A protein secretion system linked to bacteroidete gliding motility and pathogenesis.
Porphyromonas gingivalis secretes strong proteases called gingipains that are implicated in periodontal pathogenesis. Protein secretion systems common to other Gram-negative bacteria are lacking in P. gingivalis, but several proteins, including PorT, have been linked to gingipain secretion. Comparative genome analysis and genetic experiments revealed 11 additional proteins involved in gingipain secretion. Six of these (PorK, PorL, PorM, PorN, PorW, and Sov) were similar in sequence to Flavobacterium johnsoniae gliding motility proteins, and two others (PorX and PorY) were putative two-component system regulatory proteins. Real-time RT-PCR analysis revealed that porK, porL, porM, porN, porP, porT, and sov were down-regulated in P. gingivalis porX and porY mutants. Disruption of the F. johnsoniae porT ortholog resulted in defects in motility, chitinase secretion, and translocation of a gliding motility protein, SprB adhesin, to the cell surface, providing a link between a unique protein translocation system and a motility apparatus in members of the Bacteroidetes phylum.
Sato
Keiko
K
Division of Microbiology and Oral Infection, Department of Molecular Microbiology and Immunology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8588, Japan.
Naito
Mariko
M
Yukitake
Hideharu
H
Hirakawa
Hideki
H
Shoji
Mikio
M
McBride
Mark J
MJ
Rhodes
Ryan G
RG
Nakayama
Koji
K
D018829:Adhesins, Bacterial; D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism*; D041963:Bacteroidetes / Q000166:cytology / Q000472:pathogenicity* / Q000502:physiology*; D002465:Cell Movement / Q000502:physiology*; D002688:Chitinases / Q000378:metabolism; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D016680:Genome, Bacterial; D000080867:Gingipain Cysteine Endopeptidases; D046228:Microarray Analysis; D008969:Molecular Sequence Data; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism
D018829:Adhesins, Bacterial; D001426:Bacterial Proteins; D000080867:Gingipain Cysteine Endopeptidases; D012097:Repressor Proteins; D002688:Chitinases; D003546:Cysteine Endopeptidases