Abundance of translation initiation factors and interaction of eIF4G with eIF4E in myotubes depleted of PDCD4. Cells were treated with scrambled (SC) or PDCD4 oligonucleotides as in Figures 5 and 6. They were then deprived of amino acids and serum for 12 h. (A) Abundance of 4E-BP1 and eIF4E, and interaction of the two were measured. Reduced phosphorylation of 4E-BP1 is obvious in downward shifts of signals in lanes for starved cells (compare lanes 1 and 2 to lanes 3 and 4 in the top panel of Figure 7A). (B) Abundance of eIF4G and its interaction with eIF4E. (C) Quantification of eIF4G abundance (upper chart; tubulin served as loading control) and its interaction with eIF4E (lower). Data are expressed as % of SC. Means ± SE of 3 independent experiments.