FIG. 4.

ZIP kinase interacts with ATF4 in mammalian cells. COS-7 cells were transiently transfected with 5 μg of the plasmids indicated. The cells were harvested 36 h after transfection and lysed in the lysis buffer. Whole-cell extracts (WCE) were separated by SDS-PAGE and then immunoblotted with anti-FLAG M2 MAb (lanes 1 through 3) or anti-Myc 9E10 MAb (lanes 7 through 9). The same lysates were immunoprecipitated with either anti-Myc MAb or anti-FLAG MAb, and the immunoprecipitates were blotted with either anti-FLAG MAb (lane 4 through 6) or anti-Myc MAb (lanes 10 through 12). The bands corresponding to Myc-ZIP kinase and FLAG-ATF4 proteins are indicated by arrows.