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bioRxiv · 10.1101/2025.07.22.666027

Human ribosome interactions reframe neomycin toxicity

Zhang, X.·Zhu, L.·Jia, C.·Wu, K.·Bai, Y.·Sun, S.·Zhang, Z.·Guo, L.·Hou, X.·Wu, M.·Amunts, A.·Li, W.
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Abstract

Aminoglycosides such as neomycin are clinically limited by toxicity, commonly attributed to the inhibition of mitoribosomes. Here, we re-evaluate this mechanism by integrating Cryo-EM and functional assays to assess neomycins binding potential in vitro with its cellular engagement and functional consequences. Cryo-EM revealed extensive multi-site binding of neomycin on both human mitochondrial and cytosolic ribosomes in vitro, including conserved regions of the decoding center. In contrast, ribosomes isolated from neomycin-treated cells show markedly remodeled occupancy patterns, with no detectable neomycin bound to the mitoribosomes and reduced occupancy at a subset of cytosolic ribosome sites. However, neomycin remained functionally active in cells, inducing widespread stop-codon readthrough while having minimal effects on global mitochondrial and cytosolic protein synthesis. These findings reveal a disconnect between structural binding potential and cellular target engagement and identify disruption of translational fidelity, rather than global translational inhibition, as a major cellular consequence of neomycin exposure.

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Zhang, X., Zhu, L., Jia, C., Wu, K., Bai, Y., Sun, S., Zhang, Z., Guo, L., Hou, X., Wu, M., Amunts, A., Li, W.. 2025-07-26. Human ribosome interactions reframe neomycin toxicity. https://doi.org/10.1101/2025.07.22.666027

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