KinCond · Mechanism of protein kinases in biomolecular condensates

Protein phosphorylation, mediated by kinases, plays a pivotal role in cellular regulation, with kinase dysregulation strongly associated with diseases like cancer, inflammation, and neurodegenerative disorders. Alzheimer's disease (AD) represents a significant global health challenge as the population ages at an accelerating pace. A key pathological feature of AD is the accumulation of hyperphosphorylated Tau, which disrupts normal neuronal function. Emerging evidence suggests that Tau undergoes liquid-liquid phase separation (LLPS), potentially linking AD and biomolecular condensation. Moreover, recent findings propose that LLPS intricately manages kinase signalling, creating condensed-phase structures (biomolecular condensates) that serve as recognizable sites for kinases. However, molecular mechanisms governing kinase behaviour within condensates are poorly understood. The central hypothesis of KinCond project is that the conformational landscape of protein kinases undergoes significant remodelling within biomolecular condensates, controlling substrate selectivity and specificity. This project focuses on the microtubule affinity-regulating kinase MARK2, a central player in the abnormal phosphorylation of Tau. KinCond is meticulously structured into three work packages: (1) investigating the specificity and reaction kinetics of MARK2 within Tau condensates, (2) deciphering the conformational landscape of MARK2 through advanced nuclear magnetic resonance methods and molecular dynamics simulations and (3) analyse the effect of biomolecular condensation on the conformational landscape of MARK2. The outcomes of KinCond are expected to provide crucial insights into the behaviour of protein kinases within biomolecular condensates, shedding much-needed light on the mechanisms of Tau phosphorylation in AD. Furthermore, the atomic-detail information obtained has the potential to open new avenues for the development of enhanced drugs targeting protein kinases.