A Voltage-Gated H+ Channel Underlying pH Homeostasis in Calcifying Coccolithophores
Marine coccolithophorid phytoplankton are major producers of biogenic calcite, playing a significant role in the global carbon cycle. Predicting the impacts of ocean acidification on coccolithophore calcification has received much recent attention and requires improved knowledge of cellular calcific...
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ftsouthampton:oai:eprints.soton.ac.uk:340274 2023-07-30T04:06:03+02:00 A Voltage-Gated H+ Channel Underlying pH Homeostasis in Calcifying Coccolithophores Falkowski, Paul G. Taylor, Alison R. Chrachri, Abdul Wheeler, Glen Goddard, Helen Brownlee, Colin 2011-06-21 application/octet-stream https://eprints.soton.ac.uk/340274/ https://eprints.soton.ac.uk/340274/1/fetchObject.action_uri%253Dinfo_doi%25252F10.1371%25252Fjournal.pbio.1001085%2526representation%253DPDF en eng https://eprints.soton.ac.uk/340274/1/fetchObject.action_uri%253Dinfo_doi%25252F10.1371%25252Fjournal.pbio.1001085%2526representation%253DPDF Falkowski, Paul G., Taylor, Alison R., Chrachri, Abdul, Wheeler, Glen, Goddard, Helen and Brownlee, Colin (2011) A Voltage-Gated H+ Channel Underlying pH Homeostasis in Calcifying Coccolithophores. PLoS Biology, 9 (6), e1001085. (doi:10.1371/journal.pbio.1001085 <http://dx.doi.org/10.1371/journal.pbio.1001085>). other Article PeerReviewed 2011 ftsouthampton https://doi.org/10.1371/journal.pbio.1001085 2023-07-09T21:39:49Z Marine coccolithophorid phytoplankton are major producers of biogenic calcite, playing a significant role in the global carbon cycle. Predicting the impacts of ocean acidification on coccolithophore calcification has received much recent attention and requires improved knowledge of cellular calcification mechanisms. Uniquely amongst calcifying organisms, coccolithophores produce calcified scales (coccoliths) in an intracellular compartment and secrete them to the cell surface, requiring large transcellular ionic fluxes to support calcification. In particular, intracellular calcite precipitation using HCO3? as the substrate generates equimolar quantities of H+ that must be rapidly removed to prevent cytoplasmic acidification. We have used electrophysiological approaches to identify a plasma membrane voltage-gated H+ conductance in Coccolithus pelagicus ssp braarudii with remarkably similar biophysical and functional properties to those found in metazoans. We show that both C. pelagicus and Emiliania huxleyi possess homologues of metazoan Hv1 H+ channels, which function as voltage-gated H+ channels when expressed in heterologous systems. Homologues of the coccolithophore H+ channels were also identified in a diversity of eukaryotes, suggesting a wide range of cellular roles for the Hv1 class of proteins. Using single cell imaging, we demonstrate that the coccolithophore H+ conductance mediates rapid H+ efflux and plays an important role in pH homeostasis in calcifying cells. The results demonstrate a novel cellular role for voltage gated H+ channels and provide mechanistic insight into biomineralisation by establishing a direct link between pH homeostasis and calcification. As the coccolithophore H+ conductance is dependent on the trans-membrane H+ electrochemical gradient, this mechanism will be directly impacted by, and may underlie adaptation to, ocean acidification. The presence of this H+ efflux pathway suggests that there is no obligate use of H+ derived from calcification for intracellular CO2 generation. ... Article in Journal/Newspaper Ocean acidification University of Southampton: e-Prints Soton PLoS Biology 9 6 e1001085 |
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Open Polar |
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University of Southampton: e-Prints Soton |
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ftsouthampton |
language |
English |
description |
