Format

Send to

Choose Destination
Sci Rep. 2016 Feb 5;6:20442. doi: 10.1038/srep20442.

Tuning of the Na,K-ATPase by the beta subunit.

Author information

1
Danish Research Institute of Translational Neuroscience - DANDRITE, Nordic EMBL Partnership for Molecular Medicine, Aarhus University, DK-8000 Aarhus, Denmark.
2
Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus, Denmark.
3
Centre for Membrane Pumps in Cells and Disease - PUMPKIN, Danish National Research Foundation, DK-8000 Aarhus, Denmark.
4
MEMPHYS: Centre for Biomembrane Physics, University of Southern Denmark, DK-8000 Aarhus, Denmark.
5
Department of Biomedicine, Aarhus University, DK-8000 Aarhus, Denmark.
6
Aarhus Institute of Advanced Studies (AIAS), Aarhus University, DK-8000 Aarhus, Denmark.

Abstract

The vital gradients of Na(+) and K(+) across the plasma membrane of animal cells are maintained by the Na,K-ATPase, an αβ enzyme complex, whose α subunit carries out the ion transport and ATP hydrolysis. The specific roles of the β subunit isoforms are less clear, though β2 is essential for motor physiology in mammals. Here, we show that compared to β1 and β3, β2 stabilizes the Na(+)-occluded E1P state relative to the outward-open E2P state, and that the effect is mediated by its transmembrane domain. Molecular dynamics simulations further demonstrate that the tilt angle of the β transmembrane helix correlates with its functional effect, suggesting that the relative orientation of β modulates ion binding at the α subunit. β2 is primarily expressed in granule neurons and glomeruli in the cerebellum, and we propose that its unique functional characteristics are important to respond appropriately to the cerebellar Na(+) and K(+) gradients.

PMID:
26847162
PMCID:
PMC4742777
DOI:
10.1038/srep20442
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Nature Publishing Group Icon for PubMed Central
Loading ...
Support Center