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Protein

Complement C1q subcomponent subunit C

Gene

C1QC

Organism
Homo sapiens (Human)
Status
Reviewed-Annotation score: Annotation score: 5 out of 5-Experimental evidence at protein leveli

Functioni

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 Ca2+-dependent C1r2C1s2 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.

GO - Molecular functioni

GO - Biological processi

  • complement activation Source: Reactome
  • complement activation, classical pathway Source: Reactome
  • immune response Source: UniProtKB
  • innate immune response Source: UniProtKB-KW
  • negative regulation of granulocyte differentiation Source: BHF-UCL
  • negative regulation of macrophage differentiation Source: BHF-UCL
Complete GO annotation...

Keywords - Biological processi

Complement pathway, Immunity, Innate immunity

Enzyme and pathway databases

BioCyciZFISH:ENSG00000159189-MONOMER.
ReactomeiR-HSA-166663. Initial triggering of complement.
R-HSA-173623. Classical antibody-mediated complement activation.

Names & Taxonomyi

Protein namesi
Recommended name:
Complement C1q subcomponent subunit C
Gene namesi
Name:C1QC
Synonyms:C1QG
OrganismiHomo sapiens (Human)
Taxonomic identifieri9606 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo
Proteomesi
  • UP000005640 Componenti: Chromosome 1

Organism-specific databases

HGNCiHGNC:1245. C1QC.

Subcellular locationi

GO - Cellular componenti

  • blood microparticle Source: UniProtKB
  • collagen trimer Source: UniProtKB-KW
  • extracellular exosome Source: UniProtKB
  • extracellular region Source: UniProtKB
  • extracellular space Source: UniProtKB
Complete GO annotation...

Keywords - Cellular componenti

Secreted

Pathology & Biotechi

Involvement in diseasei

Complement component C1q deficiency (C1QD)1 Publication
The disease is caused by mutations affecting the gene represented in this entry.
Disease descriptionA disorder caused by impaired activation of the complement classical pathway. It generally leads to severe immune complex disease with features of systemic lupus erythematosus and glomerulonephritis.
See also OMIM:613652
Feature keyPosition(s)DescriptionActionsGraphical viewLength
Natural variantiVAR_00854234G → R in C1QD. 1 PublicationCorresponds to variant rs200206736dbSNPEnsembl.1

Keywords - Diseasei

Disease mutation

Organism-specific databases

DisGeNETi714.
MalaCardsiC1QC.
MIMi613652. phenotype.
OpenTargetsiENSG00000159189.
Orphaneti169147. Immunodeficiency due to an early component of complement deficiency.
PharmGKBiPA25626.

Chemistry databases

DrugBankiDB00054. Abciximab.
DB00051. Adalimumab.
DB00092. Alefacept.
DB00087. Alemtuzumab.
DB00074. Basiliximab.
DB00112. Bevacizumab.
DB00002. Cetuximab.
DB00111. Daclizumab.
DB00095. Efalizumab.
DB00005. Etanercept.
DB00056. Gemtuzumab ozogamicin.
DB00078. Ibritumomab.
DB00075. Muromonab.
DB00108. Natalizumab.
DB00110. Palivizumab.
DB00073. Rituximab.
DB00081. Tositumomab.
DB00072. Trastuzumab.

Polymorphism and mutation databases

BioMutaiC1QC.
DMDMi20178281.

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Signal peptidei1 – 281 PublicationAdd BLAST28
ChainiPRO_000000352429 – 245Complement C1q subcomponent subunit CAdd BLAST217

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Disulfide bondi32Interchain
Modified residuei364-hydroxyproline1 Publication1
Modified residuei394-hydroxyproline1 Publication1
Modified residuei424-hydroxyproline1 Publication1
Modified residuei454-hydroxyproline1 Publication1
Modified residuei544-hydroxyproline1 Publication1
Modified residuei634-hydroxyproline1 Publication1
Modified residuei755-hydroxylysine1 Publication1
Glycosylationi75O-linked (Gal...)1
Modified residuei814-hydroxyproline1 Publication1
Modified residuei934-hydroxyproline1 Publication1
Modified residuei964-hydroxyproline1 Publication1
Modified residuei994-hydroxyproline1 Publication1
Modified residuei1054-hydroxyproline1 Publication1

Post-translational modificationi

O-linked glycans consist of Glc-Gal disaccharides bound to the oxygen atom of post-translationally added hydroxyl groups.

