Fig. 4. Effect of the inhibition of lysosomal hydrolases by monensin or of the proteasome by lacatacystin on the amount of Fas protein in Jurkat cells and in the sublines. a and b, 2 x 106 Jurkat, Jurkat-ws (a), or Jurkat-hp (b) cells were incubated for the times indicated in the absence (C) or presence of 10 µg/ml of monensin. c, 2 x 106 Jurkat, Jurkat-ws, or Jurkat-hp cells were incubated for the times indicated in the absence (C) or presence of 2 µM of lactacystin. Proteins were extracted with a buffer containing 1% Triton X-100, separated by SDS-PAGE, transferred, and immunoblotted with the polyclonal anti-Fas antibody C20. Equivalent protein loading in each lane was controlled by reblotting of the same membrane with antitubulin antibody (top panels in a and b). The positions of molecular weight markers are indicated on the left. The experiments shown are representative of at least three different experiments for each experimental condition.