# Cell-Based Sensors and Drug-Like Moldulators Targeting ppGalNAc-Transferases

> **NIH NIH U01** · CARNEGIE-MELLON UNIVERSITY · 2020 · $153,528

## Abstract

SUMMARY
Glycosylation, which fine-tunes the function of proteins, is the most abundant and diverse posttranslational
modification. Despite well documented connections to major diseases such as osteoporosis, dyslipidemia,
heart disease, chronic obstructive lung disease, cancer, and viral outbreaks, the enzymes that mediate mucin-
type O-glycosylation in the Golgi apparatus have yet to be discovered as druggable targets. The initiating
enzymes, a family of 20 ppGalNAc-transferase isozymes (herein termed GalNAc-Ts or T1-T20), determine
which substrates are modified and at which sites. Significant questions remain regarding their specificity,
regulation, targets and functions and the lack of an in situ activity assay and a pharmacological approach have
been critical limitations. To address these shortcomings we are developing a panel of isozyme-specific, cell-
based fluorescent sensors for GalNAc-transferase activity. They are being used in high-throughput screening
to identify isoform-specific, small molecule modulators of ppGalNAc-T mediated O-glycosylation. We will
carryout simultaneous screening of compounds with these sensors, which will greatly minimize off-target
effects allowing identification of candidates that directly target the enzymes. Preliminary work has resulted in
several isozyme-selective biosensors and a few promising drug-like candidates including a remarkably
selective inhibitor of T3 that works in both cells and mice with no apparent toxicity. Hits from the screening will
be validated using a battery of assays starting with a multi-well format glycosylation assay using purified
enzyme preparations that identifies direct-effect compounds. Beyond the scope of this proposal, we plan
structural characterization and optimization of any lead compounds as well as initial tests of therapeutic value.
Successful identification of isoform-selective modulators promises to be transformative to this area of
glycobiology research, and potentially, the clinic.

## Key facts

- **NIH application ID:** 9966931
- **Project number:** 5U01CA230677-03
- **Recipient organization:** CARNEGIE-MELLON UNIVERSITY
- **Principal Investigator:** ADAM D LINSTEDT
- **Activity code:** U01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $153,528
- **Award type:** 5
- **Project period:** 2018-08-01 → 2022-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9966931

## Citation

> US National Institutes of Health, RePORTER application 9966931, Cell-Based Sensors and Drug-Like Moldulators Targeting ppGalNAc-Transferases (5U01CA230677-03). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/9966931. Licensed CC0.

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