Phosphorylation-independent effects of CagA during interaction between Helicobacter pylori and T84 polarized monolayers.
To extend our knowledge of host-cell targets of Helicobacter pylori, we characterized the interaction between H. pylori and human T84 epithelial cell polarized monolayers. Transcriptional analysis by use of human microarrays and a panel of isogenic H. pylori mutants revealed distinct responses to infection. Of the 670 genes whose expression changed, most (92%) required the cag pathogenicity island (PAI). Although altered expression of many genes was dependent on CagA (80% of the PAI-dependent genes), expression of >30% of these host genes occurred independent of the phosphorylation state of the CagA protein. Similarly, we found that injected CagA localized to the apical surface of cells and showed preferential accumulation at the apical junctions in a phosphorylation-independent manner. These data suggest the presence of distinct functional domains within the CagA protein that play essential roles in protein targeting and alteration of host-cell signaling pathways.
El-Etr
Sahar H
SH
Department of Microbiology and Immunology, Stanford University Medical School, Stanford, California 94305, USA. seletr@stanford.edu.
Mueller
Anne
A
Tompkins
Lucy S
LS
Falkow
Stanley
S
Merrell
D Scott
DS
D000942:Antigens, Bacterial / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor / Q000382:microbiology* / Q000502:physiology; D016764:Cell Polarity; D048430:Cell Shape; D005786:Gene Expression Regulation; D016480:Helicobacter pylori / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity; D006801:Humans; D018613:Microscopy, Confocal; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D010766:Phosphorylation; D015398:Signal Transduction; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism*
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D037521:Virulence Factors; C080866:cagA protein, Helicobacter pylori