Marine coccolithophorid phytoplankton are major producers of biogenic calcite, playing a significant role in the global carbon cycle. Predicting the impacts of ocean acidification on coccolithophore calcification has received much recent attention and requires improved knowledge of cellular calcification mechanisms. Uniquely amongst calcifying organisms, coccolithophores produce calcified scales (coccoliths) in an intracellular compartment and secrete them to the cell surface, requiring large transcellular ionic fluxes to support calcification. In particular, intracellular calcite precipitation using HCO3? as the substrate generates equimolar quantities of H+ that must be rapidly removed to prevent cytoplasmic acidification. We have used electrophysiological approaches to identify a plasma membrane voltage-gated H+ conductance in Coccolithus pelagicus ssp braarudii with remarkably similar biophysical and functional properties to those found in metazoans. We show that both C. pelagicus and Emiliania huxleyi possess homologues of metazoan Hv1 H+ channels, which function as voltage-gated H+ channels when expressed in heterologous systems. Homologues of the coccolithophore H+ channels were also identified in a diversity of eukaryotes, suggesting a wide range of cellular roles for the Hv1 class of proteins. Using single cell imaging, we demonstrate that the coccolithophore H+ conductance mediates rapid H+ efflux and plays an important role in pH homeostasis in calcifying cells. The results demonstrate a novel cellular role for voltage gated H+ channels and provide mechanistic insight into biomineralisation by establishing a direct link between pH homeostasis and calcification. As the coccolithophore H+ conductance is dependent on the trans-membrane H+ electrochemical gradient, this mechanism will be directly impacted by, and may underlie adaptation to, ocean acidification. The presence of this H+ efflux pathway suggests that there is no obligate use of H+ derived from calcification for intracellular CO2 generation. ... |
format |
Article in Journal/Newspaper |
author |
Falkowski, Paul G. Taylor, Alison R. Chrachri, Abdul Wheeler, Glen Goddard, Helen Brownlee, Colin |
spellingShingle |
Falkowski, Paul G. Taylor, Alison R. Chrachri, Abdul Wheeler, Glen Goddard, Helen Brownlee, Colin A Voltage-Gated H+ Channel Underlying pH Homeostasis in Calcifying Coccolithophores |
author_facet |
Falkowski, Paul G. Taylor, Alison R. Chrachri, Abdul Wheeler, Glen Goddard, Helen Brownlee, Colin |
author_sort |
Falkowski, Paul G. |
title |
A Voltage-Gated H+ Channel Underlying pH Homeostasis in Calcifying Coccolithophores |
title_short |
A Voltage-Gated H+ Channel Underlying pH Homeostasis in Calcifying Coccolithophores |
title_full |
A Voltage-Gated H+ Channel Underlying pH Homeostasis in Calcifying Coccolithophores |
title_fullStr |
A Voltage-Gated H+ Channel Underlying pH Homeostasis in Calcifying Coccolithophores |
title_full_unstemmed |
A Voltage-Gated H+ Channel Underlying pH Homeostasis in Calcifying Coccolithophores |
title_sort |
voltage-gated h+ channel underlying ph homeostasis in calcifying coccolithophores |
publishDate |
2011 |
url |
https://eprints.soton.ac.uk/340274/ https://eprints.soton.ac.uk/340274/1/fetchObject.action_uri%253Dinfo_doi%25252F10.1371%25252Fjournal.pbio.1001085%2526representation%253DPDF |
genre |
Ocean acidification |
genre_facet |
Ocean acidification |
op_relation |
https://eprints.soton.ac.uk/340274/1/fetchObject.action_uri%253Dinfo_doi%25252F10.1371%25252Fjournal.pbio.1001085%2526representation%253DPDF Falkowski, Paul G., Taylor, Alison R., Chrachri, Abdul, Wheeler, Glen, Goddard, Helen and Brownlee, Colin (2011) A Voltage-Gated H+ Channel Underlying pH Homeostasis in Calcifying Coccolithophores. PLoS Biology, 9 (6), e1001085. (doi:10.1371/journal.pbio.1001085 <http://dx.doi.org/10.1371/journal.pbio.1001085>). |
op_rights |
other |
op_doi |
https://doi.org/10.1371/journal.pbio.1001085 |
container_title |
PLoS Biology |
container_volume |
9 |
container_issue |
6 |
container_start_page |
e1001085 |
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1772818419496779776 |