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Aliases for C1S Gene

Aliases for C1S Gene

  • Complement Component 1, S Subcomponent 2 3 5
  • EC 4 63
  • Complement Component 1 Subcomponent S 4
  • C1 Esterase 4
  • EC 3.4.21 63

External Ids for C1S Gene

Previous GeneCards Identifiers for C1S Gene

  • GC12U990009
  • GC12P006975
  • GC12P007038
  • GC12P007096
  • GC12P007028
  • GC12P007042
  • GC12P007182

Summaries for C1S Gene

Entrez Gene Summary for C1S Gene

  • This gene encodes a serine protease, which is a major constituent of the human complement subcomponent C1. C1s associates with two other complement components C1r and C1q in order to yield the first component of the serum complement system. Defects in this gene are the cause of selective C1s deficiency. [provided by RefSeq, Mar 2009]

GeneCards Summary for C1S Gene

C1S (Complement Component 1, S Subcomponent) is a Protein Coding gene. Diseases associated with C1S include C1s Deficiency and Immunodeficiency Due To An Early Component Of Complement Deficiency. Among its related pathways are Immune System and Creation of C4 and C2 activators. GO annotations related to this gene include calcium ion binding and serine-type endopeptidase activity. An important paralog of this gene is HP.

UniProtKB/Swiss-Prot for C1S Gene

  • 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.

Gene Wiki entry for C1S Gene

No data available for Tocris Summary , PharmGKB "VIP" Summary , fRNAdb sequence ontologies and piRNA Summary for C1S Gene

Genomics for C1S Gene

Regulatory Elements for C1S Gene

Enhancers for C1S Gene
GeneHancer Identifier Score Enhancer Sources TSS distance (kb) Number of Genes Away Size (kb) Transcription Factor Binding Sites within enhancer Other Gene Targets for Enhancer

Enhancers around C1S on UCSC Golden Path with GeneCards custom track

Genomic Location for C1S Gene

6,988,259 bp from pter
7,071,032 bp from pter
82,774 bases
Plus strand

Genomic View for C1S Gene

Genes around C1S on UCSC Golden Path with GeneCards custom track

Cytogenetic band:
C1S Gene in genomic location: bands according to Ensembl, locations according to GeneLoc (and/or Entrez Gene and/or Ensembl if different)
Genomic Location for C1S Gene
GeneLoc Logo Genomic Neighborhood Exon StructureGene Density

RefSeq DNA sequence for C1S Gene

Proteins for C1S Gene

  • Protein details for C1S Gene (UniProtKB/Swiss-Prot)

    Protein Symbol:
    Recommended name:
    Complement C1s subcomponent
    Protein Accession:
    Secondary Accessions:
    • D3DUT4
    • Q9UCU7
    • Q9UCU8
    • Q9UCU9
    • Q9UCV0
    • Q9UCV1
    • Q9UCV2
    • Q9UCV3
    • Q9UCV4
    • Q9UCV5
    • Q9UM14

    Protein attributes for C1S Gene

    688 amino acids
    Molecular mass:
    76684 Da
    Quaternary structure:
    • C1 is a calcium-dependent trimolecular complex of C1q, C1r and C1s in the molar ration of 1:2:2. Activated C1s is an disulfide-linked heterodimer of a heavy chain and a light chain.

    Three dimensional structures from OCA and Proteopedia for C1S Gene

neXtProt entry for C1S Gene

Proteomics data for C1S Gene at MOPED

Post-translational modifications for C1S Gene

  • The iron and 2-oxoglutarate dependent 3-hydroxylation of aspartate and asparagine is (R) stereospecific within EGF domains.
  • Glycosylation at Asn 174 and Asn 406
  • Modification sites at PhosphoSitePlus

Antibody Products

  • R&D Systems Antibodies for C1S (Complement Component C1s)
  • Abcam antibodies for C1s

Domains & Families for C1S Gene

Gene Families for C1S Gene

Suggested Antigen Peptide Sequences for C1S Gene

GenScript: Design optimal peptide antigens:

Graphical View of Domain Structure for InterPro Entry



  • Contains 2 CUB domains.
  • Belongs to the peptidase S1 family.
  • Contains 2 CUB domains.
  • Contains 1 EGF-like domain.
  • Contains 1 peptidase S1 domain.
  • Contains 2 Sushi (CCP/SCR) domains.
  • Belongs to the peptidase S1 family.
genes like me logo Genes that share domains with C1S: view

