UBP12 and UBP13 negatively regulate the activity of the ubiquitin-dependent peptidases DA1, DAR1 and DAR2
- VIB/UGent, Belgium
Abstract
Protein ubiquitination is a very diverse post-translational modification leading to protein degradation or delocalization, or altering protein activity. In Arabidopsis thaliana, two E3 ligases, BIG BROTHER (BB) and DA2, activate the latent peptidases DA1, DAR1 and DAR2 by mono-ubiquitination at multiple sites. Subsequently, these activated peptidases destabilize various positive regulators of growth. Here, we show that two ubiquitin-specific proteases, UBP12 and UBP13, deubiquitinate DA1, DAR1 and DAR2, hence reducing their peptidase activity. Overexpression of UBP12 or UBP13 strongly decreased leaf size and cell area, and resulted in lower ploidy levels. Mutants in which UBP12 and UBP13 were downregulated produced smaller leaves that contained fewer and smaller cells. Remarkably, neither UBP12 nor UBP13 were found to be cleavage substrates of the activated DA1. Our results therefore suggest that UBP12 and UBP13 work upstream of DA1, DAR1 and DAR2 to restrict their protease activity and hence fine-tune plant growth and development.
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Funding
Ghent University Bijzonder Onderzoeksfondsen (BOF08/01M00408)
- Mattias Vermeersch
Ghent University Bijzonder Onderzoeksfondsen (01SC3117)
- Ying Chen
Chinese Scholarship Council (201604910566)
- Ying Chen
Research Foundation Flanders (12V0218N)
- Hannes Vanhaeren
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2020, Vanhaeren 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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UBP12 and UBP13 negatively regulate the activity of the ubiquitin-dependent peptidases DA1, DAR1 and DAR2
eLife 9:e52276.
https://doi.org/10.7554/eLife.52276
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