# Activity-based regulome profiling for the discovery of covalent transcription factor inhibitors

> **NIH NIH R44** · TALUS BIOSCIENCE, INC. · 2024 · $821,779

## Abstract

RESEARCH SUMMARY
The human genome encodes more than 1,600 transcription factors (TFs), along with additional
cofactors, chromatin regulators, and structural proteins that collectively execute the regulatory
instructions encoded within the nuclear DNA. Dysfunctions of these proteins are known to drive
multiple diseases such as cancer, inflammation-related, and neurological conditions. In cancer,
these proteins are frequently amplified or overexpressed to drive a gene expression program
that facilitates the initiation and progression of various types of leukemia, sarcoma and other
tumors. Despite the importance of these proteins, TFs have been considered undruggable due
to challenges in modeling their activity in vitro. We have solved these shortcomings by
implementing an in-cell functional proteomics drug discovery platform that quantifies the effects
of small-molecules on the abundance of TF bound to the genome in a diversity of cell and tissue
types. The platform is based on Chromatin Extraction by Salt Separation, coupled to Data
Independent Analysis mass spectrometry (ChESS-DIA), which was recently reported. In this
proposal, we adapt this technology to enable the discovery of covalent small molecule inhibitors,
a type of chemistry that has recently enabled targeting of the previously undruggable KRAS
protein. First, we will compare the efficacy of several different covalent screening approaches in
combination with ChESS-DIA proteome analysis, determining which strategy is best for
compound discovery. Computational tools will also be built to robustly identify functional
covalent hit compounds, and to identify the compound:protein adducts that are formed upon
compound binding. Several well-characterized covalent inhibitors will be used to validate the
accuracy of these methods. With a validated covalent screening TF assay, we will then optimize
a secondary assay using intact protein to verify that hit compounds can label target proteins in a
stoichiometric, specific way. With these tools in hand, we will then perform a pilot screen to
prove the assay’s utility in a discovery setting, using a subset of a commercial covalent
compound library. These compounds contain a diverse array of reactive warheads, and this will
allow us to understand various performance metrics of the optimized assay. This data package
will enable us to perform full-scale internal screens for compounds that target Talus’ TFs of
interest, as well as provide the foundation for business development discussions with biotech
and pharmaceutical companies interested in TF inhibition.

## Key facts

- **NIH application ID:** 10932643
- **Project number:** 4R44TR004349-02
- **Recipient organization:** TALUS BIOSCIENCE, INC.
- **Principal Investigator:** Alexander Federation
- **Activity code:** R44 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $821,779
- **Award type:** 4N
- **Project period:** 2023-08-14 → 2026-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10932643

## Citation

> US National Institutes of Health, RePORTER application 10932643, Activity-based regulome profiling for the discovery of covalent transcription factor inhibitors (4R44TR004349-02). Retrieved via AI Analytics 2026-05-27 from https://api.ai-analytics.org/grant/nih/10932643. Licensed CC0.

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