Fig. 4.

NIK protein level and activity are controlled by a negative feedback loop involving TRAF2/3. (A) Western blot analysis of TRAF2 and TRAF3 protein levels in purified splenic B cells of the indicated genotypes. (B) Western blot analysis of cytoplasmic (C) and nuclear (N) protein amounts of NIK, p100/p52, RelB, TRAF2, and TRAF3 in splenic B cells. (C) Northern blot analysis of Traf2, Traf3, and IκBα mRNA levels in CD43-depleted splenic B cells. Numbers in red indicate average quantifications (normalized to the respective loading controls) relative to controls of three (A), one (B), or two to three (C) experiments.