Involvement of minor components associated with the FimA fimbriae of Porphyromonas gingivalis in adhesive functions.
The FimA fimbriae of Porphyromonas gingivalis, the causative agent of periodontitis, have been implicated in various aspects of pathogenicity, such as colonization, adhesion and aggregation. In this study, the four open reading frames (ORF1, ORF2, ORF3 and ORF4) downstream of the fimbrilin gene (fimA) in strain ATCC 33277 were examined. ORF2, ORF3 and ORF4 were demonstrated to encode minor components of the fimbriae and were therefore renamed fimC, fimD and fimE, respectively. Immunoblotting analyses revealed that inactivation of either fimC or fimD by an ermF-ermAM insertion, but not inactivation of ORF1, was accompanied by concomitant loss of the products from the downstream genes, raising the possibility that fimC, fimD and fimE constitute a transcription unit. The fimE mutant produced FimC and FimD, but fimbriae purified from it contained neither protein, suggesting that FimE is required for the assembly of FimC and FimD onto the fimbrilin (FimA) fibre. The fimC, fimD and fimE mutants lost autoaggregation abilities. Fimbriae purified from these three mutants showed attenuated binding activities to glyceraldehyde-3-phosphate dehydrogenase of Streptococcus oralis and to two extracellular matrix proteins, fibronectin and type I collagen. These results suggest that FimE, as well as FimC and FimD, play critical roles in the adhesive activities of the mature FimA fimbriae in P. gingivalis.
Nishiyama
So-Ichiro
SI
Department of Microbiology, School of Dentistry, Aichi-Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya, Aichi 464-8650, Japan.
Murakami
Yukitaka
Y
Department of Microbiology, School of Dentistry, Aichi-Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya, Aichi 464-8650, Japan.
Nagata
Hideki
H
Department of Preventive Dentistry, Graduate School of Dentistry, Osaka University, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan.
Shizukuishi
Satoshi
S
Department of Preventive Dentistry, Graduate School of Dentistry, Osaka University, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan.
Kawagishi
Ikuro
I
Department of Biological Science, Graduate School of Science and Institute for Advanced Research, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan.
Yoshimura
Fuminobu
F
Department of Microbiology, School of Dentistry, Aichi-Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya, Aichi 464-8650, Japan.
D001422:Bacterial Adhesion / Q000502:physiology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D024042:Collagen Type I / Q000378:metabolism; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D005353:Fibronectins / Q000378:metabolism; D036781:Fimbriae Proteins / Q000235:genetics / Q000378:metabolism*; D010861:Fimbriae, Bacterial / Q000737:chemistry* / Q000235:genetics / Q000502:physiology; D017353:Gene Deletion; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000378:metabolism; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D009876:Operon / Q000235:genetics; D016966:Porphyromonas gingivalis / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D011485:Protein Binding; D017422:Sequence Analysis, DNA; D019533:Streptococcus oralis
D001426:Bacterial Proteins; D024042:Collagen Type I; D004269:DNA, Bacterial; D005353:Fibronectins; C063055:fimbrillin; D036781:Fimbriae Proteins; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases