The GluTR-binding protein is the heme-binding factor for feedback control of glutamyl-tRNA reductase

  1. Andreas S Richter  Is a corresponding author
  2. Claudia Banse
  3. Bernhard Grimm  Is a corresponding author
  1. Humboldt University of Berlin, Germany

Abstract

Synthesis of 5-aminolevulinic acid (ALA) is the rate-limiting step in tetrapyrrole biosynthesis in land plants. In photosynthetic eukaryotes and many bacteria, glutamyl-tRNA reductase (GluTR) is the most tightly controlled enzyme upstream of ALA. Higher plants possess two GluTR species: GluTR1 is predominantly expressed in green tissue, and GluTR2 is constitutively expressed in all organs. Although proposed long time ago, the molecular mechanism of heme-dependent inhibition of GluTR in planta has remained elusive. Here, we report that accumulation of heme, induced by feeding with ALA, stimulates Clp-protease-dependent degradation of Arabidopsis GluTR1. We demonstrate that binding of heme to the GluTR-binding protein (GBP) inhibits interaction of GBP with the N-terminal regulatory domain of GluTR1, thus making it accessible to the Clp protease. The results presented uncover a functional link between heme content and the post-translational control of GluTR stability, which helps to ensure adequate availability of chlorophyll and heme.

Data availability

All data generated or analysed during this study are included in the manuscript and supporting files.

Article and author information

Author details

  1. Andreas S Richter

    Institute of Biology/Plant Physiology, Humboldt University of Berlin, Berlin, Germany
    For correspondence
    andreas.richter@hu-berlin.de
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-2293-7297
  2. Claudia Banse

    Institute of Biology/Plant Physiology, Humboldt University of Berlin, Berlin, Germany
    Competing interests
    The authors declare that no competing interests exist.
  3. Bernhard Grimm

    Institute of Biology/Plant Physiology, Humboldt University of Berlin, Berlin, Germany
    For correspondence
    bernhard.grimm@hu-berlin.de
    Competing interests
    The authors declare that no competing interests exist.

Funding

Deutsche Forschungsgemeinschaft (317556048)

  • Bernhard Grimm

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Iqbal Hamza, University of Maryland, United States

Version history

  1. Received: February 21, 2019
  2. Accepted: June 12, 2019
  3. Accepted Manuscript published: June 13, 2019 (version 1)
  4. Version of Record published: June 27, 2019 (version 2)

Copyright

© 2019, Richter 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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  1. Andreas S Richter
  2. Claudia Banse
  3. Bernhard Grimm
(2019)
The GluTR-binding protein is the heme-binding factor for feedback control of glutamyl-tRNA reductase
eLife 8:e46300.
https://doi.org/10.7554/eLife.46300

Share this article

https://doi.org/10.7554/eLife.46300

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