Ketosamine-3-kinase (FN3KRP)
The protein contains 309 amino acids for an estimated molecular weight of 34412 Da.
Ketosamine-3-kinase involved in protein deglycation by mediating phosphorylation of ribuloselysine and psicoselysine on glycated proteins, to generate ribuloselysine-3 phosphate and psicoselysine-3 phosphate, respectively (PubMed:14633848, PubMed:15137908). Ribuloselysine-3 phosphate and psicoselysine-3 phosphate adducts are unstable and decompose under physiological conditions (PubMed:14633848, PubMed:15137908). Not able to phosphorylate fructoselysine (PubMed:14633848). (updated: Oct. 16, 2019)
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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| Variant | Description |
|---|---|
| dbSNP:rs3748811 |
The reference OMIM entry for this protein is 611683
Fructosamine 3-kinase-related protein
Fn3k-related protein; fn3krp
DESCRIPTION
FN3KRP and FN3K (608425) protect proteins from nonenzymatic glycation by phosphorylating the modified amino acid. This phosphorylation destabilizes the sugar-amine linkage and leads to spontaneous decomposition (Conner et al., 2004).CLONING
By searching an EST database for homologs of FN3K, Collard et al. (2003) identified FN3KRP. The deduced 309-amino acid protein has a calculated molecular mass of 34.4 kD and shares 88% identity with mouse Fn3krp. Like FN3K, FN3KRP has an HGDxxxxN motif that is also found in aminoglycoside kinases. Northern blot analysis detected Fn3krp expression in all mouse tissues examined except intestinal mucosa. Highest expression was in bone marrow, brain, spleen, and kidney. Using RT-PCR, Conner et al. (2004) detected FN3KRP expression in all human tissues examined.GENE FUNCTION
Collard et al. (2003) partially purified FN3KRP following expression in human embryonic kidney cells and found that it phosphorylated psicosamines and ribulosamines, but not fructosamines. Mass spectrometry and NMR spectroscopy of a phosphorylated synthetic psicose substrate identified C3 as the phosphorylated carbon. Collard et al. (2003) concluded that FN3KRP is a ketosamine 3-kinase with a substrate specificity distinct from that of FN3K. Collard et al. (2004) found that human erythrocytes had higher intracellular levels of active FN3KRP than FN3K. Szwergold et al. (2007) found that human erythrocytes that contain both FN3K and FN3KRP phosphorylated N-methylglucamine to 2 different products, and FN3KRP specifically phosphorylated the C-4 hydroxyl. FN3KRP also phosphorylated other glucitolamines at the C-4 position. Szwergold et al. (2007) noted that all substrates used to characterize FN3KRP to that time were nonphysiologic. This and the unique stereospecificity displayed by FN3KRP suggested to them that the primary role of FN3KRP may not be as a deglycating enzyme.GENE STRUCTURE
Collard et al. (2003) determined that the FN3KRP gene contains 6 exons. Conner et al. (2004) found that the promoter region of the FN3KRP gene has a high GC content, but no TATA or CAAT boxes.MAPPING
By genomic sequence analysis, Collard et al. (2003) mapped the FN3KR gene 8.5 kb upstream of the FN3K gene on chromosome 17q25. ... More on the omim web site
Oct. 27, 2019: Protein entry updated
Automatic update: Entry updated from uniprot information.
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 611683 was added.