GENETICS OF THE MAMMALIAN CARBONIC-ANHYDRASES

This chapter discusses the genetics of the mammalian carbonic anhydrases. The chapter provides information about various evolutionarily genes coding for enzymes that can surpass the carbonic anhydrase (CA) multigene family with respect to the distributional and functional diversity of their gene products. The CA gene family in mammals consists of eight genes coding for seven CA isozymes (CA I–CA VII) and a CA related protein (CARP). These genes may be expressed in certain cells of virtually all tissues or limited in expression to a single tissue, with the other CA genes ranging in their expression between these two extremes. Considerable chemical and biological information is now accumulated on the CAs regarding their primary and tertiary structures, enzyme kinetics, active site mechanisms, physiological roles, cellular and sub cellular locations, genetics, and evolution. Therefore, the related CA genes appear to be an attractive model for the study of the molecular genetics and evolution of a multigene family. It is possible that both types of carbonic anhydrase may be present in bacteria. The CA found in Neisseria sicca—and probably other bacteria—may be related to the algal and animal CAs, whereas the CA products of the cynT gene of E. coli and the IcfA gene of the cyanobacterium, Synechoccus sp. belong to the β-CA family. © 1992, Academic Press Inc.