Figure 5.

Nuclear translocation of ERK3 is cell cycle dependent. HeLa cells growing on coverslips were transiently transfected with GFP-ERK3 FL and then incubated in 2 mM thymidine containing media for 18 h. Six slides were collected and fixed after this first treatment with thymidine. Two time points were collected after release from the thymidine block; 4 and 9 h. Six slides/condition and time point were subsequently processed for immunofluorescence analysis. Percentage of Golgi refers to the percentage of transfected cells with GFP-ERK3 restricted to the Golgi. Percentage of nuclear entry includes all transfected cells containing nuclear ERK3. The slides were fixed and immunostained with the cy3FLAG antibody. Only cells exhibiting green and red fluorescence were scored. The cell cycle profiles of asynchronously growing and synchronized cells (as determined by FACS analysis) are presented below the quantitation of the localization data.