title: Contact-dependent protein secretion in Porphyromonas gingivalis.
abstract: Porphyromonas gingivalis can induce its uptake by host epithelial cells; however, the nature and role of the P. gingivalis molecules involved in this invasion process have yet to be determined. In this study, modulation of secreted P. gingivalis proteins following association with gingival epithelial cells was investigated. Western immunoblot analysis showed that contact with epithelial cells or epithelial cell growth media induces P. gingivalis 33277 to secrete several proteins with molecular masses between 35 and 95 kDa. Secretion of the Arg-gingipain and Lys-gingipain proteases was repressed under these conditions. The contact-induced secreted protein profile was altered in Arg-gingipain-deficient and Lys-gingipain-deficient mutants, indicating a possible role for these proteases in the secretion pathway. The P. gingivalis contact-dependent protein secretion pathway differs to some extent from type III protein secretion pathways in enteric pathogens, as a gene homologous to the invA family genes was not detected in P. gingivalis. The secreted proteins of P. gingivalis may play a role in the interactions of the organism with host cells.
authors.affiliation: Department of Oral Biology, School of Dentistry, University of Washington, Seattle, Washington 98195, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Park
authors.forename: R J
authors.initials: RJ
authors.lastname: Lamont
mesh_terms: D018829:Adhesins, Bacterial / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000032:analysis / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D003546:Cysteine Endopeptidases / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D004847:Epithelial Cells / Q000382:microbiology*; D036781:Fimbriae Proteins; D005798:Genes, Bacterial; D000080867:Gingipain Cysteine Endopeptidases; D005881:Gingiva / Q000166:cytology / Q000382:microbiology*; D006388:Hemagglutinins / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D016254:Mutagenesis, Insertional; D016966:Porphyromonas gingivalis / Q000235:genetics / Q000378:metabolism*; D017421:Sequence Analysis; D015398:Signal Transduction
chemical_list: D018829:Adhesins, Bacterial; D001426:Bacterial Proteins; D000080867:Gingipain Cysteine Endopeptidases; D006388:Hemagglutinins; C063055:fimbrillin; C075518:invA protein, Bacteria; D036781:Fimbriae Proteins; D003546:Cysteine Endopeptidases