Function for C1S Gene

Molecular function for C1S Gene

GENATLAS Biochemistry:
complement component 1,s subcomponent,83kDa,tetramerizing with C1r (2C1r,2C1S),activating C2 and C4 after cleavage,classical pathway of C3 activation
UniProtKB/Swiss-Prot BiophysicochemicalProperties:
Kinetic parameters: KM=12.3 uM for complement component C2 (at 37 degrees Celsius) {ECO:0000269 PubMed:11527969}; KM=1.9 uM for complement component C4 (at 37 degrees Celsius) {ECO:0000269 PubMed:11527969}; Note=Less efficient than MASP2 in C4 cleavage.;
UniProtKB/Swiss-Prot CatalyticActivity:
Cleavage of Arg- -Ala bond in complement component C4 to form C4a and C4b, and Lys(or Arg)- -Lys bond in complement component C2 to form C2a and C2b: the classical pathway C3 convertase.
UniProtKB/Swiss-Prot EnzymeRegulation:
Inhibited by SERPING1.
UniProtKB/Swiss-Prot Function:
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.

Enzyme Numbers (IUBMB) for C1S Gene

genes like me logo Genes that share phenotypes with C1S: view

Human Phenotype Ontology for C1S Gene

HPO Id HPO Name Alternative Ids Definition Synonyms

Animal Model Products

No data available for Gene Ontology (GO) - Molecular Function , Animal Models , Transcription Factor Targets and HOMER Transcription for C1S Gene

Localization for C1S Gene

Subcellular locations from

Jensen Localization Image for C1S Gene COMPARTMENTS Subcellular localization image for C1S gene
Compartment Confidence
extracellular 5
plasma membrane 2
lysosome 1
vacuole 1

Gene Ontology (GO) - Cellular Components for C1S Gene

GO ID Qualified GO term Evidence PubMed IDs
GO:0072562 blood microparticle IDA 22516433
genes like me logo Genes that share ontologies with C1S: view

No data available for Subcellular locations from UniProtKB/Swiss-Prot for C1S Gene

Pathways & Interactions for C1S Gene

genes like me logo Genes that share pathways with C1S: view

Gene Ontology (GO) - Biological Process for C1S Gene

GO ID Qualified GO term Evidence PubMed IDs
GO:0045087 innate immune response IEA,TAS --
genes like me logo Genes that share ontologies with C1S: view

No data available for SIGNOR curated interactions for C1S Gene

Drugs & Compounds for C1S Gene

(27) Drugs for C1S Gene - From: DrugBank, FDA Approved Drugs, HMDB, and Novoseek

Name Status Disease Links Group Role Mechanism of Action Clinical Trials
Abciximab Approved Pharma Target 64
Adalimumab Approved Pharma Target 451
Cetuximab Approved Pharma Target EGFR Inhibitors, Therapeutic Antibodies, Epidermal growth factor receptor (EGFR) inhibitors 717
Daclizumab Approved, Investigational Pharma Target 97,129
Etanercept Approved, Investigational Pharma Target 389

(8) Additional Compounds for C1S Gene - From: Novoseek

Name Synonyms Role CAS Number PubChem IDs PubMed IDs
genes like me logo Genes that share compounds with C1S: view

Transcripts for C1S Gene

mRNA/cDNA for C1S Gene

(3) REFSEQ mRNAs :
(6) Additional mRNA sequences :
(10) Selected AceView cDNA sequences:
(21) Ensembl transcripts including schematic representations, and UCSC links where relevant :

Unigene Clusters for C1S Gene

Complement component 1, s subcomponent:
Representative Sequences:

Alternative Splicing Database (ASD) splice patterns (SP) for C1S Gene

ExUns: 1a · 1b · 1c · 1d · 1e ^ 2a · 2b ^ 3a · 3b ^ 4a · 4b ^ 5 ^ 6a · 6b · 6c · 6d · 6e ^ 7a · 7b · 7c ^ 8a · 8b · 8c ^ 9a · 9b · 9c ·
SP1: - - - - - - -
SP2: - - - - -
SP3: - -
SP4: - - - - - - - - - - - - - - -
SP5: - - - - - - - - - -
SP6: - - - - - - - - - - - - -
SP7: - - - - - - - - - - - - - - - - -
SP9: - - - - - - - - - - -
SP10: - - - - - - - - - - - - -
SP11: - - - - -
SP12: - - -
SP13: - - -
SP14: -
SP15: - - -
SP16: - -
SP18: - - - - -
SP19: - - - - - - - -
SP21: - - - - -

ExUns: 9d · 9e ^ 10a · 10b ^ 11 ^ 12a · 12b · 12c ^ 13a · 13b · 13c ^ 14a · 14b ^ 15a · 15b · 15c ^ 16 ^ 17 ^ 18a · 18b · 18c
SP1: - -
SP2: - -
SP3: -
SP7: - - - -
SP8: - - -

Relevant External Links for C1S Gene

GeneLoc Exon Structure for
ECgene alternative splicing isoforms for

Expression for C1S Gene

mRNA expression in normal human tissues for C1S Gene

mRNA expression in embryonic tissues and stem cells from LifeMap Discovery

mRNA differential expression in normal tissues according to GTEx for C1S Gene

This gene is overexpressed in Liver (x7.6).

