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    C1QA complement C1q A chain [ Homo sapiens (human) ]

    Gene ID: 712, updated on 10-Dec-2024

    Summary

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    Official Symbol
    C1QAprovided by HGNC
    Official Full Name
    complement C1q A chainprovided by HGNC
    Primary source
    HGNC:HGNC:1241
    See related
    Ensembl:ENSG00000173372 MIM:120550; AllianceGenome:HGNC:1241
    Gene type
    protein coding
    RefSeq status
    REVIEWED
    Organism
    Homo sapiens
    Lineage
    Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae; Homo
    Also known as
    C1QD1
    Summary
    This gene encodes the A-chain polypeptide of serum complement subcomponent C1q, which associates with C1r and C1s to yield the first component of the serum complement system. C1q deficiency is associated with lupus erythematosus and glomerulonephritis. 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. Alternate splicing results in multiple transcript variants. [provided by RefSeq, Nov 2016]
    Expression
    Broad expression in spleen (RPKM 445.5), lymph node (RPKM 179.4) and 16 other tissues See more
    Orthologs
    mouse all
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    Genomic context

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    See C1QA in Genome Data Viewer
    Location:
    1p36.12
    Exon count:
    3
    Annotation release Status Assembly Chr Location
    RS_2024_08 current GRCh38.p14 (GCF_000001405.40) 1 NC_000001.11 (22636463..22639678)
    RS_2024_08 current T2T-CHM13v2.0 (GCF_009914755.1) 1 NC_060925.1 (22461488..22464703)
    RS_2024_09 previous assembly GRCh37.p13 (GCF_000001405.25) 1 NC_000001.10 (22962956..22966171)

    Chromosome 1 - NC_000001.11Genomic Context describing neighboring genes Neighboring gene H3K4me1 hESC enhancer GRCh37_chr1:22890520-22891020 Neighboring gene H3K4me1 hESC enhancer GRCh37_chr1:22898749-22899308 Neighboring gene EPH receptor A8 Neighboring gene Sharpr-MPRA regulatory region 15208 Neighboring gene microRNA 6127 Neighboring gene complement C1q C chain Neighboring gene complement C1q B chain

    Genomic regions, transcripts, and products

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    Go to nucleotide: Graphics FASTA GenBank

    Bibliography

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    Related articles in PubMed

    1. C1q: A fresh look upon an old molecule. Thielens NM, et al. Mol Immunol, 2017 Sep. PMID 28601358, Free PMC Article
    2. A regulatory variant in the C1Q gene cluster is associated with tuberculosis susceptibility and C1qA plasma levels in a South African population. Bruiners N, et al. Immunogenetics, 2020 Jul. PMID 32556499
    3. Common germ-line polymorphism of C1QA and breast cancer survival. Azzato EM, et al. Br J Cancer, 2010 Apr 13. PMID 20332777, Free PMC Article
    4. Expression of C1q complement component in Barrett's esophagus and esophageal adenocarcinoma. Bobryshev YV, et al. J Gastrointest Surg, 2010 Aug. PMID 20496011
    5. New insight into the autoimmunogenicity of the complement protein C1q. Stoyanova V, et al. Mol Immunol, 2011 Jan. PMID 21159384

    See all (196) citations in PubMed

    GeneRIFs: Gene References Into Functions

    What's a GeneRIF?
    1. An integrative analysis of single-cell and bulk transcriptome and bidirectional mendelian randomization analysis identified C1Q as a novel stimulated risk gene for Atherosclerosis.
      Title: An integrative analysis of single-cell and bulk transcriptome and bidirectional mendelian randomization analysis identified C1Q as a novel stimulated risk gene for Atherosclerosis.
    2. Complement C1q and von Willebrand factor interaction in atherosclerosis of human carotid artery.
      Title: Complement C1q and von Willebrand factor interaction in atherosclerosis of human carotid artery.
    3. Association between serum complement 1q and the associated factors of acute ischemic stroke in patients with type 2 diabetes.
      Title: Association between serum complement 1q and the associated factors of acute ischemic stroke in patients with type 2 diabetes.
    4. Complement Activation-Independent Attenuation of SARS-CoV-2 Infection by C1q and C4b-Binding Protein.
      Title: Complement Activation-Independent Attenuation of SARS-CoV-2 Infection by C1q and C4b-Binding Protein.
    5. Complement protein C1q stimulates hyaluronic acid degradation via gC1qR/HABP1/p32 in malignant pleural mesothelioma.
      Title: Complement protein C1q stimulates hyaluronic acid degradation via gC1qR/HABP1/p32 in malignant pleural mesothelioma.
    6. Roles of mesangial C3 and C1q deposition in the clinical manifestations and prognosis of IgAN.
      Title: Roles of mesangial C3 and C1q deposition in the clinical manifestations and prognosis of IgAN.
    7. Gene polymorphisms within regions of complement component C1q in HIV associated preeclampsia.
      Title: Gene polymorphisms within regions of complement component C1q in HIV associated preeclampsia.
    8. Complement component C1q initiates extrinsic coagulation via the receptor for the globular head of C1q in adventitial fibroblasts and vascular smooth muscle cells.
      Title: Complement component C1q initiates extrinsic coagulation via the receptor for the globular head of C1q in adventitial fibroblasts and vascular smooth muscle cells.
    9. C1QA, C1QB, and GZMB are novel prognostic biomarkers of skin cutaneous melanoma relating tumor microenvironment.
      Title: C1QA, C1QB, and GZMB are novel prognostic biomarkers of skin cutaneous melanoma relating tumor microenvironment.
    10. Neuroinflammation and psychiatric disorders: Relevance of C1q, translocator protein (18 kDa) (TSPO), and neurosteroids.
      Title: Neuroinflammation and psychiatric disorders: Relevance of C1q, translocator protein (18 kDa) (TSPO), and neurosteroids.
    Submit: New GeneRIF Correction See all GeneRIFs (109)

