Description du sujet de thèse

Summary: Intracellular signaling pathways are controlled by chemical signals, but physical signals have recently emerged as important regulators of signal transduction. Currently, our understanding of the molecular events that connect changes in membrane electrical potential (Vm) to signaling pathways in non-excitable cells is limited. Our preliminary results demonstrate that the Wnt/β-catenin signaling pathway is activated during membrane depolarization. However, how this change in Vm contributes to the activation of the Wnt/β-catenin signaling remains unknown.
In this project, we aim to address this question at the molecular, cellular, and multicellular levels by investigating the following issues. (1) What is the molecular mechanism that establishes the link between membrane depolarization and the activation of the Wnt/β-catenin signaling? (2) What are the molecular effectors responsible for the depolarization-induced activation of the Wnt pathway? (3) How does a change in membrane potential (Vm) influence the regulation of Wnt pathway activity? To answer these questions, we will combine various approaches, including biochemistry, cell biology, optogenetics, and electrophysiology.
To understand the effects of Wnt/β-catenin signaling activation associated with membrane depolarization, we will use colon-derived organoids. These results will shed light on a novel regulatory mechanism of Wnt signaling in non-excitable cells, thereby enhancing our understanding of the involvement of this signaling pathway in epithelial physiology and associated pathologies.
Selected Publications:
Rapetti-Mauss et al. PNAS 2017
Rapetti-Mauss et al. Gut 2023
Berenguier et al. Oncogene 2025

Contexte de travail

The successful candidate will work under the guidance of Dr. Raphael Rapetti-Mauss at the Institute of Biology Valrose (iBV) in Nice. iBV is a dynamic and multidisciplinary research center located on the French Riviera, with over 200 researchers across 27 groups.