title: PcrH of Pseudomonas aeruginosa is essential for secretion and assembly of the type III translocon.
abstract: Pseudomonas aeruginosa harbors a type III secretion system that translocates antihost effectors into an infected eukaryotic cell. PcrH is a key component of type III secretion in this essential virulence strategy. In the absence of PcrH, P. aeruginosa is translocation deficient because of a specific reduction in presecretory stability and subsequent secretion of PopB and PopD, 2 proteins essential for the translocation process. PcrH exerts this chaperone function by binding directly to PopB and PopD. Consistent with the genetic relatedness of PcrH with LcrH of pathogenic Yersinia species, these proteins are functionally interchangeable with respect to their ability to complement the translocation defect associated with either a lcrH or pcrH null mutant, respectively. Thus, the translocator class of chaperones performs a critical function in ensuring the assembly of a translocation competent type III secreton. Finally, unlike the regulatory roles of other translocator-class chaperones (e.g., LcrH, SicA of Salmonella enterica, and IpgC of Shigella species), in vitro regulation of P. aeruginosa type III secretion does not involve PcrH.
authors.affiliation: Department of Medical Countermeasures, Swedish Defence Research Agency, Umeå, Sweden.
authors.forename: Jeanette E
authors.initials: JE
authors.lastname: Bröms
authors.forename: Anna-Lena
authors.initials: AL
authors.lastname: Forslund
authors.forename: Ake
authors.initials: A
authors.lastname: Forsberg
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Francis
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D017353:Gene Deletion; D005816:Genetic Complementation Test; D006367:HeLa Cells / Q000382:microbiology / Q000473:pathology; D006801:Humans; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D009154:Mutation; D010957:Plasmids; D052899:Pore Forming Cytotoxic Proteins; D011485:Protein Binding; D011552:Pseudomonas Infections / Q000382:microbiology / Q000473:pathology; D011550:Pseudomonas aeruginosa / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity; D020798:Two-Hybrid System Techniques; D014774:Virulence; D015007:Yersinia / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D018832:Molecular Chaperones; C412007:PopB protein, Ralstonia solanacearum; D052899:Pore Forming Cytotoxic Proteins; C118339:SycD protein, bacteria