The α-carbonic anhydrases (α-CAs) are a large and ancient group of metazoan-specific enzymes. They generate bicarbonate from metabolic carbon dioxide and through calcium carbonate crystal formation play a key role in the regulation of mineralized structures. To better understand how α-CAs contribute to shell mineralization in the marine Mediterranean mussel (Mytilus galloprovincialis) we characterized them in the mantle. Phylogenetic analysis revealed that mollusc α-CA evolution was affected by lineage and species-specific events. Ten α-CAs were found in the Mediterranean mussel mantle and the most abundant form was named, MgNACR, as it grouped with oyster nacreins (NACR). Exposure of the Mediterranean mussel to reduced water salinity (18 vs 37 ppt), caused a significant reduction (p < 0.05) in mantle esterase activity and MgNACR transcript abundance (p < 0.05). Protonograms revealed multiple proteins in the mantle with α-CA hydratase activity and mapped to a protein with a similar size to that deduced for monomeric MgNACR. Our data indicate that MgNACR is a major α-CA enzyme in mantle and that by homology with oyster nacreins likely regulates mussel shell production. We propose that species-dependent α-CA evolution may contribute to explain the diversity of bivalve shell structures and their vulnerability to environmental changes.Agência financiadora European Union 605051
Portuguese national funds from FCT - Foundation for Science and Technology
UID/Multi/04326/2019
operational programmes CRESC Algarve 2020 and COMPETE 2020 through project EMBRC
FCT
UID/Multi/04326/2019
SFRH/BPD/79105/2011
SFRH/BPD/89811/2012
EMBRIC (European Union's Horizon 2020 research and innovation programme)
654008
CAPES, Brazil
88887.116718/2016-00
PT ALG-01-0145-FEDER-022121info:eu-repo/semantics/publishedVersio
