Urea transporter 1 (SLC14A1)
The protein contains 389 amino acids for an estimated molecular weight of 42528 Da.
Urea channel that facilitates transmembrane urea transport down a concentration gradient. A constriction of the transmembrane channel functions as selectivity filter through which urea is expected to pass in dehydrated form. The rate of urea conduction is increased by hypotonic stress. Plays an important role in the kidney medulla collecting ducts, where it allows rapid equilibration between the lumen of the collecting ducts and the interstitium, and thereby prevents water loss driven by the high concentration of urea in the urine. Facilitates urea transport across erythrocyte membranes. May also play a role in transmembrane water transport, possibly by indirect means. (updated: Jan. 7, 2015)
Protein identification was indicated in the following studies:
- Goodman and co-workers. (2013) The proteomics and interactomics of human erythrocytes. Exp Biol Med (Maywood) 238(5), 509-518.
- Lange and co-workers. (2014) Annotating N termini for the human proteome project: N termini and Nα-acetylation status differentiate stable cleaved protein species from degradation remnants in the human erythrocyte proteome. J Proteome Res. 13(4), 2028-2044.
- Hegedűs and co-workers. (2015) Inconsistencies in the red blood cell membrane proteome analysis: generation of a database for research and diagnostic applications. Database (Oxford) 1-8.
- Wilson and co-workers. (2016) Comparison of the Proteome of Adult and Cord Erythroid Cells, and Changes in the Proteome Following Reticulocyte Maturation. Mol Cell Proteomics. 15(6), 1938-1946.
- Bryk and co-workers. (2017) Quantitative Analysis of Human Red Blood Cell Proteome. J Proteome Res. 16(8), 2752-2761.
- D'Alessandro and co-workers. (2017) Red blood cell proteomics update: is there more to discover? Blood Transfus. 15(2), 182-187.
- Chu and co-workers. (2018) Quantitative mass spectrometry of human reticulocytes reveal proteome-wide modifications during maturation. Br J Haematol. 180(1), 118-133.
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 annotated as membranous in Gene Ontology, is annotated as membranous in UniProt, is predicted to be membranous by TOPCONS.
(right-click above to access to more options from the contextual menu)
| Variant | Description |
|---|---|
| dbSNP:rs2298720 | |
| Jk(null) | |
| Jk(null) | |
| dbSNP:rs9948825 | |
| Jk(b) | |
| Jk(null) | |
| Jk(null) | |
| Jk(null) |
No binding partner found
The reference OMIM entry for this protein is 111000
Blood group--kidd system; jk
A number sign (#) is used with this entry because the antigens of the Kidd blood group system are encoded by the SLC14A1 gene (613868).
DESCRIPTION
The Kidd blood group locus encodes a urea transporter (SLC14A1) that is expressed on human red cells and in the kidney. The Kidd blood group system (Jk) is defined by 2 alleles, Jk(a) and Jk(b), whose products were first identified with alloantibodies responsible for haemolytic disease of the newborn or transfusion reactions (summary by Olives et al., 1997).CLINICAL FEATURES
Although Jk-null red blood cells have reduced urea permeability, the Jk deficiency is not associated with any obvious clinical syndrome except for a urine concentration defect (Sands et al., 1992) that probably results from the absence of the Jk protein expressed on endothelial cells of the vasa recta of kidney (Xu et al., 1997; Promeneur et al., 1996). Persons with the Jk-null phenotype are detected because antibody against Jk3 can develop after immunization by transfusion or pregnancy, and this antibody may cause immediate and delayed hemolytic transfusion reactions (Lucien et al. (2002)).MAPPING
HGM9 concluded provisionally that the Jk locus is at 18q11-q12 (Geitvik et al., 1987). The L2.7 probe used in the assignment to chromosome 18 was thought to lie on the short arm, close to the centromere. The maximum lod score was 8.53 at recombination fraction of 0.03 (upper probability limit 0.11). In these data also, linkage of Jk to IGK (147200) was found (total lods = 4.12 at theta = 0.30) (see alsoHISTORY
). No obvious explanation for the conflicting gene mapping data could be found. Geitvik et al. (1987) quoted deletion data excluding Jk from a considerable part of chromosome 18 and contributing to the assignment of 18q11-q12. The Kidd blood group had been assigned to 18p by linkage to a polymorphic anonymous DNA probe, L2.7 (Gedde-Dahl, 1986). Leppert et al. (1987) also found linkage of blood group Kidd to 2 DNA markers on chromosome 18; the maximum lod scores were 3.61 at theta = 0.168 and 4.18 at theta = 0.218.MOLECULAR GENETICS
Olives et al. (1997) determined the genetic basis for the Kidd blood group polymorphism by sequencing reverse-transcribed reticulocyte RNAs from Jk(a+b-) and Jk(a-b+) donors. They found that the difference between Jk(a) and Jk(b) was a G-to-A transition at nucleotide 838, resulting in an asp280-to-asn amino acid substitution (613868.0001) and an MnlI RFLP.HISTORY
On the basis of studies of a patient with deletion of part of the long arm of chromosome 7, Shokeir et al. (1973) proposed that the Kidd blood group is on the deleted segment. The parents were homozygous Jk(a) and Jk(b) and all 9 sibs of the proband were heterozygous as one would expect. The proband herself was Jk(a). Hulten et al. (1968) previously suggested that the Kidd locus is on either chromosome 2 or a C group chromosome, but banding techniques were not then available. Mace and Robson (1974) found a hint of linkage between 'red-cell' acid phosphatase (171500), which is coded by chromosome 2, and Kidd blood group. Mohr and Eiberg (1977) found a lod score of plus 2.57 for the linkage of Kidd and Colton. Each had been tentatively assigned to chromosome 7. Under 3 different genetic models for IDDM, Hodge et al. (1981) found evidence for linkage with 2 different sets of marker loci: HLA (see 142800), properdin factor B (138470), and glyoxalase-1 (138750) on chromo ... More on the omim web site
May 13, 2019: Protein entry updated
Automatic update: model status changed
Nov. 17, 2018: Protein entry updated
Automatic update: model status changed
Feb. 2, 2018: Protein entry updated
Automatic update: Uniprot description updated
Dec. 19, 2017: Protein entry updated
Automatic update: Uniprot description updated
Oct. 27, 2017: Protein entry updated
Automatic update: model status changed
March 16, 2016: Protein entry updated
Automatic update: OMIM entry 111000 was added.
Jan. 25, 2016: Protein entry updated
Automatic update: model status changed