STAGE Structural analysis of the mechanism of interaction of strigolactones and non-cleavable strigolactone mimics with their PsD14/RMS3 receptor

Date de mise à jour de l’offre

INRAE (INSTITUT NATIONAL DE RECHERCHE POUR L’AGRICULTURE, L’ALIMENTATION ET L’ENVIRONNEMENT) :

Le stage se déroulera à l'Institut Jean-Pierre Bourgin (IJPB), une unité mixte de recherche (UMR1318) sous la tutelle conjointe INRAE et AgroParisTech et appartenant à l’Université Paris-Saclay. L'IJPB est également membre fondateur de l’Ecole Universitaire de Recherche (EUR) Saclay Plant Sciences (SPS). L’IJPB est un des plus grands centres de recherche européens dans le domaine de la biologie des plantes. Il regroupe un ensemble de ressources et de compétences pluridisciplinaires en biologie, chimie et mathématiques uniques en France. Notre but : développer une recherche pluridisciplinaire sur le végétal pour produire des connaissances fondamentales en biologie, les inscrire dans un processus d’innovation et répondre ainsi aux défis scientifiques et sociétaux à venir.

Description de la mission

Strigolactones (SLs) are a family of small molecules derived from carotenoids that constitute the latest class of hormones identified in plants controlling their aerial and root architecture and that are also known for their function in the rhizosphere during symbiotic and parasitic interactions 1,2. SLs are therefore key molecules that are essential for the development of agroecology and for changing the model of agriculture. The study of SLs (biosynthetic pathway, signaling pathway, mode of action) has potential repercussions not only on the yield of cultivated species but also on plant nutrition (mainly phosphate), water stress or tolerance to root parasitic plants. The characterization of the SL receptor remains a major challenge even though significant progress has been made in understanding the receptor and the signaling pathway. We have been studying these molecules for several years and have highlighted their receptor in pea with an original mode of action for a plant hormone 3. This one is an α/β-hydrolase (Dwarf14 = D14) with retained enzymatic activity. SLs comprise a tricyclic system or more complex system linked to a butenolide. In the mechanism of perception of SLs, their D14 receptor generates an enzymatic reaction to produce its own covalent ligand.
This project is a continuation of different studies conducted since 2016, whether still on the PsD14 receptor or also on the SL receptor of parasitic plants 3-5. The objective is to better understand the interaction of SLs with PsD14 and how a class of SL mimics that is not cleaved by PsD14 is able to interact with the protein to enable biological activity, with, as for SLs, an inhibition of pea axillary bud growth. Until now, no SL receptor has been studied by NMR, this work will allow to understand more precisely the mechanism of SL perception which is still controversial. This project is in the context of Plant Sciences and benefits from a interaction between CNRS-ICSN (Carine van Heijenoort, Nelly Morellet, François-Didier Boyer, Gif sur Yvette) and INRAE-Institut Jean-Pierre Bourgin (Catherine Rameau, Alexandre de Saint Germain, Versailles) federating plant biologists, structural biologists, biochemists and organic chemists. It is a new collaboration between NMR group at ICSN and Strigolactones and Allelochemicals Signaling at IJPB.

Profil recherché

Currently, we have mastered in the laboratory the conditions of expression of PsD14/RMS3 in quantities compatible with an NMR study and we have already been able to record STD spectra showing the interaction between a non-cleavable mimic and PsD14 and obtain 2D spectra of PsD14 alone. The internship project will address the following questions: 1- Production of the 13C/15N/D labeled PsD14/RMS3 protein for NMR study to gain sensitivity 2- NMR assignment of the different amino acids of the PsD14/RMS3 protein with particularly those of the active site (catalytic triad Ser96, His247, Asp218) 3- Study of the interaction between PsD14/RMS3 with biologically active ligands not cleaved by the protein 4- Comparison of the interaction between PsD14/RMS3 and SL with that of the receptor and the non-cleavable mimic.

Niveau de qualification requis

Bac + 4/5 et +
  • Employeur
    INRAE (INSTITUT NATIONAL DE RECHERCHE POUR L’AGRICULTURE, L’ALIMENTATION ET L’ENVIRONNEMENT)
  • Secteur d’activité de la structure
    Enseignement - Formation - Recherche
  • Effectif de la structure
    Plus de 250 salariés
  • Site internet de la structure
    https://ijpb.versailles.inrae.fr
  • Type de stage ou contrat
    Stage pour lycéens et étudiants en formation initiale
  • Date prévisionnelle de démarrage
  • Durée du stage ou contrat
    Plus de 4 mois et jusqu'à 6 mois
  • Le stage est-il rémunéré ?
    Oui
  • Niveau de qualification requis

    Bac + 4/5 et +
  • Lieu du stage
    inrae
    RD 10- Route de Saint Cyr
    78000 VERSAILLES
  • Accès et transports
    Accès facile par la Gare de Versailles Chantier ou Versailles Château Rive-Gauche puis Bus (lignes 11, 40, 401, 44,) arrêt INRA Ou Gare de Saint-Cyr l’Ecole puis 15 min de marche jusqu’au centre INRAE