FIG. 2.

Expression of the constitutively active IκBβ inhibits the persistent NF-κB activity. (A and B) EMSA with a palindromic κB and nuclear extracts from control (C, lanes 1 to 3) or transgenic (Tg, lanes 4 to 6) thymocytes treated with PMA-PHA (A) or mouse TNF-α (B) for the indicated periods. The arrowhead indicates p50/RelA heterodimers, and the arrow indicates p50 homodimers. The corresponding cytoplasmic extracts were analyzed by Western blotting with antibodies against IκBα, IκBβ, and LDH. EMSA with Oct-I oligonucleotide was used as a loading control. (C) Determination of the composition of the NF-κB complexes inhibited by mIκBβ by preincubation of the 30-min TNF-α-stimulated extracts with the indicated antibodies. (D) Western blot analysis of whole-cell extracts from control and transgenic thymuses with anti-p50 and anti-RelA antibodies.