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Updated: Jun 24, 2026
10:24
Detection of Ligand-activated G Protein-coupled Receptor Internalization by Confocal Microscopy
Published on: April 9, 2017
GRP78: a multifunctional receptor on the cell surface
Mario Gonzalez-Gronow1, Maria Angelica Selim, John Papalas
1Department of Pathology, Duke University Medical Center, Durham, North Carolina 27710, USA. gonza002@mc.duke.edu
Antioxidants & Redox Signaling
|April 1, 2009
Summary
The 78 kDa glucose-regulated protein (GRP78) acts as a cell surface receptor beyond its endoplasmic reticulum chaperone role. It binds diverse ligands and interacts with various proteins, influencing viral entry and angiogenesis.
Area of Science:
- Cell Biology
- Molecular Biology
- Immunology
Background:
- The 78 kDa glucose-regulated protein (GRP78) is primarily known as an endoplasmic reticulum chaperone.
- Emerging evidence suggests GRP78 also functions on the cell surface, acting as a receptor and autoantigen.
Purpose of the Study:
- To explore the multifaceted roles of cell surface GRP78.
- To investigate its interactions with various ligands and cellular proteins.
- To understand the mechanisms of GRP78 cell surface translocation.
Main Methods:
- Literature review and synthesis of existing research on GRP78.
- Analysis of GRP78's interactions with ligands like alpha2-macroglobulin and viral proteins.
- Examination of GRP78's association with cell surface proteins such as VDAC and MHC-I.
Main Results:
- Cell surface GRP78 functions as a receptor for diverse ligands, including viral particles and angiogenic peptides.
- GRP78 is implicated in viral entry (e.g., coxsackie B, dengue fever) and angiogenesis.
- GRP78 associates with proteins like VDAC, MHC-I, Cripto, and MTJ-1, suggesting a unique cell surface topography.
Conclusions:
- Cell surface GRP78 has critical roles beyond intracellular protein folding.
- Its interactions mediate important biological processes including viral entry and angiogenesis.
- Understanding GRP78's cell surface localization and interactions is key to its diverse functions.
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