English
 
Help Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
  Structural Arrangement and Conformational Dynamics of the γ Subunit of the Na+/K+-ATPase

Dempski, R. E., Lustig, J., Friedrich, T., & Bamberg, E. (2008). Structural Arrangement and Conformational Dynamics of the γ Subunit of the Na+/K+-ATPase. Biochemistry, 47(1), 257-266. doi: 10.1021/bi701799b.

Item is

Files

show Files

Locators

show

Creators

show
hide
 Creators:
Dempski, Robert E.1, Author              
Lustig, Janna1, Author              
Friedrich, Thomas, Author
Bamberg, Ernst1, Author              
Affiliations:
1Department of Biophysical Chemistry, Max Planck Institute of Biophysics, Max Planck Society, ou_2068289              

Content

show
hide
Free keywords: -
 Abstract: The Na+/K+-ATPase couples the chemical energy in ATP to transport Na+ and K+ across the plasma membrane against a concentration gradient. The ion pump is composed of two mandatory subunits: the alpha subunit, which is the major catalytic subunit, and the beta subunit, which is required for proper trafficking of the complex to the plasma membrane. In some tissues, the ion pump also contains an optional third subunit, gamma, which modulates the pump activity. To examine the conformational dynamics of the gamma subunit during ion transport and its position in relation to the alpha and the beta subunits, we have used fluorescence resonance energy transfer under voltage clamp conditions. From these experiments, evidence is provided that the gamma subunit is located adjacent to the M2-M6-M9 pocket of the alpha subunit at the transmembrane-extracellular interface. We have also used fluorescence resonance energy transfer to investigate the relative movement of the three subunits as the ion pump shuttles between the two main conformational states, E1 and E2, as described by the Albers-Post scheme. The results from this study suggest that there is no relative change in distance between the alpha and gamma subunits but there is a relative change in distance between the beta and gamma subunits during the E2 to E1 transition. It was also observed that labeling the gamma subunit at specific residues with fluorophores induces a decrease in K+-induced stationary current. This result could be due to a perturbation in the K+ branch of the reaction cycle of the pump, representing a new way to inhibit the pump.

Details

show
hide
Language(s): eng - English
 Dates: 2008-01
 Publication Status: Published in print
 Pages: 10
 Publishing info: -
 Table of Contents: -
 Rev. Type: Peer
 Identifiers: eDoc: 413791
DOI: 10.1021/bi701799b
 Degree: -

Event

show

Legal Case

show

Project information

show

Source 1

show
hide
Title: Biochemistry
Source Genre: Journal
 Creator(s):
Affiliations:
Publ. Info: Columbus, Ohio : American Chemical Society
Pages: - Volume / Issue: 47 (1) Sequence Number: - Start / End Page: 257 - 266 Identifier: ISSN: 0006-2960
CoNE: https://pure.mpg.de/cone/journals/resource/954925384103