Cell invasion of Yersinia pseudotuberculosis by invasin and YadA requires protein kinase C, phospholipase C-gamma1 and Akt kinase.
The outer membrane proteins YadA and invasin of Yersinia pseudotuberculosis promote invasion into mammalian cells through beta(1)-integrins and trigger the production of interleukin (IL)-8. FAK, c-Src and the PI3 kinase were previously found to be important for both YadA- and invasin-promoted uptake. Here, we demonstrate that two different downstream effectors of PI3 kinase, Akt and phospholipase Cgamma1 are required for efficient cell invasion. Inhibition of Akt or phospholipase C-gamma (PLC-gamma)1 by pharmaceutical agents as well as reduced expression of the isoforms Akt1 and Akt2, and of PLC-gamma1 by RNA interference decreased entry of YadA- and Inv-expressing bacteria significantly. In addition, we report that the conventional protein kinases C (PKC)alpha and -beta, positioned downstream of PLC-gamma1, are activated upon Inv- or YadA-promoted cell entry. They colocalize with intracellular bacteria and their depletion by siRNA treatment also resulted in a strong reduction of cell entry. In contrast, neither Akt nor PLC-gamma1, and the PKCs are essential for YadA- and Inv-mediated IL-8 synthesis and release. We conclude that YadA and invasin of Y. pseudotuberculosis both trigger similar signal transduction pathways during integrin-mediated phagocytosis into epithelial cells, which lead to the activation of Akt, PLC-gamma1, PKCalpha and -beta downstream of PI3 kinase, separate from the MAPK-dependent pathway that triggers IL-8 production.
Uliczka
Frank
F
Institut für Mikrobiologie, Technische Universität Braunschweig, 38106 Braunschweig, Germany.
Kornprobst
Tina
T
Eitel
Julia
J
Schneider
Daniela
D
Dersch
Petra
P
D018829:Adhesins, Bacterial / Q000378:metabolism*; D002460:Cell Line; D004791:Enzyme Inhibitors / Q000008:administration & dosage; D054884:Host-Pathogen Interactions / Q000187:drug effects; D006801:Humans; D016209:Interleukin-8 / Q000096:biosynthesis; D051058:Oncogene Protein v-akt / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D010587:Phagocytosis; D051966:Phospholipase C gamma / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D015398:Signal Transduction / Q000187:drug effects; D015011:Yersinia pseudotuberculosis / Q000235:genetics / Q000378:metabolism*; D015012:Yersinia pseudotuberculosis Infections / Q000378:metabolism* / Q000382:microbiology
D018829:Adhesins, Bacterial; D004791:Enzyme Inhibitors; D016209:Interleukin-8; D034741:RNA, Small Interfering; C064832:YadA protein, Yersinia; C053476:invasin, Yersinia; D051058:Oncogene Protein v-akt; D011493:Protein Kinase C; D051966:Phospholipase C gamma