Biochem/physiol Actions
Voltage-gated proton (hydrogen) channels play an important role in cellular defense against acidic stress. They are unique among ion channels with respect to their extremely high selectivity, marked temperature dependence, and unitary conductance, which is 3 orders of magnitude lower than that of most other ion channels. NOX1 is a homolog of the catalytic subunit of the superoxide-generating NADPH oxidase of phagocytes, gp91phox.Voltage-gated proton (hydrogen) channels play an important role in cellular defense against acidic stress. They are unique among ion channels with respect to their extremely high selectivity, marked temperature dependence, and unitary conductance, which is 3 orders of magnitude lower than that of most other ion channels. NOX1 is a homolog of the catalytic subunit of the superoxide-generating NADPH oxidase of phagocytes, gp91phox. Three splice variants of NOX1 have been identified, NOH-1L, NOH-1S and NOH-1Lv. The NOH-1S currents were reversibly blocked by zinc, a known H+ channel inhibitor. The NOH-1S variant does not contain an electron transport chain and it is thought that H+ conductance is its main physiologic function, whereas NOH-1L may conduct H+ ions as part of its electron transport mechanism.
