C1QC (complement C1q C chain)

Gene

• Entrez ID: 714
• Gene name: Complement C1q C chain
• Gene symbol: C1QC
• Synonyms: C1Q-C, C1QG
• Chromosome: 1
• Chromosome location: 1p36.12
• Summary: This gene encodes the C-chain polypeptide of serum complement subcomponent C1q, which associates with C1r and C1s to yield the first component of the serum complement system. C1q is composed of 18 polypeptide chains which include 6 A-chains, 6 B-chains, and 6 C-chains. Each chain contains an N-terminal collagen-like region and a C-terminal C1q globular domain. C1q deficiency is associated with lupus erythematosus and glomerulonephritis. [provided by RefSeq, Dec 2016]

SNPs

SNP ID	Visualize variation	Clinical significance	Consequence
rs200206736	G>A	Pathogenic	Missense variant, intron variant, coding sequence variant
rs377549148	C>T	Pathogenic	Coding sequence variant, 5 prime UTR variant, stop gained
rs752596663	G>A	Pathogenic	Coding sequence variant, missense variant
rs761681612	CC>-,C	Pathogenic	Frameshift variant, 5 prime UTR variant, coding sequence variant

Gene ontology (GO)

GO ID	Ontology	Definition	Evidence	Reference
GO:0005515	Function	Protein binding	IPI	28018340, 32296183
GO:0005576	Component	Extracellular region	NAS	9777412
GO:0005576	Component	Extracellular region	TAS
GO:0005581	Component	Collagen trimer	IEA
GO:0005615	Component	Extracellular space	HDA	22664934
GO:0006955	Process	Immune response	NAS	9777412
GO:0006956	Process	Complement activation	TAS
GO:0006958	Process	Complement activation, classical pathway	TAS
GO:0030449	Process	Regulation of complement activation	TAS
GO:0030853	Process	Negative regulation of granulocyte differentiation	IDA	10961870
GO:0045087	Process	Innate immune response	IEA
GO:0045202	Component	Synapse	ISS
GO:0045650	Process	Negative regulation of macrophage differentiation	IDA	10961870
GO:0062023	Component	Collagen-containing extracellular matrix	HDA	25037231, 28344315, 28675934
GO:0072562	Component	Blood microparticle	HDA	22516433
GO:0098794	Component	Postsynapse	ISS
GO:0098883	Process	Synapse pruning	ISS

Other IDs

• MIM: 120575
• HGNC: 1245
• e!Ensembl: ENSG00000159189

Protein

• UniProt ID: P02747
• Protein name: Complement C1q subcomponent subunit C
• Protein function: C1q associates with the proenzymes C1r and C1s to yield C1, the first component of the serum complement system. The collagen-like regions of C1q interact with the Ca(2+)-dependent C1r(2)C1s(2) proenzyme complex, and efficient activation of C1 takes place on interaction of the globular heads of C1q with the Fc regions of IgG or IgM antibody present in immune complexes.
• PDB: 1PK6, 2JG8, 2JG9, 2WNU, 2WNV, 5HKJ, 5HZF, 6FCZ, 6Z6V
• Family and domains:

  Pfam

  Accession	ID	Position in sequence	Description	Type
  PF01391	Collagen	61 → 117	Collagen triple helix repeat (20 copies)	Repeat
  PF00386	C1q	121 → 242	C1q domain	Domain

• Sequence:

  MDVGPSSLPHLGLKLLLLLLLLPLRGQANTGCYGIPGMPGLPGAPGKDGYDGLPGPKGEP
  GIPAIPGIRGPKGQKGEPGLPGHPGKNGPMGPPGMPGVPGPMGIPGEPGEEGRYKQKFQS
  VFTVTRQTHQPPAPNSLIRFNAVLTNPQGDYDTSTGKFTCKVPGLYYFVYHASHTANLCV
  LLYRSGVKVVTFCGHTSKTNQVNSGGVLLRLQVGEEVWLAVNDYYDMVGIQGSDSVFSGF
  LLFPD

• Sequence length: 245