UniProtKB - P02745 (C1QA_HUMAN)
Complement C1q subcomponent subunit A
C1QA
Functioni
GO - Molecular functioni
- amyloid-beta binding Source: ARUK-UCL
GO - Biological processi
- aging Source: ARUK-UCL
- astrocyte activation Source: ARUK-UCL
- cell-cell signaling Source: ProtInc
- complement activation Source: Reactome
- complement activation, classical pathway Source: Reactome
- complement-mediated synapse pruning Source: ARUK-UCL
- innate immune response Source: UniProtKB-KW
- microglial cell activation Source: ARUK-UCL
- neuron remodeling Source: ARUK-UCL
- positive regulation of neuron death Source: ARUK-UCL
- regulation of complement activation Source: Reactome
- response to iron ion Source: Ensembl
- synapse organization Source: ARUK-UCL
- synapse pruning Source: ARUK-UCL
- vertebrate eye-specific patterning Source: ARUK-UCL
- viral process Source: UniProtKB-KW
Keywordsi
Biological process | Complement pathway, Host-virus interaction, Immunity, Innate immunity |
Enzyme and pathway databases
PathwayCommonsi | P02745 |
Reactomei | R-HSA-166663, Initial triggering of complement R-HSA-173623, Classical antibody-mediated complement activation R-HSA-977606, Regulation of Complement cascade |
Names & Taxonomyi
Protein namesi | Recommended name: Complement C1q subcomponent subunit A |
Gene namesi | Name:C1QA |
Organismi | Homo sapiens (Human) |
Taxonomic identifieri | 9606 [NCBI] |
Taxonomic lineagei | Eukaryota › Metazoa › Chordata › Craniata › Vertebrata › Euteleostomi › Mammalia › Eutheria › Euarchontoglires › Primates › Haplorrhini › Catarrhini › Hominidae › Homo |
Proteomesi |
|
Organism-specific databases
HGNCi | HGNC:1241, C1QA |
MIMi | 120550, gene |
neXtProti | NX_P02745 |
VEuPathDBi | HostDB:ENSG00000173372.16 |
Subcellular locationi
Extracellular region or secreted
Extracellular region or secreted
- collagen-containing extracellular matrix Source: BHF-UCL
- complement component C1 complex Source: ProtInc
- extracellular region Source: Reactome
Other locations
- collagen trimer Source: UniProtKB-KW
- postsynapse Source: ARUK-UCL
- synapse Source: ARUK-UCL
Keywords - Cellular componenti
SecretedPathology & Biotechi
Involvement in diseasei
Complement component C1q deficiency (C1QD)
Organism-specific databases
DisGeNETi | 712 |
MalaCardsi | C1QA |
MIMi | 613652, phenotype |
OpenTargetsi | ENSG00000173372 |
Orphaneti | 300345, Autosomal systemic lupus erythematosus 169147, Immunodeficiency due to a classical component pathway complement deficiency |
PharmGKBi | PA25622 |
Miscellaneous databases
Pharosi | P02745, Tbio |
Chemistry databases
DrugBanki | DB00112, Bevacizumab DB00002, Cetuximab DB00111, Daclizumab DB00005, Etanercept DB00110, Palivizumab |
Genetic variation databases
BioMutai | C1QA |
DMDMi | 399138 |
PTM / Processingi
Molecule processing
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Signal peptidei | 1 – 22 | 1 PublicationAdd BLAST | 22 | |
ChainiPRO_0000003517 | 23 – 245 | Complement C1q subcomponent subunit AAdd BLAST | 223 |
Amino acid modifications
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Disulfide bondi | 26 | Interchain (with C-29 in B chain) | ||
Modified residuei | 33 | 5-hydroxylysine1 Publication | 1 | |
Glycosylationi | 33 | O-linked (Gal...) hydroxylysine1 Publication | 1 | |
Modified residuei | 39 | 4-hydroxyproline1 Publication | 1 | |
Modified residuei | 45 | 4-hydroxyproline1 Publication | 1 | |
Modified residuei | 48 | 5-hydroxylysine1 Publication | 1 | |
Glycosylationi | 48 | O-linked (Gal...) hydroxylysine1 Publication | 1 | |
Modified residuei | 54 | 4-hydroxyproline1 Publication | 1 | |
Modified residuei | 57 | 4-hydroxyproline1 Publication | 1 | |
Modified residuei | 67 | 5-hydroxylysine1 Publication | 1 | |
Glycosylationi | 67 | O-linked (Gal...) hydroxylysine1 Publication | 1 | |
Modified residuei | 73 | 4-hydroxyproline1 Publication | 1 | |
Modified residuei | 79 | 4-hydroxyproline1 Publication | 1 | |
Modified residuei | 85 | 4-hydroxyproline1 Publication | 1 | |
Modified residuei | 100 | 5-hydroxylysine1 Publication | 1 | |
Glycosylationi | 100 | O-linked (Gal...) hydroxylysine1 Publication | 1 | |
Glycosylationi | 146 | N-linked (GlcNAc...) asparagine2 Publications | 1 |
Post-translational modificationi
Keywords - PTMi
Disulfide bond, Glycoprotein, HydroxylationProteomic databases
jPOSTi | P02745 |
MassIVEi | P02745 |
PaxDbi | P02745 |
PeptideAtlasi | P02745 |
PRIDEi | P02745 |
ProteomicsDBi | 51561 |
PTM databases
GlyConnecti | 1142, 7 N-Linked glycans (1 site) |
GlyGeni | P02745, 5 sites, 5 N-linked glycans (1 site) |
iPTMneti | P02745 |
Expressioni
Gene expression databases
Bgeei | ENSG00000173372, Expressed in spleen and 223 other tissues |
ExpressionAtlasi | P02745, baseline and differential |
Genevisiblei | P02745, HS |
Organism-specific databases
HPAi | ENSG00000173372, Tissue enhanced (lymphoid) |
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.