    Phenotypes

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    Find tests for this gene in the NIH Genetic Testing Registry (GTR)

    Review eQTL and phenotype association data in this region using PheGenI

    Associated conditions

    Description Tests
    C1Q deficiency 1
    MedGen: CN376805 OMIM: 613652 GeneReviews: Not available
    		not available

    Variation

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    See variants in ClinVar

    See studies and variants in dbVar

    See Variation Viewer (GRCh37.p13)

    See Variation Viewer (GRCh38)

    HIV-1 interactions

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    Protein interactions

    Protein Gene Interaction Pubs
    Envelope surface glycoprotein gp120 env Fibronectin, which is present in submandibular saliva, binds to HIV-1 gp120/160 and enhances the interaction of C1q with gp120/160 PubMed
    env Free C1q binds to HIV-1 gp120; digestion of the C1q stem portion with collagenase completely eliminates its binding to recombinant gp120, suggesting that the collagen-like stem region of C1q participates in the binding to gp120 PubMed
    Envelope transmembrane glycoprotein gp41 env The interaction between C1q and HIV-gp41 is dependent upon the presence of calcium; calcium can not be replaced by larger cations such as strontium, barium, lead or smaller ions such as magnesium and manganese PubMed
    env HIV-1 gp41 (amino acid residues 561-575, 591-605 and 601-620) binds to complement C1q and activates the C1 complex in a dose- and time-dependent manner PubMed
    env Three sites (amino acids 526-538, 590-613 and 625-655) of the cell-external part of HIV-1 gp41 bind both HIV-1 gp120 and C1q PubMed

    Go to the HIV-1, Human Interaction Database

    Pathways from PubChem

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    Interactions

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    Products Interactant Other Gene Complex Source Pubs Description

    General gene information

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    Markers

    Potential readthrough

    Included gene: C1QC

    Homology

    Gene Ontology Provided by GOA

    Function Evidence Code Pubs
    enables amyloid-beta binding TAS
    Traceable Author Statement
    more info
    		 PubMed 
    enables protein binding IPI
    Inferred from Physical Interaction
    more info
    		 PubMed 
    Process Evidence Code Pubs
    involved_in astrocyte activation ISS
    Inferred from Sequence or Structural Similarity
    more info
    		  
    involved_in cell-cell signaling TAS
    Traceable Author Statement
    more info
    		 PubMed 
    involved_in complement activation TAS
    Traceable Author Statement
    more info
    		 PubMed 
    involved_in complement activation, classical pathway IDA
    Inferred from Direct Assay
    more info
    		 PubMed 
    involved_in complement activation, classical pathway NAS
    Non-traceable Author Statement
    more info
    		 PubMed 
    involved_in complement-mediated synapse pruning ISS
    Inferred from Sequence or Structural Similarity
    more info
    		  
    involved_in innate immune response IEA
    Inferred from Electronic Annotation
    more info
    		  
    involved_in microglial cell activation ISS
    Inferred from Sequence or Structural Similarity
    more info
    		  
    involved_in neuron remodeling ISS
    Inferred from Sequence or Structural Similarity
    more info
    		  
    involved_in synapse organization ISS
    Inferred from Sequence or Structural Similarity
    more info
    		  
    involved_in synapse pruning ISS
    Inferred from Sequence or Structural Similarity
    more info
    		  
    involved_in vertebrate eye-specific patterning ISS
    Inferred from Sequence or Structural Similarity
    more info
    		  
    Component Evidence Code Pubs
    part_of collagen trimer IEA
    Inferred from Electronic Annotation
    more info
    		  
    located_in collagen-containing extracellular matrix HDA PubMed 
    part_of complement component C1 complex NAS
    Non-traceable Author Statement
    more info
    		 PubMed 
    part_of complement component C1q complex IPI
    Inferred from Physical Interaction
    more info
    		 PubMed 
    located_in extracellular region IDA
    Inferred from Direct Assay
    more info
    		 PubMed 
    located_in extracellular region NAS
    Non-traceable Author Statement
    more info
    		 PubMed 
    located_in extracellular region TAS
    Traceable Author Statement
    more info
    		  
    located_in extrinsic component of postsynaptic membrane IEA
    Inferred from Electronic Annotation
    more info
    		  
    located_in extrinsic component of presynaptic membrane IEA
    Inferred from Electronic Annotation
    more info
    		  
    located_in glutamatergic synapse IEA
    Inferred from Electronic Annotation
    more info
    		  
    located_in postsynapse ISS
    Inferred from Sequence or Structural Similarity
    more info
    		  
    located_in synapse ISS
    Inferred from Sequence or Structural Similarity
    more info
    		  

