CA4

A gene on chromosome 17q23 that encodes a carbonic anhydrase, a zinc metalloenzyme that catalyses the reversible hydration of carbon dioxide. Carbonic anhydrases participate various biological processes, including respiration, calcification, maintaining acid-base balance, bone resorption and producing aqueous humour, cerebrospinal fluid, saliva and gastric acid. Carbonic anhydrase IV is a glycosylphosphatidyl-inositol-anchored membrane isozyme expressed on the luminal surfaces of pulmonary (and other) capillaries and proximal renal tubules; it is thought to have a role in hereditary defects in bicarbonate transport.