Intracellular accumulation of S-methyl DM1 in cells via its low-affinity interaction tubulin.

The large number of intracellular tubulin molecules leads to accumulation of S-methyl DM1 inside cells at low external concentrations. S-methyl DM1 loosely associated with tubulin is available for binding to the tips of mitotic spindle microtubules, which leads to suppression of their dynamic instability, interfering with faithful chromosome segregation during mitosis. This in turn induces cell cycle arrest and subsequent cell death.