# Hijacking Post-Translational Arginylation for Targeted Protein Degradation

> **NIH NIH R21** · RUTGERS BIOMEDICAL AND HEALTH SCIENCES · 2024 · $202,682

## Abstract

Project summary
Posttranslational arginylation on proteins installed by arginyltransferase ATE1 is a critical modification for cancer
progression and metastasis. ATE1 is a beneficiary regulator, inhibition of which often results in elevated
metastasis (e.g., prostate cancer) and poorer outcomes. Unfortunately, the physiological roles of ATE1 (and its
arginylation activity) in cancers remain poorly understood, mostly due to the lack of analytical methods to
discover the protein substrates of ATE1 from cancer samples. Arginylation regulates protein half-lives in cellular
systems through the Arg/N-degron pathway and represents one of the three (arginine, proline, and acetylation)
N-terminal degradation signals (N-degrons) for protein turnover. Here, we aim to discover the protein substrates
of ATE1 in cancers for the development of targeted protein degradation (TPD) by hijacking ATE1 and its
arginylation activity. We have developed an unbiased proteomic profiling method to discover the ATE1
substrates and their precise arginylation sites, the method is termed activity-based arginylation profiling
(ABAP). Using ABAP, we have successfully profiled arginylation from 12 samples including 4 cancer cell lines.
In this proposal, we would like to establish a library of cancerous substrates from commonly used cancer cell
lines using the NCI60 pellets. To take advantage of arginylation for targeted protein degradation against cancers,
we have engaged ATE1 with protein of interest (POI) through our model Halo-FKBP system. We discovered, for
the first time, that engagement of ATE1 with cancer targets (e.g., SHOC2 and RAD52) successfully induced POI
degradation in cellular models. We termed this technology arginylation targeting chimera (ArgTAC). Our
preliminary data on degradation data from the first few POIs encouraged us to further develop this technology
as a novel approach in the TPD field. We will apply a series of state-of-the-art approaches including proteomics
and molecular biology to characterize the mechanism of action of induced POI degradation after engagement
with ATE1. A series of molecular events will be characterized including cellular proximity between ATE1 and
POI, the arginylation and polyubiquitination of POI, and the POI degradation dependency on UBR E3 ligases
and proteasome. To achieve optimal degradation of broad cancer targets, we will expand our tool compounds
designed for the Halo-FKBP system. We will also further develop new ATE1 binders/recruiters through peptide
optimization based on LIAT1 (ligand of ATE1) binding domain to ATE1 using screening and structure/computer
modeling-based drug discovery. More ArgTACs targeting other POIs will be synthesized and tested for
degradation activities in cell models to expand the application of ArgTACs. The proposed ABAP and ArgTAC
platform here will likely generate a catalog of oncoproteins regulated by arginylation, and offer a general and
revolutionary TPD technology targeting oncoprotein deg...

## Key facts

- **NIH application ID:** 11517223
- **Project number:** 7R21CA292191-02
- **Recipient organization:** RUTGERS BIOMEDICAL AND HEALTH SCIENCES
- **Principal Investigator:** Zongtao Lin
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $202,682
- **Award type:** 7
- **Project period:** 2024-08-02 → 2026-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/11517223

## Citation

> US National Institutes of Health, RePORTER application 11517223, Hijacking Post-Translational Arginylation for Targeted Protein Degradation (7R21CA292191-02). Retrieved via AI Analytics 2026-06-12 from https://api.ai-analytics.org/grant/nih/11517223. Licensed CC0.

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