# Enhanced Sampling of G-Protein-Coupled Receptor-G Protein Interactions

> **NIH NIH R01** · UNIVERSITY OF KANSAS LAWRENCE · 2020 · $287,206

## Abstract

Project Summary
G-protein-coupled receptors (GPCRs) are the largest superfamily of human membrane proteins and serve as
primary targets of about 1/3 of currently marketed drugs. Four subtypes of adenosine receptors, the A1, A2A, A2B,
and A3, mediate a broad range of physiological functions. They have emerged as important therapeutic targets
for treating cardiac ischemia, neuropathic pain and cancer. During function, the A1 and A3 receptors bind the Gi/o
proteins, while the A2A and A2B receptors bind the Gs proteins. Moreover, the GPCR–G protein interactions are
modulated by allosteric ligands. These ligands bind to a putative extracellular site of adenosine receptors, which
exhibit divergent sequences and conformations. In contrast to traditional agonists that target at the highly
conserved adenosine-binding site and often cause off-target side effects, allosteric modulators have emerged
as promising candidates as selective GPCR drugs. To date, adenosine receptors are the sole subfamily of
GPCRs that have X-ray or cryo-EM structures determined in complex with distinct G proteins. Although these
structures provide valuable insights into the GPCR–G protein interactions, they are rather static images of the
protein complexes. Current limitations include: (1) It remains unknown how the flexible GPCRs and G proteins
dynamically recognize each other. (2) The determinants of specific GPCR–G protein interactions remain unclear.
(3) The structural basis and mechanism of allosteric modulator binding in the adenosine receptors remain elusive.
These limitations have greatly hindered effective drug design targeting the adenosine receptors. In order to
overcome these limitations, our specific aims include: (1) Develop a new computational method based on recent
success of a robust Gaussian accelerated molecular dynamics (GaMD) technique to enable all-atom simulations
of protein-protein interactions (PPIs), called “PPI-GaMD”. (2) Implement PPI-GaMD in widely used open source
simulation packages. (3) Test PPI-GaMD on simulations of specific G protein interactions with the A1 and A2A
receptors. (4) Apply PPI-GaMD simulations to determine mechanisms of allosteric modulator binding to the A1
and A2A receptors and allosteric modulation of the GPCR–G protein interactions. (5) Validate simulations in vitro
by mutagenesis and binding assays and in vivo by cellular functional assays through collaboration with a leading
GPCR experimental group. In turn, the simulations will help us to interpret the experimental data at an atomistic
level. Our long-term goals are (1) to develop robust computational methodologies to quantitatively characterize
biomolecular recognition in disease-associated cellular signaling pathways and (2) to design effective drug
molecules targeting important receptors.

## Key facts

- **NIH application ID:** 9899274
- **Project number:** 5R01GM132572-02
- **Recipient organization:** UNIVERSITY OF KANSAS LAWRENCE
- **Principal Investigator:** Yinglong Miao
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $287,206
- **Award type:** 5
- **Project period:** 2019-04-01 → 2024-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9899274

## Citation

> US National Institutes of Health, RePORTER application 9899274, Enhanced Sampling of G-Protein-Coupled Receptor-G Protein Interactions (5R01GM132572-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9899274. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*