Complement C1s subcomponent (C1S)
The protein contains 688 amino acids for an estimated molecular weight of 76684 Da.
C1s B chain is a serine protease that combines with C1q and C1r to form C1, the first component of the classical pathway of the complement system. C1r activates C1s so that it can, in turn, activate C2 and C4. (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.
- 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:rs12146727 | |
| dbSNP:rs2239170 | |
| dbSNP:rs20573 | |
| EDSPD2 |
Biological Process
Complement activation
Complement activation, classical pathway
Complement activation, lectin pathway
Innate immune response
Regulation of complement activation
Cellular Component
Blood microparticle
Extracellular exosome
Extracellular region
Extracellular space
The reference OMIM entry for this protein is 120580
Complement component 1, s subcomponent; c1s
Complement component c1s
CLONING
MacKinnon et al. (1987) derived the complete amino acid sequence of C1s from molecular cloning of cDNA. Tosi et al. (1987) presented the complete cDNA sequence of C1s. Kusumoto et al. (1988) found that the amino acid sequence of C1s was 40.5% identical to that of C1r (216950), with excellent matches of tentative disulfide bond locations conserving the overall domain structure of C1r.MAPPING
By means of a cDNA in somatic cell hybrids, Cohen-Haguenauer et al. (1986) assigned the C1S and C1R (216950) genes to chromosome 12. Leppert et al. (1987) found a maximum lod score of 5.99 at theta = 0.038 for linkage between C1S and one of the PRP loci (see 168710); the maximum lod score between C1R and another PRP locus was 4.21 at theta = 0.001. Although C1r and C1s are structurally and functionally similar, with a significant degree of sequence homology suggesting origin by gene duplication, cDNA probes for human C1r and C1s do not cross-hybridize even at mild stringency conditions and are therefore gene-specific. Using a panel of human-rodent cell hybrids, Van Cong et al. (1988) independently assigned the C1r and C1s genes to chromosome 12. In situ hybridization confirmed these assignments and localized the genes to 12p13. By hybridization of C1r and C1s probes to restriction endonuclease fragments of genomic DNA, Tosi et al. (1987) demonstrated close physical linkage of the genes. This finding was consistent with their evolution through tandem gene duplication and was also consistent with the previously observed combined hereditary deficiencies of C1r and C1s (see 216950). Their coordinate expression may depend on the close linkage. The 2 genes lie in a DNA stretch not longer than 50 kb. By DNA blotting and sequencing analyses of genomic DNA and of an isolated genomic DNA clone, Kusumoto et al. (1988) showed that the C1r and C1s genes are closely located in a 'tail-to-tail' arrangement at a distance of about 9.5 kb.MOLECULAR GENETICS
Inoue et al. (1998) reported a patient with selective C1s deficiency (613783) resulting from a homozygous mutation in the C1S gene (120580.0001). In a 27-month-old girl with multiple autoimmune diseases, Dragon-Durey et al. (2001) detected selective C1S deficiency (613783) resulting from a homozygous nonsense mutation in exon 12 of the C1S gene (120580.0002). ... 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 25, 2017: Additional information
No protein expression data in P. Mayeux work for C1S
March 16, 2016: Protein entry updated
Automatic update: OMIM entry 120580 was added.
Jan. 24, 2016: Protein entry updated
Automatic update: model status changed