Campylobacter jejuni is a foodborne pathogen that binds to and invades the epithelial cells 38
lining the human intestinal tract. Maximal invasion of host cells by C. jejuni requires cell binding 39
and delivery of the Campylobacter invasion antigens (Cia) to the cytosol of the targeted cells via 40
the flagellum. The CiaD effector facilitates cell invasion through the activation of Erk 1/2, which 41
in turn phosphorylates cortactin and stimulates actin reorganization. The objective of this study 42
was to determine the host cell target of CiaD. We identified and verified that CiaD binds to the 43
host cell protein IQGAP1 and explored the mechanistic basis for C. jejuni invasion of host cells. 44
We found that the binding of CiaD to IQGAP1 displaces RacGAP1 from the IQGAP1 complex, 45
resulting in unconstrained Rac1 activity. These findings represent the first published 46
identification of a host cell protein targeted by a flagellar secreted effector protein.
Published: May 9, 2021
Citation
Negretti N.M., C.R. Gourley, P.K. Talukdar, G. Clair, C.M. Klappenbach, C.J. Lauritsen, and J.N. Adkins, et al. 2021.The Campylobacter jejuni CiaD effector co-opts the host cell protein IQGAP1 to promote cell entry.Nature Communications 12, no. 1:1339.PNNL-SA-152634.doi:10.1038/s41467-021-21579-5