# The Nucleolar Detention Center: a Hub of Long Noncoding RNAs that Imprison Proteins During Stress

> **NIH NIH R01** · UNIVERSITY OF MIAMI SCHOOL OF MEDICINE · 2020 · $312,257

## Abstract

The Nucleolar Detention Center: A Hub of Long Noncoding RNA that Imprison Proteins During Stress
 NIGMS R01 (R01GM115342) Grant Renewal
 Project Summary
The ability of cells to adapt to a wide variety of stress conditions plays a critical role in various physiological and
pathological settings, including development, cancer and neurological disorders. In this current grant cycle, we
reported the surprising discovery of stress-induced low complexity noncoding RNA derived from stimuli-specific
loci of the ribosomal intergenic spacer (rIGSRNA); an enigmatic region of the human genome historically
dismissed as “junk” DNA. We showed that low complexity rIGSRNA activate a physiological amyloidogenic
program that converts the nucleolus into Amyloid Bodies (A-bodies): a molecular prison of immobilized proteins
in an amyloid-like state. This rather unusual post-translational regulatory pathway enables cells to rapidly and
reversibly store an array of endogenous proteins in A-bodies and enter quiescence in response to severe
environmental insults. While many membrane-less compartments have been described as liquid-like (e.g. stress
granules, P-bodies, germ cell granules), our discovery of A-bodies provided evidence of an amyloidogenic
process that can physiologically transition biological matter to a solid-like state. In this grant renewal, we will
show that the ribosomal intergenic spacer produces a large family of low complexity RNA that differ in their
length, dinucleotide content and repetitive arrangement. These variable properties of rIGSRNA operate as
architectural determinants that recruit common and distinct proteins to seed condition-specific A-bodies. We will
also provide preliminary data that A-bodies enclose groups of polyadenylated RNA that may be involved in stress
recovery. Conceptually, this NIGMS-funded research has uncovered an adaptive program that relies on a class
of inducible low complexity RNA molecules to control cellular fate by assembling our newly-discovered nuclear
membrane-less organelle: A-bodies. Based on these aforementioned rationales, we hypothesize that “Low
complexity rIGSRNA activate physiological amyloidogenic programs that assemble stress-specific A-bodies”. In
the Specific Aims, we will: 1. Uncover dinucleotide repeat motifs in rIGSRNA that seed A-bodies; 2. Explore the
mechanisms that confer A-body identity; and 3. Examine processes involved in polyadenylated RNA storage by
A-bodies. Our proposed work on low complexity rIGSRNA will open new lines of investigation on the
physiological role of simple long intergenic dinucleotide repeats observed across the genome, but commonly
ignored as non-functional DNA/RNA. In addition, the observation that low complexity RNA activate an
amyloidogenic process of physiological liquid-to-solid transition will provide alternative insights into pathological
amyloidogenesis involved in many human diseases. Finally, our planned experiments on polyadenylated RNA
storage by A-bodies will...

## Key facts

- **NIH application ID:** 9903375
- **Project number:** 5R01GM115342-06
- **Recipient organization:** UNIVERSITY OF MIAMI SCHOOL OF MEDICINE
- **Principal Investigator:** Stephen Lee
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $312,257
- **Award type:** 5
- **Project period:** 2015-07-24 → 2023-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9903375

## Citation

> US National Institutes of Health, RePORTER application 9903375, The Nucleolar Detention Center: a Hub of Long Noncoding RNAs that Imprison Proteins During Stress (5R01GM115342-06). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9903375. Licensed CC0.

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