FIG. 4.

Autoradiographic image of PKR electrophoretically separated from immune complexes derived from labeled infected HeLa cells. Replicate HeLa cell cultures were mock infected or infected with R7023, R5103, or R5104 as described in Materials and Methods. At 18 h after infection, the cells were harvested and lysed, and immune precipitates obtained with the anti-PKR antibody (K-17; Santa Cruz Research) were electrophoretically separated on a 12% polyacrylamide gel, transferred to a nitrocellulose sheet, and subjected to autoradiography. The positions of the M_r-200,000, -90,000, and -67,000 proteins determined from the molecular weight markers (Pharmacia) are indicated on the left. The heavily labeled bands with an apparent M_r of 67,000 were identified as PKR (7).