Format

Send to:

Choose Destination

C1QA complement component 1, q subcomponent, A chain [ Homo sapiens (human) ]

Gene ID: 712, updated on 12-May-2016
Official Symbol
C1QAprovided by HGNC
Official Full Name
complement component 1, q subcomponent, A chainprovided by HGNC
Primary source
HGNC:HGNC:1241
See related
Ensembl:ENSG00000173372 HPRD:00393; MIM:120550; Vega:OTTHUMG00000002893
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
Summary
This gene encodes a major constituent of the human complement subcomponent C1q. C1q associates with C1r and C1s in order to yield the first component of the serum complement system. Deficiency of C1q has been associated with lupus erythematosus and glomerulonephritis. C1q is composed of 18 polypeptide chains: six A-chains, six B-chains, and six C-chains. Each chain contains a collagen-like region located near the N terminus and a C-terminal globular region. The A-, B-, and C-chains are arranged in the order A-C-B on chromosome 1. This gene encodes the A-chain polypeptide of human complement subcomponent C1q. [provided by RefSeq, Jul 2008]
Orthologs
Location:
1p36.12
Exon count:
3
Annotation release Status Assembly Chr Location
107 current GRCh38.p2 (GCF_000001405.28) 1 NC_000001.11 (22636625..22639682)
105 previous assembly GRCh37.p13 (GCF_000001405.25) 1 NC_000001.10 (22963118..22966175)

Chromosome 1 - NC_000001.11Genomic Context describing neighboring genes Neighboring gene EPH receptor A8 Neighboring gene microRNA 6127 Neighboring gene complement component 1, q subcomponent, C chain Neighboring gene complement component 1, q subcomponent, B chain

GeneRIFs: Gene References Into FunctionsWhat's a GeneRIF?

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

  • Chagas disease (American trypanosomiasis), organism-specific biosystem (from KEGG)
    Chagas disease (American trypanosomiasis), organism-specific biosystemTrypanosoma cruzi is an intracellular protozoan parasite that causes Chagas disease. The parasite life cycle involves hematophagous reduviid bugs as vectors. Once parasites enter the host body, they ...
  • Chagas disease (American trypanosomiasis), conserved biosystem (from KEGG)
    Chagas disease (American trypanosomiasis), conserved biosystemTrypanosoma cruzi is an intracellular protozoan parasite that causes Chagas disease. The parasite life cycle involves hematophagous reduviid bugs as vectors. Once parasites enter the host body, they ...
  • Classical antibody-mediated complement activation, organism-specific biosystem (from REACTOME)
    Classical antibody-mediated complement activation, organism-specific biosystemC1, the first component of complement is a complex containing three protein species, C1q, C1r, and C1s. C1q is assembled from six identical subunits each of which consists of three homologous chains ...
  • Complement Activation, Classical Pathway, organism-specific biosystem (from WikiPathways)
    Complement Activation, Classical Pathway, organism-specific biosystemThe complement system is a biochemical cascade that helps, or ???complements???, the ability of antibodies to clear pathogens from an organism. It is part of the immune system called the innate immun...
  • Complement and Coagulation Cascades, organism-specific biosystem (from WikiPathways)
    Complement and Coagulation Cascades, organism-specific biosystemBlood coagulation is a series of coordinated and calcium-dependent proenzyme-to-serine protease conversions likely to be localized on the surfaces of activated cells in vivo. It culminates in the for...
  • Complement and coagulation cascades, organism-specific biosystem (from KEGG)
    Complement and coagulation cascades, organism-specific biosystemThe complement system is a proteolytic cascade in blood plasma and a mediator of innate immunity, a nonspecific defense mechanism against pathogens. There are three pathways of complement activation:...
  • Complement and coagulation cascades, conserved biosystem (from KEGG)
    Complement and coagulation cascades, conserved biosystemThe complement system is a proteolytic cascade in blood plasma and a mediator of innate immunity, a nonspecific defense mechanism against pathogens. There are three pathways of complement activation:...
  • Complement cascade, organism-specific biosystem (from REACTOME)
    Complement cascade, organism-specific biosystemIn the complement cascade, a panel of soluble molecules rapidly and effectively senses a danger or damage and triggers reactions to provide a response that discriminates among foreign intruders, cell...
  • Creation of C4 and C2 activators, organism-specific biosystem (from REACTOME)
    Creation of C4 and C2 activators, organism-specific biosystemTwo pathways lead to a complex capable of activating C4 and C2.The classical pathway is triggered by activation of the C1-complex, which consists of hexameric molecule C1q and a tetramer comprising t...
  • Immune System, organism-specific biosystem (from REACTOME)
    Immune System, organism-specific biosystemHumans are exposed to millions of potential pathogens daily, through contact, ingestion, and inhalation. Our ability to avoid infection depends on the adaptive immune system and during the first crit...
  • Initial triggering of complement, organism-specific biosystem (from REACTOME)
    Initial triggering of complement, organism-specific biosystemComplement activation is due to a cascade of proteolytic steps, performed by serine protease domains in some of the components. Three different pathways of activation are distinguished triggered by t...
  • Innate Immune System, organism-specific biosystem (from REACTOME)
    Innate Immune System, organism-specific biosystemInnate immunity encompases the nonspecific part of immunity tha are part of an individual's natural biologic makeup
  • Pertussis, organism-specific biosystem (from KEGG)
    Pertussis, organism-specific biosystemPertussis, also known as whooping cough, is an acute respiratory infectious disease caused by a bacteria called Bordetella Pertussis. The characteristic symptoms are paroxysmal cough, inspiratory whe...
  • Pertussis, conserved biosystem (from KEGG)
    Pertussis, conserved biosystemPertussis, also known as whooping cough, is an acute respiratory infectious disease caused by a bacteria called Bordetella Pertussis. The characteristic symptoms are paroxysmal cough, inspiratory whe...
  • Prion diseases, organism-specific biosystem (from KEGG)
    Prion diseases, organism-specific biosystemPrion diseases, also termed transmissible spongiform encephalopathies (TSEs), are a group of fatal neurodegenerative diseases that affect humans and a number of other animal species. The etiology of ...
  • Prion diseases, conserved biosystem (from KEGG)
    Prion diseases, conserved biosystemPrion diseases, also termed transmissible spongiform encephalopathies (TSEs), are a group of fatal neurodegenerative diseases that affect humans and a number of other animal species. The etiology of ...
  • Staphylococcus aureus infection, organism-specific biosystem (from KEGG)
    Staphylococcus aureus infection, organism-specific biosystemStaphylococcus aureus can cause multiple forms of infections ranging from superficial skin infections to food poisoning and life-threatening infections. The organism has several ways to divert the ef...
  • Staphylococcus aureus infection, conserved biosystem (from KEGG)
    Staphylococcus aureus infection, conserved biosystemStaphylococcus aureus can cause multiple forms of infections ranging from superficial skin infections to food poisoning and life-threatening infections. The organism has several ways to divert the ef...
  • Systemic lupus erythematosus, organism-specific biosystem (from KEGG)
    Systemic lupus erythematosus, organism-specific biosystemSystemic lupus erythematosus (SLE) is a prototypic autoimmune disease characterised by the production of IgG autoantibodies that are specific for self-antigens, such as DNA, nuclear proteins and cert...
  • Systemic lupus erythematosus, conserved biosystem (from KEGG)
    Systemic lupus erythematosus, conserved biosystemSystemic lupus erythematosus (SLE) is a prototypic autoimmune disease characterised by the production of IgG autoantibodies that are specific for self-antigens, such as DNA, nuclear proteins and cert...
Products Interactant Other Gene Complex Source Pubs Description

