Emerging views on integrin signaling via Rac1 during invasin-promoted bacterial uptake.
Enteropathogenic Yersinia species encode invasin, which promotes uptake into host cells by binding beta1 integrins. Invasin may cluster integrin heterodimers extracellularly and cause the integrin alpha and beta chains to splay apart in the cytoplasm. Cdc42 signaling is not essential for Yersinia uptake, whereas invasin crucially triggers Rac1-mediated signals that enable internalization. The signals linking invasin-mediated adhesion to Rac1 activation are not clear, but a novel kinase may release it from RhoGDI so that Rac1 can be activated, for example by Dock180. Rac1 may act via Arp2/3, phosphatidylinositol 4,5-bisphosphate and capping-proteins in the formation of nascent phagosomes during Yersinia uptake.
Wong
Ka-Wing
KW
Department of Molecular Biology and Microbiology, Howard Hughes Medical Institute, Tufts University School of Medicine, 150 Harrison Avenue, Boston, MA 02111, USA.
Isberg
Ralph R
RR
D018829:Adhesins, Bacterial / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D016023:Integrins / Q000378:metabolism*; D010587:Phagocytosis; D015398:Signal Transduction; D015007:Yersinia / Q000145:classification / Q000472:pathogenicity*; D020830:rac1 GTP-Binding Protein / Q000378:metabolism*
D018829:Adhesins, Bacterial; D016023:Integrins; C053476:invasin, Yersinia; D020830:rac1 GTP-Binding Protein