Recombination Signal Binding Protein For Immunoglobulin Kappa J Region (RBPJ)

RBPJ is a human homolog for the Drosophila gene Suppressor of Hairless. It is classically used as a promoter region to demonstrate Notch1 signaling.The Igkjrb protein, identified in nuclear extracts from a mouse pre-B-cell line as a binding protein specific to Jk-type RS, may also be involved. The IGKJRB gene is well conserved among many species such as human, mouse, Xenopus, and Drosophila. Three types of cDNA with different 5-prime sequences were isolated, suggesting the presence of 3 protein isoforms. Two of these may be specific to human cells because the mouse counterparts were not detected. The amino acid sequences of the human and mouse genes are 98% identical in exons 2 through 11, whereas the homology of the human and mouse exon 1 sequences were 75%.