ABSTRACT
First Person is a series of interviews with the first authors of a selection of papers published in Journal of Cell Science, helping early-career researchers promote themselves alongside their papers. François Tyckaert is first author on ‘ Rac1, the actin cytoskeleton and microtubules are key players in clathrin-independent endophilin-A3-mediated endocytosis’, published in JCS. François conducted the research described in this article while a PhD student in Pierre Morsomme's lab at the Louvain Institute of Biomolecular Science and Technology (LIBST), UCLouvain, Louvain-la-Neuve, Belgium. He is now a postdoc in the lab of Henri-François Renard at Namur Research Institute for Life Sciences (NARILIS), UNamur, Namur, Belgium, investigating the regulation of unconventional endocytic mechanisms and their role in cellular physiology.
François Tyckaert
How would you explain the main findings of your paper in lay terms?
In mammalian cells, we studied the way a protein called CD166 is removed from the cell surface by a process termed ‘endocytosis’. CD166 is a kind of ‘Velcro’ that contributes to the adhesion of cells to each other, and it has been linked to cancer progression in numerous studies. Endocytosis is a fundamental mechanism that involves the inward deformation of the cell surface to engulf membrane components – such as CD166 – and extracellular material. We therefore believe that endocytosis can regulate the adhesive and migratory properties of cancer cells by regulating the abundance of CD166 exposed at their surface. In our study, we discovered new molecular components of the mechanism that drives CD166 endocytosis. First, we observed that the skeleton of the cell, composed of actin molecules, appears to assist the ‘banana-shaped’ protein endophilin-A3 in the formation of the membrane pits that engulf CD166. Secondly, we discovered that the protein Rac1 orchestrates the action of actin in this process. Finally, we observed that the release of vesicles containing CD166 inside the cell is assisted by another component of the cellular skeleton – the microtubules – and motor proteins called kinesins.
Were there any specific challenges associated with this project? If so, how did you overcome them?
Monitoring endocytosis of cell surface cargoes is not something trivial, as the experiments are often very sensitive to the slightest inconsistencies of the experimenter. This requires being extremely robust and constant when reproducing experiments. In addition, imaging vesicular trafficking events in live cells using microscopy also proved to be a challenge owing to their highly dynamic nature. This was overcome thanks to the use of bioimaging devices with high spatial and temporal resolution.
When doing the research, did you have a particular result or ‘eureka’ moment that has stuck with you?
Observing the importance of microtubules and kinesin-14 molecular motors in our mechanism was definitely a particular moment. Even if these data remain preliminary in the current study, they pave the way for exciting new research directions.
Why did you choose Journal of Cell Science for your paper?
Because Journal of Cell Science is renowned in the community for the quality of its publications in the field of cell biology. Journal of Cell Science also actively supports young scientists by highlighting their work.
Have you had any significant mentors who have helped you beyond supervision in the lab? How was their guidance special?
During my early scientific career, I had the opportunity to be directly trained and mentored by Professor Henri-François Renard, who shared with me his expertise in membrane trafficking and transmitted his passion for advanced microscopy approaches. At the time, he was a senior postdoc in Professor Pierre Morsomme's lab. I felt really privileged to be accompanied at the bench by someone so experienced and always available to give me advice.
What motivated you to pursue a career in science, and what have been the most interesting moments on the path that led you to where you are now?
My main motivation was the essence of science, which is all about discovery, and the excitement it generates in me. I find it fascinating that through ‘simple’ experiments, we can become the first witness of things never seen before. My stay at McGill University as part of the Erasmus Programme was a defining moment in my scientific journey. There, I had the opportunity to attend a course on cellular trafficking given by Professor Heidi McBride, which really resonated with me. This experience gave me my first real contact with the field of membrane trafficking and of endocytosis in particular.
Who are your role models in science? Why?
I don't have a unique role model. I am enthusiastic about the work and success of many recognized researchers in my field, such as Harvey McMahon, Emmanuel Boucrot and Ludger Johannes (whom I had the chance to count a member of my PhD thesis committee). Of course, these are just a few names in the field, and many more could be cited.
What's next for you?
My future is not written yet! I just defended my PhD a few weeks ago, and I am now actively working on what is next for me.
Tell us something interesting about yourself that wouldn't be on your CV
I am a self-taught guitar player who loves progressive metal. I'm also an active sport enthusiast – mainly football and hockey.
François Tyckaert's contact details: UNamur, Namur Research Institute for Life Sciences (NARILIS), Rue de Bruxelles 61, B-5000 Namur, Belgium.
E-mail: [email protected]