Protein differential expression in normal tissues from HIPED for C1S Gene

This gene is overexpressed in Serum (25.9), Plasma (13.3), and Synovial fluid (9.6).

Integrated Proteomics: protein expression in normal tissues and cell lines from ProteomicsDB, PaxDb, MOPED, and MaxQB for C1S Gene

SOURCE GeneReport for Unigene cluster for C1S Gene Hs.458355

genes like me logo Genes that share expression patterns with C1S: view

Protein tissue co-expression partners for C1S Gene

- Elite partner

No data available for mRNA Expression by UniProt/SwissProt for C1S Gene

Orthologs for C1S Gene

This gene was present in the common ancestor of chordates.

Orthologs for C1S Gene

Organism Taxonomy Gene Similarity Type Details
(Bos Taurus)
Mammalia C1S 35
  • 79.99 (n)
  • 75 (a)
C1S 36
  • 74 (a)
(Canis familiaris)
Mammalia C1S 35
  • 84.88 (n)
  • 79.8 (a)
C1S 36
  • 79 (a)
(Mus musculus)
Mammalia Gm5077 35
  • 80.01 (n)
  • 74.67 (a)
C1s2 16
C1s 36
  • 74 (a)
Gm5077 36
  • 74 (a)
(Pan troglodytes)
Mammalia C1S 35
  • 99.18 (n)
  • 98.98 (a)
C1S 36
  • 93 (a)
(Rattus norvegicus)
Mammalia C1s 35
  • 80.3 (n)
  • 76.13 (a)
(Monodelphis domestica)
Mammalia C1S 36
  • 69 (a)
(Ornithorhynchus anatinus)
Mammalia C1S 36
  • 67 (a)
(Gallus gallus)
Aves C1S 35
  • 63.15 (n)
  • 56.3 (a)
C1S 36
  • 56 (a)
(Anolis carolinensis)
Reptilia -- 36
  • 58 (a)
-- 36
  • 55 (a)
tropical clawed frog
(Silurana tropicalis)
Amphibia c1s 35
  • 58.03 (n)
  • 52.88 (a)
African clawed frog
(Xenopus laevis)
Amphibia Xl.5153 35
(Danio rerio)
Actinopterygii c1r 36
  • 36 (a)
C1S (2 of 3) 36
  • 34 (a)
C1S (3 of 3) 36
  • 35 (a)
sea squirt
(Ciona savignyi)
Ascidiacea -- 36
  • 27 (a)
-- 36
  • 28 (a)
-- 36
  • 26 (a)
-- 36
  • 26 (a)
CSA.10613 36
  • 23 (a)
Species with no ortholog for C1S:
  • A. gosspyii yeast (Ashbya gossypii)
  • Actinobacteria (Mycobacterium tuberculosis)
  • African malaria mosquito (Anopheles gambiae)
  • Alicante grape (Vitis vinifera)
  • alpha proteobacteria (Wolbachia pipientis)
  • amoeba (Dictyostelium discoideum)
  • Archea (Pyrococcus horikoshii)
  • baker's yeast (Saccharomyces cerevisiae)
  • barley (Hordeum vulgare)
  • beta proteobacteria (Neisseria meningitidis)
  • bread mold (Neurospora crassa)
  • Chromalveolata (Phytophthora infestans)
  • common water flea (Daphnia pulex)
  • corn (Zea mays)
  • E. coli (Escherichia coli)
  • filamentous fungi (Aspergillus nidulans)
  • Firmicute bacteria (Streptococcus pneumoniae)
  • fission yeast (Schizosaccharomyces pombe)
  • fruit fly (Drosophila melanogaster)
  • green algae (Chlamydomonas reinhardtii)
  • honey bee (Apis mellifera)
  • K. lactis yeast (Kluyveromyces lactis)
  • loblloly pine (Pinus taeda)
  • malaria parasite (Plasmodium falciparum)
  • medicago trunc (Medicago Truncatula)
  • moss (Physcomitrella patens)
  • orangutan (Pongo pygmaeus)
  • pig (Sus scrofa)
  • rainbow trout (Oncorhynchus mykiss)
  • rice (Oryza sativa)
  • rice blast fungus (Magnaporthe grisea)
  • schistosome parasite (Schistosoma mansoni)
  • sea anemone (Nematostella vectensis)
  • sea urchin (Strongylocentrotus purpuratus)
  • sorghum (Sorghum bicolor)
  • soybean (Glycine max)
  • stem rust fungus (Puccinia graminis)
  • sugarcane (Saccharum officinarum)
  • thale cress (Arabidopsis thaliana)
  • tomato (Lycopersicon esculentum)
  • toxoplasmosis (Toxoplasma gondii)
  • Trichoplax (Trichoplax adhaerens)
  • wheat (Triticum aestivum)
  • worm (Caenorhabditis elegans)

