Fig. 4.

PKR activation in SK-N-SH cells after HSV-1 infection. (A) PKR was immunoprecipitated from whole cell extracts prepared from SK-N-SH cells harvested at 4 or 6 h after mock infection or infection with HSV-1(F) or R51204 as described in Materials and Methods. The immune complex was subjected to an in vitro kinase assay in the presence of histone H1, analyzed on a denaturing 10% polyacrylamide gel, electrically transferred to a nitrocellulose sheet, and subsequently subjected to autoradiography to detect substrate phosphorylation. (B) Quantification of the amount of phosphorylated substrate relative to mock-infected cells obtained with the aid of the Molecular Dynamics Storm 860 PhosphorImager.