# Biochemical and genomic tools to study histone ADP ribosylation signaling

> **NIH NIH R44** · EPICYPHER, INC. · 2024 · $1,274,494

## Abstract

PROJECT SUMMARY
 Histone ADP-ribosylation (ADPr) is a complex post-translational modification (PTM) with strong disease
associations. ADPr occurs on all five histone proteins in diverse states (e.g., mono-, di-, tri-, poly-ADPr) that are
dynamically regulated to control various cellular functions. The proteins that add, recognize, and remove histone
ADPr are rapidly emerging as high-value therapeutic targets. For example, one class of enzymes that catalyze
histone poly-ADPr (e.g., PARPs) is the target of many FDA-approved therapeutics for cancer and part of many
on-going clinical trials for other disease indications. Despite this, an understanding of the biological roles and
therapeutic potential of histone ADPr and histone ADPr-interacting enzymes remains largely unrealized due to
a dearth of molecular tools to study ADPr in vivo and in vitro.
 The goal of this Direct-to-Phase-II proposal is to develop a novel molecular toolkit to enable the study of
histone ADPr, advancing our knowledge of this important PTM and providing access to new therapeutic targets
in an emerging segment of histone biology. EpiCypher® is pioneering the development of fully-defined designer
nucleosomes (dNucs), which we and others have shown to be the ideal physiological substrates and controls for
diverse epigenetic assays. The power of EpiCypher’s fully-defined dNuc platform stems from its broad chemical
diversity, containing >100 unique dNucs carrying the most widely studied PTM classes (e.g., lysine methylation
and acetylation, serine phosphorylation). Our team has successfully leveraged the diversity of this flagship
technology for a range of high value applications including: I) high-throughput biochemical assays for drug
discovery, inhibitor screening, and antibody profiling (EpiDyne® and dCypher® assays) and II) ultra-sensitive
genomic mapping (CUTANA® CUT&RUN / CUT&Tag assays). The central innovations of this proposal are I) the
development of a novel chemoenzymatic manufacturing approach to generate the first fully-defined histone ADPr
dNucs (ADPr-dNucs) at commercial scale and II) leveraging these novel tools to develop cutting-edge assays to
enable new avenues of histone ADPr research and access new drug targets. In Phase I Equivalent feasibility
studies, we partnered with ADPr expert Dr. Glen Liszczak of the University of Texas Southwestern to develop a
novel two-step chemoenzymatic ADPr-dNuc manufacturing method and generate a focused panel of defined
ADPr-dNucs, whose functional importance was validated in a chromatin remodeling assay. Here, we will expand
our catalog of ADPr-dNucs (Aim 1) and use these reagents to develop robust biochemical (Aim 2) and genomics
(Aim 3) assays to accelerate histone ADPr basic and drug development research. Together, this work will lead
to the development and commercialization of a first-in-class molecular toolkit for the study of histone ADPr,
enabling multiple high-value applications to drive novel research into currently ...

## Key facts

- **NIH application ID:** 10820006
- **Project number:** 1R44GM153000-01
- **Recipient organization:** EPICYPHER, INC.
- **Principal Investigator:** Sabrina Robin Hunt
- **Activity code:** R44 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $1,274,494
- **Award type:** 1
- **Project period:** 2024-03-01 → 2026-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10820006

## Citation

> US National Institutes of Health, RePORTER application 10820006, Biochemical and genomic tools to study histone ADP ribosylation signaling (1R44GM153000-01). Retrieved via AI Analytics 2026-06-02 from https://api.ai-analytics.org/grant/nih/10820006. Licensed CC0.

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