Microtubule-dependent regulation of chromatin dynamics by the Smc5/6 complex

Proper centromeres and pericentromeres folding is crucial for maintaining genome integrity and ensuring accurate chromosome segregation. Smc5/6 complex, which localizes at pericentromeres, can bind microtubules, yet its role in chromatin folding is unclear. Here, we investigate the functional relevance of Smc5/6 binding to microtubules in yeast using a separation-of-function mutant (smc5-2KE) that disrupt this interaction but leaves other biochemical activities of the complex intact. We demonstrate that Smc5/6 binding to microtubules constrains chromatin dynamics and regulates pericentromeric chromatin organization, as revealed by high-temporal-resolution imaging, polymer modelling, and in vitro approaches. Weakening of kinetochore activity in smc5 mutant cells leads to significant spindle defects and triggers the spindle checkpoint. Ultimately, the inability of Smc5/6 to associate effectively with microtubules and regulate pericentric chromatin compromise homologous recombination repair of DNA damage near centromeres. Overall, our findings indicate that Smc5/6 – microtubules association preserves pericentromeric chromatin architecture and genome stability during mitosis.