Evolution for C1S Gene

Gene Tree for C1S (if available)
Gene Tree for C1S (if available)

Paralogs for C1S Gene

Paralogs for C1S Gene

genes like me logo Genes that share paralogs with C1S: view

Variants for C1S Gene

Sequence variations from dbSNP and Humsavar for C1S Gene

SNP ID Clin Chr 12 pos Sequence Context AA Info Type
rs20573 - 7,067,724(+) CATCC(A/G)CTACA reference, missense
rs12146727 - 7,063,032(+) AGAGC(A/G)TTTTA reference, missense
rs2239170 - 7,066,625(+) TTGAA(A/C/G)TTGTG reference, missense
rs7183 -- 7,070,715(+) CTTAT(G/T)ATATT utr-variant-3-prime
rs13694 -- 7,070,756(+) ACGAG(C/T)GAATG utr-variant-3-prime

Variation tolerance for C1S Gene

Residual Variation Intolerance Score: 26.8% of all genes are more intolerant (likely to be disease-causing)
Gene Damage Index Score: 6.59; 78.06% of all genes are more intolerant (likely to be disease-causing)

Relevant External Links for C1S Gene

Human Gene Mutation Database (HGMD)

No data available for Polymorphic Variants from UniProtKB/Swiss-Prot and Structural Variations from Database of Genomic Variants (DGV) for C1S Gene

Disorders for C1S Gene

MalaCards: The human disease database

(17) MalaCards diseases for C1S Gene - From: OMIM, Orphanet, DISEASES, Novoseek, and GeneCards

Disorder Aliases PubMed IDs
c1s deficiency
  • complement component c1s deficiency
immunodeficiency due to an early component of complement deficiency
  • immunodeficiency due to a c1, c4, or c2 component complement deficiency
hereditary angioedema
  • c1 inhibitor deficiency
  • angioneurotic edema
capillary leak syndrome
- elite association - COSMIC cancer census association via MalaCards
Search C1S in MalaCards View complete list of genes associated with diseases


  • Complement component C1s deficiency (C1SD) [MIM:613783]: A rare defect resulting in C1 deficiency and impaired activation of the complement classical pathway. C1 deficiency generally leads to severe immune complex disease with features of systemic lupus erythematosus and glomerulonephritis. {ECO:0000269 PubMed:11390518}. Note=The disease is caused by mutations affecting the gene represented in this entry.

Genatlas disease for C1S Gene

lupus systemic-like syndrome

Relevant External Links for C1S

Genetic Association Database (GAD)
Human Genome Epidemiology (HuGE) Navigator
Atlas of Genetics and Cytogenetics in Oncology and Haematology:
genes like me logo Genes that share disorders with C1S: view

Publications for C1S Gene

  1. X-ray structure of the Ca2+-binding interaction domain of C1s. Insights into the assembly of the C1 complex of complement. (PMID: 12788922) Gregory L.A. … Gaboriaud C. (J. Biol. Chem. 2003) 3 4 23 67
  2. Genetic analysis of complement C1s deficiency associated with systemic lupus erythematosus highlights alternative splicing of normal C1s gene. (PMID: 18062908) Amano M.T. … Isaac L. (Mol. Immunol. 2008) 3 23
  3. Molecular basis of a selective C1s deficiency associated with early onset multiple autoimmune diseases. (PMID: 11390518) Dragon-Durey M.-A. … Fridman W.-H. (J. Immunol. 2001) 3 23
  4. Interaction of C1q and mannan-binding lectin (MBL) with C1r, C1s, MBL-associated serine proteases 1 and 2, and the MBL-associated protein MAp19. (PMID: 10878362) Thiel S. … Jensenius J.C. (J. Immunol. 2000) 3 23
  5. Heparin binding and augmentation of C1 inhibitor activity. (PMID: 9882449) Caldwell E.E. … Weiler J.M. (Arch. Biochem. Biophys. 1999) 3 23

Products for C1S Gene

Sources for C1S Gene