Cargando…

Molecular Characterization of a Dual Domain Carbonic Anhydrase From the Ctenidium of the Giant Clam, Tridacna squamosa, and Its Expression Levels After Light Exposure, Cellular Localization, and Possible Role in the Uptake of Exogenous Inorganic Carbon

A Dual-Domain Carbonic Anhydrase (DDCA) had been sequenced and characterized from the ctenidia (gills) of the giant clam, Tridacna squamosa, which lives in symbiosis with zooxanthellae. DDCA was expressed predominantly in the ctenidium. The complete cDNA coding sequence of DDCA from T. squamosa comp...

Descripción completa

Detalles Bibliográficos
Autores principales: Koh, Clarissa Z. Y., Hiong, Kum C., Choo, Celine Y. L., Boo, Mel V., Wong, Wai P., Chew, Shit F., Neo, Mei L., Ip, Yuen K.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5879104/
https://www.ncbi.nlm.nih.gov/pubmed/29632495
http://dx.doi.org/10.3389/fphys.2018.00281
_version_ 1783310937872138240
author Koh, Clarissa Z. Y.
Hiong, Kum C.
Choo, Celine Y. L.
Boo, Mel V.
Wong, Wai P.
Chew, Shit F.
Neo, Mei L.
Ip, Yuen K.
author_facet Koh, Clarissa Z. Y.
Hiong, Kum C.
Choo, Celine Y. L.
Boo, Mel V.
Wong, Wai P.
Chew, Shit F.
Neo, Mei L.
Ip, Yuen K.
author_sort Koh, Clarissa Z. Y.
collection PubMed
description A Dual-Domain Carbonic Anhydrase (DDCA) had been sequenced and characterized from the ctenidia (gills) of the giant clam, Tridacna squamosa, which lives in symbiosis with zooxanthellae. DDCA was expressed predominantly in the ctenidium. The complete cDNA coding sequence of DDCA from T. squamosa comprised 1,803 bp, encoding a protein of 601 amino acids and 66.7 kDa. The deduced DDCA sequence contained two distinct α-CA domains, each with a specific catalytic site. It had a high sequence similarity with tgCA from Tridacna gigas. In T. squamosa, the DDCA was localized apically in certain epithelial cells near the base of the ctenidial filament and the epithelial cells surrounding the tertiary water channels. Due to the presence of two transmembrane regions in the DDCA, one of the Zn(2+)-containing active sites could be located externally and the other one inside the cell. These results denote that the ctenidial DDCA was positioned to dehydrate [Formula: see text] to CO(2) in seawater, and to hydrate the CO(2) that had permeated the apical membrane back to [Formula: see text] in the cytoplasm. During insolation, the host clam needs to increase the uptake of inorganic carbon from the ambient seawater to benefit the symbiotic zooxanthellae; only then, can the symbionts conduct photosynthesis and share the photosynthates with the host. Indeed, the transcript and protein levels of DDCA/DDCA in the ctenidium of T. squamosa increased significantly after 6 and 12 h of exposure to light, respectively, denoting that DDCA could participate in the light-enhanced uptake and assimilation of exogenous inorganic carbon.
format Online
Article
Text
id pubmed-5879104
institution National Center for Biotechnology Information
language English
publishDate 2018
publisher Frontiers Media S.A.
record_format MEDLINE/PubMed
spelling pubmed-58791042018-04-09 Molecular Characterization of a Dual Domain Carbonic Anhydrase From the Ctenidium of the Giant Clam, Tridacna squamosa, and Its Expression Levels After Light Exposure, Cellular Localization, and Possible Role in the Uptake of Exogenous Inorganic Carbon Koh, Clarissa Z. Y. Hiong, Kum C. Choo, Celine Y. L. Boo, Mel V. Wong, Wai P. Chew, Shit F. Neo, Mei L. Ip, Yuen K. Front Physiol Physiology A Dual-Domain Carbonic Anhydrase (DDCA) had been sequenced and characterized from the ctenidia (gills) of the giant clam, Tridacna squamosa, which lives in symbiosis with zooxanthellae. DDCA was expressed predominantly in the ctenidium. The complete cDNA coding sequence of DDCA from T. squamosa comprised 1,803 bp, encoding a protein of 601 amino acids and 66.7 kDa. The deduced DDCA sequence contained two distinct α-CA domains, each with a specific catalytic site. It had a high sequence similarity with tgCA from Tridacna gigas. In T. squamosa, the DDCA was localized apically in certain epithelial cells near the base of the ctenidial filament and the epithelial cells surrounding the tertiary water channels. Due to the presence of two transmembrane regions in the DDCA, one of the Zn(2+)-containing active sites could be located externally and the other one inside the cell. These results denote that the ctenidial DDCA was positioned to dehydrate [Formula: see text] to CO(2) in seawater, and to hydrate the CO(2) that had permeated the apical membrane back to [Formula: see text] in the cytoplasm. During insolation, the host clam needs to increase the uptake of inorganic carbon from the ambient seawater to benefit the symbiotic zooxanthellae; only then, can the symbionts conduct photosynthesis and share the photosynthates with the host. Indeed, the transcript and protein levels of DDCA/DDCA in the ctenidium of T. squamosa increased significantly after 6 and 12 h of exposure to light, respectively, denoting that DDCA could participate in the light-enhanced uptake and assimilation of exogenous inorganic carbon. Frontiers Media S.A. 2018-03-26 /pmc/articles/PMC5879104/ /pubmed/29632495 http://dx.doi.org/10.3389/fphys.2018.00281 Text en Copyright © 2018 Koh, Hiong, Choo, Boo, Wong, Chew, Neo and Ip. