The evolution of metazoan α-carbonic anhydrases and their roles in calcium carbonate biomineralization

• Autor(a) principal: Le Roy, Nathalie
• Data de Publicação: 2014
• Outros Autores: Jackson, Daniel J, Marie, Benjamin, Ramos-Silva, Paula, Marin, Frédéric
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.7/386
• topic: α -Carbonic anhydrase; Metazoa; Biocalcification; Biomineralization; Molecular evolution; Low complexity domains (LCDs); Repetitive low complexity domains (RLCDs)

The carbonic anhydrase (CA; EC 4.2.1.1) superfamily is a class of ubiquitous metallo-enzymes that catalyse the reversible hydration of carbon dioxide. The ?-CA family, present in all metazoan clades, is a key enzyme involved in a wide range of physiological functions including pH regulation, respiration, photosynthesis, and biocalcification. This paper reviews the evolution of the ?-CA family, with an emphasis on metazoan ?-CA members involved in biocalcification. Phylogenetic analyses reveal a complex evolutionary history of ?-CAs, and suggest ?-CA was independently co-opted into a variety of skeleton forming roles (e.g. as a provider of HCO3? ions, a structural protein, a nucleation activator, etc.) in multiple metazoan lineages. This evolutionary history is most likely the result of multiple gene duplications coupled with the insertion of repetitive or non-repetitive low-complexity domains (RLCDs/LCDs). These domains, of largely unknown function, appear to be lineage-specific, and provide further support for the hypothesis of independent recruitment of ?-CAs to diverse metazoan biocalcification processes. An analysis of ?-CA sequences associated with biocalcification processes indicates that the domains involved in the activity and conformation of the active site are extremely conserved among metazoans.