FIG. 3.

NPM sets a threshold for p53 response to UV radiation. The figure shows results of Western blot analyses. (A) RKO cells treated with siNPM or control scrambled RNA (siCont) were exposed to UV radiation and harvested. The proteins (30 μg) were reacted with NPM Ab. (B) Same as panel A, but the cells were exposed to the indicated dose of UV radiation and 200 μg of protein was loaded before the blot was reacted with p21 Ab. (C) Same as panel B, but the proteins (200 μg) were reacted with p53 Ab. (D) Same as panel B, except that the blot was reacted with a p53 Ab specific for phosphorylation at Ser15. All blots were reacted with actin Ab for a loading control.