ISOLATION AND CHARACTERIZATION OF A CARBONIC-ANHYDRASE HOMOLOG FROM THE ZEBRAFISH (DANIO-RERIO)

We have isolated a 29,000-Da carbonic anhydrase (CA) protein from the zebrafish, Danio rerio, sequenced two peptide fragments, and tentative ly identified it as a high-activity CA by inhibition kinetics. We have also characterized a 1,537-bp message whose deduced sequence of 260 a mino acids matches that of the isolated protein. This CA is clearly an alpha-CA based on the similarity of its sequence to that of other mem bers of the alpha-CA gene family. A phylogenetic analysis suggested CA H-Z diverged after the branching of the CA-V and CA-VII genes and prio r to the duplications that generated the CA-I, CA-II, and CA-III genes of amniotes. This marks the first characterization of the mRNA and it s protein product from the CA gene of a teleost.