Keywords - PTMi

Disulfide bond, Glycoprotein, Hydroxylation

Proteomic databases

PaxDbiP02747.
PeptideAtlasiP02747.
PRIDEiP02747.

PTM databases

PhosphoSitePlusiP02747.

Miscellaneous databases

PMAP-CutDBP02747.

Expressioni

Gene expression databases

BgeeiENSG00000159189.
CleanExiHS_C1QC.
ExpressionAtlasiP02747. baseline and differential.
GenevisibleiP02747. HS.

Organism-specific databases

HPAiCAB009828.
HPA001471.

Interactioni

Subunit structurei

C1 is a calcium-dependent trimolecular complex of C1q, R and S in the molar ration of 1:2:2. C1q subcomponent is composed of nine subunits, six of which are disulfide-linked dimers of the A and B chains, and three of which are disulfide-linked dimers of the C chain.

Protein-protein interaction databases

BioGridi107175. 2 interactors.
IntActiP02747. 4 interactors.
MINTiMINT-6630018.
STRINGi9606.ENSP00000363768.

Structurei

Secondary structure

1245
Legend: HelixTurnBeta strandPDB Structure known for this area
Show more details
Feature keyPosition(s)DescriptionActionsGraphical viewLength
Helixi116 – 118Combined sources3
Beta strandi121 – 125Combined sources5
Beta strandi142 – 145Combined sources4
Turni153 – 155Combined sources3
Beta strandi157 – 159Combined sources3
Beta strandi164 – 176Combined sources13
Beta strandi178 – 184Combined sources7
Beta strandi187 – 194Combined sources8
Beta strandi197 – 199Combined sources3
Beta strandi201 – 211Combined sources11
Beta strandi216 – 225Combined sources10
Beta strandi236 – 244Combined sources9

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum
1PK6X-ray1.85C117-245[»]
2JG8X-ray2.05C/F115-245[»]
2JG9X-ray1.90C/F115-245[»]
2WNUX-ray2.30C/F115-245[»]
2WNVX-ray1.25C/F115-245[»]
5HKJX-ray1.35A115-245[»]
5HZFX-ray1.55A115-245[»]
ProteinModelPortaliP02747.
SMRiP02747.
ModBaseiSearch...
MobiDBiSearch...

Miscellaneous databases

EvolutionaryTraceiP02747.

Family & Domainsi

Domains and Repeats

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Domaini31 – 112Collagen-likeAdd BLAST82
Domaini115 – 245C1qPROSITE-ProRule annotationAdd BLAST131

Sequence similaritiesi

Contains 1 C1q domain.PROSITE-ProRule annotation
Contains 1 collagen-like domain.Curated

Keywords - Domaini

Collagen, Repeat, Signal

Phylogenomic databases

eggNOGiENOG410IWVM. Eukaryota.
ENOG4111MQB. LUCA.
GeneTreeiENSGT00760000118830.
HOGENOMiHOG000085653.
HOVERGENiHBG108220.
InParanoidiP02747.
KOiK03988.
OMAiKVTTFCD.
OrthoDBiEOG091G0L3Y.
PhylomeDBiP02747.
TreeFamiTF329591.

Family and domain databases

Gene3Di2.60.120.40. 1 hit.
InterProiIPR001073. C1q_dom.
IPR008160. Collagen.
IPR008983. Tumour_necrosis_fac-like_dom.
[Graphical view]
PfamiPF00386. C1q. 1 hit.
PF01391. Collagen. 1 hit.
[Graphical view]
PRINTSiPR00007. COMPLEMNTC1Q.
SMARTiSM00110. C1Q. 1 hit.
[Graphical view]
SUPFAMiSSF49842. SSF49842. 1 hit.
PROSITEiPS50871. C1Q. 1 hit.
[Graphical view]

Sequencei

Sequence statusi: Complete.

Sequence processingi: The displayed sequence is further processed into a mature form.

