FIG. 10.

Suppression of differentiation by the dominant-negative η isoform. Twelve hours after infection with Ax-lacZ (stippled bars) or Ax-D/Nη (hatched bars) at an MOI of 12, normal human keratinocytes grown in KGM were exposed to CaCl₂ (Ca²⁺; 0.2 mM), 1α,25-dihydroxyvitamin D3 (Vit.D3; 12 nM), or TPA (1 ng/ml) for 24 h; measurement of TGase 1 activity followed. Values shown are the means ± standard deviations of three cultures. Asterisks indicate values that are significantly different from the values of Ax-lacZ-infected cells (∗, P < 0.05; ∗∗, P < 0.01).