Gill-specific (Na(+), K(+))-ATPase activity and α-subunit mRNA expression during low-salinity acclimation of the ornate blue crab Callinectes ornatus (Decapoda, Brachyura).
Comp Biochem Physiol B Biochem Mol Biol
; 186: 59-67, 2015 Aug.
Article
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| MEDLINE
| ID: mdl-25934083
ABSTRACT
We evaluate (Na(+), K(+))-ATPase activity, and protein and gene expression of the α-subunit in posterior gills 6 and 7 of Callinectes ornatus, a euryhaline crab, during a 10-day acclimation period from seawater (33 S) to low salinity (21 S). (Na(+), K(+))-ATPase activity decreased within 1h after transfer to 21 S, values recovering by 24h and attaining a maximum of ≈180 nmol Pi min(-1) mg(-1) after 10 days (≈2.5-fold increase). (Na(+), K(+))-ATPase activity is ≈1.5-fold greater in gill 6 than in gill 7, independently of salinity. Relative expression of (Na(+), K(+))-ATPase α-subunit mRNA increased in both gills within 1- to 2-h exposure to low salinity, reaching an ≈8-fold maximum after 24-h exposure, decreasing slightly by 10 days acclimation to low salinity. This increase in α-subunit mRNA expression may underpin the increased (Na(+), K(+))-ATPase activity seen after 10 days acclimation to low salinity. Enzyme affinity for ATP was greater in gill 6 than in gill 7, in contrast to ouabain affinity that was greater in gill 7. Western blotting analysis identified a single immunoreactive band against the (Na(+), K(+))-ATPase α-subunit with an Mr of ≈105 kDa, independently of gill number and low salinity acclimation. Despite these differences, gills 6 and 7 appear to perform similar functions in salt uptake from the dilute medium. The partial cDNA sequence obtained for the gill (Na(+), K(+))-ATPase of C. ornatus (GenBank deposit KF056804) showed 97 to 91% identities with similar sequences from other portunid crab gills. The regulation of gill (Na(+), K(+))-ATPase activity during acclimation to low salinity is discussed.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
ATPasa Intercambiadora de Sodio-Potasio
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Braquiuros
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Proteínas de Artrópodos
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Branquias
Límite:
Animals
Idioma:
En
Revista:
Comp Biochem Physiol B Biochem Mol Biol
Asunto de la revista:
BIOLOGIA MOLECULAR
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BIOQUIMICA
Año:
2015
Tipo del documento:
Article