P02747-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MDVGPSSLPH LGLKLLLLLL LLPLRGQANT GCYGIPGMPG LPGAPGKDGY
60 70 80 90 100
DGLPGPKGEP GIPAIPGIRG PKGQKGEPGL PGHPGKNGPM GPPGMPGVPG
110 120 130 140 150
PMGIPGEPGE EGRYKQKFQS VFTVTRQTHQ PPAPNSLIRF NAVLTNPQGD
160 170 180 190 200
YDTSTGKFTC KVPGLYYFVY HASHTANLCV LLYRSGVKVV TFCGHTSKTN
210 220 230 240
QVNSGGVLLR LQVGEEVWLA VNDYYDMVGI QGSDSVFSGF LLFPD
Length:245
Mass (Da):25,774
Last modified:April 16, 2002 - v3
Checksum:iFA17117EB7ABFC12
GO

Experimental Info

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Sequence conflicti14K → R in BAB71575 (PubMed:14702039).Curated1
Sequence conflicti23P → A no nucleotide entry (PubMed:1706597).Curated1
Sequence conflicti26 – 27GQ → AK in AAP97191 (Ref. 2) Curated2
Sequence conflicti57K → P AA sequence (PubMed:486087).Curated1
Sequence conflicti66P → K AA sequence (PubMed:486087).Curated1
Sequence conflicti72K → P AA sequence (PubMed:486087).Curated1
Sequence conflicti84P → K AA sequence (PubMed:486087).Curated1
Sequence conflicti87N → D AA sequence (PubMed:486087).Curated1
Sequence conflicti90M → N AA sequence (PubMed:486087).Curated1
Sequence conflicti104I → F in AAP97191 (Ref. 2) Curated1
Sequence conflicti149G → E in AAP97191 (Ref. 2) Curated1
Sequence conflicti215E → G in BAB71575 (PubMed:14702039).Curated1

Natural variant

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Natural variantiVAR_00854234G → R in C1QD. 1 PublicationCorresponds to variant rs200206736dbSNPEnsembl.1

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AF087892 mRNA. Translation: AAP97191.1.
AK057792 mRNA. Translation: BAB71575.1.
AL158086 Genomic DNA. Translation: CAI22894.1.
BC009016 mRNA. Translation: AAH09016.1.
CCDSiCCDS227.1.
PIRiS14351. C1HUQC.
RefSeqiNP_001107573.1. NM_001114101.1.
NP_758957.2. NM_172369.3.
UniGeneiHs.467753.

Genome annotation databases

EnsembliENST00000374637; ENSP00000363768; ENSG00000159189.
ENST00000374639; ENSP00000363770; ENSG00000159189.
ENST00000374640; ENSP00000363771; ENSG00000159189.
GeneIDi714.
KEGGihsa:714.
UCSCiuc001bga.5. human.

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AF087892 mRNA. Translation: AAP97191.1.
AK057792 mRNA. Translation: BAB71575.1.
AL158086 Genomic DNA. Translation: CAI22894.1.
BC009016 mRNA. Translation: AAH09016.1.
CCDSiCCDS227.1.
PIRiS14351. C1HUQC.
RefSeqiNP_001107573.1. NM_001114101.1.
NP_758957.2. NM_172369.3.
UniGeneiHs.467753.

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum
1PK6X-ray1.85C117-245[»]
2JG8X-ray2.05C/F115-245[»]
2JG9X-ray1.90C/F115-245[»]
2WNUX-ray2.30C/F115-245[»]
2WNVX-ray1.25C/F115-245[»]
5HKJX-ray1.35A115-245[»]
5HZFX-ray1.55A115-245[»]
ProteinModelPortaliP02747.
SMRiP02747.
ModBaseiSearch...
MobiDBiSearch...

Protein-protein interaction databases

BioGridi107175. 2 interactors.
IntActiP02747. 4 interactors.
MINTiMINT-6630018.
STRINGi9606.ENSP00000363768.

Chemistry databases

DrugBankiDB00054. Abciximab.
DB00051. Adalimumab.
DB00092. Alefacept.
DB00087. Alemtuzumab.
DB00074. Basiliximab.
DB00112. Bevacizumab.
DB00002. Cetuximab.
DB00111. Daclizumab.
DB00095. Efalizumab.
DB00005. Etanercept.
DB00056. Gemtuzumab ozogamicin.
DB00078. Ibritumomab.
DB00075. Muromonab.
DB00108. Natalizumab.
DB00110. Palivizumab.
DB00073. Rituximab.
DB00081. Tositumomab.
DB00072. Trastuzumab.

PTM databases

PhosphoSitePlusiP02747.

Polymorphism and mutation databases

BioMutaiC1QC.
DMDMi20178281.

Proteomic databases

PaxDbiP02747.
PeptideAtlasiP02747.
PRIDEiP02747.

