Genomic organization and chromosomal mapping of mouse nuclear factor kappa B 2 (NFKB2)

NFKB2 is a member of the NFKB/Rel gene family, which is known to be a pivotal regulator of the acute phase and immune responses. NF-kappaB2 is initially synthesized as a approximately 100 000 Mr protein which needs to be processed in order to bind DNA, either as homodimer or as heterodimer with other members of the NF-kappaB/Rel family. The unprocessed form of NF-kappaB2 acts as an IkappaB-like protein. Therefore, NF-kappaB2 has a dual function. In this report we describe the genomic structure, expression pattern, and chromosomal localization of mouse NFKB2. Genomic clones were isolated, which span the entire gene of approximately 8.5 kilobases (kb) including 1.5 kb of the promoter region. Comparison to its human and avian homologues revealed a strong evolutionary conservation of the gene structure including the exon/intron borders, sequence, and position of the nuclear localization signal, the glycine-hinge region, and the ankyrin repeats. By fluorescence in situ hybridization, mouse NFKB2 was mapped to Chromosome (Chr) MMU 19C3-D2, which is homologous to human Chr 10q24, at which position the human NFKB2 was previously located. NFKB2 is ubiquitously expressed, highest in lymph nodes and thymus, underlining its role in the immune function.