# Molecular recognition of pathological tau fibril conformations

> **NIH NIH F32** · UNIVERSITY OF CALIFORNIA, SAN FRANCISCO · 2022 · $69,874

## Abstract

ABSTRACT
Tau is an intrinsically disordered protein that binds microtubules in healthy neurons but forms filamentous
aggregates that drive neurodegenerative diseases known as tauopathies. Cryo-EM structures from patient
samples revealed that these amyloid fibrils adopt unique tauopathy-dependent conformations that differ from
those of heparin-induced recombinant tau fibrils in vitro. These observations suggest that tau fibril morphology
begets disease phenotype, and that these aggregates propagate from neuron to neuron, recruiting tau monomer
in a “prion-like” mechanism. However, the mechanistic basis for transformation of the healthy intracellular tau
pool to pathological aggregation remains largely undefined, and there are no in vitro methods for generating
tauopathy-like fibril conformations with recombinant tau. Recently characterized alternative inducers of tau
fibrillization in vitro may faithfully recapitulate tauopathy-associated fibril morphologies; however, an
understanding of the cellular and environmental factors driving conformation-specific fibrillization is hampered
by the lack of tools for readily determining fibril conformation and the incomplete understanding of molecular
crosstalk with tau posttranslational modifications (PTMs). Here, I propose to leverage two unique molecular
recognition platforms to develop conformationally selective tools for rapid identification of tau fibril conformations.
My hypothesis is that cellular factors modulate the tau conformational landscape to promote amyloid fibril
formation in neurodegenerative disease and that new tools for detecting and inhibiting this process will be useful
therapeutics. For my first aim, I will utilize a small molecule fluorogenic probe library to identify molecules that
recognize disease-associated fibril conformations by comparing dye binding profiles of Alzheimer’s disease
patient-derived fibrils and fibrils generated in vitro with diverse polyanionic inducers. For my second aim, I will
use a yeast-displayed humanized nanobody library system to identify tau conformation-selective nanobodies
that will and serve as candidates for immunotherapeutics that inhibit the addition of monomers to tau fibrils and
expand and multiplex molecular recognition of fibrils. For my third aim, I will use chemical biology approaches to
reconstitute disease-associated tau ubiquitinations and, in combination with newly identified, conformationally
unique in vitro-induced tau fibrils, systematically examine the effect of ubiquitination on fibrillization propensity,
kinetics, and conformation and changes in fibril protein-protein interaction networks. Upon the successful
completion of this proposal, I envision a new toolkit for neurodegenerative disease precision medicine in which
small molecule fluorogenic probes detect tau fibril conformation/PTM status, and then fibril propagation is
specifically inhibited using nanobody immunotherapeutics.

## Key facts

- **NIH application ID:** 10389134
- **Project number:** 1F32AG076281-01
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
- **Principal Investigator:** Emma C Carroll
- **Activity code:** F32 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $69,874
- **Award type:** 1
- **Project period:** 2022-05-01 → 2025-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10389134

## Citation

> US National Institutes of Health, RePORTER application 10389134, Molecular recognition of pathological tau fibril conformations (1F32AG076281-01). Retrieved via AI Analytics 2026-05-27 from https://api.ai-analytics.org/grant/nih/10389134. Licensed CC0.

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