FIG. 4.
Autoradiographic image of roscovitine-sensitive histone H1 phosphorylation by cdc2 or UL42 immunocomplexes. Mock- or HSV-1-infected HEp-2 cell lysates were subjected to immunoprecipitation (IP) by antibodies (Ab) to cdc2 or UL42. Immunocomplexes were preincubated with 0, 1, 5, or 20 μM roscovitine and subjected to in vitro kinase assays using histone H1 as the substrate. Phosphorylated histone 1 from the reactions was resolved by polyacrylamide gel electrophoresis, and the blots were developed by autoradiography. Histone phosphorylation was quantified by PhosphorImager analysis. Samples not treated roscovitine were assigned a value of 1.