ER lumen protein-retaining receptor 2 (KDELR2)
The protein contains 212 amino acids for an estimated molecular weight of 24422 Da.
Receptor for the C-terminal sequence motif K-D-E-L that is present on endoplasmic reticulum resident proteins and that mediates their recycling from the Golgi back to the endoplasmic reticulum (PubMed:1325562, PubMed:18086916). Binding is pH dependent, and is optimal at pH 5-5.4 (By similarity). (updated: May 8, 2019)
Protein identification was indicated in the following studies:
Methods
The following articles were analysed to gather the proteome content of erythrocytes.
The gene or protein list provided in the studies were processed using the ID mapping API of Uniprot in September 2018. The number of proteins identified and mapped without ambiguity in these studies is indicated below.
Only Swiss-Prot entries (reviewed) were considered for protein evidence assignation.
| Publication | Identification 1 | Uniprot mapping 2 | Not mapped / Obsolete | TrEMBL | Swiss-Prot |
|---|---|---|---|---|---|
| Goodman (2013) | 2289 (gene list) | 2278 | 53 | 20599 | 2269 |
| Lange (2014) | 1234 | 1234 | 7 | 28 | 1224 |
| Hegedus (2015) | 2638 | 2622 | 0 | 235 | 2387 |
| Wilson (2016) | 1658 | 1528 | 170 | 291 | 1068 |
| d'Alessandro (2017) | 1826 | 1817 | 2 | 0 | 1815 |
| Bryk (2017) | 2090 | 2060 | 10 | 108 | 1942 |
| Chu (2018) | 1853 | 1804 | 55 | 362 | 1387 |
1 as available in the article and/or in supplementary material
2 uniprot mapping returns all protein isoforms as one entry
The compilation of older studies can be retrieved from the Red Blood Cell Collection database.
The data and differentiation stages presented below come from the proteomic study and analysis performed by our partners of the GReX consortium, more details are available in their published work.
This protein is predicted to be membranous by TOPCONS.
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Biological Process
Endoplasmic reticulum to Golgi vesicle-mediated transport
Intracellular protein transport
Protein retention in ER lumen
Protein transport
Retrograde vesicle-mediated transport, Golgi to endoplasmic reticulum
The reference OMIM entry for this protein is 609024
Kdel endoplasmic reticulum protein retention receptor 2; kdelr2
Erd2-like protein 1; elp1
Erd2.2
DESCRIPTION
Resident soluble proteins within the lumen of the endoplasmic reticulum (ER) are retained there by virtue of a C-terminal tetrapeptide ER retention signal, commonly lys-asp-glu-leu (KDEL) in mammals. KDELR2 is one of the receptors that cycle between the Golgi apparatus and the ER, returning proteins containing the KDEL signal to the ER (Lewis and Pelham, 1992).CLONING
By screening cDNA libraries with a KDELR1 (131235) sequence, followed by 5-prime RACE of a Burkitt lymphoma cell line cDNA library, Lewis and Pelham (1992) cloned KDELR2, which they designated ERD2.2. The deduced 212-amino acid protein contains 7 transmembrane domains and shares 83.5% identity with KDELR1, with most differences between the 2 receptors in the transmembrane spans. Using degenerate PCR primers designed from a conserved region of KDELR1 to amplify related cDNAs from an erythroleukemia cell line cDNA library, followed by screening a T-cell cDNA library, Hsu et al. (1992) cloned KDELR2, which they called ELP1. The deduced 214-amino acid protein has a calculated molecular mass of 24.6 kD. Northern blot analysis detected a KDELR2 transcript of about 1.2 kb.GENE FUNCTION
Lewis and Pelham (1992) observed that KDELR2 transfected into COS-7 cells accumulated predominantly in the Golgi complex, but when the receptor was coexpressed with a target protein containing the KDEL ER retention signal, it redistributed to the ER, mirroring the behavior of KDELR1 under the same conditions. Hsu et al. (1992) found that about half of KDELR1- or KDELR2-transfected COS cells expressed the receptors in a juxtanuclear, Golgi-like pattern, while the remainder showed a reticular, ER-like pattern with nuclear envelope staining. Overexpression of the KDEL receptors led to the ER-like pattern and was associated with the collapse of the Golgi apparatus into the ER, as seen in cells treated with brefeldin A. In addition to the loss of the Golgi apparatus as a distinct organelle, overexpression resulted in redistribution of the Golgi coat protein, beta-COP (COPB; 600959), to the cytosol, addition of complex oligosaccharides to resident ER glycoproteins, and blockage of anterograde traffic. Hsu et al. (1992) concluded that the KDEL receptors provide signals that regulate retrograde traffic between the Golgi and the ER.MAPPING
The International Radiation Hybrid Mapping Consortium mapped the KDELR2 gene to chromosome 7 (TMAP SHGC-55953). ... More on the omim web site
May 11, 2019: Protein entry updated
Automatic update: Entry updated from uniprot information.
Nov. 17, 2018: Protein entry updated
Automatic update: OMIM entry 609024 was added.
Oct. 19, 2018: Additional information
Initial protein addition to the database. This entry was referenced in Bryk and co-workers. (2017).