MAP2K1 and infection: Experiments were performed to assess membrane ruffling of INT 407 cells upon infection with the C. jejuni wild-type strain, ciaD mutant, and ciaD mutant expressing a wild-type copy of ciaD in trans (ciaD complemented isolate), as well as cells infected with a C. jejuni wild-type strain that had been pretreated with the MEK 1/2 inhibitor PD98059 that blocks Erk 1/2 activation.