FIG. 2.

Kinase activity in adenovirus-infected cells. (A) Autophosphorylation of the η isoform expressed in COS1 cells. COS1 cells were infected with Ax-lacZ (lacZ; MOI = 6), Ax-PKCη (η; lane 2, MOI = 3; lane 3, MOI = 6), or the dominant-negative mutant of PKCη (D/Nη; MOI = 6) for 48 h. The extracts were immunoprecipitated with antibody against the η isoform and reacted with [γ-³²P]ATP; this was followed by SDS-PAGE and autoradiography. The arrowhead indicates the position of the η isoform. Molecular weight (MW) standards in thousands (K) are shown on the left. (B) Kinase activities of the cells overexpressing the α, δ, η, and ζ isoforms. Partially purified cell extracts were incubated for kinase assay in the presence of PS (50 μg/ml) plus TPA (50 ng/ml) or CS (25 μM). (C) MOI-dependent kinase activity of the Ax-PKCη-infected normal human keratinocytes. Partially purified cell extracts were incubated for assay of kinase activity in the presence (hatched bars) or absence (stippled bars) of PS (50 μg/ml) plus TPA (50 ng/ml).