Identification of a second inducible DNA-protein interaction in the kappa immunoglobulin enhancer

Control of kappa immunoglobulin light-chain gene expression requires the interaction of tissue specific and developmentally regulated DNA-binding proteins with the kappa gene enhancer. Deletion of enhancer sequences upstream from the NF-kB binding site has been shown to impair enhancer function, implying additional proteins may interact with these sequences. In surveying this region for sites of protein binding, a novel DNA-protein interaction, designated kBF-A, was detected. The binding activity of this factor appears to be specific to activated pre-B cells and correlates with high level induction of kappa transcription in these cells.