Interacts (via C-terminus) with CD33; this interaction activates CD33 inhibitory motifs (PubMed:28325905).
Interacts with CR1 (via Sushi 24 and Sushi 25 domains) (PubMed:29563915, PubMed:9324355).
3 Publications(Microbial infection) Interacts with Staphylococcus aureus protein Cna; this interaction results in the inhibition of the classical complement pathway.
1 PublicationBinary interactionsi
Hide detailsP02745
Protein-protein interaction databases
BioGRIDi | 107173, 20 interactors |
ComplexPortali | CPX-1919, Complement component C1q complex |
CORUMi | P02745 |
IntActi | P02745, 21 interactors |
MINTi | P02745 |
STRINGi | 9606.ENSP00000363773 |
Miscellaneous databases
RNActi | P02745, protein |
Structurei
Secondary structure
3D structure databases
SASBDBi | P02745 |
SMRi | P02745 |
ModBasei | Search... |
PDBe-KBi | Search... |
Miscellaneous databases
EvolutionaryTracei | P02745 |
Family & Domainsi
Domains and Repeats
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Domaini | 31 – 109 | Collagen-likeAdd BLAST | 79 | |
Domaini | 110 – 245 | C1qPROSITE-ProRule annotationAdd BLAST | 136 |
Keywords - Domaini
Collagen, Repeat, SignalPhylogenomic databases
eggNOGi | ENOG502RZM2, Eukaryota |
GeneTreei | ENSGT00940000162143 |
HOGENOMi | CLU_001074_3_1_1 |
InParanoidi | P02745 |
OMAi | VWIEKDP |
OrthoDBi | 1258047at2759 |
PhylomeDBi | P02745 |
TreeFami | TF329591 |
Family and domain databases
Gene3Di | 2.60.120.40, 1 hit |
InterProi | View protein in InterPro IPR001073, C1q_dom IPR008160, Collagen IPR037572, Complement_C1q_A IPR008983, Tumour_necrosis_fac-like_dom |
PANTHERi | PTHR15427:SF26, PTHR15427:SF26, 1 hit |
Pfami | View protein in Pfam PF00386, C1q, 1 hit PF01391, Collagen, 1 hit |
PRINTSi | PR00007, COMPLEMNTC1Q |
SMARTi | View protein in SMART SM00110, C1Q, 1 hit |
SUPFAMi | SSF49842, SSF49842, 1 hit |
PROSITEi | View protein in PROSITE PS50871, C1Q, 1 hit |
(1+)i Sequence
Sequence statusi: Complete.
