Vpr expression is sufficient to reduce the levels of phosphorylated eIF4E and 4E-BP1.

<p>(A) Serum deprivation or pharmacological cell cycle arrest is sufficient to reduce accumulation of phosphorylated eIF4E and 4E-BP1. HEK 293 cells were incubated in complete medium (serum +) or in low serum medium (−serum) for 24 hour. Equivalent whole-cell extracts were harvested and immunoblotted with phospho-eIF4E Ser209, total eIF4E, phospho-4E-BP1 Ser65, total 4E-BP1, phospho-Mnk1 Thr197/202, total Mnk1, phospho-eIF2α Ser51 and total eIF2α, antibodies respectively <i>(left panel)</i>. CEMx174 cells were incubated in complete medium that lacked or contained nocodazole (Noc) for 24 hour, and equivalent whole-cell extracts were immunoblotted with the indicated antiserum. (B) HEK 293 cells were transfected with expression plasmids encoding Vpr, indicated Vpr substitution mutant, or Vif, and whole-cell extracts were immunoblotted with the indicated antiserum.