FIG. 9.

Schematic representation of ICP0 and ICP4 isoforms observed after two-dimensional separation of lysates of HSV-1-infected HEL fibroblasts. (A) Absence of specific isoforms from lysates of HEL fibroblasts infected with HSV-1 mutants or with wild-type virus and treated with roscovitine. Isoforms E and F failed to accumulate in lysates of R325-infected or roscovitine-treated, HSV-1-infected cells. These isoforms are putative nuclear forms, and their processing is dependent on cdc2 kinase. HEL fibroblasts infected with R7914 or wild-type virus and treated with MG132 failed to accumulate the G isoform, and this isoform appears to be associated with ICP0 translocated into the cytoplasm. (B) Isoforms D′ and E′ of ICP4 failed to accumulate in HEL fibroblasts infected with R325 mutant. The most negatively charged, E′ isoform of ICP4 was not detected in significant amounts in cells infected with wild-type virus and treated with roscovitine. The accumulation of the ICP4 isoform E′ may also be dependent on cdc2 kinase.