Talin mEchaNosensitive phoSphoregulatION by CDK1

Descrizione del progetto

Regolazione dell’adesione meccano-chimica durante la divisione cellulare

Le adesioni focali sono grandi complessi multiproteici che ancorano le cellule alla matrice extracellulare e convertono le forze meccaniche in segnali biochimici, regolando processi cellulari di primaria importanza. Quando una cellula si divide, queste ancore devono disassemblarsi temporaneamente, secondo un processo precisamente programmato che, se gestito male, può causare errori nella separazione dei cromosomi; i meccanismi molecolari che coordinano la progressione del ciclo cellulare e le dinamiche di adesione, tuttavia, sono sconosciuti. Sostenuto dal programma di azioni Marie Skłodowska-Curie, il progetto TENSION mira a studiare una potenziale regolazione meccano-chimica dell’adesione mediante l’utilizzo di strumenti innovativi a singola molecola volti a monitorare le reazioni biochimiche sulle proteine sottoposte a forze meccaniche fisiologiche, realizzando scoperte che potrebbero rimodellare radicalmente la nostra comprensione in merito alle modalità con cui i segnali fisici e chimici cooperano per controllare i processi vitali fondamentali.

Obiettivo

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.