1
|
Etherington RD, Bailey M, Boyer JB, Armbruster L, Cao X, Coates JC, Meinnel T, Wirtz M, Giglione C, Gibbs DJ. Nt-acetylation-independent turnover of SQUALENE EPOXIDASE 1 by Arabidopsis DOA10-like E3 ligases. Plant Physiol 2023; 193:2086-2104. [PMID: 37427787 PMCID: PMC10602611 DOI: 10.1093/plphys/kiad406] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 06/09/2023] [Accepted: 06/12/2023] [Indexed: 07/11/2023]
Abstract
The acetylation-dependent (Ac/)N-degron pathway degrades proteins through recognition of their acetylated N-termini (Nt) by E3 ligases called Ac/N-recognins. To date, specific Ac/N-recognins have not been defined in plants. Here we used molecular, genetic, and multiomics approaches to characterize potential roles for Arabidopsis (Arabidopsis thaliana) DEGRADATION OF ALPHA2 10 (DOA10)-like E3 ligases in the Nt-acetylation-(NTA)-dependent turnover of proteins at global- and protein-specific scales. Arabidopsis has two endoplasmic reticulum (ER)-localized DOA10-like proteins. AtDOA10A, but not the Brassicaceae-specific AtDOA10B, can compensate for loss of yeast (Saccharomyces cerevisiae) ScDOA10 function. Transcriptome and Nt-acetylome profiling of an Atdoa10a/b RNAi mutant revealed no obvious differences in the global NTA profile compared to wild type, suggesting that AtDOA10s do not regulate the bulk turnover of NTA substrates. Using protein steady-state and cycloheximide-chase degradation assays in yeast and Arabidopsis, we showed that turnover of ER-localized SQUALENE EPOXIDASE 1 (AtSQE1), a critical sterol biosynthesis enzyme, is mediated by AtDOA10s. Degradation of AtSQE1 in planta did not depend on NTA, but Nt-acetyltransferases indirectly impacted its turnover in yeast, indicating kingdom-specific differences in NTA and cellular proteostasis. Our work suggests that, in contrast to yeast and mammals, targeting of Nt-acetylated proteins is not a major function of DOA10-like E3 ligases in Arabidopsis and provides further insight into plant ERAD and the conservation of regulatory mechanisms controlling sterol biosynthesis in eukaryotes.
Collapse
Affiliation(s)
- Ross D Etherington
- School of Biosciences, University of Birmingham, Edgbaston, West Midlands, B15 2TT, UK
| | - Mark Bailey
- School of Biosciences, University of Birmingham, Edgbaston, West Midlands, B15 2TT, UK
| | - Jean-Baptiste Boyer
- CEA, CNRS, Université Paris-Saclay, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, 91198, France
| | - Laura Armbruster
- Centre for Organismal Studies Heidelberg, Heidelberg University, Heidelberg, 69120, Germany
| | - Xulyu Cao
- School of Biosciences, University of Birmingham, Edgbaston, West Midlands, B15 2TT, UK
| | - Juliet C Coates
- School of Biosciences, University of Birmingham, Edgbaston, West Midlands, B15 2TT, UK
| | - Thierry Meinnel
- CEA, CNRS, Université Paris-Saclay, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, 91198, France
| | - Markus Wirtz
- Centre for Organismal Studies Heidelberg, Heidelberg University, Heidelberg, 69120, Germany
| | - Carmela Giglione
- CEA, CNRS, Université Paris-Saclay, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, 91198, France
| | - Daniel J Gibbs
- School of Biosciences, University of Birmingham, Edgbaston, West Midlands, B15 2TT, UK
| |
Collapse
|
2
|
Chustecki JM, Etherington RD, Gibbs DJ, Johnston IG. Altered collective mitochondrial dynamics in the Arabidopsis msh1 mutant compromising organelle DNA maintenance. J Exp Bot 2022; 73:5428-5439. [PMID: 35662332 PMCID: PMC9467644 DOI: 10.1093/jxb/erac250] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 06/01/2022] [Indexed: 05/19/2023]
Abstract
Mitochondria form highly dynamic populations in the cells of plants (and almost all eukaryotes). The characteristics and benefits of this collective behaviour, and how it is influenced by nuclear features, remain to be fully elucidated. Here, we use a recently developed quantitative approach to reveal and analyse the physical and collective 'social' dynamics of mitochondria in an Arabidopsis msh1 mutant where the organelle DNA maintenance machinery is compromised. We use a newly created line combining the msh1 mutant with mitochondrially targeted green fluorescent protein (GFP), and characterize mitochondrial dynamics with a combination of single-cell time-lapse microscopy, computational tracking, and network analysis. The collective physical behaviour of msh1 mitochondria is altered from that of the wild type in several ways: mitochondria become less evenly spread, and networks of inter-mitochondrial encounters become more connected, with greater potential efficiency for inter-organelle exchange-reflecting a potential compensatory mechanism for the genetic challenge to the mitochondrial DNA population, supporting more inter-organelle exchange. We find that these changes are similar to those observed in friendly, where mitochondrial dynamics are altered by a physical perturbation, suggesting that this shift to higher connectivity may reflect a general response to mitochondrial challenges, where physical dynamics of mitochondria may be altered to control the genetic structure of the mtDNA population.
