FIGURE 6.

Differential requirements of the Lysine 67, 87, and 89 residues for activation or repression of Pax5 target genes. Pax5^−/− mouse pro B cells (G5) were reconstituted with recombinant retrovirus expressing the wild-type Pax5 or different lysine-to-alanine Pax5 mutants. A, cell surface CD19 expression was monitored by FACS analysis. Transduced cells expressing different Pax5 constructs can be tracked by gating on GFP⁺ cells. The percentages of CD19⁺GFP⁺ cells are indicated. Results shown are representatives from three independent transduction experiments. B–G, the GFP⁺ cells were purified by FACS sorting, and the expression levels of Cd19 (B), Blnk (C), Mb1 (D), IgJ chain (E), Notch1 (F), and Ccl3 (G) were analyzed by real-time RT-PCR. For induction of the Cd19, Blnk, and Mb1 genes, the results are presented as relative fold induction over that in cells only expressing GFP. For repression of IgJ chain, Notch1, and Ccl3, the results are presented as relative expression levels compared with that in cells only expressing GFP (set as 100). Results presented are mean ± S.D. from triplicate PCR amplifications. The reconstitution experiments were performed three times.