Markers

Potential readthrough

Included gene: C1QC

Homology

Gene Ontology Provided by GOA

Function Evidence Code Pubs
protein binding IPI
Inferred from Physical Interaction
more info
PubMed 
serine-type endopeptidase activity TAS
Traceable Author Statement
more info
 
Process Evidence Code Pubs
cell-cell signaling TAS
Traceable Author Statement
more info
PubMed 
complement activation TAS
Traceable Author Statement
more info
 
complement activation, classical pathway TAS
Traceable Author Statement
more info
 
innate immune response IEA
Inferred from Electronic Annotation
more info
 
proteolysis IEA
Inferred from Electronic Annotation
more info
 
response to iron ion IEA
Inferred from Electronic Annotation
more info
 
Component Evidence Code Pubs
collagen trimer IEA
Inferred from Electronic Annotation
more info
 
complement component C1 complex TAS
Traceable Author Statement
more info
PubMed 
extracellular exosome IDA
Inferred from Direct Assay
more info
PubMed 
extracellular region TAS
Traceable Author Statement
more info
 
Preferred Names
complement C1q subcomponent subunit A
Names
complement component 1, q subcomponent, alpha polypeptide
complement component C1q, A chain

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_015991.2NP_057075.1  complement C1q subcomponent subunit A precursor

    See identical proteins and their annotated locations for NP_057075.1

    Status: REVIEWED

    Source sequence(s)
    BC030153, BC071986, BG548439, BX369252
    Consensus CDS
    CCDS226.1
    UniProtKB/Swiss-Prot
    P02745
    UniProtKB/TrEMBL
    A0A024RAG6
    Related
    ENSP00000363773, OTTHUMP00000002936, ENST00000374642, OTTHUMT00000008087
    Conserved Domains (2) summary
    smart00110
    Location:108244
    C1Q; Complement component C1q domain
    pfam01391
    Location:48106
    Collagen; Collagen triple helix repeat (20 copies)

RefSeqs of Annotated Genomes: Homo sapiens Annotation Release 107 details...

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

Reference GRCh38.p2 Primary Assembly

Genomic

  1. NC_000001.11 Reference GRCh38.p2 Primary Assembly

    Range
    22636625..22639682
    Download
    GenBank, FASTA, Sequence Viewer (Graphics)

Alternate CHM1_1.1

Genomic

  1. NC_018912.2 Alternate CHM1_1.1

    Range
    23075637..23078694
    Download
    GenBank, FASTA, Sequence Viewer (Graphics)