How Zinc Affects HIV-1 Tat Protein and Microtubule Assembly
Author Information
Author(s): Egelé Caroline, Barbier Pascale, Didier Pascal, Piémont Etienne, Allegro Diane, Chaloin Olivier, Muller Sylviane, Peyrot Vincent, Mély Yves
Primary Institution: Université Louis Pasteur, Strasbourg
Hypothesis
Zinc binding to the HIV-1 Tat protein modulates its interaction with microtubules and affects apoptosis.
Conclusion
The study shows that the zinc-bound form of Tat (holo-Tat) is the active form that promotes microtubule stability and apoptosis, while the apo-Tat form does not.
Supporting Evidence
- Both forms of Tat bind tubulin dimers, but only holo-Tat forms discrete complexes.
- Holo-Tat decreases the critical concentration of tubulin and stabilizes microtubules.
- Apo-Tat induces tubulin aggregates instead of stable microtubules.
- Zinc binding prevents Tat oxidation and promotes local folding.
- Holo-Tat promotes microtubule assembly more effectively than apo-Tat.
Takeaway
Zinc helps a protein from HIV called Tat to work better with tiny structures in our cells called microtubules, which are important for cell function and can lead to cell death if messed up.
Methodology
The study used fluorescence correlation spectroscopy, analytical ultracentrifugation, turbidity measurements, and electron microscopy to analyze the interaction of Tat with tubulin.
Limitations
The study does not address the in vivo effects of Tat and zinc binding in a living organism.
Digital Object Identifier (DOI)
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