FIG. 1.

Transient expression of the poliovirus 2A protease results in the cleavage of eIF4GI and in induction of cell death. 293-EcR cells were transiently transfected with pEGFP-N1 (Clontech) together with a pIND plasmid encoding an HA-tagged 2A protease (HA-2A), with an inactive variant of this protease in which cysteine 109 was replaced by alanine (HA-D2A), or with a pIND plasmid encoding LacZ (Mock). MurA was added to the growth medium 6 h posttransfection, and cellular extracts were prepared after additional 18 h. Cellular extracts were fractionated by electrophoresis and subjected to Western blot analysis with an anti-HA antibody (A) and anti-eIF4GI antibodies that recognize specifically the N-terminal fragment (B) or the C-terminal fragment (C). The N (Cp-N)- and C (Cp-C)-terminal cleavage products of eIF4GI are indicated. The percentage of dead cells out of all GFP-expressing cells was determined by microscopic inspection (D). EtOH, ethanol.