: The displayed sequence is further processed into a mature form. Sequence processingi
This entry has 1 described isoform and 1 potential isoform that is computationally mapped.Show allAlign All
10 20 30 40 50
MEGPRGWLVL CVLAISLASM VTEDLCRAPD GKKGEAGRPG RRGRPGLKGE
60 70 80 90 100
QGEPGAPGIR TGIQGLKGDQ GEPGPSGNPG KVGYPGPSGP LGARGIPGIK
110 120 130 140 150
GTKGSPGNIK DQPRPAFSAI RRNPPMGGNV VIFDTVITNQ EEPYQNHSGR
160 170 180 190 200
FVCTVPGYYY FTFQVLSQWE ICLSIVSSSR GQVRRSLGFC DTTNKGLFQV
210 220 230 240
VSGGMVLQLQ QGDQVWVEKD PKKGHIYQGS EADSVFSGFL IFPSA
Computationally mapped potential isoform sequencesi
There is 1 potential isoform mapped to this entry.BLASTAlignShow allAdd to basketX6RLJ0 | X6RLJ0_HUMAN | Complement C1q subcomponent subunit... | C1QA | 220 | Annotation score: |
Experimental Info
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Sequence conflicti | 97 | P → K AA sequence (PubMed:486087).Curated | 1 | |
Sequence conflicti | 103 | K → P AA sequence (PubMed:486087).Curated | 1 | |
Sequence conflicti | 172 | C → N AA sequence (PubMed:6981411).Curated | 1 | |
Sequence conflicti | 178 | S → W AA sequence (PubMed:6981411).Curated | 1 | |
Sequence conflicti | 240 – 243 | LIFP → ILPGF AA sequence (PubMed:6981411).Curated | 4 |
Natural variant
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Natural variantiVAR_021090 | 23 | E → K1 PublicationCorresponds to variant dbSNP:rs17887074EnsemblClinVar. | 1 |
Sequence databases
Select the link destinations: EMBLi GenBanki DDBJi Links Updated | AF135157 mRNA Translation: AAD32626.1 AY789471 Genomic DNA Translation: AAV40828.1 AL158086 Genomic DNA Translation: CAI22892.1 AK311980 mRNA Translation: BAG34919.1 AL158086 Genomic DNA Translation: CAI22893.1 CH471134 Genomic DNA Translation: EAW95014.1 BC030153 mRNA Translation: AAH30153.1 BC071986 mRNA Translation: AAH71986.1 |
CCDSi | CCDS226.1 |
PIRi | S14350, C1HUQA |
RefSeqi | NP_001334394.1, NM_001347465.1 NP_001334395.1, NM_001347466.1 NP_057075.1, NM_015991.3 |
Genome annotation databases
Ensembli | ENST00000374642; ENSP00000363773; ENSG00000173372 ENST00000402322; ENSP00000385564; ENSG00000173372 |
GeneIDi | 712 |
KEGGi | hsa:712 |
UCSCi | uc001bfy.4, human |
Similar proteinsi
Cross-referencesi
Web resourcesi
C1QAbase C1QA mutation db |
SeattleSNPs |
Sequence databases
Select the link destinations: EMBLi GenBanki DDBJi Links Updated | AF135157 mRNA Translation: AAD32626.1 AY789471 Genomic DNA Translation: AAV40828.1 AL158086 Genomic DNA Translation: CAI22892.1 AK311980 mRNA Translation: BAG34919.1 AL158086 Genomic DNA Translation: CAI22893.1 CH471134 Genomic DNA Translation: EAW95014.1 BC030153 mRNA Translation: AAH30153.1 BC071986 mRNA Translation: AAH71986.1 |
CCDSi | CCDS226.1 |
PIRi | S14350, C1HUQA |
RefSeqi | NP_001334394.1, NM_001347465.1 NP_001334395.1, NM_001347466.1 NP_057075.1, NM_015991.3 |
3D structure databases
Select the link destinations: PDBei RCSB PDBi PDBji Links Updated | PDB entry | Method | Resolution (Å) | Chain | Positions | PDBsum |
1PK6 | X-ray | 1.85 | A | 112-244 | [»] | |
2JG8 | X-ray | 2.05 | A/D | 112-245 | [»] | |
2JG9 | X-ray | 1.90 | A/D | 112-245 | [»] | |
2WNU | X-ray | 2.30 | A/D | 112-245 | [»] | |
2WNV | X-ray | 1.25 | A/D | 112-245 | [»] | |
5HKJ | X-ray | 1.35 | A | 110-245 | [»] | |
5HZF | X-ray | 1.55 | A | 110-245 | [»] | |
6FCZ | electron microscopy | 10.00 | A | 112-244 | [»] | |
6Z6V | X-ray | 2.19 | A/D | 110-245 | [»] | |
SASBDBi | P02745 | |||||
SMRi | P02745 | |||||
ModBasei | Search... | |||||
PDBe-KBi | Search... |
Protein-protein interaction databases
BioGRIDi | 107173, 20 interactors |
ComplexPortali | CPX-1919, Complement component C1q complex |
CORUMi | P02745 |
IntActi | P02745, 21 interactors |
MINTi | P02745 |
STRINGi | 9606.ENSP00000363773 |
Chemistry databases
