New evidences on Tau-DNA interactions and relevance to neurodegeneration

Area of Science:

• Molecular Biology
• Biochemistry
• Neuroscience

Background:

• Tau protein is primarily cytoplasmic but also found in the nucleus.
• Limited data exists on Tau's DNA-binding potential and direct interactions with DNA.

Purpose of the Study:

• To investigate the novel DNA nicking potential of Tau protein.
• To elucidate the effects of Tau on DNA structure, conformation, and integrity.

Main Methods:

• Incubation of supercoiled DNA (scDNA) with Tau protein.
• Assessing DNA structural changes using gel electrophoresis.
• Evaluating the influence of magnesium ions and aurinetricarboxylic acid (ATA) on Tau's DNA nicking activity.
• Analyzing DNA conformational transitions (B-C-A) and DNAse I digestion sensitivity.

Main Results:

• Tau protein demonstrated nicking of supercoiled DNA, producing open circular and linear forms.
• Magnesium ions enhanced Tau's DNA nicking ability, while ATA inhibited it.
• Tau induced B-C-A mixed conformational transitions in DNA and altered DNA stability, evidenced by increased sensitivity to DNAse I digestion.

Conclusions:

• Tau protein possesses intrinsic DNA nicking activity.
• Tau alters DNA helicity, integrity, and conformation.
• These findings suggest a novel role for Tau in modulating DNA, with potential implications for neuronal dysfunction.