Polar localization of the NIP5;1 boric acid channel is maintained by endocytosis and facilitates boron transport in arabidopsis roots

Sheliang Wang, Akira Yoshinari, Tomoo Shimada, Ikuko Hara-Nishimura, Namiki Mitani-Ueno, Jian Feng Ma, Satoshi Naito, Junpei Takano

Research output: Contribution to journalArticlepeer-review

43 Citations (Scopus)

Abstract

Boron uptake in Arabidopsis thaliana is mediated by nodulin 26-like intrinsic protein 5;1 (NIP5;1), a boric acid channel that is located preferentially on the soil side of the plasma membrane in root cells. However, the mechanism underlying this polar localization is poorly understood. Here, we show that the polar localization of NIP5;1 in epidermal and endodermal root cells is mediated by the phosphorylation of Thr residues in the conserved TPG (ThrProGly) repeat in the N-terminal region of NIP5;1. Although substitutions of Ala for three Thr residues in the TPG repeat did not affect lateral diffusion in the plasma membrane, these substitutions inhibited endocytosis and strongly compromised the polar localization of GFP-NIP5;1. Consistent with this, the polar localization was compromised in m subunit mutants of the clathrin adaptor AP2. The Thr-to-Ala substitutions did not affect the boron transport activity of GFP-NIP5;1 in Xenopus laevis oocytes but did inhibit the ability to complement boron translocation to shoots and rescue growth defects in nip5;1-1 mutant plants under boron-limited conditions. These results demonstrate that the polar localization of NIP5;1 is maintained by clathrin-mediated endocytosis, is dependent on phosphorylation in the TPG repeat, and is necessary for the efficient transport of boron in roots.

Original languageEnglish
Pages (from-to)824-842
Number of pages19
JournalPlant Cell
Volume29
Issue number4
DOIs
Publication statusPublished - Apr 2017

ASJC Scopus subject areas

  • Plant Science
  • Cell Biology

Fingerprint Dive into the research topics of 'Polar localization of the NIP5;1 boric acid channel is maintained by endocytosis and facilitates boron transport in arabidopsis roots'. Together they form a unique fingerprint.

Cite this