Description du sujet de thèse

Towards a quantitative description of GPCR heretodimer structural dynamics using single molecule FRET.

Contexte de travail

We have an opening for a fully funded PhD student position at the edge of Biophysics and Structural Biology, based in the “Integrative Biophysics of Membranes” group at “Center for Structural Biology (CBS) in Montpellier, France. Our group investigates the molecular mechanisms of G protein-coupled receptor (GPCR) activation and signal transduction, with a focus on how ligands and transducers shape their conformational landscape and dynamics.

Project Overview
GPCRs are central to cell signaling and represent major drug targets. While static structures have revealed high-resolution snapshots of the major inactive and active conformational states, the dynamic structural transitions underlying activation, especially those triggered by different classes of ligands and transducers, remain poorly understood. This PhD project aims to unravel the equilibrium and activation kinetics of selected GPCR heterodimers by combining single-molecule Förster Resonance Energy Transfer (smFRET) with fast microfluidic mixing.
Why smFRET?
Unlike ensemble-averaged techniques such as cryo-EM or X-ray crystallography, smFRET provides real-time, molecule-by-molecule insight into protein conformational landscapes. This technique allows us to directly monitor the dynamics and transitions between multiple functional states of GPCRs, even when they are transient or sparsely populated. Moreover, combined with rapid microfluidic mixing, smFRET can provide information on the conformational changes directly related to ligand activation in a quantitative manner through sub-nanometer structural and sub-millisecond dynamics information. This bears great potential to provide insights into the initial step of their signaling mechanisms, which is invisible to traditional structural methods.

Your Role
• Design, construct, express and purify GPCR mutants from mammalian cells for site-specific labeling using unnatural amino acids and biorthogonal chemistries based on protocols established in our lab
• Design, fabricate and implement microfluidic devices for rapid mixing
• Carry out single-molecule FRET experiments at equilibrium and upon rapid mixing
• Derive inter-probe distances and conformational dynamics in a quantitative manner
• Collaborate with team members with complementary expertise in biochemistry, biophysics, nanotechnology and structural biology

Candidate Profile
• Candidates should hold a master's degree in Biophysics or Quantitative Biology, however a degree in Structural Biology, Biochemistry, or related fields demonstrating a solid understanding of biophysics may be considered
• Experience in fluorescence microscopy/spectroscopy, preferably single molecule techniques
• Basic prior experience in molecular biology and protein expression (mammalian systems preferred)
• Basic knowledge in coding and structural modeling/dynamics simulations is a plus
• Strong interest in membrane protein structure-function relationships
• Proficient in spoken and written English

We Offer
• A collaborative, interdisciplinary, and supportive research environment
• Joint supervision by E Margeat (Biophysicist) and RB Quast (Biochemist)
• Access to cutting-edge facilities for single-molecule fluorescence and membrane protein biochemistry
• Mentoring and career development opportunities
• Funding for 3 years (with possibility to apply for a 4th year funding)
• Opportunities to present at international conferences

Contraintes et risques

Please submit the following as a single PDF:
• Cover letter detailing your motivation and research interests
• CV including academic history, grades and any research experience
• Names and contact information for at least 2 academic referees
• A copy of your MSc thesis or any publications