EMR1

Structure

Adhesion GPCRs are characterized by an extended extracellular region often possessing N-terminal protein modules that is linked to a TM7 region via a domain known as the GPCR-Autoproteolysis INducing (GAIN) domain.

The N-terminal fragment (NTF) of EMR1 contains 4-6 Epidermal Growth Factor-like (EGF-like) domains in human and 4-7 EGF-like domains in the mouse.

Tissue distribution

EMR1 expression in human is restricted to eosinophils and is a specific marker for these cells. The murine homolog of EMR1, F4/80, is a well-known and widely used marker of murine macrophage populations.

Function

F4/80 is not necessary for the development of tissue macrophages but is required for the induction of efferent CD8+ regulatory T cells needed for peripheral tolerance.

Clinical significance

EMR1 can serve as a therapeutic target for depletion of these cells in eosinophilic disorders by using afucosylated antibodies.

References

References

1. (March 1995). "EMR1, an unusual member in the family of hormone receptors with seven transmembrane segments". Genomics.
2. (March 1998). "The EGF-TM7 family: unusual structures at the leukocyte surface". Journal of Leukocyte Biology.
3. "Entrez Gene: EMR1 egf-like module containing, mucin-like, hormone receptor-like 1".
4. (September 1994). "Markers of mouse macrophage development detected by monoclonal antibodies". Journal of Immunological Methods.
5. (April 2015). "International Union of Basic and Clinical Pharmacology. XCIV. Adhesion G protein-coupled receptors". Pharmacological Reviews.
6. (2011). "Adhesion-GPCRs: Structure to Function (Advances in Experimental Medicine and Biology)". Springer.
7. (May 2013). "Sticky signaling--adhesion class G protein-coupled receptors take the stage". Science Signaling.
8. (March 2012). "A novel evolutionarily conserved domain of cell-adhesion GPCRs mediates autoproteolysis". The EMBO Journal.
9. (September 2011). "F4/80 and the related adhesion-GPCRs". European Journal of Immunology.
10. (October 2007). "EMR1, the human homolog of F4/80, is an eosinophil-specific receptor". European Journal of Immunology.
11. (October 1981). "F4/80, a monoclonal antibody directed specifically against the mouse macrophage". European Journal of Immunology.
12. (May 2005). "The macrophage F4/80 receptor is required for the induction of antigen-specific efferent regulatory T cells in peripheral tolerance". The Journal of Experimental Medicine.
13. (May 2014). "The eosinophil surface receptor epidermal growth factor-like module containing mucin-like hormone receptor 1 (EMR1): a novel therapeutic target for eosinophilic disorders". The Journal of Allergy and Clinical Immunology.