PcrV protein of Type III secretion system (PcrV)

The PcrV protein is an essential needle-tip component of the Type III secretion system (T3SS) in Pseudomonas aeruginosa and other Gram-negative bacteria. It functions as part of a translocator complex critical for virulence, assembling at the tip of the T3SS needle and enabling the regulated insertion of PopB and PopD proteins into host cell membranes to form a translocation pore. This pore allows direct delivery of bacterial effector proteins (toxins) into the host cytosol, manipulating host immunity and other cellular processes. PcrV plays a pivotal role in sensing host contact, orchestrating the assembly of the translocon, and triggering effector secretion. Orthologs (such as LcrV in Yersinia) also function similarly. PcrV is a validated therapeutic target; antibodies against it reduce infection severity by neutralizing pore assembly and toxin delivery, and PcrV-derived vaccines are under investigation as anti-infective agents.

Other names

Type III secretion needle tip proteinT3SS tip proteinLcrV homolog (in context of Yersinia spp. orthologs)

Antibodies block PcrV, impairing assembly of translocation pore and effector delivery. Inhibition of PcrV disrupts T3SS-mediated cytotoxin translocation, protecting host cells.