Constitutive expression of the N-terminal deletion mutant of TRAF3 blocks NF-κB activation following CD40 ligation.

(A) KMH2 transfectants expressing the full-length TRAF 3 construct (F-TRAF3) or the selectable marker alone (pSV2) were stimulated for 1 hour with CD40L. Nuclear extracts were analyzed for NF-κB DNA-binding activity EMSA. (B) KMH2 transfectants expressing the deletion mutant of TRAF3 (δ300TRAF3) or the selectable marker alone (pSV2neo) were stimulated for 1 hour with CD40L and nuclear extracts were analyzed for NF-κB DNA-binding activity. (C) Mean ± SE of densitometric results from 3 independent experiments as performed in panels A and B. Comp indicates competitor; ns, nonspecific; wt, wild type; mt, mutant; none, untransfected. Arrowheads indicate shifted oligonucleotide. The bars above the gels indicate the transfected construct contained in the KMH2 cells used in the experiment.