Collapse
Affiliation(s)
| | | | - Daniel J Gibbs
- School of Biosciences, University of Birmingham, Birmingham, UK
| | | |
Collapse
|
3
|
Bailey M, Ivanauskaite A, Grimmer J, Akintewe O, Payne AC, Osborne R, Labandera AM, Etherington RD, Rantala M, Baginsky S, Mulo P, Gibbs DJ. Retraction Note: The Arabidopsis NOT4A E3 ligase promotes PGR3 expression and regulates chloroplast translation. Nat Commun 2022; 13:2913. [PMID: 35595752 PMCID: PMC9122975 DOI: 10.1038/s41467-022-30354-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Mark Bailey
- School of Biosciences, University of Birmingham, Edgbaston, B15 2TT, UK.,Plant Sciences Department, Rothamsted Research, Harpenden, AL5 2JQ, UK
| | | | - Julia Grimmer
- Institute of Biochemistry and Biotechnology, Martin-Luther-University Halle-Wittenberg, Kurt-Mothes-Str. 3a, 06120, Halle, Saale, Germany
| | | | - Adrienne C Payne
- School of Biosciences, University of Birmingham, Edgbaston, B15 2TT, UK
| | - Rory Osborne
- School of Biosciences, University of Birmingham, Edgbaston, B15 2TT, UK
| | | | | | - Marjaana Rantala
- Molecular Plant Biology, University of Turku, 20520, Turku, Finland
| | - Sacha Baginsky
- Institute of Biochemistry and Biotechnology, Martin-Luther-University Halle-Wittenberg, Kurt-Mothes-Str. 3a, 06120, Halle, Saale, Germany.,Biochemistry of Plants, Faculty for Biology and Biotechnology, Ruhr-University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Paula Mulo
- Molecular Plant Biology, University of Turku, 20520, Turku, Finland
| | - Daniel J Gibbs
- School of Biosciences, University of Birmingham, Edgbaston, B15 2TT, UK.
| |
Collapse
|
4
|
Gibbs DJ, Bailey M, Etherington RD. A stable start: cotranslational Nt-acetylation promotes proteome stability across kingdoms. Trends Cell Biol 2022; 32:374-376. [DOI: 10.1016/j.tcb.2022.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 02/22/2022] [Indexed: 10/18/2022]
|
5
|
Huber M, Armbruster L, Etherington RD, De La Torre C, Hawkesford MJ, Sticht C, Gibbs DJ, Hell R, Wirtz M. Disruption of the N α-Acetyltransferase NatB Causes Sensitivity to Reductive Stress in Arabidopsis thaliana. Front Plant Sci 2022; 12:799954. [PMID: 35046984 PMCID: PMC8761761 DOI: 10.3389/fpls.2021.799954] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 11/22/2021] [Indexed: 06/14/2023]
Abstract
In Arabidopsis thaliana, the evolutionary conserved N-terminal acetyltransferase (Nat) complexes NatA and NatB co-translationally acetylate 60% of the proteome. Both have recently been implicated in the regulation of plant stress responses. While NatA mediates drought tolerance, NatB is required for pathogen resistance and the adaptation to high salinity and high osmolarity. Salt and osmotic stress impair protein folding and result in the accumulation of misfolded proteins in the endoplasmic reticulum (ER). The ER-membrane resident E3 ubiquitin ligase DOA10 targets misfolded proteins for degradation during ER stress and is conserved among eukaryotes. In yeast, DOA10 recognizes conditional degradation signals (Ac/N-degrons) created by NatA and NatB. Assuming that this mechanism is preserved in plants, the lack of Ac/N-degrons required for efficient removal of misfolded proteins might explain the sensitivity of NatB mutants to protein harming conditions. In this study, we investigate the response of NatB mutants to dithiothreitol (DTT) and tunicamycin (TM)-induced ER stress. We report that NatB mutants are hypersensitive to DTT but not TM, suggesting that the DTT hypersensitivity is caused by an over-reduction of the cytosol rather than an accumulation of unfolded proteins in the ER. In line with this hypothesis, the cytosol of NatB depleted plants is constitutively over-reduced and a global transcriptome analysis reveals that their reductive stress response is permanently activated. Moreover, we demonstrate that doa10 mutants are susceptible to neither DTT nor TM, ruling out a substantial role of DOA10 in ER-associated protein degradation (ERAD) in plants. Contrary to previous findings in yeast, our data indicate that N-terminal acetylation (NTA) does not inhibit ER targeting of a substantial amount of proteins in plants. In summary, we provide further evidence that NatB-mediated imprinting of the proteome is vital for the response to protein harming stress and rule out DOA10 as the sole recognin for substrates in the plant ERAD pathway, leaving the role of DOA10 in plants ambiguous.
Collapse
Affiliation(s)
- Monika Huber
- Centre for Organismal Studies, Molecular Biology of Plants Group, Heidelberg University, Heidelberg, Germany
| | - Laura Armbruster
- Centre for Organismal Studies, Molecular Biology of Plants Group, Heidelberg University, Heidelberg, Germany
| | | | - Carolina De La Torre
- Institute of Clinical Chemistry, NGS Core Facility, Medical Faculty Mannheim of Heidelberg University, Heidelberg, Germany
| | | | - Carsten Sticht
- Institute of Clinical Chemistry, NGS Core Facility, Medical Faculty Mannheim of Heidelberg University, Heidelberg, Germany
| | - Daniel J. Gibbs
- School of Biosciences, University of Birmingham, Edgbaston, United Kingdom
| | - Rüdiger Hell
- Centre for Organismal Studies, Molecular Biology of Plants Group, Heidelberg University, Heidelberg, Germany
| | - Markus Wirtz
- Centre for Organismal Studies, Molecular Biology of Plants Group, Heidelberg University, Heidelberg, Germany
| |
Collapse
|
6
|
Labandera A, Tedds HM, Bailey M, Sprigg C, Etherington RD, Akintewe O, Kalleechurn G, Holdsworth MJ, Gibbs DJ. The PRT6 N-degron pathway restricts VERNALIZATION 2 to endogenous hypoxic niches to modulate plant development. New Phytol 2021; 229:126-139. [PMID: 32043277 PMCID: PMC7754370 DOI: 10.1111/nph.16477] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 02/04/2020] [Indexed: 05/20/2023]
Abstract
VERNALIZATION2 (VRN2), an angiosperm-specific subunit of the polycomb repressive complex 2 (PRC2), is an oxygen (O2 )-regulated target of the PCO branch of the PRT6 N-degron pathway of ubiquitin-mediated proteolysis. How this post-translational regulation coordinates VRN2 activity remains to be fully established. Here we use Arabidopsis thaliana ecotypes, mutants and transgenic lines to determine how control of VRN2 stability contributes to its functions during plant development. VRN2 localizes to endogenous hypoxic regions in aerial and root tissues. In the shoot apex, VRN2 differentially modulates flowering time dependent on photoperiod, whilst its presence in lateral root primordia and the root apical meristem negatively regulates root system architecture. Ectopic accumulation of VRN2 does not enhance its effects on flowering, but does potentiate its repressive effects on root growth. In late-flowering vernalization-dependent ecotypes, VRN2 is only active outside meristems when its proteolysis is inhibited in response to cold exposure, as its function requires concomitant cold-triggered increases in other PRC2 subunits and cofactors. We conclude that the O2 -sensitive N-degron of VRN2 has a dual function, confining VRN2 to meristems and primordia, where it has specific developmental roles, whilst also permitting broad accumulation outside of meristems in response to environmental cues, leading to other functions.
Collapse
Affiliation(s)
| | - Hannah M. Tedds
- School of BiosciencesUniversity of BirminghamEdgbastonB15 2TTUK
| | - Mark Bailey
- School of BiosciencesUniversity of BirminghamEdgbastonB15 2TTUK
| | - Colleen Sprigg
- School of BiosciencesUniversity of BirminghamEdgbastonB15 2TTUK
| | | | | | | | | | - Daniel J. Gibbs
- School of BiosciencesUniversity of BirminghamEdgbastonB15 2TTUK
| |
Collapse
|