Chemical approaches for characterising and controlling physiological microtubule composition and dynamics

• Applicant: Dr. Oliver Thorn-Seshold
• Subject Area: Biological and Biomimetic Chemistry
• Term: since 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 400324123

Microtubules fulfil a range of critical biological roles especially in development, neuroscience, cell division and cancer. However, our understanding of these processes is limited, because there are no high-specificity tools to study the spatiotemporal orchestration of the microtubules themselves. My proposal will synthesise temporally-, spatially-, and biochemically-selective reagents to deliver such high-specificity studies of microtubule biology. We will install these three selectivity mechanisms over three project Objectives; though we can already apply the reagents from each stage to perform cutting-edge biological studies.In Objective 1, we synthesise compounds allowing temporally precise modulation of microtubule structure and dynamics within single selected cells. We especially synthesise optically controlled microtubule stabilisers and reagents for use in tissue or in vivo studies. In a key neuroscience application, we study whether and how axonal degeneration may be reversed by microtubule inhibition within the injured neuron: which offers exciting applications towards preventing neurodegeneration after trauma as well as from chronic diseases.In Objective 2, we develop tubulin-modifying reagents that convert the endogenous tubulin protein into a light-sensitive adduct. This will allow us to modulate microtubule structure and dynamics with subcellular spatial resolution, for studies of the distinct, spatially-organised roles of microtubules within live cells. With these reagents we will tackle outstanding questions about what the distinct subsets of microtubules are needed for during cell division.Tubulin isotypes are thought to "Code" microtubules for their diverse functions. However, without tools to study the isotypes, little is known: except that isotype patterns strongly correlate to chemotherapy side-effects as well as chemoresistance. In Objective 3, we will equip tubulin-modifying compounds with fluorescent tags and/or biochemically-specific reactive groups, to give reagents for isotype-selectively imaging and modulating tubulin dynamics in live cells. We will use these tools to study the spatiotemporal coordination of isotype dynamics during cell migration and cell division, processes with great significance for cancer therapy, hoping to identify crucial isotype roles which may be targets for therapeutic intervention.Taken together, the proposal will deliver a range of novel reagents that we will use to address significant questions in fundamental and applied cytoskeleton research. Our work will also advance the general development of chemical biology by showing the novel selectivities that chemical design can achieve. Lastly, our work will be of greatest impact by providing the missing tools for biology researchers to work towards a more general understanding of the physiology and pathology of the microtubule cytoskeleton.

• DFG Programme: Independent Junior Research Groups