DrugBanki | DB00112, Bevacizumab DB00002, Cetuximab DB00111, Daclizumab DB00005, Etanercept DB00110, Palivizumab |
PTM databases
GlyConnecti | 1142, 7 N-Linked glycans (1 site) |
GlyGeni | P02745, 5 sites, 5 N-linked glycans (1 site) |
iPTMneti | P02745 |
Genetic variation databases
BioMutai | C1QA |
DMDMi | 399138 |
Proteomic databases
jPOSTi | P02745 |
MassIVEi | P02745 |
PaxDbi | P02745 |
PeptideAtlasi | P02745 |
PRIDEi | P02745 |
ProteomicsDBi | 51561 |
Protocols and materials databases
Antibodypediai | 707, 398 antibodies |
DNASUi | 712 |
Genome annotation databases
Ensembli | ENST00000374642; ENSP00000363773; ENSG00000173372 ENST00000402322; ENSP00000385564; ENSG00000173372 |
GeneIDi | 712 |
KEGGi | hsa:712 |
UCSCi | uc001bfy.4, human |
Organism-specific databases
CTDi | 712 |
DisGeNETi | 712 |
GeneCardsi | C1QA |
HGNCi | HGNC:1241, C1QA |
HPAi | ENSG00000173372, Tissue enhanced (lymphoid) |
MalaCardsi | C1QA |
MIMi | 120550, gene 613652, phenotype |
neXtProti | NX_P02745 |
OpenTargetsi | ENSG00000173372 |
Orphaneti | 300345, Autosomal systemic lupus erythematosus 169147, Immunodeficiency due to a classical component pathway complement deficiency |
PharmGKBi | PA25622 |
VEuPathDBi | HostDB:ENSG00000173372.16 |
GenAtlasi | Search... |
Phylogenomic databases
eggNOGi | ENOG502RZM2, Eukaryota |
GeneTreei | ENSGT00940000162143 |
HOGENOMi | CLU_001074_3_1_1 |
InParanoidi | P02745 |
OMAi | VWIEKDP |
OrthoDBi | 1258047at2759 |
PhylomeDBi | P02745 |
TreeFami | TF329591 |
Enzyme and pathway databases
PathwayCommonsi | P02745 |
Reactomei | R-HSA-166663, Initial triggering of complement R-HSA-173623, Classical antibody-mediated complement activation R-HSA-977606, Regulation of Complement cascade |
Miscellaneous databases
BioGRID-ORCSi | 712, 4 hits in 876 CRISPR screens |
ChiTaRSi | C1QA, human |
EvolutionaryTracei | P02745 |
GeneWikii | C1QA |
GenomeRNAii | 712 |
Pharosi | P02745, Tbio |
PROi | PR:P02745 |
RNActi | P02745, protein |
SOURCEi | Search... |
Gene expression databases
Bgeei | ENSG00000173372, Expressed in spleen and 223 other tissues |
ExpressionAtlasi | P02745, baseline and differential |
Genevisiblei | P02745, HS |
Family and domain databases
Gene3Di | 2.60.120.40, 1 hit |
InterProi | View protein in InterPro IPR001073, C1q_dom IPR008160, Collagen IPR037572, Complement_C1q_A IPR008983, Tumour_necrosis_fac-like_dom |
PANTHERi | PTHR15427:SF26, PTHR15427:SF26, 1 hit |
Pfami | View protein in Pfam PF00386, C1q, 1 hit PF01391, Collagen, 1 hit |
PRINTSi | PR00007, COMPLEMNTC1Q |
SMARTi | View protein in SMART SM00110, C1Q, 1 hit |
SUPFAMi | SSF49842, SSF49842, 1 hit |
PROSITEi | View protein in PROSITE PS50871, C1Q, 1 hit |
ProtoNeti | Search... |
MobiDBi | Search... |
Entry informationi
Entry namei | C1QA_HUMAN | |
Accessioni | P02745Primary (citable) accession number: P02745 Secondary accession number(s): B2R4X2, Q5T963 | |
Entry historyi | Integrated into UniProtKB/Swiss-Prot: | July 21, 1986 |
Last sequence update: | July 1, 1993 | |
Last modified: | February 10, 2021 | |
This is version 217 of the entry and version 2 of the sequence. See complete history. | ||
Entry statusi | Reviewed (UniProtKB/Swiss-Prot) | |
Annotation program | Chordata Protein Annotation Program | |
Disclaimer | Any 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, Direct protein sequencing, Reference proteomeDocuments
- Human chromosome 1
Human chromosome 1: entries, gene names and cross-references to MIM - Human entries with genetic variants
List of human entries with genetic variants - Human variants curated from literature reports
Index of human variants curated from literature reports - MIM cross-references
Online Mendelian Inheritance in Man (MIM) cross-references in UniProtKB/Swiss-Prot - PDB cross-references
Index of Protein Data Bank (PDB) cross-references