Laemmli Prize 2024 shared by Arthur RADOUX and Vincent LOUVEL

Arthur did his PhD in the lab of Miriam Stoeber working on G protein-coupled receptor (GPCR) trafficking and signaling. Whereas it was known that the opioid receptors could localize both to the Golgi Apparatus and the plasma membrane, the differences in signaling upon activation of these receptors at these two locations remained unclear. Arthur discovered that the same receptor, when activated at the plasma membrane or the Golgi apparatus, triggers strikingly different signaling outcomes, including distinct transducer recruitment and differential modulation of gene expression. Using an unbiased high-throughput imaging assay, he also profiled the localization profile of > 120 GPCRs, revealing the intracellular location of several receptors. Additionally, he also described a novel interaction mode between GPCRs and the transducers β-arrestins, which refined our knowledge of the regulation of GPCR endocytosis.

Arthur Radoux-Mergault defended his thesis [1] in Molecular Biosciences in April 2024 and is currently a postdoctoral fellow in Buzz Baum's lab at MRC-LMB (Cambridge, UK). Arthur said “I am honoured to have been awarded the Laemmli prize for my thesis. As scientific research is rarely the work of one, I am grateful to all the members of Prof. Stoeber’s lab for their guidance and support during my PhD. This recognition strengthens my motivation to continue exploring the exciting path of scientific research.”

Vincent did his PhD in the laboratory of Pr. Paul Guichard and Dr. Virginie Hamel . Vincent’s doctoral thesis [2] focused on the development of innovative tools for fluorescence microscopy, on the principle of expansion microscopy and the development of a new expansion microscopy protocol called iU-ExM. This protocol allows to expand biological sample up to 26 times, artificially reducing the resolution of common fluorescence microscope from 200 to 10-20 nm. His work addressed unresolved biological questions with the discovery to the nanoscale localization of proteins in the infectious organelle of Toxoplasma gondii or in the connecting cilium of mouse retina, helping to understand retinopathies. Without investing into new costly microscopes, scientists have now an easy and reliable tool to perform new biological discoveries.

The Laemmli Prize is awarded in honor of Ulrich Laemmli, for an exceptional thesis in Life Sciences in a field related to molecular biology. The prize of 6’000 CHF is generously sponsored by the royalties of a patent endowed to Ulrich Laemmli’s former departments at UNIGE.

1. RADOUX-MERGAULT, Arthur. GPCR localization and signaling at distinct subcellular sites. Doctoral Thesis, 2024. doi: 10.13097/archive-ouverte/unige:179736

2. LOUVEL, Vincent et al. iU-ExM: nanoscopy of organelles and tissues with iterative ultrastructure expansion microscopy. In: Nature communications, 2023, vol. 14, n° 1, p. 7893. doi: 10.1038/s41467-023-43582-8