FIGURE 6.

Protein synthesis in murine embryonic fibroblasts lacking 4EBP expression or containing non-phosphorylatable eIF2α is resistant to cordycepin. Protein synthesis in MEFs from animals lacking expression of 4EBP1 and 4EBP2 (double knock-out, DKO) (A) and MEFs from animals with the S51A mutation in eIF2α (B), and their corresponding wild-type controls, was measured by [³⁵S]methionine incorporation into protein. The cells were pre-treated with 0, 50, and 200 μm cordycepin for 1.5 h and then labeled for 1 h. The data are corrected for total protein concentration and are shown as the means ± S.E. of three replicates for each treatment.