coil domain protein IpaC. Analysis IpaC mutant defective ruffle formation shows polymerization-dependent opening distinct from previously described ruffles are internalization. Moreover, not other functions, including docking or insertion Thus, activation multilayered process signals sensed by leading