Membrane receptor that binds the K-D-E-L sequence motif in the C-terminal part of endoplasmic reticulum resident proteins and maintains their localization in that compartment by participating to their vesicle-mediated recycling back from the Golgi (By similarity). Binding is pH dependent, and is optimal at pH 5-5.4 (PubMed:30846601). Localized in the Golgi in the absence of bound proteins with the sequence motif K-D-E-L. Trafficks back to the endoplasmic reticulum together with cargo proteins containing the sequence motif K-D-E-L. Binds the C-terminal sequence motif K-D-E-L in a hydrophilic cavity between the transmembrane domains. This triggers a conformation change that exposes a Lys-rich patch on the cytosolic surface of the protein (PubMed:30846601). This patch mediates recycling from the Golgi to the endoplasmic reticulum, probably via COPI vesicles (By similarity). Belongs to the ERD2 family.