NADH-ascorbate free radical and -ferricyanide reductase activities represent different levels of plasma membrane electron transport

1993 ◽  
Vol 25 (4) ◽  
pp. 411-417 ◽  
Author(s):  
J. M. Villalba ◽  
A. Canalejo ◽  
J. C. Rodr�guez-Aguilera ◽  
M. I. Bur�n ◽  
D. James Morr� ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Free Radical ◽  
Electron Transport ◽  
Ferricyanide Reductase ◽  
Ascorbate Free Radical ◽  
Plasma Membrane Electron Transport ◽  
Different Levels

scholarly journals Trans-Plasma Membrane Electron Transport and Ascorbate Efflux by Skeletal Muscle

Antioxidants ◽  
2017 ◽  
Vol 6 (4) ◽  
pp. 89 ◽  
Author(s):  
Amanda Eccardt ◽  
Thomas Bell ◽  
Lyn Mattathil ◽  
Rohan Prasad ◽  
Shannon Kelly ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Plasma Membrane ◽  
Electron Transport ◽  
Plasma Membrane Electron Transport

Inhibition of neutral Mg 2+ -dependent sphingomyelinase by ubiquinol-mediated plasma membrane electron transport

PROTOPLASMA ◽  
2003 ◽  
Vol 221 (1-2) ◽  
pp. 109-116 ◽  
Author(s):  
S. F. Mart�n ◽  
C. G�mez-D�az ◽  
R. I. Bello ◽  
P. Navas ◽  
J. M. Villalba
Keyword(s):  
Plasma Membrane ◽  
Electron Transport ◽  
Plasma Membrane Electron Transport

scholarly journals Plasma membrane electron transport in pancreatic β-cells is mediated in part by NQO1

2011 ◽  
Vol 301 (1) ◽  
pp. E113-E121 ◽  
Author(s):  
Joshua P. Gray ◽  
Timothy Eisen ◽  
Gary W. Cline ◽  
Peter J. S. Smith ◽  
Emma Heart
Keyword(s):  
Plasma Membrane ◽  
Electron Transport ◽  
Potassium Cyanide ◽  
Cell Types ◽  
Glycolytic Flux ◽  
Dependent Manner ◽  
Β Cells ◽  
Quinone Oxidoreductase ◽  
Plasma Membrane Electron Transport ◽  
Diphenylene Iodonium

Plasma membrane electron transport (PMET), a cytosolic/plasma membrane analog of mitochondrial electron transport, is a ubiquitous system of cytosolic and plasma membrane oxidoreductases that oxidizes cytosolic NADH and NADPH and passes electrons to extracellular targets. While PMET has been shown to play an important role in a variety of cell types, no studies exist to evaluate its function in insulin-secreting cells. Here we demonstrate the presence of robust PMET activity in primary islets and clonal β-cells, as assessed by the reduction of the plasma membrane-impermeable dyes WST-1 and ferricyanide. Because the degree of metabolic function of β-cells (reflected by the level of insulin output) increases in a glucose-dependent manner between 4 and 10 mM glucose, PMET was evaluated under these conditions. PMET activity was present at 4 mM glucose and was further stimulated at 10 mM glucose. PMET activity at 10 mM glucose was inhibited by the application of the flavoprotein inhibitor diphenylene iodonium and various antioxidants. Overexpression of cytosolic NAD(P)H-quinone oxidoreductase (NQO1) increased PMET activity in the presence of 10 mM glucose while inhibition of NQO1 by its inhibitor dicoumarol abolished this activity. Mitochondrial inhibitors rotenone, antimycin A, and potassium cyanide elevated PMET activity. Regardless of glucose levels, PMET activity was greatly enhanced by the application of aminooxyacetate, an inhibitor of the malate-aspartate shuttle. We propose a model for the role of PMET as a regulator of glycolytic flux and an important component of the metabolic machinery in β-cells.

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