In May 2023, Christina Vizcarra, assistant professor of chemistry, will publish new research in the Journal of Inorganic Biochemistry, alongside several colleagues, including Rachel Narehood Austin, Diana T. and P. Roy Vagelos Professor of Chemistry, Research Technician Rabina Lakha, and Barnard graduate Carla Hachicho ’19. Their work, titled “Metallothionein-3 attenuates the effect of Cu²ᐩ ions on actin filaments,” explores the link between the actin cytoskeleton and metallothionein-3 (MT-3), a cysteine-rich metal-binding protein expressed mostly in the mammalian central nervous system.
For this analysis, the researchers generated purified, recombinant mouse MT-3 bound to various metal ions, including copper (Cu), zinc (Zn), and lead (Pb). Using a combination of microscopy, spectroscopy, and mass spectrometry, the researchers showed that there was no direct interaction between MT-3 and actin, either in actin’s monomeric or filament form. They also showed that copper ions have dramatic effects on actin filament formation and length, effects that are reversed in the presence of MT-3. Overall, this study suggests that MT-3 and actin do not interact directly with high affinity and that MT-3 outcompetes actin for binding copper ions.