Toxic effects of zinc ions on kinesin - Potential molecular cause of impaired intracellular transport

- Zinc ions are able to inhibit kinesin ATPase and kinesin-based motility generation.
- Zinc-induced inhibition depends on the zinc/magnesium ion ratio.
- Zinc-induced inhibition depends on temperature.
- Zinc-induced inhibition might be one molecular cause of impaired intracellular transport.

In healthy organisms the metabolism of the trace element zinc is well balanced. If this balance becomes destroyed the free zinc level might increase and cause toxic effects. The present study demonstrates that under definite conditions zinc ions are able to inhibit the ATPase activity of neuron-specific KIF5A (kinesin-1). Correspondingly, the motility activity of KIF5A also decreased. The inhibition rates have been found to depend on the magnesium ion concentration. Lowering the magnesium concentration weakens the inhibition. In addition, also decreases of temperature or increasing the ATP concentration result in reduced inhibition. Zinc ion-mediated inhibition of KIF5A activity might be one molecular cause contributing to impaired transport processes within brain and other organs in cases of zinc dyshomeostasis.

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