EFCBP1/NECAB1, a brain-specifically expressed gene with highest abundance in temporal lobe, encodes a protein containing EF-hand and antibiotic biosynthesis monooxygenase domains.

Human EFCBP/NECAB family consists of important participants in neuronal calcium signaling, including EFCBP1/NECAB1, EFCBP2/NECAB2 and EFCBP3/NECAB3. In the present study, we identified the full-length 5229 bp EFCBP1 cDNA which was not described before. Human EFCBP1 encodes a 351 amino acid protein containing two EF-hand motifs and an antibiotic biosynthesis monooxygenase (ABM) domain, sharing 49.9 and 56.8% global homology with human EFCBP2 and EFCBP3. Northern hybridization revealed that EFCBP1 is specifically expressed in brain and its abundance varies in different brain regions. EFCBP1's abundance in temporal lobe, frontal lobe and occipital pole is about 3.4, 1.9 and 1.5 folds of the average abundance in cerebral cortex, respectively. The expression level of EFCBP1 equals in putamen and cerebral cortex, while no hybridization signal was detected in spinal cord. In addition, we found that EFCBP1, EFCBP2 and EFCBP3 share a similar exon distribution mode, though their chromosomal localizations, genomic sizes and intron sizes are diverse.