# Chemical Approaches to Understand O-GlcNAc Glycosylation and Its Roles in Neurodegeneration

> **NIH NIH R01** · CALIFORNIA INSTITUTE OF TECHNOLOGY · 2024 · $821,056

## Abstract

Project Summary/Abstract
Carbohydrates (also known as glycans) comprise one of the largest, most diverse collections of biologically
active molecules. However, relative to other biomolecules such as nucleic acids and proteins, carbohydrates
remain poorly understood due to challenges in their detection, synthesis, and analysis. The broad objective of
this program is to develop chemical approaches to advance a fundamental understanding of the roles of
carbohydrates in biology and disease. In the last granting period, we developed a novel Networking of Interactors
and SubstratEs (NISE) method to study the biological functions of O-linked β-N-acetylglucosamine (O-GlcNAc)
glycosylation. O-GlcNAc is an abundant, essential post-translational modification that is emerging as a key
regulator of many physiological functions, ranging from epigenetic and transcriptional gene regulation to insulin
signaling, cancer cell metabolism, and neurodegeneration. Our NISE approach combines new chemoproteomic
tools, genetic engineering, mass spectrometry analysis, and bioinformatics methods to quantitatively profile O-
GlcNAc sites and O-GlcNAc transferase (OGT) interactors across the proteome and to determine key
interconnections between the interactors and substrates. The resulting networks have revealed novel,
unexpected functions for O-GlcNAc and highlighted potential mechanisms to explain the unique specificity of
OGT. In the coming granting period, we will expand on this approach and investigate the roles of O-
GlcNAcylation in neurons and in the context of neurodegenerative diseases as we continue to tackle the next
critical barriers in the field. In Aim 1, we will focus on understanding how O-GlcNAcylation within intrinsically
disordered, low-complexity domains of proteins affects their functions and alters biomolecular condensate (BMC)
formation, composition, and dynamics. These studies should provide new paradigms and methods for
understanding the fundamental mechanisms by which O-GlcNAc regulates proteins and its role in aberrant BMC
activity linked to Alzheimer’s disease and related dementias (AD/ADRDs). In Aim 2, we will test specific
hypotheses revealed by our NISE networks regarding the regulation of OGT activity at neuronal synapses and
specifically toward proteins implicated in AD/ADRDs. In Aim 3, we will apply our NISE method to examine directly
how O-GlcNAcylation of specific proteins and pathways becomes dysregulated during AD pathogenesis and with
disease-specific mutations by using patient-derived induced pluripotent stem cells (iPSCs) and human AD brain
samples. Together, the proposed studies will provide a powerful approach to identify and understand
physiologically important and/or disease-causing O-GlcNAcylation events. In turn, this information is expected
to provide new potential therapeutic targets and/or strategies to combat progressive neurodegeneration and
AD/ADRDs.

## Key facts

- **NIH application ID:** 10986021
- **Project number:** 2R01AG060540-14
- **Recipient organization:** CALIFORNIA INSTITUTE OF TECHNOLOGY
- **Principal Investigator:** Linda C Hsieh-Wilson
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $821,056
- **Award type:** 2
- **Project period:** 2002-12-01 → 2029-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10986021

## Citation

> US National Institutes of Health, RePORTER application 10986021, Chemical Approaches to Understand O-GlcNAc Glycosylation and Its Roles in Neurodegeneration (2R01AG060540-14). Retrieved via AI Analytics 2026-06-02 from https://api.ai-analytics.org/grant/nih/10986021. Licensed CC0.

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