Talin mEchaNosensitive phoSphoregulatION by CDK1

Description du projet

Régulation mécanochimique de l’adhésion pendant la division cellulaire

Les adhérences focales sont de grands complexes multiprotéiques qui ancrent les cellules à la matrice extracellulaire et convertissent les forces mécaniques en signaux biochimiques, régulant ainsi des processus cellulaires clés. Lorsqu’une cellule se divise, ces points d’ancrage doivent se désassembler temporairement selon un processus précisément synchronisé qui, s’il est mal exécuté, peut entraîner des erreurs de séparation des chromosomes. Les mécanismes moléculaires qui coordonnent la progression du cycle cellulaire et la dynamique de l’adhésion restent inconnus. Avec le soutien du programme Actions Marie Skłodowska-Curie, le projet TENSION vise à étudier une possible régulation mécanochimique de l’adhésion au moyen d’outils révolutionnaires à molécule unique permettant de suivre les réactions biochimiques sur des protéines soumises à des forces mécaniques physiologiques. Les résultats pourraient remodeler en profondeur notre compréhension de la manière dont les signaux physiques et chimiques coopèrent pour contrôler les processus fondamentaux du vivant.

Objectif

Mechanical forces are increasingly recognized as key regulators of cell behavior, acting alongside traditional chemical and electrical cues. These forces are detected at focal adhesions (FAs), large multiprotein complexes thar convert physical stimuli into biochemical signals that control key cellular processes. During mitotic entry, however, FAs must disassemble to ensure correct chromosome segregation, suggesting a tightly regulated interplay between adhesion dynamics and cell cycle progression. Yet, the molecular mechanisms underpinning this crosstalk remain unknown. Talin is the core mechanosensitive protein in FAs, directly linking integrins to actin and recruiting binding partners in a force-dependent manner. Preliminary data and recent literature indicate that CDK1, the master cell-cycle kinase, interacts with talin domains to potentially phosphorylate them, hinting at a previously unrecognized mechanochemical pathway for adhesion regulation. However, how mechanical forces regulate chemical reactivity to govern mechanotransduction processes remains poorly understood. This owes mainly to experimental limitations in the study of the biochemistry of mechanically stretched proteins. Leveraging on novel single-molecule technology developed by the host lab, I aim to characterize how CDK1 interacts and phosphorylates talin domains under physiological forces to regulate its function in FAs. This novel enabling methodology will allow me to directly monitor binding and enzymatic reactions and characterize their mechanical regulation. By integrating these single-molecule data with novel protein biochemistry methods and cellular models, I will establish a cross-scale understanding of how CDK1-mediated talin phosphorylation regulates FA remodeling across the cell cycle. The results of the project will provide a new mechanochemical framework for adhesion regulation and establish a broadly applicable toolkit for studying the chemical regulation of mechanosensitive proteins.