FIGURE 7.

UVB irradiation activates TC-PTP in keratinocytes. A, TC-PTP activity was assessed at the indicated time after UVB irradiation (10 mJ/cm²) in 3PC keratinocytes. Results are the mean ± S.D. (error bars) from three independent experiments. *, p < 0.05 by Student's t test for equality of means. B, TC-PTP activity was assessed 3 h after different doses of UVB irradiation in keratinocytes. C, TC-PTP activity was measured at the indicated times after UVB irradiation (10 mJ/cm²) in control (empty vector) or TC-PTP-overexpressing keratinocytes.