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What is your research topic?

My research team has been studying ubiquitination processes and their implications for the regulation of protein activity for several years now. Adding a small label called ubiquitin to some cell membrane proteins changes their function or fate in the cell. Although these functions are conserved in most eukaryotes, the ubiquitination machinery has strongly diverged in higher plants. Using plants as a model thus allows us not only to better understand the basics of ubiquitination, but also to understand its functional importance in a multicellular organism. Our work has highlighted the major role of ubiquitin in endocytosis and vacuolar degradation of cell surface proteins, such as hormone receptors or nutrient transporters.

One of our particularities is to study these mechanisms from the molecular scale to that of the whole plant. We have shown that a lack of ubiquitination has a very important impact on the growth, development and ability of plants to cope with  environmental constraints. The study of the role of ubiquitin on the dynamics of plant membrane proteins requires intensive use of imaging, including high resolution imaging, as well as proteomics, biochemistry and molecular biology.

Why move your team within TULIP and the LRSV?

The processes we are studying are conserved in animals, even though the cellular machinery involved is relatively different. This probably explains why I mainly worked in general institutes (Salk Institute - San Diego, Institute of Integrative Cell Biology - Gif / Yvette) where different models such as yeast, Caenorhabditis elegans, Drosophila melanogaster or human cells are used. Although very rewarding, these experiences isolated me from the plant world. Joining the LRSV and TULIP will allow me to get closer to the French "vegetalist" community and benefit from scientific interactions with my neighbors. The strong involvement of the LRSV in the training of students interested in plant biology will also allow me to be more visible and attractive. Finally, the scientific context of TULIP offers me the opportunity to study the evolutionary aspects of ubiquitination, both on the machinery and the molecular mechanisms using this post-translational modification.

How did the TULIP package get you to come and how does it help you settle down?

Moving a research team is a logistically complicated and risky adventure for non-permanent staff. In my case, it is more likestarting a new team, since several permanent staff of my team do not have the opportunity to join me in this adventure. The support from TULIP was therefore a determining factor in my decision. The TULIP package indeed offers the possibility of making the team quickly functional while waiting for the transfer of my current research contracts. This is crucial that PhD students moving to Toulouse are not penalized and can focus on their research. In addition, the TULIP package is an excellent way to quickly strengthen the team by recruiting qualified staff over several years.

What are your future projects?

Except from continuing our current projects on ubiquitin-mediated endocytosis, I want to study new cell functions that require a particular type of ubiquitin and have not yet been identified in other model organisms. We have developed a sensor that allows us to follow this type of ubiquitin at the cellular and biochemical levels. These approaches have revealed an implication in translation, metabolism, and many other functions. Now, the goal is to identify the most promising functions for the future... This type of project is very risky and cannot be conceived in the current scheme of funding research by the ANR. The TULIP package is therefore an excellent opportunity to explore these new domains that I hope will turn into a niche.