cDNA sequence of human carbonic anhydrase-related protein, CA-RP X: mRNA expressions of CA-RP X and XI in human brain

A full-length cDNA clone of human carbonic anhydrase-related protein (CA-RP ) X was obtained and sequenced. The 2720 bp long cDNA sequence was predicte d to encode a 328 amino acid polypeptide. The deduced amino acid sequence s howed an overall similarity of 25-57% to other CA isozymes and the highest % similarity to a CA-RP XI. Similar to CA-RP XI, CA-RP X lacked two out of three zinc-liganded histidine residues, suggesting no biological activity o f CA. Northern blot analysis demonstrated an approx. 2.8 kb transcript in t he human brain and kidney. RNA dot blotting showed significant signals for CA-RP X and XI mRNA expressions in the adult total brain and almost all par ts of the central nervous system. but no expression in the fetal brain. The se results suggest that CA-RP X and XI play some role in human brain, espec ially in brain development. (C) 2001 Elsevier Science B.V. All rights reser ved.