Figure 1. UVB induced activation of PKD in primary mouse keratinocytes.

Near-confluent primary mouse keratinocytes were irradiated with 30 mJ/cm² UVB and the control cells were sham-irradiated (rinsed and placed into the irradiator box for the appropriate time but without turning on the UV lamp). The cells were lysed at various time points after UVB irradiation as indicated and processed for western blotting employing antibodies against phosphoserine⁹¹⁶ PKD (indicative of activated PKD) and total PKD. Actin served as the loading control. Illustrated in the upper panel is a blot representative of 3 separate experiments. Shown in the lower panel are the phosphoserine⁹¹⁶ PKD levels from 3 experiments quantified, normalized by total PKD levels and expressed as the means ± SEM; *p<0.01 versus time zero by ANOVA followed by a Dunnett’s post-hoc test. Note that normalizing phosphoserine⁹¹⁶ PKD by actin levels gave essentially identical results in this and subsequent experiments.