The overall goal of this proposal was to understand the molecular mechanisms that allow the learning and memory processes. The neuronal communication (and its efficiency) is driven by plastic and specific connections between neurons, called synapses, which are finely refined by our cognitive experiences. At synapses, a neurotransmitter released from the pre-synaptic terminal activates post-synaptic receptors which will transduce their activation by initiating specific signaling pathways in the post-synaptic neuron. Receptors functions at synapses rely on their ability to engage in specific protein-protein interactions and to form complexes that are dynamically regulated by stimuli. Intracellular proteins (scaffolds) interact with receptors to control their specific sub-cellular targeting, allow receptor cell-surface expression, specify their cellular effectors and modify specific connections between neurons, enabling concerted activities of neuronal ensembles to trigger physiological functions. Thus understanding how proteins are activated as free molecules or part of complexes was an essential biological issue to offer new possibilities to target exclusively the therapeutically relevant signaling pathway of a given receptor.
1) We first developped technological approaches to follow protein-protein interaction dynamics and receptor signaling in cellulo and and in vivo. These developments encompase new imaging technologies (1, 2, 5, 6, 7), biosensors engineering to report signaling pathways involved in plasiticty, like mTOR, ERK, or MMP9 activation (1, 9, 10, 13), protocols to follow signalings from neuronal ensembles in vitro and in vivo (6, 7, 11), and molecular tools to constrain protein-protein interaction dynamics and neuronal signalings (3, 8, 12, 14).
2) We used these state-of-the-art technologies to identify functional consequences of protein-protein interactions dynamics in physiological conditions and deficiencies in mouse models of neurological disorders. Briefly, we found the importance of protein-protein interaction dynamics in the receptor trafficking to a specific subcellular compartment of the neuron (12), specific cellular signaling (1, 3, 9, 10), structural (4) and functional (3, 14) neuronal plasticty. Besides, we identified and repaired protein-protein interaction deficiencies in mouse models of L-Dopa-induced dyskinesia (8) and autisum spectrum disorders (14), which improved related cognitive behaviors.
3) Finally, we identified new receptors associated proteins involved in neuronal plasticity and memory deficiencies (4), a screening that defines new therapeutic target opportunities for future studies.
1- Fast and high resolution single-cell BRET imaging
2- Agonist-Specific Recruitment of Arrestin Isoforms Differentially Modify Delta Opioid Receptor Function
3- Elevated CaMKIIα and Hyperphosphorylation of Homer Mediate Circuit Dysfunction in a Fragile X Syndrome Mouse Model
4- Cell Type-Specific mRNA Dysregulation in Hippocampal CA1 Pyramidal Neurons of the Fragile X Syndrome Mouse Model
5- Fluorescent-Based Strategies to Investigate G Protein-Coupled Receptors: Evolution of the Techniques to a Better Understanding
6- Image Processing for Bioluminescence Resonance Energy Transfer Measurement—BRET-Analyzer
7- Fast confocal fluorescence imaging in freely behaving mice
8- D1-mGlu5 heteromers mediate noncanonical dopamine signaling in Parkinson’s disease
9- AIMTOR, a BRET biosensor for live imaging, reveals subcellular mTOR signaling and dysfunctions
10- Gelatinase Biosensor Reports Cellular Remodeling During Epileptogenesis
11- Procedures for Culturing and Genetically Manipulating Murine Hippocampal Postnatal Neurons
12- SNAP23–Kif5 complex controls mGlu1 receptor trafficking
13- AIMTOR, a BRET Biosensor for Live Recording of mTOR Activity in Cell Populations and Single Cells
14- Restoring glutamate receptosome dynamics at synapses rescues autism-like deficits in Shank3-deficient mice
