CA3 Gene: Carbonic Anhydrase 3 - Function, Mutations, and Disease Associations

The CA3 gene encodes carbonic anhydrase 3 (CAIII), a member of the alpha-carbonic anhydrase family. CAIII is predominantly expressed in skeletal muscle and adipose tissue, where it catalyzes the reversible hydration of carbon dioxide to bicarbonate and protons. Unlike other carbonic anhydrases, CAIII has low catalytic activity and is involved in oxidative stress response, lipid metabolism, and protection against reactive oxygen species. It also functions as a phosphotyrosine phosphatase and interacts with various signaling molecules.

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• Metabolism of carbon dioxide (Reactome: R-HSA-1475029)

• Oxidative stress response (Reactome: R-HSA-2262752)

Carbonic anhydrase 3 (CAIII) is a 29.5 kDa protein predominantly expressed in skeletal muscle and adipose tissue. It catalyzes the reversible hydration of carbon dioxide to bicarbonate and protons, but with lower efficiency than other carbonic anhydrases. CAIII also exhibits phosphotyrosine phosphatase activity and acts as an antioxidant by scavenging reactive oxygen species. The protein is involved in lipid metabolism, insulin signaling, and protection against oxidative damage. Its expression is regulated by hormones and metabolic states, and dysregulation is linked to obesity, diabetes, and muscle atrophy.