title: Putrescine importer PlaP contributes to swarming motility and urothelial cell invasion in Proteus mirabilis.
abstract: Previously, we reported that the speA gene, encoding arginine decarboxylase, is required for swarming in the urinary tract pathogen Proteus mirabilis. In addition, this previous study suggested that putrescine may act as a cell-to-cell signaling molecule (Sturgill, G., and Rather, P. N. (2004) Mol. Microbiol. 51, 437-446). In this new study, PlaP, a putative putrescine importer, was characterized in P. mirabilis. In a wild-type background, a plaP null mutation resulted in a modest swarming defect and slightly decreased levels of intracellular putrescine. In a P. mirabilis speA mutant with greatly reduced levels of intracellular putrescine, plaP was required for the putrescine-dependent rescue of swarming motility. When a speA/plaP double mutant was grown in the presence of extracellular putrescine, the intracellular levels of putrescine were greatly reduced compared with the speA mutant alone, indicating that PlaP functioned as the primary putrescine importer. In urothelial cell invasion assays, a speA mutant exhibited a 50% reduction in invasion when compared with wild type, and this defect could be restored by putrescine in a PlaP-dependent manner. The putrescine analog Triamide-44 partially inhibited the uptake of putrescine by PlaP and decreased both putrescine stimulated swarming and urothelial cell invasion in a speA mutant.
authors.affiliation: Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia 30322, USA.
authors.forename: Shin
authors.initials: S
authors.lastname: Kurihara
authors.forename: Yumi
authors.initials: Y
authors.lastname: Sakai
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Suzuki
authors.forename: Aaron
authors.initials: A
authors.lastname: Muth
authors.forename: Otto
authors.initials: O
authors.lastname: Phanstiel
authors.forename: Philip N
authors.initials: PN
authors.lastname: Rather
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D006801:Humans; D009154:Mutation; D011512:Proteus Infections / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology; D011513:Proteus mirabilis / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity; D011700:Putrescine / Q000378:metabolism*; D019459:Urothelium / Q000382:microbiology* / Q000473:pathology
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D011700:Putrescine
keywords: Bacteria; Bacterial Pathogenesis; Drug Design; Microbial Pathogenesis; Microbiology; Polyamines; Transporters