Fig. 4.

Tcl1 inhibits MEKK1-mediated cell death. (A) Some 293 cells were transfected with 1.5 μg of pCMV5-empty vector, 0.5 μg of pFC-MEKK and 1 μg of pCMV5-empty, pCMV5-Tcl1 WT, or pCMV5-Tcl1 T38I constructs. Western blot analysis was carried out as described in Methods. (B and C) Some 293 cells were transfected with 1.5 μg of pCMV5-empty vector, or0.5 μg of pFC-MEKK and 1 μg of pCMV5-empty or pCMV5-Tcl1 WT constructs. Sixteen hours later, cells were fixed, permeabilized, and stained with Hoechst 33342. (B) Percentage of apoptotic cells. For each transfection at least 20 fields were selected for counting the percentage of dead cells (indicated by fragmented nucleus). (C) Results of the same experiment were visualized by using confocal microscopy. (Magnification: 63×.)