    General protein information

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    Preferred Names
    complement C1q subcomponent subunit A
    Names
    complement C1q chain A
    complement component 1, q subcomponent, A chain
    complement component 1, q subcomponent, alpha polypeptide
    complement component C1q, A chain

    NCBI Reference Sequences (RefSeq)

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    RefSeqs maintained independently of Annotated Genomes

    These reference sequences exist independently of genome builds. Explain

    These reference sequences are curated independently of the genome annotation cycle, so their versions may not match the RefSeq versions in the current genome build. Identify version mismatches by comparing the version of the RefSeq in this section to the one reported in Genomic regions, transcripts, and products above.

    Genomic

    1. NG_007282.1 RefSeqGene

      Range
      5001..8058
      Download
      GenBank, FASTA, Sequence Viewer (Graphics), LRG_22

    mRNA and Protein(s)

    1. NM_001347465.2 → NP_001334394.1  complement C1q subcomponent subunit A precursor

      Status: REVIEWED

      Description
      Transcript Variant: This variant (2) represents the longest transcript. Variants 1-3 encode the same protein.
      Source sequence(s)
      BC030153, BC071986, BM920911, BX369252, DT215188
      Consensus CDS
      CCDS226.1
      UniProtKB/Swiss-Prot
      B2R4X2, P02745, Q5T963
      UniProtKB/TrEMBL
      A0A024RAG6, A0A3B0J657, X6RLJ0
      Related
      ENSP00000385564.1, ENST00000402322.2
      Conserved Domains (2) summary
      smart00110
      Location:108 → 244
      C1Q; Complement component C1q domain
      pfam01391
      Location:48 → 106
      Collagen; Collagen triple helix repeat (20 copies)

    2. NM_001347466.2 → NP_001334395.1  complement C1q subcomponent subunit A precursor

      Status: REVIEWED

      Description
      Transcript Variant: This variant (3) contains an alternate exon in the 5' UTR, compared to variant (2). Variants 1-3 encode the same protein.
      Source sequence(s)
      AL158086, BC071986, BI837739, BX369252
      Consensus CDS
      CCDS226.1
      UniProtKB/Swiss-Prot
      B2R4X2, P02745, Q5T963
      UniProtKB/TrEMBL
      A0A024RAG6, A0A3B0J657, X6RLJ0
      Related
      ENSP00000416841.2, ENST00000438241.2
      Conserved Domains (2) summary
      smart00110
      Location:108 → 244
      C1Q; Complement component C1q domain
      pfam01391
      Location:48 → 106
      Collagen; Collagen triple helix repeat (20 copies)

    3. NM_015991.4 → NP_057075.1  complement C1q subcomponent subunit A precursor

      See identical proteins and their annotated locations for NP_057075.1

      Status: REVIEWED

      Description
      Transcript Variant: This variant (1) uses an alternate splice site in the 5' UTR, compared to variant (2). Variants 1-3 encode the same protein.
      Source sequence(s)
      BC030153, BC071986, BG548439, BX369252
      Consensus CDS
      CCDS226.1
      UniProtKB/Swiss-Prot
      B2R4X2, P02745, Q5T963
      UniProtKB/TrEMBL
      A0A024RAG6, A0A3B0J657, X6RLJ0
      Related
      ENSP00000363773.3, ENST00000374642.8
      Conserved Domains (2) summary
      smart00110
      Location:108 → 244
      C1Q; Complement component C1q domain
      pfam01391
      Location:48 → 106
      Collagen; Collagen triple helix repeat (20 copies)

    RefSeqs of Annotated Genomes: GCF_000001405.40-RS_2024_08

    The following sections contain reference sequences that belong to a specific genome build. Explain

    Reference GRCh38.p14 Primary Assembly

    Genomic

    1. NC_000001.11 Reference GRCh38.p14 Primary Assembly

      Range
      22636463..22639678
      Download
      GenBank, FASTA, Sequence Viewer (Graphics)

    Alternate T2T-CHM13v2.0

    Genomic

    1. NC_060925.1 Alternate T2T-CHM13v2.0

      Range
      22461488..22464703
      Download
      GenBank, FASTA, Sequence Viewer (Graphics)
    Nucleotide Protein
    Heading Accession and Version
    Protein Accession Links
    GenPept Link UniProtKB Link
    P02745.2 GenPept UniProtKB/Swiss-Prot:P02745

    Gene LinkOut

    The following LinkOut resources are supplied by external providers. These providers are responsible for maintaining the links.

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