Albumin (ALB)
The protein contains 609 amino acids for an estimated molecular weight of 69367 Da.
Binds water, Ca(2+), Na(+), K(+), fatty acids, hormones, bilirubin and drugs (Probable). Its main function is the regulation of the colloidal osmotic pressure of blood (Probable). Major zinc transporter in plasma, typically binds about 80% of all plasma zinc (PubMed:19021548). Major calcium and magnesium transporter in plasma, binds approximately 45% of circulating calcium and magnesium in plasma (By similarity). Potentially has more than two calcium-binding sites and might additionally bind calcium in a non-specific manner (By similarity). The shared binding site between zinc and calcium at residue Asp-273 suggests a crosstalk between zinc and calcium transport in the blood (By similarity). The rank order of affinity is zinc > calcium > magnesium (By similarity). Binds to the bacterial siderophore enterobactin and inhibits enterobactin-mediated iron uptake of E.coli from ferric transferrin, and may thereby limit the utilization of iron and growth of enteric bacteria such as E.coli (PubMed:6234017). Does not prevent iron uptake by the bacterial siderophore aerobactin (PubMed:6234017). (updated: June 17, 2020)
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.
- 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.
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Biological Process
Cellular protein metabolic process
Cellular response to starvation
Heme biosynthetic process
Heme catabolic process
High-density lipoprotein particle remodeling
Maintenance of mitochondrion location
Negative regulation of apoptotic process
Negative regulation of programmed cell death
Platelet degranulation
Post-translational protein modification
Receptor-mediated endocytosis
Retina homeostasis
The reference OMIM entry for this protein is 103600
Albumin; alb
DESCRIPTION
Albumin is the major protein of the blood plasma, amounting to 60 to 65% of its total protein. The principal functions of albumin are to support the oncotic pressure, which aids in keeping the blood within the circulation, and to sequester and transport many metabolites within the body, particularly less soluble, hydrophobic ones. It is also an important circulating antioxidant and possesses enzymatic properties (summary by Minchiotti et al., 2008).CLONING
Albumin is a globular unglycosylated serum protein of molecular weight 65,000 Da. The albumin variant first described by Fraser et al. (1959) in a Welsh family was characterized as a dimer by Jamieson and Ganguly (1969). The amino acid sequence has been determined in fragments of serum albumin of man (Dayhoff, 1972). Albumin is synthesized in the liver as preproalbumin, which has an N-terminal peptide that is removed before the nascent protein is released from the rough endoplasmic reticulum. The product, proalbumin, is in turn cleaved in the Golgi vesicles to give the secreted albumin (summary by Brennan and Carrell, 1978).MAPPING
Weitkamp et al. (1966) concluded that the albumin locus (ALB) is closely linked with the GC locus (139200). Using the Naskapi variant, Kaarsalo et al. (1967) found close linkage of the ALB and GC loci. Harper and Dugaiczyk (1983) mapped the albumin gene to chromosome 4 by in situ hybridization. Dextran sulfate was used to enhance labeling, and their technique permitted G-banding of the chromosomes with Wright's stain on the same preparations used for autoradiography without pretreatment. The regional localization (to 4q11-q13) agreed remarkably with that arrived at by indirect methods. Kao et al. (1982) assigned the albumin locus to chromosome 4 by use of a human albumin cDNA probe in human/Chinese hamster somatic cell hybrids. The ALB and alpha-fetoprotein (AFP; 104150) genes are within 50 kb of each other (Urano et al., 1984) and show strong linkage disequilibrium (Murray et al., 1984). Magenis et al. (1989) used in situ hybridization to localize the ALB and AFP genes to orangutan chromosome 3q11-q15 and gorilla chromosome 3q11-q12 which are considered homologous to 4q11-q13. As reviewed by Shibata and Abe (1996), vitamin D-binding protein (GC) and serum protease inhibitor are linked not only in humans, but also in horse, cattle, and sheep in mammals, and chicken in avian species. They added the Japanese quail to the group.EVOLUTION
The characteristic 3-domain structure of albumin and alpha-fetoprotein has been conserved throughout mammalian evolution. Thus, 35.2% amino acid homology is found between bovine serum albumin and murine AFP. Ohno (1981) addressed the vexing question of why this conservation occurs despite the nonessential nature of serum albumin as indicated by cases of analbuminemia. Minghetti et al. (1985) found a high rate of both silent substitutions and effective substitutions with amino acid changes in serum albumin. Although the rates of effective substitution in amino acid changes were not as high in albumin as in alpha-fetoprotein, they were still faster than those of either hemoglobin or cytochrome c. This high evolutionary change rate for albumin may be consistent with the fact that inherited analbuminemia produces surprisingly few symptoms despite the virtually complete absence of albumin.GENE STRUCTURE
Minghetti et al. (1986) found that the human albumin gene i ... More on the omim web site
June 30, 2020: Protein entry updated
Automatic update: OMIM entry 103600 was added.
June 29, 2020: Protein entry updated
Automatic update: Entry updated from uniprot information.
Aug. 20, 2019: Protein entry updated
Automatic update: Entry updated from uniprot information.
Oct. 19, 2018: Additional information
Initial protein addition to the database. This entry was referenced in Bryk and co-workers. (2017).