Characterization of VDAC1 as a plasma membrane NADH-oxidoreductase

BioFactors ◽  
2004 ◽  
Vol 21 (1-4) ◽  
pp. 215-221 ◽  
Author(s):  
Mark A. Baker ◽  
Jennifer D. Ly ◽  
Alfons Lawen
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Giulia Tedeschi ◽  
Lorenzo Scipioni ◽  
Maria Papanikolaou ◽  
Geoffrey W. Abbott ◽  
Michelle A. Digman

AbstractVoltage-gated potassium (Kv) channels are a family of membrane proteins that facilitate K+ ion diffusion across the plasma membrane, regulating both resting and action potentials. Kv channels comprise four pore-forming α subunits, each with a voltage sensing domain, and they are regulated by interaction with β subunits such as those belonging to the KCNE family. Here we conducted a comprehensive biophysical characterization of stoichiometry and protein diffusion across the plasma membrane of the epithelial KCNQ1-KCNE2 complex, combining total internal reflection fluorescence (TIRF) microscopy and a series of complementary Fluorescence Fluctuation Spectroscopy (FFS) techniques. Using this approach, we found that KCNQ1-KCNE2 has a predominant 4:4 stoichiometry, while non-bound KCNE2 subunits are mostly present as dimers in the plasma membrane. At the same time, we identified unique spatio-temporal diffusion modalities and nano-environment organization for each channel subunit. These findings improve our understanding of KCNQ1-KCNE2 channel function and suggest strategies for elucidating the subunit stoichiometry and forces directing localization and diffusion of ion channel complexes in general.


1979 ◽  
Vol 9 (5) ◽  
pp. 402-408 ◽  
Author(s):  
Harold N. Rode ◽  
Bernd Mähler ◽  
Alois Loracher ◽  
Klaus Resch
Keyword(s):  

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