Examination of bundlin expression and processing by EPEC. Whole-cell extracts were prepared from EPEC strains (left to right) E2348/69, UMD932, UMD901, UMD934, E2348/69 (pTrcphoA), UMD934 (pTrcphoA), and UMD934 (pTEB41) after growth in DMEM/F-12 for 6 h. Extracts were separated by SDS-PAGE using a 15% polyacrylamide gel. A monoclonal antibody was used to detect bundlin.