Unraveling the impact of pathological Tau phosphorylations on the early Tau interactome in Alzheimer's disease

ongoing

The Tau protein during Alzheimer's disease (AD) becomes hyperphosphorylated, misfolds, and aggregates into neurofibrillary tangles (NFTs). Despite knowing the involvement of Tau in AD, the exact mechanism that drives Tau-mediated toxicity is largely unclear. Studying the Tau interactome is an excellent way to decipher the mechanism of Tau toxicity. Most interactome studies have primarily focused on Tau interactions related to NFTs, which represent the mature form of aggregated Tau. This emphasis has led to the overlooking of early-stage Tau interactions, mainly due to the lack of tools to access early Tau forms. My aim is to investigate the Tau interactome at these early stages, which are crucial in AD pathology. I hypothesize that extensive phosphorylation of Tau in the early stages of AD significantly alters its protein interaction network. This alteration contributes to Tau aggregation and subsequent toxicity in AD. To address this hypothesis, I will use an interdisciplinary approach to systematically identify interacting proteins associated with early Tau forms (non-phosphorylated, site-specifically phosphorylated, and hyperphosphorylated). I will use a protein semisynthesis technique to generate early Tau forms and employ affinity purification-mass spectrometry to identify the interactome associated with them from human brain tissue. Unique interacting proteins of Tau forms detected from the proteomic data, will be assessed in high-throughput Tau biosensor-based cellular screening to identify potential Tau aggregation modifiers. Finally, in vitro biophysical studies will be conducted to characterize the molecular interactions between Tau modifiers and Tau forms. The findings from this project will advance our mechanistic understanding of Tau phosphorylations in AD, elucidate the complex molecular interactions and pathways involved, and pave the way for the development of innovative therapeutic strategies targeting early Tau interactome.