N-acetylneuraminate lyase (NPL)
The protein contains 320 amino acids for an estimated molecular weight of 35163 Da.
Catalyzes the cleavage of N-acetylneuraminic acid (sialic acid) to form pyruvate and N-acetylmannosamine via a Schiff base intermediate. It prevents sialic acids from being recycled and returning to the cell surface. Involved in the N-glycolylneuraminic acid (Neu5Gc) degradation pathway. Although human is not able to catalyze formation of Neu5Gc due to the inactive CMAHP enzyme, Neu5Gc is present in food and must be degraded (By similarity). (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.
- 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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The reference OMIM entry for this protein is 611412
N-acetylneuraminate pyruvate lyase; npl
Chromosome 1 open reading frame 13; c1orf13
Dihydrodipicolinate synthase
C112
DESCRIPTION
N-acetylneuraminate pyruvate lyase (EC 4.1.3.3) controls the cellular concentration of sialic acid by catalyzing the conversion of sialic acid into acylmannosamines and pyruvate (Wu et al., 2005).CLONING
By searching for genes in a region of chromosome 1 associated with hereditary prostate cancer (HPC1; 601518), followed by screening cDNA libraries, Sood et al. (2001) cloned NPL, which they called C112. The deduced protein contains 320 amino acids. Northern blot analysis detected weak expression of a 5-kb transcript in all human tissues examined. By large-scale sequence analysis of clones obtained from a fetal brain cDNA library, Wu et al. (2005) cloned a splice variant of NPL. The deduced 301-amino acid splice variant, which they called NPLV2, contains an N-terminal dihydrodipicolinate synthase (DHDPS) domain and 5 putative N-terminal phosphorylation sites. RT-PCR detected highest expression in liver, kidney, and peripheral blood leukocytes, and lower expression in placenta, pancreas, spleen, thymus, ovary, and small intestine. By database analysis, Wu et al. (2005) identified 3 other NPL splice variants.GENE STRUCTURE
Wu et al. (2005) determined that the NPL gene contains 11 exons and spans over 40 kb.MAPPING
By genomic sequence analysis, Sood et al. (2001) mapped the NPL gene to chromosome 1q25. ... 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 611412 was added.