The arachidonate-activatable, NADPH oxidase-associated H+ channel is contained within the multi-membrane-spanning N-terminal region of gp91-phox.
The generation of superoxide by the NADPH oxidase of neutrophils is accompanied by the efflux of H+ ions through a H+ channel. gp91-phox, a protein component of the oxidase, has been shown previously to function as a H+ channel [Henderson, Banting and Chappell (1995) J. Biol. Chem. 270, 5909-5916]. We have constructed a CHO cell line (CHO-N) that expresses an N-terminal fragment of gp91-phox containing the predicted multiple transmembrane domains of the protein. These cells exhibit H+ fluxes in response to an imposed proton motive force and in the presence of arachidonate (to open the channel). The H+ fluxes were indistinguishable from those observed in cells expressing full-length gp91-phox. Therefore the N-terminal 230 amino acids of gp91-phox contain all that is required to function as the NADPH oxidase-associated H+ channel.
Henderson
L M
LM
Department of Biochemistry, School of Medical Sciences, University of Bristol, University Walk, Bristol BS8 1TD, U.K.
Thomas
S
S
Banting
G
G
Chappell
J B
JB
D000818:Animals; D016718:Arachidonic Acid / Q000494:pharmacology*; D016466:CHO Cells; D002462:Cell Membrane / Q000378:metabolism; D006224:Cricetinae; D005452:Fluoresceins; D006863:Hydrogen-Ion Concentration; D008562:Membrane Glycoproteins / Q000378:metabolism*; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases / Q000378:metabolism*; D011522:Protons
D005452:Fluoresceins; D008562:Membrane Glycoproteins; D011522:Protons; D016718:Arachidonic Acid; C043829:2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein; C056558:CYBB protein, human; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases