Sialic acid synthase (NANS)
The protein contains 359 amino acids for an estimated molecular weight of 40308 Da.
Produces N-acetylneuraminic acid (Neu5Ac) and 2-keto-3-deoxy-D-glycero-D-galacto-nononic acid (KDN). Can also use N-acetylmannosamine 6-phosphate and mannose 6-phosphate as substrates to generate phosphorylated forms of Neu5Ac and KDN, respectively. (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.
Biological Process
Carbohydrate biosynthetic process
Cellular protein metabolic process
CMP-N-acetylneuraminate biosynthetic process
Dolichol-linked oligosaccharide biosynthetic process
Glycosylation
Lipopolysaccharide biosynthetic process
Post-translational protein modification
Protein N-linked glycosylation via asparagine
The reference OMIM entry for this protein is 605202
N-acetylneuraminic acid phosphate synthase; nans
Sialic acid synthase; sas
DESCRIPTION
The sialic acids are a family of 9-carbon 2-keto-3-deoxy sugars. They are frequently the terminal sugars on secreted and cell surface glycoproteins and glycolipids. Sialic acids participate in many important biologic recognition events.CLONING
By searching a human EST database for sequences that are homologous to the E. coli sialic acid synthase gene neuB, Lawrence et al. (2000) identified SAS. They isolated a full-length human SAS coding sequence. The deduced 359-amino acid SAS protein shares approximately 36% amino acid sequence identity with the E. coli neuB protein. Expression of the SAS gene in an E. coli neuB-negative mutant resulted in partial restoration of sialic acid synthase activity. In insect cells, expression of SAS caused N-acetylneuraminic acid (Neu5Ac) and 2-keto-3-deoxy-D-glycero-D-galacto-nononic acid (KDN) production. In vitro, SAS used N-acetylmannosamine 6-phosphate and mannose-6-phosphate as substrates to generate phosphorylated forms of Neu5Ac and KDN, respectively; however, it exhibited much higher activity toward the Neu5Ac phosphate product. Northern blot analysis detected an approximately 1.3-kb SAS transcript in all human tissues examined. ... 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 16, 2016: Protein entry updated
Automatic update: OMIM entry 605202 was added.
Feb. 24, 2016: Protein entry updated
Automatic update: model status changed