Discovery and Characterization of a cGAMP-Specific ENPP1 Mutant
Abstract/Contents
- Abstract
- Cancer immunotherapy is a rapidly growing field that utilizes the body’s intrinsic ability to avert disease through adaptive and innate immunity. Recently, immunotherapy research has found that the stimulator of interferon genes (STING) pathway induces a potent antiviral and anticancer immune response through the production of interferons (IFNs), a cytokine family that amplifies the immune response. A hallmark of genomically unstable cancer cells is the shedding of self-dsDNA into the cytosol, which activates the STING pathway via cyclic GMP-AMP (cGAMP) as a second messenger. However, ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) decreases the levels of extracellular cGAMP and reduces IFN production, thereby weakening the immune response. This work sought to identify a point mutation in ENPP1 that eliminates its cGAMP hydrolysis activity whilst retaining its catalytic activity for other messengers, such as ATP. The goal of this effort is to increase downstream IFN levels and stimulate an anticancer immune response. Through screening a panel of induced point mutations by enzyme kinetic experiments such as radioactive TLC and CellTiter-Glo assay, we discovered that the residue H362 is critical for cGAMP hydrolysis, but does not alter ATP hydrolysis. ENPP1 H362 mutants will be a tool to uncouple the effects of extracellular cGAMP and ATP, expand our understanding of extracellular cGAMP signaling mechanisms in cancer, and potentially serve as a noninvasive cancer therapeutic.
Description
| Type of resource | text |
|---|---|
| Date created | June 2021 |
Creators/Contributors
| Author | AlSaif, Yasmeen |
|---|---|
| Primary advisor | Li, Lingyin |
| Advisor | Dixon, Scott |
| Degree granting institution | Stanford University, Department of Biology, 2021 |
Subjects
| Subject | Biology |
|---|---|
| Subject | cGAMP |
| Subject | STING |
| Subject | ENPP1 |
| Subject | H362 |
| Subject | IFN |
| Subject | Immunotherapy |
| Genre | Thesis |
Bibliographic information
| Related Publication |
1) Carozza JA, Brown JA, Böhnert V, et al. Structure-Aided Development of Small-Molecule Inhibitors of ENPP1, the Extracellular Phosphodiesterase of the Immunotransmitter cGAMP. Cell Chem Biol. Published online July 28, 2020. doi:10.1016/j.chembiol.2020.07.007 2) Carozza JA, Cordova AF, AlSaif Y, Böhnert V, Skariah G, & Li L. Probing pathophysiology of extracellular cGAMP with substrate-selective ENPP1. bioRxiv 2021.05.04.442665 (2021) doi:10.1101/2021.05.04.442665 |
|---|---|
| Location | https://purl.stanford.edu/st641jn2169 |
Access conditions
- Use and reproduction
- User agrees that, where applicable, content will not be used to identify or to otherwise infringe the privacy or confidentiality rights of individuals. Content distributed via the Stanford Digital Repository may be subject to additional license and use restrictions applied by the depositor.
- License
- This work is licensed under a Creative Commons Attribution Share Alike 3.0 Unported license (CC BY-SA).
Preferred citation
- Preferred Citation
- AlSaif Y, Carozza JA, & Li L. (2021). Discovery and Characterization of a cGAMP-Specific ENPP1 Mutant. Stanford Digital Repository. Available at: https://purl.stanford.edu/st641jn2169
Collection
Undergraduate Theses, Department of Biology, 2020-2021
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- Contact
- yalsaif@stanford.edu
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