© Crédit Zhou Yi 2019

Arnaud HubstenbergerInstitut de biologie valrose (iBV) - CNRS / Inserm / Université Côte d'Azur

Multi-scale and multi-phase organization of the cytosolic transcriptome: structure and regulation during development and in response to the environment.

Mes recherches

I was trained as a molecular and cellular biologist at l’Ecole Normale Supérieure de Lyon and obtained my PhD from the University of Grenoble in 2006. I joined Thomas Evans team at the University of Colorado for my first post-doctorate, where I was among the very first to introduce the phase separations/transitions framework to study nucleic acid organization on a supramolecular scale in biological systems. Combining advanced imaging techniques with genetic screens, I uncovered that the material properties of RNA condensates are tightly regulated in the oocyte. During my second post-doctorate, in Dominique Weil’s team at l’Institut de Biologie Paris-Seine, I developed a cutting-edge purification method of RNA condensates and coupled this method to proteomic and transcriptomic analysis to uncover a higher scale of organisation and coordination of the transcriptome. I was subsequently recruited as a permanent CR1 researcher at CNRS in 2016, and created an ATIP-AVENIR team at the Institute of Biology Valrose, that is part of University Côte d’Azur. To further study the coordination and adaptation of RNA expression during development and in response to the environment, I currently dissect how RNA phase separations, RNA phase transitions, and RNA condensates structure the transcriptome on a supramolecular scale.

Mon projet ATIP-Avenir

Epi-transcriptomics : RNP multiscale organization, phase transitions, and the adaptive regulations of gene expression during early development.

Gene expression integrates developmental and environmental cues to define and adapt cell identity. Large coassemblies of nucleic acids and proteins are a common feature of gene expression pathways. Using C. elegans germline as a model, we previously showed that the material properties of cytosolic RNPs can switch states. Single RNP can further coassemble into liquid droplets or solid aggregates that can reach a few microns in size. These phase transitions coordinate the exchange of RNAs, their local concentrations, and their subcellular distributions. Currently we dissect how condensation buffers repressed mRNAs to promote robustness in translation control during development. In parallel, to uncover the quiescent potential of silent transcripts that accumulate in various RNP droplets, we took advantage of our recently validated method to purify RNP droplets, and identify changes in their composition and organization in response to developmental and environmental cues. In summary, using cutting edge multidisciplinary approaches, we will dissect the structural principles of RNP phase transitions, and test their functionality in adapting gene expression during development and in changing environments.