Fig. 6. Effect of Cdk5 and Cdk5T33 on localization of active Src in A6(1) cells. A6(1) corneal epithelial cells were transiently transfected with EGFP-Cdk5 (A,B) or EGFP-Cdk5T33 (C,D) and then cultured overnight. Cells were immunostained with antibody specific for active Src(pY416) and rhodamine-tagged secondary antibody. (A) EGFP fluorescence showing a cell transfected with EGFP-Cdk5. (B) Rhodamine fluorescence of the same field showing the localization of active Src in transfected and untransfected cells. In the EGFP-Cdk5-transfected cell, active Src is located primarily in the perinuclear region (arrow), with little active Src in cell processes. By contrast, cell processes are well stained in untransfected cells in the same field (arrowhead). (C) EGFP fluorescence of a cell transfected with EGFP-Cdk5T33. (D) Rhodamine fluorescence of the same field, showing the localization of active Src in transfected and untransfected cells. In the EGFP-Cdk5T33-transfected cell, cell processes are well stained, with high concentrations of active Src in cell processes (arrowhead). Active Src is also present in lamellipodia (double arrow). Bar, 25 µm.