Coordinated Expression To IRX2 (CEI)

CEI contains 4 exons, spans 3.25 kb, and is relatively GC rich. It shares a potential bidirectional promoter with IRXA2 that is embedded within a large CpG island that continues into both genes.Wu et al. (2006) identified a novel gene, CEI, within the promoter region of the IRXA2 gene (IRX2;). they identified3 CEI splice variants encoding predicted 70-, 138-, and 226-amino acid proteins. All 3 isoforms share the first 65 N-terminal residues, including a signal peptide, and the 2 larger isoforms share an additional 45 residues. RT-PCR analysis revealed high CEI expression in small intestine, testis, and kidney, moderate expression in brain and heart, low expression in colon, and no expression in liver, adrenal gland, and pancreas. The expression pattern of CEI was nearly identical to that of IRXA2. Phylogenetic analysis indicated that the CEI gene is restricted to primates and is highly conserved.