LcrV

In molecular biology, LcrV is a protein found in Yersinia pestis and several other bacterial species. It forms part of the Yersinia pestis virulence protein factors that also includes all Yops, or Yersinia outer protein, but the name has been kept out of convention. LcrV's main function is not actually known, but it is essential for the production of other Yops.

LcrV
the structure of yersinia pestis v-antigen, an essential virulence factor and mediator of immunity against plague
Identifiers
SymbolLcrV
PfamPF04792
InterProIPR005413
SCOPe1r6f / SUPFAM

The type III secretion system of Gram-negative bacteria is used to transport virulence factors from the pathogen directly into the host cell and is only triggered when the bacterium comes into close contact with the host.[1] Effector proteins secreted by the type III system do not possess a secretion signal, and are considered unique because of this. Yersinia spp. secrete effector proteins called YopB and YopD that facilitate the spread of other translocated proteins through the type III needle and the host cell cytoplasm.[2] In turn, the transcription of these moieties is thought to be regulated by another gene, lcrV, found on the Yops virulon that encodes the entire type III system.[3] The product of this gene, LcrV protein, also regulates the secretion of YopD through the type III translocon, and itself acts as a protective "V" antigen for Yersinia pestis, the causative agent of plague.[4][5]

A homologue of the Y. pestis LcrV protein, PcrV, has been found in Pseudomonas aeruginosa, an opportunistic pathogen. In vivo studies using mice found that immunisation with the protein protected burned animals from infection by P. aeruginosa, and enhanced survival. In addition, it is speculated that PcrV determines the size of the needle pore for type III secreted effectors.[6]

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.[7][8]

The polypeptide is encoded on a plasmid and is only present when the surroundings are around 37o Celsius

References
  1. Hueck CJ (June 1998). "Type III protein secretion systems in bacterial pathogens of animals and plants". Microbiol. Mol. Biol. Rev. 62 (2): 379–433. PMC 98920. PMID 9618447.
  2. Williams AW, Straley SC (January 1998). "YopD of Yersinia pestis plays a role in negative regulation of the low-calcium response in addition to its role in translocation of Yops". J. Bacteriol. 180 (2): 350–8. PMC 106890. PMID 9440524.
  3. Sarker MR, Neyt C, Stainier I, Cornelis GR (March 1998). "The Yersinia Yop virulon: LcrV is required for extrusion of the translocators YopB and YopD". J. Bacteriol. 180 (5): 1207–14. PMC 107009. PMID 9495760.
  4. DeBord KL, Lee VT, Schneewind O (August 2001). "Roles of LcrG and LcrV during type III targeting of effector Yops by Yersinia enterocolitica". J. Bacteriol. 183 (15): 4588–98. doi:10.1128/JB.183.15.4588-4598.2001. PMC 95354. PMID 11443094.
  5. Matson JS, Nilles ML (September 2001). "LcrG-LcrV interaction is required for control of Yops secretion in Yersinia pestis". J. Bacteriol. 183 (17): 5082–91. doi:10.1128/jb.183.17.5082-5091.2001. PMC 95384. PMID 11489861.
  6. Holder IA, Neely AN, Frank DW (September 2001). "PcrV immunization enhances survival of burned Pseudomonas aeruginosa-infected mice". Infect. Immun. 69 (9): 5908–10. doi:10.1128/iai.69.9.5908-5910.2001. PMC 98711. PMID 11500471.
  7. Nilles ML, Fields KA, Straley SC (1998). "The V antigen of Yersinia pestis regulates Yop vectorial targeting as well as Yop secretion through effects on YopB and LcrG". J Bacteriol. 180 (13): 3410–20. PMC 107298. PMID 9642196.
  8. Skrzypek E, Straley SC (1995). "Differential effects of deletions in lcrV on secretion of V antigen, regulation of the low-Ca2+ response, and virulence of Yersinia pestis". J Bacteriol. 177 (9): 2530–42. doi:10.1128/jb.177.9.2530-2542.1995. PMC 176914. PMID 7730287.

Further reading
  • Salyers, Abigail & Whitt, Dixie; Bacterial Pathogenesis: A Molecular Approach, AMS Press
  • Biological Weapons Defense: Infectious Diseases and Counterbioterrorism, Humana Press
This article incorporates text from the public domain Pfam and InterPro: IPR005413


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