Sequence and tissue expression of a novel human carbonic anhydrase-related protein, CARP-2, mapping to chromosome 19q13.3

In this study, we report the identification and characterisation of a novel carbonic anhydrase related-protein. We have determined that the full length coding sequence of an anonymous expressed sequenced tag, D19S799E, encodes a novel carbonic anhydrase related-protein (CARP-2) that is 328 amino acids in length. This peptide exhibits between 23.1-28.8% amino acid identity with the seven active human carbonic anhydrase (CA) isozymes. Four substitutions of key amino acids in the catalytic domain of CAs (equivalent to His94Arg, His96Leu, His119Gln, and Thr199Ser) are likely to render CARP-2 inactive as a carbonic anhydrase. Northern blot analysis of 23 human tissues indicates that CARP2 is expressed abundantly in the brain with moderate expression also present in spinal cord and thyroid. D19S799E (and thus CARP2) has previously been localised close to the polymorphic marker D19S412 and the genes DBP and FUT1/FUT2 on 19q13.3.