Ficolin-3 (FCN3)
The protein contains 299 amino acids for an estimated molecular weight of 32903 Da.
May function in innate immunity through activation of the lectin complement pathway. Calcium-dependent and GlcNAc-binding lectin. Has affinity with GalNAc, GlcNAc, D-fucose, as mono/oligosaccharide and lipopolysaccharides from S.typhimurium and S.minnesota. (updated: March 4, 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.
- 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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No binding partner found
Biological Process
Complement activation
Complement activation, lectin pathway
Defense response to virus
Innate immune response
Negative regulation of RNA biosynthetic process
Negative regulation of viral entry into host cell
Recognition of apoptotic cell
The reference OMIM entry for this protein is 604973
Ficolin 3; fcn3
Hakata antigen; haka1
Collagen/fibrinogen domain-containing lectin 3 p35
DESCRIPTION
Ficolin-3, also known as the Hakata antigen, is a recognition molecule in the lectin pathway of the complement system. It is the predominant lectin-pathway recognition molecule in plasma (summary by Munthe-Fog et al., 2009).CLONING
Based on micropeptide sequence analysis and the use of PCR to screen a lung cDNA library, Sugimoto et al. (1998) obtained a cDNA encoding the Hakata antigen, which was later designated ficolin-3 (FCN3). Sequence analysis predicted that the deduced 299-amino acid protein contains a 24-amino acid signal sequence, 1 potential N-glycosylation site, a collagen-like domain, and a fibrinogen-like domain. The Hakata antigen shows 48% sequence homology with the FCN1 (601252) and FCN2 (601624) proteins. Western blot analysis demonstrated that the Hakata antigen is expressed as a 35-kD protein that reacts with systemic lupus erythematosus (SLE; 125270) sera. Electron microscopy showed that the Hakata antigen resembles FCN1, having globular domains on the ends of thin rods.MAPPING
Gross (2013) mapped the FCN3 gene to chromosome 1p36.11 based on an alignment of the FCN3 sequence (GenBank GENBANK AY756173) with the genomic sequence (GRCh37).GENE FUNCTION
Unlike FCN1 and FCN2, Hakata antigen does not bind fibronectin (FN1; 135600), elastin (ELN; 130160), or zymosan. Like FCN1, the lectin activity of the Hakata antigen is calcium independent (Sugimoto et al., 1998). The Hakata antigen is a thermolabile beta-2-macroglycoprotein found in all human serum. Antibody to this antigen is found 14 times more frequently in the serum of patients with systemic lupus erythematosus (SLE; 152700) than in patients with other autoimmune diseases (Inaba et al., 1990).MOLECULAR GENETICS
In a patient with immunodeficiency and recurrent infections associated with complete ficolin-3 deficiency (613860), Munthe-Fog et al. (2009) found homozygosity for a truncating variant in the FCN3 gene (604973.0001; dbSNP rs28357092). He had normal levels of lymphocytes, normal T-cell responses, and normal antibodies, but a selective deficient antibody response to pneumococcal polysaccharide vaccine. Laboratory studies showed impaired complement deposition when acetylated bovine serum albumin was used, indicating a defect in complement activation. The allele frequency of the variant was 0.01 among a total of 1,282 patients with various immunodeficiencies; all were heterozygous for the variant except the index patient. Munthe-Fog et al. (2009) concluded that homozygosity for this variant in the FCN3 gene results in a recessive complement deficiency syndrome.EVOLUTION
Endo et al. (2012) noted that human FCN1 is the ortholog of mouse Fcnb. Human FCN2 is closely related to mouse Fcna, but the genes appear to have evolved independently in each murine and primate lineage. The human FCN3 gene is a pseudogene in mouse. ... 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
June 20, 2017: Protein entry updated
Automatic update: comparative model was added.
March 25, 2017: Additional information
No protein expression data in P. Mayeux work for FCN3
March 16, 2016: Protein entry updated
Automatic update: OMIM entry 604973 was added.
Jan. 28, 2016: Protein entry updated
Automatic update: model status changed
Jan. 24, 2016: Protein entry updated
Automatic update: model status changed