Adenine phosphoribosyltransferase (APRT)
The protein contains 180 amino acids for an estimated molecular weight of 19608 Da.
Catalyzes a salvage reaction resulting in the formation of AMP, that is energically less costly than de novo synthesis. (updated: April 1, 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.
- D'Alessandro and co-workers. (2017) Red blood cell proteomics update: is there more to discover? Blood Transfus. 15(2), 182-187.
- Bryk and co-workers. (2017) Quantitative Analysis of Human Red Blood Cell Proteome. J Proteome Res. 16(8), 2752-2761.
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.
Biological Process
Adenine salvage
AMP salvage
Cellular response to insulin stimulus
Grooming behavior
Lactation
Neutrophil degranulation
Nucleobase-containing small molecule metabolic process
Purine nucleobase metabolic process
Purine ribonucleoside salvage
Purine-containing compound salvage
Small molecule metabolic process
Cellular Component
Cytoplasm
Cytosol
Extracellular exosome
Extracellular region
Nucleoplasm
Secretory granule lumen
The reference OMIM entry for this protein is 102600
Adenine phosphoribosyltransferase; aprt
DESCRIPTION
The APRT gene encodes adenine phosphoribosyltransferase (EC 2.4.2.7), an enzyme that catalyzes the formation of AMP from adenine and phosphoribosylpyrophosphate. APRT acts as a salvage enzyme for the recycling of adenine into nucleic acids (summary by Broderick et al., 1987).CLONING
Wilson et al. (1986) determined the amino acid sequence of the APRT protein. The enzyme has 179 residues with a calculated molecular weight of 19.5 kD. Broderick et al. (1987) determined the nucleotide sequence of the human APRT gene. The APRT gene encodes a 180-amino acid protein (Tischfield and Ruddle, 1974). Comparative analysis by Broderick et al. (1987) showed that the amino acid sequence is highly conserved: the human protein was 82% and 90% identical to the mouse and hamster sequences, respectively. The gene is constitutively expressed and subject to little, if any, regulation. Hidaka et al. (1987) prepared a complete sequence of the APRT gene and found a number of discrepancies from the sequence reported by Broderick et al. (1987), all occurring within noncoding regions.GENE STRUCTURE
Broderick et al. (1987) determined that the APRT gene is about 2.6 kb long and contains 5 exons. The promoter region of the human APRT gene, like that of several other housekeeping genes, lacks the 'TATA' and 'CCAAT' boxes but contains 5 GC boxes that are potential binding sites for the Sp1 transcription factor. Broderick et al. (1987) found that CpG dinucleotides in the APRT gene in species as widely separated in evolution as man, mouse, hamster, and E. coli were conserved at a frequency higher than expected on the basis of randomness considering the G+C content of the gene. This suggested some importance of this sequence to the function of the gene. Although the intron 1 sequences of mouse and man had no apparent homology, both had retained a very high CpG content.MAPPING
By cell hybridization studies, Tischfield and Ruddle (1974) concluded that the APRT locus is on chromosome 16. Marimo and Giannelli (1975) confirmed this assignment by demonstrating a 1.69-fold increase in enzyme level in trisomy 16 cells. The same cells showed no difference in the levels of HGPRT (308000), G6PD (305900) or adenosine kinase (102750) from controls. Barg et al. (1982) assigned APRT to chromosome 16pter-q12. Lavinha et al. (1984) assigned APRT and DIA4 (125860) to 16q12-q22 by study of rearranged chromosomes 16 in somatic cell hybrids. For APRT, Ferguson-Smith and Cox (1984) found a smallest region of overlap (SRO) of 16q22.2-q22.3. Fratini et al. (1986) mapped the APRT locus with respect to the HP (140100) locus and the fragile site at 16q23.2 (FRA16D). A subclone of the APRT gene and a cDNA clone of HP were used for molecular hybridization to DNA from mouse-human hybrid cell lines containing specific chromosome 16 translocations. The APRT subclone was used for in situ hybridization to chromosomes expressing FRA16D. APRT was found to be distal to HP and FRA16D and was localized at 16q24, making the gene order cen--FRA16B--HP--FRA16D--APRT--qter.MOLECULAR GENETICS
Mutant forms of adenine phosphoribosyltransferase resulting in enzyme deficiency (APRTD; 614723) were described by Kelley et al. (1968) and by Henderson et al. (1969), who found the inheritance to be autosomal. A heat-stable enzyme allele had a frequency of about 15% and the heat-labile enzyme allele a frequency of about 85%. Kelley et al. (1968) found appa ... 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
March 16, 2016: Protein entry updated
Automatic update: OMIM entry 102600 was added.
Jan. 27, 2016: Protein entry updated
Automatic update: model status changed
Jan. 24, 2016: Protein entry updated
Automatic update: model status changed