The Transplasma Membrane Redox System

Plasma membranes of all cells investigated so far contain an electron transport system transferring electrons from NADH to an extracellular electron acceptor (for review, see Navas et al., 1994 and Chapter 4 of this volume). Electron transport across the plasma membrane is accompanied by release of protons from the cell, presumably due to an activation of the Na+/H+ antiport (Sun et a/., 1988). Since proton release and the concomitant increase in cytoplasmic pH have been connected to growth stimulation (Moolenar et al., 1983), it was proposed that the transplasma membrane redox system via proton release might also be involved in the regulation of proliferation. 

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