1. Structural Biology and Molecular Biophysics
  2. Plant Biology
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Mechanistic insight into a peptide hormone signaling complex mediating floral organ abscission

  1. Julia Santiago
  2. Benjamin Brandt
  3. Mari Wildhagen
  4. Ulrich Hohmann
  5. Ludwig A Hothorn
  6. Melinka A Butenko
  7. Michael Hothorn  Is a corresponding author
  1. University of Geneva, Switzerland
  2. University of Oslo, Norway
  3. Leibniz University, Germany
Research Article
  • Cited 107
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Cite this article as: eLife 2016;5:e15075 doi: 10.7554/eLife.15075

Abstract

Plants constantly renew during their life cycle and thus require to shed senescent and damaged organs. Floral abscission is controlled by the leucine-rich repeat receptor kinase (LRR-RK) HAESA and the peptide hormone IDA. It is unknown how expression of IDA in the abscission zone leads to HAESA activation. Here we show that IDA is sensed directly by the HAESA ectodomain. Crystal structures of HAESA in complex with IDA reveal a hormone binding pocket that accommodates an active dodecamer peptide. A central hydroxyproline residue anchors IDA to the receptor. The HAESA co-receptor SERK1, a positive regulator of the floral abscission pathway, allows for high-affinity sensing of the peptide hormone by binding to an Arg-His-Asn motif in IDA. This sequence pattern is conserved among diverse plant peptides, suggesting that plant peptide hormone receptors may share a common ligand binding mode and activation mechanism.

Article and author information

Author details

  1. Julia Santiago

    Structural Plant Biology Laboratory, Department of Botany and Plant Biology, University of Geneva, Geneva, Switzerland
    Competing interests
    The authors declare that no competing interests exist.
  2. Benjamin Brandt

    Structural Plant Biology Laboratory, Department of Botany and Plant Biology, University of Geneva, Geneva, Switzerland
    Competing interests
    The authors declare that no competing interests exist.
  3. Mari Wildhagen

    Department of Biosciences, Section for Genetic and Evolutionary Biology, University of Oslo, Oslo, Norway
    Competing interests
    The authors declare that no competing interests exist.
  4. Ulrich Hohmann

    Structural Plant Biology Laboratory, Department of Botany and Plant Biology, University of Geneva, Geneva, Switzerland
    Competing interests
    The authors declare that no competing interests exist.
  5. Ludwig A Hothorn

    Institute of Biostatistics, Leibniz University, Hannover, Germany
    Competing interests
    The authors declare that no competing interests exist.
  6. Melinka A Butenko

    Department of Biosciences, Section for Genetic and Evolutionary Biology, University of Oslo, Oslo, Norway
    Competing interests
    The authors declare that no competing interests exist.
  7. Michael Hothorn

    Structural Plant Biology Laboratory, Department of Botany and Plant Biology, University of Geneva, Geneve, Switzerland
    For correspondence
    michael.hothorn@unige.ch
    Competing interests
    The authors declare that no competing interests exist.

Reviewing Editor

  1. Mingjie Zhang, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, China

Publication history

  1. Received: February 8, 2016
  2. Accepted: April 7, 2016
  3. Accepted Manuscript published: April 8, 2016 (version 1)
  4. Version of Record published: April 27, 2016 (version 2)

Copyright

© 2016, Santiago et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

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