Involvement of the intermediate filament protein cytokeratin-18 in actin pedestal formation during EPEC infection.
While remaining extracellular, enteropathogenic Escherichia coli (EPEC) establish direct links with the cytoskeleton of the target epithelial cell leading to the formation of actin-rich pedestals underneath attached bacteria. The translocated adaptor protein Tir forms the transmembrane bridge between the cytoskeleton and the bacterium; the extracellular domain of Tir functions as a receptor for the bacterial adhesin intimin, while the intracellular amino and carboxy termini interact with a number of focal adhesion and other cytoskeletal proteins; and recruitment of some is dependent on phosphorylation of Tyr 474. Using Tir as bait and HeLa cell cDNA library as prey in a yeast two-hybrid screen, we identified cytokeratin 18 as a novel Tir partner protein. Cytokeratin 18 is recruited to the EPEC-induced pedestal and has a direct role in actin accretion and cytoskeleton reorganization. This study is the first to implicate intermediate filaments in microfilament reorganization following EPEC infection.
Batchelor
Miranda
M
Centre for Molecular Microbiology and Infection, Flowers Building, Imperial College London, London SW7 2AZ, UK.
Guignot
Julie
J
Patel
Amit
A
Cummings
Nicola
N
Cleary
Jennifer
J
Knutton
Stuart
S
Holden
David W
DW
Connerton
Ian
I
Frankel
Gad
G
D000199:Actins / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000382:microbiology; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D007150:Immunohistochemistry; D047468:Immunoprecipitation; D007633:Keratins / Q000378:metabolism*; D010766:Phosphorylation; D010957:Plasmids; D034741:RNA, Small Interfering / Q000235:genetics; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D014162:Transfection
D000199:Actins; D029968:Escherichia coli Proteins; D034741:RNA, Small Interfering; D011956:Receptors, Cell Surface; C109287:Tir protein, E coli; D007633:Keratins