JlpA of Campylobacter jejuni interacts with surface-exposed heat shock protein 90alpha and triggers signalling pathways leading to the activation of NF-kappaB and p38 MAP kinase in epithelial cells.
Campylobacter jejuni is a leading cause of acute bacterial gastroenteritis in humans. The mechanism by which C. jejuni interacts with host cells, however, is still poorly understood. Our previous study has shown that the C. jejuni surface lipoprotein JlpA mediates adherence of the bacterium to epithelial cells. In this report, we demonstrated that JlpA interacts with HEp-2 cell surface heat shock protein (Hsp) 90alpha and initiates signalling pathways leading to activation of NF-kappaB and p38 MAP kinase. Gel overlay and GST pull down assays showed that JlpA interacts with Hsp90alpha. Geldanamycin, a specific inhibitor of Hsp90, and anti-human Hsp90alpha antibody significantly blocked the interaction between JlpA and Hsp90alpha, suggesting a direct interaction between JlpA and HEp-2 cell surface-exposed Hsp90alpha. The treatment of HEp-2 cells with GST-JlpA initiated two signalling pathways: one leading to the phosphorylation and degradation of IkappaB and nuclear translocation of NF-kappaB; and another one to the phosphorylation of p38 MAP kinase. The activation of NF-kappaB and p38 MAP kinase in HEp-2 cells suggest that JlpA triggers inflammatory/immune responses in host cells following C. jejuni infection.
Jin
Songmu
S
Department of Medical Genetics and Microbiology, Medical Science Building, 1 King's College Circle, University of Toronto, Toronto, ON, M5S 1A8, Canada.
Song
Young C
YC
Emili
Andrew
A
Sherman
Philip M
PM
Chan
Voon Loong
VL
D018829:Adhesins, Bacterial / Q000378:metabolism*; D000954:Antigens, Surface / Q000378:metabolism*; D016227:Benzoquinones; D001665:Binding Sites; D002169:Campylobacter Infections / Q000378:metabolism / Q000382:microbiology; D016123:Campylobacter jejuni / Q000472:pathogenicity* / Q000502:physiology; D002460:Cell Line; D004789:Enzyme Activation; D004847:Epithelial Cells / Q000201:enzymology / Q000378:metabolism / Q000382:microbiology*; D018841:HSP90 Heat-Shock Proteins / Q000145:classification / Q000378:metabolism*; D006801:Humans; D047029:Lactams, Macrocyclic; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D011809:Quinones / Q000494:pharmacology; D015398:Signal Transduction; D048051:p38 Mitogen-Activated Protein Kinases
D018829:Adhesins, Bacterial; D000954:Antigens, Surface; D016227:Benzoquinones; D018841:HSP90 Heat-Shock Proteins; D047029:Lactams, Macrocyclic; D016328:NF-kappa B; D011809:Quinones; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; C001277:geldanamycin