S-methyl-5'-thioadenosine phosphorylase (MTAP)
The protein contains 283 amino acids for an estimated molecular weight of 31236 Da.
Catalyzes the reversible phosphorylation of S-methyl-5'-thioadenosine (MTA) to adenine and 5-methylthioribose-1-phosphate. Involved in the breakdown of MTA, a major by-product of polyamine biosynthesis. Responsible for the first step in the methionine salvage pathway after MTA has been generated from S-adenosylmethionine. Has broad substrate specificity with 6-aminopurine nucleosides as preferred substrates. (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.
- 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 |
|---|---|
| dbSNP:rs7023954 |
Biological Process
Cellular nitrogen compound metabolic process
Interleukin-12-mediated signaling pathway
L-methionine salvage from methylthioadenosine
Methylation
Nucleobase-containing compound metabolic process
Polyamine metabolic process
Purine ribonucleoside salvage
Response to testosterone
Small molecule metabolic process
Sulfur amino acid metabolic process
The reference OMIM entry for this protein is 112250
Diaphyseal medullary stenosis with malignant fibrous histiocytoma; dmsmfh
Bone dysplasia with medullary fibrosarcoma; bdmf
Bone dysplasia with malignant fibrous histiocytoma
Myopathy, limb-girdle, with bone fragility
A number sign (#) is used with this entry because diaphyseal medullary stenosis with malignant fibrous histiocytoma (DMSMFH) is caused by heterozygous mutation in the MTAP gene (156540) on chromosome 9p21.
DESCRIPTION
Diaphyseal medullary stenosis with malignant fibrous histiocytoma is an autosomal dominant bone dysplasia characterized by pathologic fractures due to abnormal cortical growth and diaphyseal medullary stenosis. The fractures heal poorly, and there is progressive bowing of the lower extremities. In 2 families, affected individuals also showed a limb-girdle myopathy, with muscle weakness and atrophy. Approximately 35% of affected individuals develop an aggressive form of bone sarcoma consistent with malignant fibrous histiocytoma or osteosarcoma. Thus, the disorder may be considered a tumor predisposition syndrome (summary by Camacho-Vanegas et al., 2012).CLINICAL FEATURES
Arnold (1973) described several generations of a Vermont and New York kindred demonstrating multiple areas of necrosis in the diaphyses of the large tubular bones. The radiographic appearance of this skeletal condition resembled radiation osteitis, a highly premalignant condition; however, no source of radiation exposure was found in this family. Medullary fibrosarcoma, an uncommon bone tumor, was noted in 4 of the 12 affected members. Death had occurred from widespread metastases at ages varying from 23 to 48 years. Occurrence of fibrosarcoma in idiopathic bone infarcts (Furey et al., 1960) and in an infarct in a caisson worker (Dorfman et al., 1966) has been reported. Camacho-Vanegas et al. (2012) noted that 2 affected male individuals in the family reported by Arnold (1973) died of heart disease in their early forties without other known risk factors, and suggested that this may be a manifestation of the disorder. Hardcastle et al. (1986) gave follow-up information on the original American family and reported 2 other families, one English and the other Australian. They could find no reports of any hereditary or acquired condition similar to that in these 3 families. They suggested that the malignant change should be labeled 'malignant fibrous histiocytoma' rather than fibrosarcoma because the tumors were markedly aggressive. The malignancy occurred generally in the second to fifth decades of life. They defined the skeletal dysplasia as a diaphyseal medullary stenosis with overlying cortical bone thickening. The occurrence of fracture with minimal trauma was emphasized. Norton et al. (1996) reported a 19-year-old boy who presented with a nontender mass on the left tibia that proved to be a pleiomorphic spindle cell sarcoma. Radiographs of the affected leg showed extensive diaphyseal cortical thickening and a medullary permeative pattern in the diaphysis. Radiographs of the patient's mother and maternal grandmother showed a similar bony dysplasia, with areas of infarction and medullary sclerosis. The lower extremities were more affected than the upper extremities in all 3 cases. Family history was significant for the death of the maternal great-grandmother at age 32 from 'metastatic osteosarcoma.' Norton et al. (1996) commented on the similarities to the families reported by Hardcastle et al. (1986) and noted that the malignant fibrous histiocytomas in this condition presumably begin at the sites of infarction within the affected bone. Henry et al. (1958) reported a Canadian family in which 6 men had delayed healing of fractures of ... 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
March 25, 2017: Additional information
No protein expression data in P. Mayeux work for MTAP
March 16, 2016: Protein entry updated
Automatic update: OMIM entry 112250 was added.
Jan. 28, 2016: Protein entry updated
Automatic update: model status changed
Jan. 25, 2016: Protein entry updated
Automatic update: model status changed