9.B.191.1.8
KDEL receptor of 212 aas and 7 TMSs. 84% identical to the human homologue (TC# 9.B.191.1.5). These receptors determine the specificity of the luminal ER protein retention system that are required for normal vesicular traffic through the Golgi as well as retreval from the Golgi back to the ER. Retrieval is possible via the pH-dependent recognition of a carboxyl-terminal Lys-Asp-Glu-Leu (KDEL) signal by the KDEL receptor. The crystal structures of the chicken KDEL receptor in the apo ER state and the KDEL-bound Golgi state have been solved (PDB# 6I6B; Bräuer et al. 2019). They show a transporter-like architecture similar to that observed for SWEET family members that undergoes conformational changes upon KDEL binding with a pH-dependent interaction network crucial for recognition of the carboxyl terminus of the KDEL signal in a target protein (Bräuer et al. 2019).