Tauopathies: Emerging discoveries on tau protein, with a special focus on Alzheimer's disease

Tauopathies encompass a group of neurodegenerative disorders (NDDs) driven by the abnormal accumulation of mutated tau protein, leading to hyperphosphorylation, neuronal damage, and neuroinflammation. The protein plays essential roles in brain function but undergoes hyperphosphorylation and aggregation into toxic oligomers in NDDs. Recent research emphasizes the need to understand tau's post-translational modifications (PTMs) and their role in pathological states. Insights into tau's structure, isoform-specific properties, and aggregation mechanisms are critical for elucidating its propagation in neurodegeneration. Moreover, tau's potential as a biomarker and the development of targeted therapies to mitigate tauopathies, particularly in AD, remain promising avenues. However, many strategies targeted at tau have repeatedly failed, which continues the search for better alternatives. This review focuses on recent advances in tau research, highlighting its structural and functional characteristics, and roles in disease, that may be critical to understanding their implications for new therapeutic strategies. PTMs are important for the stable structure and physiological functions of a protein. However, dysfunctional PTMs are the leading causes of tau protein aggregation. The recent shift on tau hyperphosphorylation has resulted in many discoveries related to their functions in AD. Therapeutic strategies targeting phosphorylated tau are being extensively studied worldwide. This paper gives a comprehensive view on these aspects.