DNA-binding mode transition of tau in the presence of Zinc ions

The role of non-enzymatic glycation on Tau-DNA interactions: Kinetic and mechanistic approaches

Despite the regulatory role of Tau protein in the stabilization and assembly of microtubules, this protein has an important function in the protection and stabilizing of DNA molecules in the cell nucleus. In the present study, it has been indicated that glycation of lysine residues (Lys-267, Lys-274, and Lys-280) in the microtubule-binding domain (MBD) can considerably decrease its binding affinity to DNA molecules. The structural analysis also confirmed that the decreased glycated tau-DNA complex's stability was due to structural modification of this protein after the glycation process. The study of hippocampal cells under hyperglycemic conditions showed that near to 70% of Tau proteins glycated in these cells, although the expression of Tau remained unaffected. The assessment of H3K9me2, as a marker for binding of Tau to pericentromeric heterochromatin (PCH), indicated that localization of Tau protein on PCH was remarkably decreased at high glucose conditions relative to the controls. It is suggested that increasing the structural stability of Tau protein limits the ability of this protein for DNA binding, while the molecular and physical barrier of glycated Lys residues should not be neglected.

The elusive tau molecular structures: can we translate the recent breakthroughs into new targets for intervention?

Insights into tau molecular structures have advanced significantly in recent years. This field has been the subject of recent breakthroughs, including the first cryo-electron microscopy structures of tau filaments from Alzheimer’s and Pick’s disease inclusions, as well as the structure of the repeat regions of tau bound to microtubules. Tau structure covers various species as the tau protein itself takes many forms. We will here address a range of studies that help to define the many facets of tau protein structures and how they translate into pathogenic forms. New results shed light on previous data that need now to be revisited in order to up-date our knowledge of tau molecular structure. Finally, we explore how these data can contribute the important medical aspects of this research - diagnosis and therapeutics.