Proton antiport

Sodium-proton exchanger Sodium-proton antiport... 

Eiden, L. E., Schafer, M. K.-H., Weihe, E. and Schiitz, B. The vesicular amine transporter family (SLC18) amine/proton antiporters required for vesicular accumulation and regulated exocytotic secretion of monoamines and acetylcholine. Eur. J. Physiol. 447 636-640, 2004. 

Prokaryotic organisms have developed a number of transport mechanisms for the extrusion of sodium ions against a concentration gradient. In Escherichia coli sodium efflux is linked to proton uptake and is independent of internal ATP, i.e. the cell uses a sodium/proton antiporter.70,71 In contrast in Streptococcus faecalis,72 sodium efflux involves an ATP-driven sodium-translocating ATPase, while in Halobacterium halobium the protein halorhodopsin has been postulated to catalyze the coupling of Na+ extrusion to light.73... 

Picollo, A., Pusch, M. 2005. Chloride/proton antiporter activity of mammalian CLC proteins C1C-4 and C1C-5. Nature 436 420-423. 

Miirer, H Hopfer, U., Kinne, R. (1976). Sodium/proton antiport in brush border membrane vesicles isolated from rat small intestine and kidney. Biochem. J. 154,597-604. 

Figure 10.14. Structure (a) and mode of action of reserpine. b Reserpine inhibits vesicular accumulation of dopamine and norepinephrine by blocking the vesicular proton antiporter. c Functional consequences of reserpine action. The net effect consists in reduced activity of catecholaminergic synapses.

Vinothkumar KR, Smits SH, Kuhlbrandt W. pH-induced structural change in a sodium/proton antiporter from Methanococcus jannaschii. EMBO J. 2005 24 2720-2729. 

Fig. 2.5. Interaction of Ca transport with the proton circuit, a, Ca uptake alone discharges the membrane potential b, Ca uptake in exchange for protons extruded by the respiratory chain generates a pH gradient c, Ca uptake together with a weak acid such as acetate does not build up a pH gradient d, Ca cycling in heart mitochondria driven by the proton circuit. R, respiratory chain C, calcium uniport NH, sodium/proton antiport NC, sodium/calcium antiport.

Goldberg, M., Pribyl, T., Juhnke, S., and Nies, D.H. (1999) Energetics and topology of CzcA, a cation/proton antiporter of the resistance-nodulation-ceU division protein family. The Journal of Biological Chemistry, 274 (37), 26065—26070. 

Nies, D. H. (1995). The cobalt, zinc, and cadmium efflux system czcabc from Alcaligenes eutrophus functions as a cation-proton antiporter in Escherichia coli. J. Bacteriol. 177, 2707-2712. 

Kauffman, G.W. and Jurs, P.C. (2000) Prediction of inhibition of the sodium ion-proton antiporter by benzoylguanidine derivatives from molecular structure./. Chem. Inf. Comput. Sci., 40, 753-761. 

Uptake of sucrose, Na, Ca ", and other substances into plant vacuoles is carried out by proton antiporters in the vacuolar membrane. Ion channels and proton pumps in the membrane are critical in generating a large enough proton concentration gradient to power accumulation of ions and metabolites in vacuoles by these proton antiporters (see Figure 7-23). 

Other mechanisms for producing protrusive force have been proposed, and not necessarily ruled out. Osmotic forces generated either by polymerization of actin or by activation of a sodium/proton antiport may be involved. It has been proposed that extensive cross-linking of actin filaments at the leading edge could produce osmotic forces that push the membrane forward [67, 68]. This hypothesis is consistent with the... 

For Alcaligenes eutrophus, two well-defined systems efflux divalent metal cations the Czc system transports Cd , Zn ", and Co out of the cell (Nies 1992a Nies et al. 1989), and the Cnr system transports Co " and out of the cell (Liesegang et al. 1993 Collard et al. 1993). Both systems are plasmid based. The Czc and Cnr systems do not (from their sequences) appear to be ATPases (Nies et al. 1989 Liesegang et al. 1993), and the Czc system functions as a cation/proton antiporter (Nies 1994). Little is known about the regulation of expression of these systems. The Czc system (Fig. 7) consists of four genes czcA is predicted by sequence to produce a membrane-bound protein czcB also determines a membrane protein and czcC... 

Nies DH (1994) Expression of the cobalt, zinc, and cadmium efflux system of Alcaligenes eutrophus in Escherichia coli CzcABC is a cation-proton antiporter. Eur J Biochem (submitted)... 

Among phenolics, transport of anthocyanidins has received much attention. One MATE-type (multidrug and toxin efflux) transporter, TT12, a typical proton antiporter, has been involved in flavonoids sequestration into the vacuole (Debeaujon et al, 2001). 

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