FIG. 1.

(A) Scheme of the mutated ikbb transgene. The mouse ikbb cDNA with the serines 19 and 23 (67) mutated to alanines was placed under the control of the mouse proximal lck promoter. Human growth hormone gene sequences and the human CD2 gene locus control region were added to confer transcript stability and to confer copy number-dependent and position-independent expression of the transgene, respectively. Generation of transgenic mice and PCR genotyping of tail DNA were performed as described previously (52). (B) Northern blot analysis of the different transgenic lines. Total RNA (20 μg) prepared from the thymus of control mice and different transgenic mice was hybridized with the ikbb or the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) cDNA. (C) Cytoplasmic extracts (34 μg) prepared from thymocytes of the corresponding mice were analyzed with anti-IκBβ and anti-LDH antibodies.