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Oxygen-dependent proteolysis regulates the stability of angiosperm polycomb repressive complex 2 subunit
Daniel J Gibbs1, Hannah M Tedds2, Anne-Marie Labandera2
1School of Biosciences, University of Birmingham, Edgbaston, B15 2TT, UK. d.gibbs@bham.ac.uk.
Nature Communications
|December 22, 2018
Summary
Scientists discovered a plant protein (VERNALIZATION 2) that degrades in response to oxygen levels. This epigenetic regulator
Area of Science:
- Epigenetics and Gene Regulation
- Plant Molecular Biology
- Post-Translational Modifications
Background:
- Polycomb Repressive Complex 2 (PRC2) is crucial for epigenetic gene silencing in eukaryotes.
- Mechanisms governing PRC2's developmental specificity and environmental responsiveness remain largely unknown.
- VERNALIZATION 2 (VRN2) is a plant PRC2 subunit homologous to animal Su(z)12.
Purpose of the Study:
- To investigate the regulatory mechanisms controlling VRN2 stability and PRC2 function.
- To explore the link between environmental signals and epigenetic gene regulation in plants.
Main Methods:
- Identification of an N-terminal degron in VRN2.
- Analysis of VRN2 degradation via the N-end rule pathway.
- Investigating VRN2 stability under varying oxygen (hypoxia) and temperature (cold) conditions.
- Examining transcriptional responses to hypoxia and cold.
Main Results:
- An oxygen-sensitive N-terminal degron was identified in VRN2, targeting it for degradation by the N-end rule pathway.
- This degron likely evolved early in angiosperm history through gene duplication and truncation.
- Hypoxia and prolonged cold exposure increase VRN2 abundance, potentially by inhibiting its degradation.
- VRN2 enhances tolerance to hypoxic conditions, and hypoxia and cold share overlapping transcriptional responses.
Conclusions:
- A novel mechanism of post-translational regulation of VRN2 stability links environmental cues to epigenetic control of plant development.
- VRN2's N-degron provides a mechanism for modulating PRC2 activity in response to environmental stress.
- This finding sheds light on the evolution of PRC2 function in flowering plants.
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