Alanine aminotransferase 1 (GPT)
The protein contains 496 amino acids for an estimated molecular weight of 54637 Da.
Catalyzes the reversible transamination between alanine and 2-oxoglutarate to form pyruvate and glutamate. Participates in cellular nitrogen metabolism and also in liver gluconeogenesis starting with precursors transported from skeletal muscles (By similarity). (updated: Sept. 12, 2018)
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.
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The reference OMIM entry for this protein is 138200
Glutamate pyruvate transaminase; gpt
Glutamate pyruvate transaminase, soluble red cell; gpt1
Glutamate pyruvate transaminase, soluble liver
Alanine aminotransferase 1; aat1; alt1
Alanine aminotransferase, soluble
DESCRIPTION
Glutamate-pyruvate transaminase (EC 2.6.1.2), also known as alanine aminotransferase, catalyzes the reversible conversion of L-alanine and alpha-ketoglutarate to L-glutamate and pyruvate. It has 2 distinct molecular and genetic forms: one cytoplasmic (soluble) (GPT1) and one mitochondrial (GPT2; 138210). See ALTQTL1 (612363) and ALTQTL2 (612364) for information on quantitative trait loci influencing the plasma level of alanine aminotransferase.CLONING
Sohocki et al. (1997) cloned the human GPT gene by using the homologous rat gene as a probe to screen a human chromosome 8 cosmid library. The GPT1 gene encodes a deduced 495-amino acid protein. By Northern blot analysis, Yang et al. (2002) determined that a 2.1-kb GPT1 transcript is moderately expressed in kidney, liver, heart, and fat. Another GPT1 transcript shows a slightly different expression pattern, with a 3.9-kb transcript expressed at high levels in muscle, fat, kidney, and brain and at lower levels in liver and breast.MAPPING
By studying segregation in hybrids made from a rat hepatoma cell line and various human cells of nonhepatic origin, Kielty et al. (1982) mapped the structural gene for the cytoplasmic hepatic form of GPT to chromosome 8. Studying similar hybrids, Astrin et al. (1982) also found evidence consistent with assignment to chromosome 8. By exclusion mapping applied in family studies, Cook et al. (1982) concluded that GPT1 is on chromosome 8q13-qter. O'Connell et al. (1987) established linkage between GPT and several markers on the distal part of 8q (8q24). It is noteworthy that other loci in the same region of chromosome 8--MYC (190080) and thyroglobulin (188450)--are coded by chromosome 15 of the mouse, as is GPT. The GPT tested in this case was soluble red cell GPT, as performed by Ferrell (1988). In a child with partial trisomy of chromosomes 8 and 14, Rocha et al. (1988) observed a dosage effect supporting regional assignment of GPT to 8q24.2-qter. By fluorescence in situ hybridization, Sohocki et al. (1997) mapped the human GPT gene to 8q24.3, within 200 kb of the 8q telomere. Sohocki et al. (1997) used fluorescence in situ hybridization to map the rat GPT gene to 7q33-q34, a region of synteny with human chromosome 8q24.GENE STRUCTURE
Sohocki et al. (1997) determined that the GPT1 gene contains 11 exons spanning approximately 3 kb. They found that the 2 polymorphic isozymes of GPT1 that are frequently used in linkage studies differ by a single nucleotide in codon 14 (138200.0001).MOLECULAR GENETICS
In red cell hemolysates, Chen and Giblett (1971) found polymorphism of the soluble form of glutamate-pyruvate transaminase. Allele frequencies in the GPT system vary considerably in different populations but all those studied were in a range making GPT an efficient marker for study of linkage with other loci. Electrophoretic variants were also studied by Kompf (1971). Data on gene frequencies of allelic variants were tabulated by Roychoudhury and Nei (1988).HISTORY
Linkage of the GOT and GPT loci was suggested by preliminary observations of Chen and Giblett (1971). For linkage between glutamate-pyruvate transaminase and breast cancer (114480), King et al. (1980) found a lod score of 1.84 for 6 families showing linkage and 1.43 for all 11 breast cancer families studied. Preliminary analysis of data in 2 Mormon families brought the lod score to about 2.4. McLellan et al. (1984) obtaine ... More on the omim web site
Oct. 19, 2018: Additional information
Initial protein addition to the database. This entry was referenced in Bryk and co-workers. (2017).
Oct. 19, 2018: Protein entry updated
Automatic update: OMIM entry 138200 was added.