GDNFRα, GDNFRα extracellular domain (ECD), GDNFRα variants, chimeric GDNFRα (e.g., GDNFRα immunoadhesin), and antibodies which bind thereto (including agonist and neutralizing antibodies) are disclosed. Various uses for these molecules are described, including methods to modulate cell activity and survival by response to GDNFRα-ligands, for example GDNF, by providing GDNFRα to the cell. Also provided are methods for using GDNFRα, GDNF, or agonists thereof, separately or in complex, to treat kidney diseases.