FIG. 1.

The PY motif of LMP2A is important for inhibition of involucrin expression. (A) HFK cells (4 × 10⁶) stably expressing the pBabe vector, LMP2A, LMP2A ΔITAM, and LMP2A ΔPY were resuspended in K-SFM-methylcellulose medium. An equal number of cells were plated in parallel in tissue culture plates with K-SFM. Cells were harvested after 28 and 54 h, and immunoblot analyses were performed. Induction of differentiation was assessed with antibodies against involucrin, and expression of the LMP2A constructs was determined via anti-HA immunoblotting. Antiactin was included as a loading control. (B and C) Densitometry was performed, and involucrin levels at 28 h were normalized to the corresponding actin levels (B) or to expression of LMP2A (C) and graphed.