Interaction of the enteropathogenicEscherichia coli protein, translocated intimin receptor (Tir), with focal adhesion proteins
β Scribed by Freeman, Nancy L. ;Zurawski, Daniel V. ;Chowrashi, Prokash ;Ayoob, Joseph C. ;Huang, Lily ;Mittal, Balraj ;Sanger, Jean M. ;Sanger, Joseph W.
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 579 KB
- Volume
- 47
- Category
- Article
- ISSN
- 0886-1544
No coin nor oath required. For personal study only.
β¦ Synopsis
When enteropathogenic Escherichia coli (EPEC) attach and infect host cells, they induce a cytoskeletal rearrangement and the formation of cytoplasmic columns of actin filaments called pedestals. The attached EPEC and pedestals move over the surface of the host cell in an actin-dependent reaction [Sanger et al., 1996: Cell Motil Cytoskeleton 34:279 -287]. The discovery that EPEC inserts the protein, translocated intimin receptor (Tir), into the membrane of host cells, where it binds the EPEC outer membrane protein, intimin [Kenny et al., 1997: Cell 91:511-520], suggests Tir serves two functions: tethering the bacteria to the host cell and providing a direct connection to the host's cytoskeleton. The sequence of Tir predicts a protein of 56.8 kD with three domains separated by two predicted trans-membrane spanning regions. A GST-fusion protein of the N-terminal 233 amino acids of Tir (Tir1) binds to alpha-actinin, talin, and vinculin from cell extracts. GST-Tir1 also coprecipitates purified forms of alpha-actinin, talin, and vinculin while GST alone does not bind these three focal adhesion proteins. Biotinylated probes of these three proteins also bound Tir1 cleaved from GST. Similar associations of alpha-actinin, talin, and vinculin were also detected with the C-terminus of Tir, i.e., Tir3, the last 217 amino acids. Antibody staining of EPEC-infected cultured cells reveals the presence of focal adhesion proteins beneath the attached bacteria. Our experiments support a model in which the cytoplasmic domains of Tir recruit a number of focal adhesion proteins that can bind actin filaments to form pedestals. Since pedestals also contain villin, tropomyosin and myosin II
π SIMILAR VOLUMES
The effects of some protein-modifying reagents on the interaction of colicins A, E2, E3 and K with their respective Escherichia coli cell receptors') J. SMARDA and L