# Targeting Protein Arginine Methylation in HD

> **NIH NIH R21** · JOHNS HOPKINS UNIVERSITY · 2020 · $204,688

## Abstract

Huntington’s disease (HD) is a progressive autosomal dominant neurodegenerative disorder caused by a
polyglutamine expansion in the HD gene product, huntingtin (Htt). Mechanisms of HD cellular pathogenesis
remain elusive, with no disease-modifying treatments for HD available today. Studies using cellular and mouse
models of HD have revealed disruptions in many cellular processes and functions, likely mediated by abnormal
protein interactions of polyQ-expanded Htt. Transcriptional dysregulation is widely implicated in HD
pathogenesis, and epigenetic regulation of transcription was found to play a role in transcriptional abnormalities
in HD. Arginine methylation is an important post-translational modification of proteins with an emerging role in
neurodegeneration. In addition to providing a key level of epigenetic regulation, this modification found on many
non-histone RNA-binding proteins mediates RNA processing and splicing. However, despite the fact that both
gene transcription and RNA processing abnormalities have been widely associated with HD, there is very little
information on the role of arginine methylation in HD pathogenesis. This project is a continuation of our previous
findings that arginine dimethylation of endogenous substrates is impaired in HD models due to aberrant
interactions of mutant Htt with the enzyme that carries out these modifications, PRMT5. Our findings of the
PRMT5/Htt functional interaction raise the possibility that mutant Htt exerts its effects on transcription and RNA
processing via direct interaction with histone-modifying enzymes, and by modulating their activity. We think this
warrants further studies evaluating dimethylation of arginine, and the modifying enzymes, as potential new
therapeutic targets for HD. Arginine methylation is a reversible modification, and several enzymes capable of
arginine demethylation have been described. Thus, if arginine methylation of certain key targets is decreased in
HD, there is a potential for reversal using the inhibitors of demethylases, several of which are available today,
and some are being tested for cancer therapies. In Aim 1, we will assess proteome-wide changes in protein
arginine methylation in HD, and will identify key players, focusing on histones and RNA-binding proteins involved
in RNA processing and splicing. We will use novel methods of quantitative mass spectrometry, and our novel
HD iPS cell lines, as well as human HD brain. In Aim 2, we will evaluate if Htt is directly involved in the methylation
of the key substrates, identified in Aim 1. In Aim 3 we will evaluate approaches to reverse methylation
deficiencies, and will test if such intervention is beneficial for neuronal survival. Taken together, these studies
will provide novel information of the changes in arginine methylation of proteins in HD models and will elucidate
whether abnormalities in epigenetic regulation of transcription and RNA processing represent a unifying
pathogenic mechanism yielding n...

## Key facts

- **NIH application ID:** 9890027
- **Project number:** 5R21NS109412-02
- **Recipient organization:** JOHNS HOPKINS UNIVERSITY
- **Principal Investigator:** Tamara Ratovitski
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $204,688
- **Award type:** 5
- **Project period:** 2019-03-15 → 2023-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9890027

## Citation

> US National Institutes of Health, RePORTER application 9890027, Targeting Protein Arginine Methylation in HD (5R21NS109412-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/9890027. Licensed CC0.

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