- 6 January 2021
Group leader: Patrick Moreau, research director CNRS
Post-doctoral CNRS-NSF fellow 1989-1990 (Pr. D.J. Morré, Purdue Univ., Indiana, USA)
CR1-CNRS 1990 / HDR 1992 (Univ. Bordeaux 2)
Vice-President SFBV (2001-2003) and President SFBV (2003-2005)
Deputy Dir. of BIC (Bordeaux Imaging Center, UMS 3420 CNRS/ Univ. Bordeaux since 2009
Director of the “Fédération des Plateformes labellisées d’UB”
V. Wattelet-Boyer (IE), M. Le Guedard (IR),Y. Boutté (CR), L. Maneta-Peyret (Pr), E. Testet (MCF), M. Hooks (PR), JJ. Bessoule (DR), C. Rocher (IE).
The endomembrane system is responsible for the synthesis, modification, sorting and targeting of complex molecules (proteins, lipids and polysaccharides) of the cell surface but also of the vacuolar system or the protein and lipid bodies of the plant cells. Some of these molecules can be of great economic importance. For example, the most important source of food proteins comes from the storage vacuoles of plants, reserve lipids are at the origin of oils and of many molecules of industrial interest. Investigating the dynamics of the endomembrane system and the transport machineries involved is essential for understanding the functioning of the secretory pathway of plant cells and its role in some physiological functions.
The main objectives are: 1. To identify the lipids and enzymes of lipid metabolism which are “critical molecular actors” in the function of the secretory pathway, 2. To identify and determine the role of certain proteins (SNAREs, Phytolongines) in this pathway.
Lysophosphatidic acid acyltransférases and endomembrane dynamics
Group members: Valérie Wattelet-Boyer (IE), Marina Le Guedard (IR),Yohann Boutté (CR), Lilly Maneta-Peyret (Pr), Jean-Jacques Bessoule (DR).
Lipids have long been regarded only as “constituent bricks” of membranes but they are increasingly involved in signaling pathways and as key molecular actors of the mechanisms governing membrane dynamics in the secretory pathway. We have shown that blocking the synthesis of phytosterols leads to an accumulation of microdomains at the Golgi level (Laloi et al., 2007, Plant Physiol., 143:461-472), similarly an inhibition of sphingolipid synthesis affects post-Golgi intracellular trafficking (Melser et al., 2010, Traffic 11:479-490, Wattelet-Boyer et al., 2016, Nat Commun 7:12788). The aim of this project is to determine the potential roles of “lysophosphatidic acid acyltransferases” in intracellular trafficking in plants. Brown et al. (2008, Traffic, 9:786-797) have revealed that inhibition of such enzymes may block a late stage of COPII vesicle formation, probably their fission from ER export sites. The underlying hypothesis is that these “lysophosphatidic acid acyltransferases” could participate with phospholipases in the regulation of membrane curvature in relation to the events of emission and fusion of the transport vesicles (Fig.1, Boutté and Moreau 2014 , Curr. Op. Plant Biol., 22:22-29).
Fig.1: Lands cycle and related enzymes: a link with COP vesicle formation and fusion?
Several candidate genes of these “lysophosphatidic acid acyltransferases” have been identified. The project focuses on the following aspects: characterization of the acyltransferase activities of the corresponding proteins, mutagenesis of membrane targeting domains and active sites by analogy with other proteins of this family to link subcellular localization and function, and phenotypic analysis of mutants of the corresponding genes.
Role of a new family of proteins close to SNAREs named Phytolongins in the organisation and dynamics of the secretory pathway
collaborations: Dr Carine de Marcos Lousa (Univ. Leeds Beckett), Pr Francesco Filippini (Univ. Padova)
The growing importance of SNAREs and other proteins containing a longin domain in the regulation of the vesicular traffic has led us to search for new proteins in Arabidopsis thaliana. We have identified a new family of proteins called phytolongins (Phyl, Vedovato et al., 2009, Moreau et al., UMR5200) to account for their N-ter domain close to those of the SNAREs YKT6, Sec22 and VAMP7. These new proteins containing a longin domain are not SNAREs because they are characterized by the absence of a SNARE domain (Fig.2, orange), and may be called “non-SNARE longins”. In these phytolongins, the SNARE domain is replaced by a “PhyL domain” (in green) with an unknown function (Fig.2).
Lipid metabolism in Trypanosomes: identification of new metabolic pathways specific to the parasite.
ANR projects Acetotryp 2011-2015 and Glyconov 2016-2020 and ANR AdipoTryp 2021-2024 (directed by Dr F. Bringaud, UMR CNRS 5234)
People involved: Laetitia Fouillen (IR), Lilly Maneta-Peyret (PR)
The aim is to obtain a complete understanding of the lipid metabolic pathways in the procyclic as well as in the bloodstream forms of T. brucei (protozoan parasite responsible for sleeping sickness), by analyzing KO mutants affected in key steps of this metabolism. The metabolic effects of the introduced modifications are studied using qualitative and quantitative metabolomics (radioactive labels, lipidomics, NMR and mass spectrometry, analysis / modeling of metabolic pathways). By specifying the nature of lipid metabolism in the procyclic and bloodstream forms of trypanosomes, the objective is also to be able to identify specific targets of these organisms for therapeutic developments. (Millerioux et al., 2012, J. Biol. Chem. 21:17186-17197; Millerioux et al., 2013, Mol Microbiol. 90:114-129; Mazet et al., 2013, PLOS Neglected Tropical Diseases, 7:e258; Allmann et al., 2014, PLoS ONE 9:e114628; Harijan et al., 2016, Proteins, 84:1075-1096).Sélection d’articles:
de Marcos Lousa C, Soubeyrand E, Bolognese P, Wattelet-Boyer V, Bouyssou G, Marais C, Boutté Y, Filippini F, MoreauP. (2016). Subcellular localization and trafficking of phytolongins (non-SNARE longins) in the plant secretory pathway. J Exp Bot. 67:2627-2639.
Platre MP, Noack LC, Doumane M, Bayle V, Simon MLA, Maneta-Peyret L, Fouillen L, Stanislas T, Armengot L, PejcharP, Caillaud MC, Potocký M, Čopič A, Moreau P, Jaillais Y (2018). A combinatorial lipid code shapes the electrostatic landscape of plant endomembranes. Dev. Cell, 45(4):465-480.e11. doi: 10.1016/j.devcel.2018.04.011.
Millerioux Y, Mazet M, Bouyssou G, Allmann S, Kiema TR, Bertiaux E, Fouillen L, Thapa C, Biran M, Plazolles N, Dittrich-Domergue F, Crouzols A, Wierenga RK, Rotureau B, Moreau P, Bringaud F. (2018). De novo biosynthesis of sterols and fatty acids in the Trypanosoma brucei procyclic form: Carbon source preferences and metabolic flux redistributions. PLoS Pathog. 14(5): e1007116. doi: 10.1371/journal.ppat.1007116.
Platre MP, Bayle V, Armengot L, Bareille J, Marques-Bueno M, Creff A, Maneta-Peyret L, Fiche JB, Nolmann M, Miège C, Moreau P, Martinière A and Jaillais Y. (2019). In vivo phosphatidylserine variations steer Rho GTPase signaling in a cell-context dependent manner. Science, 364: 57-62.
Ito Y, Esnay N, Platre MP, Noack LC, Menzel W, Claverol S, Moreau P, Jaillais Y and Boutté Y. (2021). Sphingolipids mediate polar sorting of PIN2 through phosphoinositide consumption at the trans-Golgi Network. Nat Commun.12(1):4267.
Wattelet-Boyer, Le Guédard M, Dittrich-Domergue F, Maneta-Peyret L, Kriechbaumer V, Boutté Y, Bessoule JJ and Moreau P. (2021). Phosphatidic acid synthesis by Lyso-Phosphatidic Acid Acyl-Transferases: Impact on intracellular protein transport in Arabidopsis thaliana root cells. J. Exp. Bot., doi: 10.1093/jxb/erab504.
- Pr Batoko H., University of Louvain, Belgium
- Dr De Marcos Lousa C., University of Leeds Beckett, UK
- Pr Filippini F., University of Padova, Italy
- Pr V. Kriechbaumer, Research School of Biological and Molecular Sciences, Oxford Brookes University, UK
- Pr Moscatelli A., University of Milan, Italy
- Dr Bringaud F., UMR 5536 CNRS-Université Bordeaux
- Dr Chatre L., Institut Pasteur-UMR 3525 CNRS, Paris
- Dr Jaillais Y., ENS Lyon, Université Lyon
- Dr Martinière A. BPMP, CNRS-INRAe-Université Montpellier
- Dr Richchetti M., Institut Pasteur-UMR 3525 CNRS, Paris
- Dr Rotureau B, Institut Pasteur-INSERM U120, Paris