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Physiology
Koh, Clarissa Z. Y.
Hiong, Kum C.
Choo, Celine Y. L.
Boo, Mel V.
Wong, Wai P.
Chew, Shit F.
Neo, Mei L.
Ip, Yuen K.
Molecular Characterization of a Dual Domain Carbonic Anhydrase From the Ctenidium of the Giant Clam, Tridacna squamosa, and Its Expression Levels After Light Exposure, Cellular Localization, and Possible Role in the Uptake of Exogenous Inorganic Carbon
title Molecular Characterization of a Dual Domain Carbonic Anhydrase From the Ctenidium of the Giant Clam, Tridacna squamosa, and Its Expression Levels After Light Exposure, Cellular Localization, and Possible Role in the Uptake of Exogenous Inorganic Carbon
title_full Molecular Characterization of a Dual Domain Carbonic Anhydrase From the Ctenidium of the Giant Clam, Tridacna squamosa, and Its Expression Levels After Light Exposure, Cellular Localization, and Possible Role in the Uptake of Exogenous Inorganic Carbon
title_fullStr Molecular Characterization of a Dual Domain Carbonic Anhydrase From the Ctenidium of the Giant Clam, Tridacna squamosa, and Its Expression Levels After Light Exposure, Cellular Localization, and Possible Role in the Uptake of Exogenous Inorganic Carbon
title_full_unstemmed Molecular Characterization of a Dual Domain Carbonic Anhydrase From the Ctenidium of the Giant Clam, Tridacna squamosa, and Its Expression Levels After Light Exposure, Cellular Localization, and Possible Role in the Uptake of Exogenous Inorganic Carbon
title_short Molecular Characterization of a Dual Domain Carbonic Anhydrase From the Ctenidium of the Giant Clam, Tridacna squamosa, and Its Expression Levels After Light Exposure, Cellular Localization, and Possible Role in the Uptake of Exogenous Inorganic Carbon
title_sort molecular characterization of a dual domain carbonic anhydrase from the ctenidium of the giant clam, tridacna squamosa, and its expression levels after light exposure, cellular localization, and possible role in the uptake of exogenous inorganic carbon
topic Physiology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5879104/
https://www.ncbi.nlm.nih.gov/pubmed/29632495
http://dx.doi.org/10.3389/fphys.2018.00281
work_keys_str_mv AT kohclarissazy molecularcharacterizationofadualdomaincarbonicanhydrasefromthectenidiumofthegiantclamtridacnasquamosaanditsexpressionlevelsafterlightexposurecellularlocalizationandpossibleroleintheuptakeofexogenousinorganiccarbon
AT hiongkumc molecularcharacterizationofadualdomaincarbonicanhydrasefromthectenidiumofthegiantclamtridacnasquamosaanditsexpressionlevelsafterlightexposurecellularlocalizationandpossibleroleintheuptakeofexogenousinorganiccarbon
AT choocelineyl molecularcharacterizationofadualdomaincarbonicanhydrasefromthectenidiumofthegiantclamtridacnasquamosaanditsexpressionlevelsafterlightexposurecellularlocalizationandpossibleroleintheuptakeofexogenousinorganiccarbon
AT boomelv molecularcharacterizationofadualdomaincarbonicanhydrasefromthectenidiumofthegiantclamtridacnasquamosaanditsexpressionlevelsafterlightexposurecellularlocalizationandpossibleroleintheuptakeofexogenousinorganiccarbon
AT wongwaip molecularcharacterizationofadualdomaincarbonicanhydrasefromthectenidiumofthegiantclamtridacnasquamosaanditsexpressionlevelsafterlightexposurecellularlocalizationandpossibleroleintheuptakeofexogenousinorganiccarbon
AT chewshitf molecularcharacterizationofadualdomaincarbonicanhydrasefromthectenidiumofthegiantclamtridacnasquamosaanditsexpressionlevelsafterlightexposurecellularlocalizationandpossibleroleintheuptakeofexogenousinorganiccarbon
AT neomeil molecularcharacterizationofadualdomaincarbonicanhydrasefromthectenidiumofthegiantclamtridacnasquamosaanditsexpressionlevelsafterlightexposurecellularlocalizationandpossibleroleintheuptakeofexogenousinorganiccarbon
AT ipyuenk molecularcharacterizationofadualdomaincarbonicanhydrasefromthectenidiumofthegiantclamtridacnasquamosaanditsexpressionlevelsafterlightexposurecellularlocalizationandpossibleroleintheuptakeofexogenousinorganiccarbon