Dissecting structural and functional determinants of microtubule stabilization through guided chemical modulation

Abstract

Paclitaxel (PTX) is a widely used chemotherapeutic, but its efficacy is limited by peripheral neuropathy, likely due to its structural impact on neuronal microtubules (MTs). To decouple MT stabilization from adverse structural changes, we designed, synthetized and characterized several PTX analogues. Our compound 1b retains PTXs stabilizing activity in vitro and in cells, and the 1b-bound MTs preserve a native-like structure. These facts allowed us to investigate the influence of specific MT structural features on motor proteins behavior and interaction with MT-associated protein Tau. PTX-induced lattice expansion disrupted dynein-mediated retrograde transport and altered kinesin-1 motility. Additionally, PTX reduced Taus initial non-cooperative binding and envelopes growth rate while increasing dwell time and suppressing dynamic binding. In contrast, 1b preserved more physiological Tau dynamics. These findings reveal that MT stabilization and structural modulation can be separated and highlight the functional importance of MT heterogeneity in maintaining neuronal transport and MAP interactions.