Protocols and materials databases

DNASUi714.
Structural Biology KnowledgebaseSearch...

Genome annotation databases

EnsembliENST00000374637; ENSP00000363768; ENSG00000159189.
ENST00000374639; ENSP00000363770; ENSG00000159189.
ENST00000374640; ENSP00000363771; ENSG00000159189.
GeneIDi714.
KEGGihsa:714.
UCSCiuc001bga.5. human.

Organism-specific databases

CTDi714.
DisGeNETi714.
GeneCardsiC1QC.
HGNCiHGNC:1245. C1QC.
HPAiCAB009828.
HPA001471.
MalaCardsiC1QC.
MIMi120575. gene.
613652. phenotype.
neXtProtiNX_P02747.
OpenTargetsiENSG00000159189.
Orphaneti169147. Immunodeficiency due to an early component of complement deficiency.
PharmGKBiPA25626.
GenAtlasiSearch...

Phylogenomic databases

eggNOGiENOG410IWVM. Eukaryota.
ENOG4111MQB. LUCA.
GeneTreeiENSGT00760000118830.
HOGENOMiHOG000085653.
HOVERGENiHBG108220.
InParanoidiP02747.
KOiK03988.
OMAiKVTTFCD.
OrthoDBiEOG091G0L3Y.
PhylomeDBiP02747.
TreeFamiTF329591.

Enzyme and pathway databases

BioCyciZFISH:ENSG00000159189-MONOMER.
ReactomeiR-HSA-166663. Initial triggering of complement.
R-HSA-173623. Classical antibody-mediated complement activation.

Miscellaneous databases

ChiTaRSiC1QC. human.
EvolutionaryTraceiP02747.
GenomeRNAii714.
PMAP-CutDBP02747.
PROiP02747.
SOURCEiSearch...

Gene expression databases

BgeeiENSG00000159189.
CleanExiHS_C1QC.
ExpressionAtlasiP02747. baseline and differential.
GenevisibleiP02747. HS.

Family and domain databases

Gene3Di2.60.120.40. 1 hit.
InterProiIPR001073. C1q_dom.
IPR008160. Collagen.
IPR008983. Tumour_necrosis_fac-like_dom.
[Graphical view]
PfamiPF00386. C1q. 1 hit.
PF01391. Collagen. 1 hit.
[Graphical view]
PRINTSiPR00007. COMPLEMNTC1Q.
SMARTiSM00110. C1Q. 1 hit.
[Graphical view]
SUPFAMiSSF49842. SSF49842. 1 hit.
PROSITEiPS50871. C1Q. 1 hit.
[Graphical view]
ProtoNetiSearch...

Entry informationi

Entry nameiC1QC_HUMAN
AccessioniPrimary (citable) accession number: P02747
Secondary accession number(s): Q7Z502, Q96DL2, Q96H05
Entry historyi
Integrated into UniProtKB/Swiss-Prot: July 21, 1986
Last sequence update: April 16, 2002
Last modified: November 30, 2016
This is version 177 of the entry and version 3 of the sequence. [Complete history]
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programChordata Protein Annotation Program
DisclaimerAny medical or genetic information present in this entry is provided for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care.

Miscellaneousi

Keywords - Technical termi

3D-structure, Complete proteome, Direct protein sequencing, Reference proteome

Documents

  1. Human chromosome 1
    Human chromosome 1: entries, gene names and cross-references to MIM
  2. Human entries with polymorphisms or disease mutations
    List of human entries with polymorphisms or disease mutations
  3. Human polymorphisms and disease mutations
    Index of human polymorphisms and disease mutations
  4. MIM cross-references
    Online Mendelian Inheritance in Man (MIM) cross-references in UniProtKB/Swiss-Prot
  5. PDB cross-references
    Index of Protein Data Bank (PDB) cross-references
  6. SIMILARITY comments
    Index of protein domains and families

Similar proteinsi

Links to similar proteins from the UniProt Reference Clusters (UniRef) at 100%, 90% and 50% sequence identity:
100%UniRef100 combines identical sequences and sub-fragments with 11 or more residues from any organism into one UniRef entry.
90%UniRef90 is built by clustering UniRef100 sequences that have at least 90% sequence identity to, and 80% overlap with, the longest sequence (a.k.a seed sequence).
50%UniRef50 is built by clustering UniRef90 seed sequences that have at least 50% sequence identity to, and 80% overlap with, the longest sequence in the cluster.