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bioRxiv · 10.1101/244467

Revisiting the functional properties of NPF6.3/NRT1.1/CHL1 in xenopus oocytes

Noguero, M.·Leran, S.·Bouguyon, E.·Brachet, C.·Tillard, P.·Nacry, P.·Gojon, A.·Krouk, G.·Lacombe, B.
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Abstract

Within the Arabidopsis NPF proteins, most of the characterized nitrate transporters are low-affinity transporters, whereas the functional characterization of NPF6.3/NRT1.1 has revealed interesting transport properties: the transport of nitrate and auxin, the eletrogenicity of the nitrate transport and a dual-affinity transport behavior for nitrate depending on external nitrate concentration. However, some of these properties remained controversial and were challenged here. We functionally express WT NPF6.3/NRT1.1 and some of its mutant in Xenopus oocytes and used a combination of uptake experiments using 15N-labelled nitrate and two-electrode voltage-clamp. In our experimental conditions in xenopus oocytes, in the presence or in the absence of external chloride, NPF6.3/NRT1.1 behaves as a non-electrogenic and pure low-affinity transporter. Moreover, further functional characterization of a NPF6.3/NRT1.1 point mutant, P492L, allowed us to hypothesize that NPF6.3/NRT1.1 is regulated by internal nitrate concentration and that the internal perception site involves the P492 residue.

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Noguero, M., Leran, S., Bouguyon, E., Brachet, C., Tillard, P., Nacry, P., Gojon, A., Krouk, G., Lacombe, B.. 2018-02-26. Revisiting the functional properties of NPF6.3/NRT1.1/CHL1 in xenopus oocytes. https://doi.org/10.1101/244467

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