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Molecular basis of a novel adaptation to hypoxic-hypercapnia in a strictly fossorial mole
BACKGROUND: Elevated blood O(2 )affinity enhances survival at low O(2 )pressures, and is perhaps the best known and most broadly accepted evolutionary adjustment of terrestrial vertebrates to environmental hypoxia. This phenotype arises by increasing the intrinsic O(2 )affinity of the hemoglobin (Hb...
Autores principales: | , , , , , , , , |
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Formato: | Texto |
Lenguaje: | English |
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BioMed Central
2010
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2927915/ https://www.ncbi.nlm.nih.gov/pubmed/20637064 http://dx.doi.org/10.1186/1471-2148-10-214 |
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author | Campbell, Kevin L Storz, Jay F Signore, Anthony V Moriyama, Hideaki Catania, Kenneth C Payson, Alexander P Bonaventura, Joseph Stetefeld, Jörg Weber, Roy E |
author_facet | Campbell, Kevin L Storz, Jay F Signore, Anthony V Moriyama, Hideaki Catania, Kenneth C Payson, Alexander P Bonaventura, Joseph Stetefeld, Jörg Weber, Roy E |
author_sort | Campbell, Kevin L |
collection | PubMed |
description | BACKGROUND: Elevated blood O(2 )affinity enhances survival at low O(2 )pressures, and is perhaps the best known and most broadly accepted evolutionary adjustment of terrestrial vertebrates to environmental hypoxia. This phenotype arises by increasing the intrinsic O(2 )affinity of the hemoglobin (Hb) molecule, by decreasing the intracellular concentration of allosteric effectors (e.g., 2,3-diphosphoglycerate; DPG), or by suppressing the sensitivity of Hb to these physiological cofactors. RESULTS: Here we report that strictly fossorial eastern moles (Scalopus aquaticus) have evolved a low O(2 )affinity, DPG-insensitive Hb - contrary to expectations for a mammalian species that is adapted to the chronic hypoxia and hypercapnia of subterranean burrow systems. Molecular modelling indicates that this functional shift is principally attributable to a single charge altering amino acid substitution in the β-type δ-globin chain (δ136Gly→Glu) of this species that perturbs electrostatic interactions between the dimer subunits via formation of an intra-chain salt-bridge with δ82Lys. However, this replacement also abolishes key binding sites for the red blood cell effectors Cl(-), lactate and DPG (the latter of which is virtually absent from the red cells of this species) at δ82Lys, thereby markedly reducing competition for carbamate formation (CO(2 )binding) at the δ-chain N-termini. CONCLUSIONS: We propose this Hb phenotype illustrates a novel mechanism for adaptively elevating the CO(2 )carrying capacity of eastern mole blood during burst tunnelling activities associated with subterranean habitation. |
format | Text |
id | pubmed-2927915 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2010 |
publisher | BioMed Central |
record_format | MEDLINE/PubMed |
spelling | pubmed-29279152010-08-26 Molecular basis of a novel adaptation to hypoxic-hypercapnia in a strictly fossorial mole Campbell, Kevin L Storz, Jay F Signore, Anthony V Moriyama, Hideaki Catania, Kenneth C Payson, Alexander P Bonaventura, Joseph Stetefeld, Jörg Weber, Roy E BMC Evol Biol Research Article BACKGROUND: Elevated blood O(2 )affinity enhances survival at low O(2 )pressures, and is perhaps the best known and most broadly accepted evolutionary adjustment of terrestrial vertebrates to environmental hypoxia. This phenotype arises by increasing the intrinsic O(2 )affinity of the hemoglobin (Hb) molecule, by decreasing the intracellular concentration of allosteric effectors (e.g., 2,3-diphosphoglycerate; DPG), or by suppressing the sensitivity of Hb to these physiological cofactors. RESULTS: Here we report that strictly fossorial eastern moles (Scalopus aquaticus) have evolved a low O(2 )affinity, DPG-insensitive Hb - contrary to expectations for a mammalian species that is adapted to the chronic hypoxia and hypercapnia of subterranean burrow systems. Molecular modelling indicates that this functional shift is principally attributable to a single charge altering amino acid substitution in the β-type δ-globin chain (δ136Gly→Glu) of this species that perturbs electrostatic interactions between the dimer subunits via formation of an intra-chain salt-bridge with δ82Lys. However, this replacement also abolishes key binding sites for the red blood cell effectors Cl(-), lactate and DPG (the latter of which is virtually absent from the red cells of this species) at δ82Lys, thereby markedly reducing competition for carbamate formation (CO(2 )binding) at the δ-chain N-termini. CONCLUSIONS: We propose this Hb phenotype illustrates a novel mechanism for adaptively elevating the CO(2 )carrying capacity of eastern mole blood during burst tunnelling activities associated with subterranean habitation. BioMed Central 2010-07-16 /pmc/articles/PMC2927915/ /pubmed/20637064 http://dx.doi.org/10.1186/1471-2148-10-214 Text en Copyright ©2010 Campbell et al; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Research Article Campbell, Kevin L Storz, Jay F Signore, Anthony V Moriyama, Hideaki Catania, Kenneth C Payson, Alexander P Bonaventura, Joseph Stetefeld, Jörg Weber, Roy E Molecular basis of a novel adaptation to hypoxic-hypercapnia in a strictly fossorial mole |
title | Molecular basis of a novel adaptation to hypoxic-hypercapnia in a strictly fossorial mole |
title_full | Molecular basis of a novel adaptation to hypoxic-hypercapnia in a strictly fossorial mole |
title_fullStr | Molecular basis of a novel adaptation to hypoxic-hypercapnia in a strictly fossorial mole |
title_full_unstemmed | Molecular basis of a novel adaptation to hypoxic-hypercapnia in a strictly fossorial mole |
title_short | Molecular basis of a novel adaptation to hypoxic-hypercapnia in a strictly fossorial mole |
title_sort | molecular basis of a novel adaptation to hypoxic-hypercapnia in a strictly fossorial mole |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2927915/ https://www.ncbi.nlm.nih.gov/pubmed/20637064 http://dx.doi.org/10.1186/1471-2148-10-214 |
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