---
_id: '8993'
abstract:
- lang: eng
  text: N-1-naphthylphthalamic acid (NPA) is a key inhibitor of directional (polar)
    transport of the hormone auxin in plants. For decades, it has been a pivotal tool
    in elucidating the unique polar auxin transport-based processes underlying plant
    growth and development. Its exact mode of action has long been sought after and
    is still being debated, with prevailing mechanistic schemes describing only indirect
    connections between NPA and the main transporters responsible for directional
    transport, namely PIN auxin exporters. Here we present data supporting a model
    in which NPA associates with PINs in a more direct manner than hitherto postulated.
    We show that NPA inhibits PIN activity in a heterologous oocyte system and that
    expression of NPA-sensitive PINs in plant, yeast, and oocyte membranes leads to
    specific saturable NPA binding. We thus propose that PINs are a bona fide NPA
    target. This offers a straightforward molecular basis for NPA inhibition of PIN-dependent
    auxin transport and a logical parsimonious explanation for the known physiological
    effects of NPA on plant growth, as well as an alternative hypothesis to interpret
    past and future results. We also introduce PIN dimerization and describe an effect
    of NPA on this, suggesting that NPA binding could be exploited to gain insights
    into structural aspects of PINs related to their transport mechanism.
acknowledgement: "This work was supported by Austrian Science Fund Grant FWF P21533-B20
  (to L.A.); German Research Foundation Grant DFG HA3468/6-1 (to U.Z.H.); and European
  Research Council Grant 742985 (to J.F.). We thank Herta Steinkellner and Alexandra
  Castilho for N. benthamiana plants, Fabian Nagelreiter for statistical advice, Lanassa
  Bassukas for help with [ɣ32P]-\r\nATP assays, and Josef Penninger for providing
  access to mass spectrometry instruments at the Vienna BioCenter Core Facilities.
  We thank PNAS reviewers for the many comments and suggestions that helped to improve
  this manuscript."
article_number: e2020857118
article_processing_charge: No
article_type: original
author:
- first_name: Lindy
  full_name: Abas, Lindy
  last_name: Abas
- first_name: Martina
  full_name: Kolb, Martina
  last_name: Kolb
- first_name: Johannes
  full_name: Stadlmann, Johannes
  last_name: Stadlmann
- first_name: Dorina P.
  full_name: Janacek, Dorina P.
  last_name: Janacek
- first_name: Kristina
  full_name: Lukic, Kristina
  id: 2B04DB84-F248-11E8-B48F-1D18A9856A87
  last_name: Lukic
  orcid: 0000-0003-1581-881X
- first_name: Claus
  full_name: Schwechheimer, Claus
  last_name: Schwechheimer
- first_name: Leonid A
  full_name: Sazanov, Leonid A
  id: 338D39FE-F248-11E8-B48F-1D18A9856A87
  last_name: Sazanov
  orcid: 0000-0002-0977-7989
- first_name: Lukas
  full_name: Mach, Lukas
  last_name: Mach
- first_name: Jiří
  full_name: Friml, Jiří
  id: 4159519E-F248-11E8-B48F-1D18A9856A87
  last_name: Friml
  orcid: 0000-0002-8302-7596
- first_name: Ulrich Z.
  full_name: Hammes, Ulrich Z.
  last_name: Hammes
citation:
  ama: Abas L, Kolb M, Stadlmann J, et al. Naphthylphthalamic acid associates with
    and inhibits PIN auxin transporters. <i>Proceedings of the National Academy of
    Sciences of the United States of America</i>. 2021;118(1). doi:<a href="https://doi.org/10.1073/pnas.2020857118">10.1073/pnas.2020857118</a>
  apa: Abas, L., Kolb, M., Stadlmann, J., Janacek, D. P., Lukic, K., Schwechheimer,
    C., … Hammes, U. Z. (2021). Naphthylphthalamic acid associates with and inhibits
    PIN auxin transporters. <i>Proceedings of the National Academy of Sciences of
    the United States of America</i>. National Academy of Sciences. <a href="https://doi.org/10.1073/pnas.2020857118">https://doi.org/10.1073/pnas.2020857118</a>
  chicago: Abas, Lindy, Martina Kolb, Johannes Stadlmann, Dorina P. Janacek, Kristina
    Lukic, Claus Schwechheimer, Leonid A Sazanov, Lukas Mach, Jiří Friml, and Ulrich
    Z. Hammes. “Naphthylphthalamic Acid Associates with and Inhibits PIN Auxin Transporters.”
    <i>Proceedings of the National Academy of Sciences of the United States of America</i>.
    National Academy of Sciences, 2021. <a href="https://doi.org/10.1073/pnas.2020857118">https://doi.org/10.1073/pnas.2020857118</a>.
  ieee: L. Abas <i>et al.</i>, “Naphthylphthalamic acid associates with and inhibits
    PIN auxin transporters,” <i>Proceedings of the National Academy of Sciences of
    the United States of America</i>, vol. 118, no. 1. National Academy of Sciences,
    2021.
  ista: Abas L, Kolb M, Stadlmann J, Janacek DP, Lukic K, Schwechheimer C, Sazanov
    LA, Mach L, Friml J, Hammes UZ. 2021. Naphthylphthalamic acid associates with
    and inhibits PIN auxin transporters. Proceedings of the National Academy of Sciences
    of the United States of America. 118(1), e2020857118.
  mla: Abas, Lindy, et al. “Naphthylphthalamic Acid Associates with and Inhibits PIN
    Auxin Transporters.” <i>Proceedings of the National Academy of Sciences of the
    United States of America</i>, vol. 118, no. 1, e2020857118, National Academy of
    Sciences, 2021, doi:<a href="https://doi.org/10.1073/pnas.2020857118">10.1073/pnas.2020857118</a>.
  short: L. Abas, M. Kolb, J. Stadlmann, D.P. Janacek, K. Lukic, C. Schwechheimer,
    L.A. Sazanov, L. Mach, J. Friml, U.Z. Hammes, Proceedings of the National Academy
    of Sciences of the United States of America 118 (2021).
date_created: 2021-01-03T23:01:23Z
date_published: 2021-01-05T00:00:00Z
date_updated: 2025-05-14T10:58:54Z
day: '05'
department:
- _id: JiFr
- _id: LeSa
doi: 10.1073/pnas.2020857118
ec_funded: 1
external_id:
  isi:
  - '000607270100073'
  pmid:
  - '33443187'
intvolume: '       118'
isi: 1
issue: '1'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://doi.org/10.1073/pnas.2020857118
month: '01'
oa: 1
oa_version: Published Version
pmid: 1
project:
- _id: 261099A6-B435-11E9-9278-68D0E5697425
  call_identifier: H2020
  grant_number: '742985'
  name: Tracing Evolution of Auxin Transport and Polarity in Plants
publication: Proceedings of the National Academy of Sciences of the United States
  of America
publication_identifier:
  eissn:
  - 1091-6490
  issn:
  - 0027-8424
publication_status: published
publisher: National Academy of Sciences
quality_controlled: '1'
related_material:
  link:
  - relation: erratum
    url: https://doi.org/10.1073/pnas.2102232118
scopus_import: '1'
status: public
title: Naphthylphthalamic acid associates with and inhibits PIN auxin transporters
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 118
year: '2021'
...