{{> infobox .infobox-protein
| name = EFNA1 Protein
| gene = EFNA1
| uniprot = P20815
| pdb = 3C8X
| molecular_weight = ~25 kDa
| localization = Cell membrane, Axon guidance cones
| family = Ephrin family
}}
{{> infobox is a protein. This page describes its structure, normal nervous system function, role in neurodegenerative disease, and potential as a therapeutic target.
EFNA1 (Ephrin-A1) is a glycosylphosphatidylinositol (GPI)-anchored protein (~205 amino acids). Unlike transmembrane ephrins, EFNA1 is attached to the outer leaflet of the plasma membrane via a GPI anchor. It contains a conserved receptor-binding domain and a C-terminal region for GPI anchoring. EFNA1 functions as a ligand for EphA receptors.
In the developing and mature nervous system, EFNA1:
[1] EFNA1 signaling is altered in AD through:
[2] In PD, EFNA1 contributes to:
[3] EFNA1 plays dual roles: