Listeria monocytogenes, an invasive bacterium, stimulates MAP kinase upon attachment to epithelial cells.
Protein tyrosine phosphorylation is an important regulatory mechanism for many cellular processes in eucaryotic cells. During the invasion of the gram-positive pathogen, Listeria monocytogenes, into host epithelial cells, two host proteins become tyrosine phosphorylated. We have identified these major tyrosine phosphorylated species to be two isoforms of mitogen-activated protein (MAP) kinase, the 42 and 44 kDa MAP kinases. This activation begins within 5 to 15 min of bacterial infection. The tyrosine kinase inhibitor, genistein, blocks invasion as well as the tyrosine phosphorylation of these MAP kinases. Using cytochalasin D to block bacterial internalization but not adhesion, we showed that bacterial adherence rather than uptake is required for MAP kinase activation. Internalin mutants, which are unable to adhere efficiently to host cells, do not trigger MAP kinase activation. Other invasive bacteria, including enteropathogenic Escherichia coli (EPEC), and E. coli expressing Yersinia enterocolitica invasion, were not observed to activate MAP kinase during invasion into cultured epithelial cells. These results suggest that L. monocytogenes activates MAP kinase during invasion and a MAP kinase signal transduction pathway may be involved in mediating bacterial uptake.
Tang
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Biotechnology Laboratory, University of British Columbia, Vancouver, Canada.
Rosenshine
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D018829:Adhesins, Bacterial; D001422:Bacterial Adhesion / Q000502:physiology; D001426:Bacterial Proteins / Q000502:physiology; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism*; D002460:Cell Line; D015638:Cytochalasin D / Q000494:pharmacology; D004789:Enzyme Activation; D004847:Epithelial Cells; D004926:Escherichia coli / Q000235:genetics / Q000502:physiology; D019833:Genistein; D006367:HeLa Cells; D006801:Humans; D007529:Isoflavones / Q000494:pharmacology; D008089:Listeria monocytogenes / Q000187:drug effects / Q000502:physiology*; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D010750:Phosphoproteins / Q000032:analysis; D010766:Phosphorylation / Q000187:drug effects; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism*; D014443:Tyrosine / Q000378:metabolism; D015008:Yersinia enterocolitica / Q000737:chemistry
D018829:Adhesins, Bacterial; D001426:Bacterial Proteins; D007529:Isoflavones; D010750:Phosphoproteins; C053476:invasin, Yersinia; C069761:internalin protein, Bacteria; D015638:Cytochalasin D; D014443:Tyrosine; D019833:Genistein; D011505:Protein-Tyrosine Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases