Pascal Genschik, PhD. Group leader at UPR 2357 – IBMP CNRS
Contact
Pascal Genschik
Phone
E-Mail
Website
UPR 2357 – IBMP CNRS
Institut de Biologie Moléculaire des Plantes du CNRS
12 rue du Général Zimmer
67084 Strasbourg Cedex
France
Research topics
- Protein degradation pathways in the model plant Arabidopsis thaliana
- Role of Cullin-RING E3 ubiquitin Ligases in plant development and stress responses
- Post-translational regulations of the RNA silencing machinery
Role in NetRNA
The group of Pascal Genschik will investigate post-translational regulations that control RNA silencing in the model plant Arabidopsis thaliana. In particular, our group should provide insights into regulatory mechanisms that control and mediate RISC (RNA induced silencing complex) turnover in normal and stress conditions.
Working Group
Publications
2023
Vergara, Zaida; Gomez, María S; Desvoyes, Bénédicte; Sequeira-Mendes, Joana; Masoud, Kinda; Costas, Celina; Noir, Sandra; Caro, Elena; Mora-Gil, Victoria; Genschik, Pascal; Gutierrez, Crisanto
Distinct roles of Arabidopsis ORC1 proteins in DNA replication and heterochromatic H3K27me1 deposition Journal Article
In: Nat Commun, vol. 14, no. 1, pp. 1270, 2023, ISSN: 2041-1723.
@article{pmid36882445,
title = {Distinct roles of Arabidopsis ORC1 proteins in DNA replication and heterochromatic H3K27me1 deposition},
author = {Zaida Vergara and María S Gomez and Bénédicte Desvoyes and Joana Sequeira-Mendes and Kinda Masoud and Celina Costas and Sandra Noir and Elena Caro and Victoria Mora-Gil and Pascal Genschik and Crisanto Gutierrez},
doi = {10.1038/s41467-023-37024-8},
issn = {2041-1723},
year = {2023},
date = {2023-03-01},
urldate = {2023-03-01},
journal = {Nat Commun},
volume = {14},
number = {1},
pages = {1270},
abstract = {Most cellular proteins involved in genome replication are conserved in all eukaryotic lineages including yeast, plants and animals. However, the mechanisms controlling their availability during the cell cycle are less well defined. Here we show that the Arabidopsis genome encodes for two ORC1 proteins highly similar in amino acid sequence and that have partially overlapping expression domains but with distinct functions. The ancestral ORC1b gene, present before the partial duplication of the Arabidopsis genome, has retained the canonical function in DNA replication. ORC1b is expressed in both proliferating and endoreplicating cells, accumulates during G1 and is rapidly degraded upon S-phase entry through the ubiquitin-proteasome pathway. In contrast, the duplicated ORC1a gene has acquired a specialized function in heterochromatin biology. ORC1a is required for efficient deposition of the heterochromatic H3K27me1 mark by the ATXR5/6 histone methyltransferases. The distinct roles of the two ORC1 proteins may be a feature common to other organisms with duplicated ORC1 genes and a major difference with animal cells.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Most cellular proteins involved in genome replication are conserved in all eukaryotic lineages including yeast, plants and animals. However, the mechanisms controlling their availability during the cell cycle are less well defined. Here we show that the Arabidopsis genome encodes for two ORC1 proteins highly similar in amino acid sequence and that have partially overlapping expression domains but with distinct functions. The ancestral ORC1b gene, present before the partial duplication of the Arabidopsis genome, has retained the canonical function in DNA replication. ORC1b is expressed in both proliferating and endoreplicating cells, accumulates during G1 and is rapidly degraded upon S-phase entry through the ubiquitin-proteasome pathway. In contrast, the duplicated ORC1a gene has acquired a specialized function in heterochromatin biology. ORC1a is required for efficient deposition of the heterochromatic H3K27me1 mark by the ATXR5/6 histone methyltransferases. The distinct roles of the two ORC1 proteins may be a feature common to other organisms with duplicated ORC1 genes and a major difference with animal cells.
2022
Wang, Zhishuo; Orosa-Puente, Beatriz; Nomoto, Mika; Grey, Heather; Potuschak, Thomas; Matsuura, Takakazu; Mori, Izumi C; Tada, Yasuomi; Genschik, Pascal; Spoel, Steven H
Proteasome-associated ubiquitin ligase relays target plant hormone-specific transcriptional activators Journal Article
In: Sci Adv, vol. 8, no. 42, pp. eabn4466, 2022, ISSN: 2375-2548.
@article{pmid36269824,
title = {Proteasome-associated ubiquitin ligase relays target plant hormone-specific transcriptional activators},
author = {Zhishuo Wang and Beatriz Orosa-Puente and Mika Nomoto and Heather Grey and Thomas Potuschak and Takakazu Matsuura and Izumi C Mori and Yasuomi Tada and Pascal Genschik and Steven H Spoel},
doi = {10.1126/sciadv.abn4466},
issn = {2375-2548},
year = {2022},
date = {2022-10-01},
urldate = {2022-10-01},
journal = {Sci Adv},
volume = {8},
number = {42},
pages = {eabn4466},
abstract = {The ubiquitin-proteasome system is vital to hormone-mediated developmental and stress responses in plants. Ubiquitin ligases target hormone-specific transcriptional activators (TAs) for degradation, but how TAs are processed by proteasomes remains unknown. We report that in , the salicylic acid- and ethylene-responsive TAs, NPR1 and EIN3, are relayed from pathway-specific ubiquitin ligases to proteasome-associated HECT-type UPL3/4 ligases. Activity and stability of NPR1 were regulated by sequential action of three ubiquitin ligases, including UPL3/4, while proteasome processing of EIN3 required physical handover between ethylene-responsive SCF and UPL3/4 ligases. Consequently, UPL3/4 controlled extensive hormone-induced developmental and stress-responsive transcriptional programs. Thus, our findings identify unknown ubiquitin ligase relays that terminate with proteasome-associated HECT-type ligases, which may be a universal mechanism for processive degradation of proteasome-targeted TAs and other substrates.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The ubiquitin-proteasome system is vital to hormone-mediated developmental and stress responses in plants. Ubiquitin ligases target hormone-specific transcriptional activators (TAs) for degradation, but how TAs are processed by proteasomes remains unknown. We report that in , the salicylic acid- and ethylene-responsive TAs, NPR1 and EIN3, are relayed from pathway-specific ubiquitin ligases to proteasome-associated HECT-type UPL3/4 ligases. Activity and stability of NPR1 were regulated by sequential action of three ubiquitin ligases, including UPL3/4, while proteasome processing of EIN3 required physical handover between ethylene-responsive SCF and UPL3/4 ligases. Consequently, UPL3/4 controlled extensive hormone-induced developmental and stress-responsive transcriptional programs. Thus, our findings identify unknown ubiquitin ligase relays that terminate with proteasome-associated HECT-type ligases, which may be a universal mechanism for processive degradation of proteasome-targeted TAs and other substrates.
Hacquard, Thibaut; Clavel, Marion; Baldrich, Patricia; Lechner, Esther; Pérez-Salamó, Imma; Schepetilnikov, Mikhail; Derrien, Benoît; Dubois, Marieke; Hammann, Philippe; Kuhn, Lauriane; Brun, Danaé; Bouteiller, Nathalie; Baumberger, Nicolas; Vaucheret, Hervé; Meyers, Blake C; Genschik, Pascal
The Arabidopsis F-box protein FBW2 targets AGO1 for degradation to prevent spurious loading of illegitimate small RNA Journal Article
In: Cell Rep, vol. 39, no. 2, pp. 110671, 2022, ISSN: 2211-1247.
@article{pmid35417704,
title = {The Arabidopsis F-box protein FBW2 targets AGO1 for degradation to prevent spurious loading of illegitimate small RNA},
author = {Thibaut Hacquard and Marion Clavel and Patricia Baldrich and Esther Lechner and Imma Pérez-Salamó and Mikhail Schepetilnikov and Benoît Derrien and Marieke Dubois and Philippe Hammann and Lauriane Kuhn and Danaé Brun and Nathalie Bouteiller and Nicolas Baumberger and Hervé Vaucheret and Blake C Meyers and Pascal Genschik},
doi = {10.1016/j.celrep.2022.110671},
issn = {2211-1247},
year = {2022},
date = {2022-04-01},
urldate = {2022-04-01},
journal = {Cell Rep},
volume = {39},
number = {2},
pages = {110671},
abstract = {RNA silencing is a conserved mechanism in eukaryotes involved in development and defense against viruses. In plants, ARGONAUTE1 (AGO1) protein plays a central role in both microRNA- and small interfering RNA-directed silencing, and its expression is regulated at multiple levels. Here, we report that the F-box protein FBW2 assembles an SCF complex that selectively targets for proteolysis AGO1 when it is unloaded and mutated. Although FBW2 loss of function does not lead to strong growth or developmental defects, it significantly increases RNA-silencing activity. Interestingly, under conditions in which small-RNA accumulation is affected, the failure to degrade AGO1 in fbw2 mutants becomes more deleterious for the plant. Accordingly, the non-degradable AGO1 protein assembles high-molecular-weight complexes and binds illegitimate small RNA, leading to off-target cleavage. Therefore, control of AGO1 homeostasis by FBW2 plays an important role in quality control of RNA silencing.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
RNA silencing is a conserved mechanism in eukaryotes involved in development and defense against viruses. In plants, ARGONAUTE1 (AGO1) protein plays a central role in both microRNA- and small interfering RNA-directed silencing, and its expression is regulated at multiple levels. Here, we report that the F-box protein FBW2 assembles an SCF complex that selectively targets for proteolysis AGO1 when it is unloaded and mutated. Although FBW2 loss of function does not lead to strong growth or developmental defects, it significantly increases RNA-silencing activity. Interestingly, under conditions in which small-RNA accumulation is affected, the failure to degrade AGO1 in fbw2 mutants becomes more deleterious for the plant. Accordingly, the non-degradable AGO1 protein assembles high-molecular-weight complexes and binds illegitimate small RNA, leading to off-target cleavage. Therefore, control of AGO1 homeostasis by FBW2 plays an important role in quality control of RNA silencing.
2021
Clavel, Marion; Lechner, Esther; Incarbone, Marco; Vincent, Timothée; Cognat, Valerie; Smirnova, Ekaterina; Lecorbeiller, Maxime; Brault, Véronique; Ziegler-Graff, Véronique; Genschik, Pascal
Atypical molecular features of RNA silencing against the phloem-restricted polerovirus TuYV Journal Article
In: Nucleic Acids Res, vol. 49, no. 19, pp. 11274–11293, 2021, ISSN: 1362-4962.
@article{pmid34614168,
title = {Atypical molecular features of RNA silencing against the phloem-restricted polerovirus TuYV},
author = {Marion Clavel and Esther Lechner and Marco Incarbone and Timothée Vincent and Valerie Cognat and Ekaterina Smirnova and Maxime Lecorbeiller and Véronique Brault and Véronique Ziegler-Graff and Pascal Genschik},
doi = {10.1093/nar/gkab802},
issn = {1362-4962},
year = {2021},
date = {2021-11-01},
urldate = {2021-11-01},
journal = {Nucleic Acids Res},
volume = {49},
number = {19},
pages = {11274--11293},
abstract = {In plants and some animal lineages, RNA silencing is an efficient and adaptable defense mechanism against viruses. To counter it, viruses encode suppressor proteins that interfere with RNA silencing. Phloem-restricted viruses are spreading at an alarming rate and cause substantial reduction of crop yield, but how they interact with their hosts at the molecular level is still insufficiently understood. Here, we investigate the antiviral response against phloem-restricted turnip yellows virus (TuYV) in the model plant Arabidopsis thaliana. Using a combination of genetics, deep sequencing, and mechanical vasculature enrichment, we show that the main axis of silencing active against TuYV involves 22-nt vsiRNA production by DCL2, and their preferential loading into AGO1. Moreover, we identify vascular secondary siRNA produced from plant transcripts and initiated by DCL2-processed AGO1-loaded vsiRNA. Unexpectedly, and despite the viral encoded VSR P0 previously shown to mediate degradation of AGO proteins, vascular AGO1 undergoes specific post-translational stabilization during TuYV infection. Collectively, our work uncovers the complexity of antiviral RNA silencing against phloem-restricted TuYV and prompts a re-assessment of the role of its suppressor of silencing P0 during genuine infection.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In plants and some animal lineages, RNA silencing is an efficient and adaptable defense mechanism against viruses. To counter it, viruses encode suppressor proteins that interfere with RNA silencing. Phloem-restricted viruses are spreading at an alarming rate and cause substantial reduction of crop yield, but how they interact with their hosts at the molecular level is still insufficiently understood. Here, we investigate the antiviral response against phloem-restricted turnip yellows virus (TuYV) in the model plant Arabidopsis thaliana. Using a combination of genetics, deep sequencing, and mechanical vasculature enrichment, we show that the main axis of silencing active against TuYV involves 22-nt vsiRNA production by DCL2, and their preferential loading into AGO1. Moreover, we identify vascular secondary siRNA produced from plant transcripts and initiated by DCL2-processed AGO1-loaded vsiRNA. Unexpectedly, and despite the viral encoded VSR P0 previously shown to mediate degradation of AGO proteins, vascular AGO1 undergoes specific post-translational stabilization during TuYV infection. Collectively, our work uncovers the complexity of antiviral RNA silencing against phloem-restricted TuYV and prompts a re-assessment of the role of its suppressor of silencing P0 during genuine infection.
Incarbone, Marco; Clavel, Marion; Monsion, Baptiste; Kuhn, Lauriane; Scheer, Hélène; Vantard, Émilie; Poignavent, Vianney; Dunoyer, Patrice; Genschik, Pascal; Ritzenthaler, Christophe
Immunocapture of dsRNA-bound proteins provides insight into Tobacco rattle virus replication complexes and reveals Arabidopsis DRB2 to be a wide-spectrum antiviral effector Journal Article
In: Plant Cell, vol. 33, no. 11, pp. 3402–3420, 2021, ISSN: 1532-298X.
@article{pmid34436604,
title = {Immunocapture of dsRNA-bound proteins provides insight into Tobacco rattle virus replication complexes and reveals Arabidopsis DRB2 to be a wide-spectrum antiviral effector},
author = {Marco Incarbone and Marion Clavel and Baptiste Monsion and Lauriane Kuhn and Hélène Scheer and Émilie Vantard and Vianney Poignavent and Patrice Dunoyer and Pascal Genschik and Christophe Ritzenthaler},
doi = {10.1093/plcell/koab214},
issn = {1532-298X},
year = {2021},
date = {2021-11-01},
urldate = {2021-11-01},
journal = {Plant Cell},
volume = {33},
number = {11},
pages = {3402--3420},
abstract = {Plant RNA viruses form organized membrane-bound replication complexes to replicate their genomes. This process requires virus- and host-encoded proteins and leads to the production of double-stranded RNA (dsRNA) replication intermediates. Here, we describe the use of Arabidopsis thaliana expressing GFP-tagged dsRNA-binding protein (B2:GFP) to pull down dsRNA and associated proteins in planta upon infection with Tobacco rattle virus (TRV). Mass spectrometry analysis of the dsRNA-B2:GFP-bound proteins from infected plants revealed the presence of viral proteins and numerous host proteins. Among a selection of nine host candidate proteins, eight showed relocalization upon infection, and seven of these colocalized with B2-labeled TRV replication complexes. Infection of A. thaliana T-DNA mutant lines for eight such factors revealed that genetic knockout of dsRNA-BINDING PROTEIN 2 (DRB2) leads to increased TRV accumulation and DRB2 overexpression caused a decrease in the accumulation of four different plant RNA viruses, indicating that DRB2 has a potent and wide-ranging antiviral activity. We propose B2:GFP-mediated pull down of dsRNA to be a versatile method to explore virus replication complex proteomes and to discover key host virus replication factors. Given the universality of dsRNA, development of this tool holds great potential to investigate RNA viruses in other host organisms.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Plant RNA viruses form organized membrane-bound replication complexes to replicate their genomes. This process requires virus- and host-encoded proteins and leads to the production of double-stranded RNA (dsRNA) replication intermediates. Here, we describe the use of Arabidopsis thaliana expressing GFP-tagged dsRNA-binding protein (B2:GFP) to pull down dsRNA and associated proteins in planta upon infection with Tobacco rattle virus (TRV). Mass spectrometry analysis of the dsRNA-B2:GFP-bound proteins from infected plants revealed the presence of viral proteins and numerous host proteins. Among a selection of nine host candidate proteins, eight showed relocalization upon infection, and seven of these colocalized with B2-labeled TRV replication complexes. Infection of A. thaliana T-DNA mutant lines for eight such factors revealed that genetic knockout of dsRNA-BINDING PROTEIN 2 (DRB2) leads to increased TRV accumulation and DRB2 overexpression caused a decrease in the accumulation of four different plant RNA viruses, indicating that DRB2 has a potent and wide-ranging antiviral activity. We propose B2:GFP-mediated pull down of dsRNA to be a versatile method to explore virus replication complex proteomes and to discover key host virus replication factors. Given the universality of dsRNA, development of this tool holds great potential to investigate RNA viruses in other host organisms.