RRC ID 2899
Author Cantarelli VV, Kodama T, Nijstad N, Abolghait SK, Iida T, Honda T.
Title Cortactin is essential for F-actin assembly in enteropathogenic Escherichia coli (EPEC)- and enterohaemorrhagic E. coli (EHEC)-induced pedestals and the alpha-helical region is involved in the localization of cortactin to bacterial attachment sites.
Journal Cell Microbiol
Abstract Enteropathogenic Escherichia coli (EPEC) and enterohaemorrhagic E. coli (EHEC) are important human pathogens. Upon attachment to host cells, EPEC and EHEC are able to induce actin polymerization, which accumulates, forming a pedestal-like structure beneath the attached bacteria. Using siRNA, we show here that EPEC- and EHEC-induced pedestals are dependent on cortactin, an F-actin-binding protein found in the mammalian cell cortex. Knock-down of cortactin by siRNA resulted in a dramatic reduction of the pedestal formation induced by both pathogens. We also show that disruption of the Src homology 3 (SH3) domain of cortactin, or its downregulation by specific point mutations, negatively affects pedestal formation, suggesting that this domain is important for regulation of F-actin assembly by EPEC and EHEC. Green fluorescent protein (GFP) fused with the SH3 domain (GFP-SH3), proline-rich region (GFP-PRR) or alpha-helical region of cortactin markedly reduced the amount of F-actin at the bacterial attachment sites. Interestingly, neither GFP-SH3 nor GFP-PRR was recruited to the vicinity of the bacterial adherence sites; however, GFP fused to the alpha-helical region was efficiently recruited and colocalized with the attached bacteria. These results demonstrate that cortactin is a requirement for pedestal formation and suggest a novel function for the predicted alpha-helical region of cortactin in actin assembly induced by EPEC and EHEC.
Volume 8(5)
Pages 769-80
Published 2006-5
DOI 10.1111/j.1462-5822.2005.00664.x
PMID 16611226
MeSH Actins / metabolism* Bacterial Adhesion* Cortactin / genetics Cortactin / metabolism* Cytoskeleton / metabolism Escherichia coli / metabolism* Escherichia coli Infections / metabolism Escherichia coli Infections / microbiology Escherichia coli O157 / metabolism HeLa Cells Humans Mutation Protein Structure, Secondary RNA, Small Interfering / genetics Recombinant Fusion Proteins / genetics Recombinant Fusion Proteins / metabolism src Homology Domains
IF 4.288
Times Cited 23
Pathogenic microorganisms ?