Na+, K+/H+ antiporters regulate the pH of endoplasmic reticulum and auxin-mediated development

0489240 - ÚEB 2019 RIV GB eng J - Journal Article
Fan, L. - Zhao, L. - Hu, W. - Li, W. - Novák, Ondřej - Strnad, Miroslav - Simon, S. - Friml, J. - Shen, J. - Jiang, L. - Qiu, Q. S.
Na+, K+/H+ antiporters regulate the pH of endoplasmic reticulum and auxin-mediated development.
Plant Cell and Environment. Roč. 41, č. 4 (2018), s. 850-864. ISSN 0140-7791. E-ISSN 1365-3040
R&D Projects: GA MŠMT(CZ) LO1204
Institutional support: RVO:61389030
Keywords : Arabidopsis * AtNHX5 * AtNHX6 * endosomal Na ,K /H antiporters * pH * pin5
OECD category: Cell biology
Impact factor: 5.624, year: 2018

AtNHX5 and AtNHX6 are endosomal Na + ,K + /H + antiporters that are critical for growth and development in Arabidopsis, but the mechanism behind their action remains unknown. Here, we report that AtNHX5 and AtNHX6, functioning as H + leak, control auxin homeostasis and auxin-mediated development. We found that nhx5 nhx6 exhibited growth variations of auxin-related defects. We further showed that nhx5 nhx6 was affected in auxin homeostasis. Genetic analysis showed that AtNHX5 and AtNHX6 were required for the function of the endoplasmic reticulum (ER)-localized auxin transporter PIN5. Although AtNHX5 and AtNHX6 were colocalized with PIN5 at ER, they did not interact directly. Instead, the conserved acidic residues in AtNHX5 and AtNHX6, which are essential for exchange activity, were required for PIN5 function. AtNHX5 and AtNHX6 regulated the pH in ER. Overall, AtNHX5 and AtNHX6 may regulate auxin transport across the ER via the pH gradient created by their transport activity. H +leak pathway provides a fine-tuning mechanism that controls cellular auxin fluxes.
Permanent Link: http://hdl.handle.net/11104/0283685