IKKα and combined noncanonical and canonical NF-κB regulate Pax5 and Irf4 promoter activities and BM B-cell differentiation. (A) The activities of Pax5, Irf4, mutant Pax5, and mutant Irf4 promoters containing mutations within κB1 (mκB1) or κB2 (mκB2) in pGL3b luciferase reporter vectors were examined in Raji B cells using the luciferase reporter assay. +IKKα indicates coexpression of IKKα and promoter plasmids; +IKKα-KA, coexpression of IKKα-KA and promoter plasmids. (B) Flow cytometric analyses of B220⁺ BM B cells in RPMI 1640 medium supplemented with 10% FBS for 3 days after reintroduction of IKKα, IKKα-KA, Pax5, and IKKα+Pax5 plasmids into BM B cells using AMAXA nucleofection. (C) Levels of Ter119, M-CSFR, and C/EBPα in cultured WT and KA/KA BM B cells were detected with Western blotting. β-actin, protein-loading control. (D) RT-PCR showing expression levels of Tnfsf11 and GAGA1 in cultured WT and KA/KA BM B cells. ++, +, cDNA dilution; -, negative control; β-actin, PCR control.