# Elucidating mechanisms of amyloid nucleation in vivo

> **NIH NIH R01** · STOWERS INSTITUTE FOR MEDICAL RESEARCH · 2021 · $317,625

## Abstract

Project Summary
Amyloids exert numerous physiological and pathological activities. On the one hand, they perpetuate molecular
memories and transduce intracellular signals; on the other, they precipitate incurable neurodegenerative and
age-associated diseases. These disparate activities unfold over time scales that exceed the lifespan of the
proteins or even the cells that harbor them. Our long-term goal is to determine whether, and how, these time
scales emerge from the kinetics of amyloid formation in living cells. Toward this goal, we have focused on the
critical first step of amyloid formation: nucleation. The probabilistic nature of nucleation has made its study
exceedingly difficult with established cytological tools. We therefore developed Distributed Amphifluoric FRET
(DAmFRET) to quantify nucleation as a function of a given protein’s concentration in living cells. We have now
used DAmFRET to analyze nucleation of diverse amyloids and related polymers, and these data lead us to
propose the central hypothesis of this grant: low-specificity interactions critically influence the rates and
structural outcomes of amyloid nucleation in vivo. This hypothesis makes the following predictions that will be
tested in our Specific Aims: that nucleation will favor increasingly labile amyloids with 1) increasing protein
concentration or 2) condensation of the protein; and 3) that the ability of amyloids of one protein to nucleate
amyloids of a different protein depends on their disordered content rather than their structure. Completing this
investigation will reveal critical mechanistic features of nucleation by diverse proteins in living cells, including
the thermodynamic underpinnings of nucleation barriers, and networks of pathological cross-seeding. It will also
have opened a conduit to fundamental physical insights that are presently beyond the reach of cell biology.
These will yield a deeper understanding of, and ultimately new therapeutic options for, age- associated and
neurodegenerative diseases.

## Key facts

- **NIH application ID:** 10076837
- **Project number:** 5R01GM130927-02
- **Recipient organization:** STOWERS INSTITUTE FOR MEDICAL RESEARCH
- **Principal Investigator:** Randal Arthur Halfmann
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $317,625
- **Award type:** 5
- **Project period:** 2020-01-01 → 2023-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10076837

## Citation

> US National Institutes of Health, RePORTER application 10076837, Elucidating mechanisms of amyloid nucleation in vivo (5R01GM130927-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10076837. Licensed CC0.

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