Yersinia pestis, the aetiologic agent of plague, secretes a set of environmentally regulated, plasmid pCD1-encoded virulence proteins termed Yops and V antigen (LcrV) by a type III secretion mechanism. LcrV is a multifunctional protein that has been shown to act at the level of secretion control by binding the Ysc inner-gate protein LcrG and to modulate the host immune response by altering cytokine production. LcrV is also necessary for full induction of low-calcium response (LCR) stimulon virulence gene transcription. Family members are not confined to Yersinia pestis [1,2].

1: The V antigen of Yersinia pestis regulates Yop vectorial targeting as well as Yop secretion through effects on YopB and LcrG. Nilles ML, Fields KA, Straley SC; J Bacteriol 1998;180:3410-3420. PMID:9642196

2: Differential effects of deletions in lcrV on secretion of V antigen, regulation of the low-Ca2+ response, and virulence of Yersinia pestis. Skrzypek E, Straley SC; J Bacteriol 1995;177:2530-2542. PMID:7730287