Cortexin 3 (CTXN3)

CTXN3, a new human gene that was specifically expressed in the kidney and brain due to tissue-specific alternative exon 1 usage, on chromosome 5q23.2 using digital gene expression displayer (DGED) and a novel in silico cloning approach based on both expressed sequence tags (ESTs) and genomic sequence.

CTXN3 included 3 exons and spanned an approximate 9.6-kb region of human chromosome 5q23. The predicted human CTXN3 protein had 43% identity with function-unknown protein cortexin, which showed brain-specific expression. Selective expression of CTXN3 in the kidney and brain, the amino acid identity to cortexin, and its high conservation among different species indicate that CTXN3 may be involved in a process specifically restricted to kidney and brain tissue function.