Inorganic pyrophosphatase (PPA1)
The protein contains 289 amino acids for an estimated molecular weight of 32660 Da.
No function (updated: March 4, 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.
- 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.
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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| Variant | Description |
|---|---|
| a breast cancer sample; somatic mutation |
The reference OMIM entry for this protein is 179030
Pyrophosphatase, inorganic, 1; ppa1
Pp
DESCRIPTION
Inorganic pyrophosphates are generated as byproducts of many biosynthetic reactions, including DNA and RNA synthesis, fatty acid and amino acid activation, and cyclic nucleotide synthesis. Inorganic pyrophosphatases (EC 3.6.1.1), such as PPA1, maintain the thermodynamic favorability of these reactions by catalyzing the hydrolysis of pyrophosphates into organic phosphates, which are then exported across the cell membrane (Curbo et al., 2006).CLONING
Fairchild and Patejunas (1999) cloned PPA1 from a human heart cDNA library. The deduced 289-amino acid protein has a calculated molecular mass of 32.7 kD and shares 94% amino acid identity with bovine pyrophosphatase. Northern blot analysis detected a 1.4-kb PPA1 transcript in all tissues examined. RNA dot blot analysis confirmed ubiquitous PPA1 expression. Curbo et al. (2006) found that fluorescence-tagged PPA1 was expressed in both the cytosol and nucleus of transfected HeLa cells.GENE FUNCTION
Curbo et al. (2006) found that recombinant PPA1 hydrolyzed pyrophosphate in vitro. The reaction was dependent on Mg(2+) and inhibited by Ca(2+).MAPPING
Assignment of the PPA1 gene to chromosome 10 was first reported by Van Cong et al. (1975) and confirmed by somatic cell hybrid studies in 2 other laboratories (McAlpine et al., 1976; Chern, 1976). From dosage studies in a patient trisomic for 10pter-10q11.1, Snyder et al. (1984) showed that PPA1 is not on the short arm; red cell PP levels were normal. By radiation hybrid analysis, Fairchild and Patejunas (1999) mapped the PPA1 gene to chromosome 10q21.3.MOLECULAR GENETICS
Among 3,000 unrelated persons, Fisher et al. (1974) found no genetically determined variants of the PP enzyme in red cells. ... More on the omim web site
Feb. 2, 2018: Protein entry updated
Automatic update: Uniprot description updated
Dec. 19, 2017: Protein entry updated
Automatic update: Uniprot description updated
Nov. 23, 2017: Protein entry updated
Automatic update: Uniprot description updated
June 20, 2017: Protein entry updated
Automatic update: comparative model was added.
March 16, 2016: Protein entry updated
Automatic update: OMIM entry 179030 was added.