TCDB is operated by the Saier Lab Bioinformatics Group
TCIDNameDomainKingdom/PhylumProtein(s)
9.B.191.1.1









Putative ER lumen protein-retaining receptor of 215 aas and 7 TMSs.

Eukaryota
Fungi
ER lumen protein-retaining receptor of Chaetomium globosum
9.B.191.1.2









The ER-retrevial receptor of 217 aas and 7 TMSs, Ter1.

Eukaryota
Intramacronucleata
Ter1 of Tetrahymena thermophila
9.B.191.1.3









Uncharacterized protein of 262 aas and 8 TMSs

Eukaryota
Saprolegniales
UP of Aphanomyces astac
9.B.191.1.4









ER retention receptor, ER_ret_rcpt.protein of 371 aas and 6 or 7 TM

Eukaryota
Apicomplexa
ER_ret_rcot of Toxoplasma gondii
9.B.191.1.5









KDEL receptor, KDELR of 212 aas and 7 TMSs.  Required for the retention of luminal endoplasmic reticulum resident proteins via vesicular recycling. This receptor recognizes the C-terminal K-D-E-L motif. COPI-coated transport intermediates, either in the form of round vesicles or as tubular processes, mediate retrograde traffic of the KDEL receptor-ligand complexes. Also required for normal vesicular traffic through the Golgi (Giannotta et al. 2015). Intra-Golgi transport as well as the known mechanisms for the retention of Golgi resident proteins and for the sorting and export of transmembrane cargo proteins have been reviewed (Lujan and Campelo 2021).

 

Eukaryota
Metazoa
KDELR of Homo sapiens
9.B.191.1.6









Endoplasmic reticulum retention receptor of 287 aas and 6 TMSs

Eukaryota
Perkinsida
ER retention receptor of Perkinsus marinus
9.B.191.1.7









Putative ER lumen protein retaining receptor protein of 391 aas.

Eukaryota
Fungi
ER retention recptor of Eutypa lata (Grapevine dieback disease fungus) (Eutypa armeniacae)
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).

Eukaryota
Metazoa
KDELR of Gallus gallus (Chicken)
9.B.191.1.9









Uncharacterized protein of 681 aas and 7 N-terminal TMSs as well as a long C-terminal hydrophilic domain that is homologous to the protein with TC# 1.H.3.3.2.

Eukaryota
Sar
UP of Perkinsus chesapeaki
9.B.191.1.10









ER lumen protein-retaining receptor, Erd-2.1, ERD-2.1 or Erd2.1, of 213 aas and 7 TMSs. It is required for the retention of luminal endoplasmic reticulum proteins and determines the specificity of the system. it is also required for normal vesicular trafficing through the Golgi. It is 67% identical to the human receptor with TC# 9.B.191.1.5. It catalyzes COPI-dependent Golgi-to-ER retrograde traffic. There seems to be an interaction between the vesicular acetylcholine transporter and ERD2 receptor.

 

Eukaryota
Opisthokonta
Erd-2.1 of Caenorhabditis elegans
9.B.191.2.1









Uncharacterized protein of 204 aas and 7 TMSs.

Bacteria
Proteobacteria
UP of Alteromonadales bacterium TW-7
9.B.191.2.2









Uncharacterized protein of 208 aas and 7 TMSs in a 1 + 2 + 2 + 2 TMS arrangement.  This protein shows appreciable sequence similarity with the proteins with TC# 9.B.191.1.7 and 9.B.191.1.9 as well as high similarity with 1.B.191.2.1.

Bacteria
Proteobacteria
UP of Pseudoalteromonas citrea