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

Summary

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

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_000001.11 Genomic Context describing neighboring genes

Genomic regions, transcripts, and products

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Go to reference sequence details

Genomic Sequence:

Go to nucleotide: Graphics FASTA GenBank

Expression

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See details

Project title: HPA RNA-seq normal tissues HPA RNA-seq normal tissues
Description: RNA-seq was performed of tissue samples from 95 human individuals representing 27 different tissues in order to determine tissue-specificity of all protein-coding genes
BioProject: PRJEB4337
Publication: PMID 24309898
Analysis date: Wed Apr 4 07:08:55 2018

Bibliography

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GeneRIFs: Gene References Into Functions

What's a GeneRIF?

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.
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.
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.
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.
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.
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.
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.
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.
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.
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

Interactions

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Products	Interactant	Other Gene	Complex	Source	Pubs	Description

General gene information

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Markers

D1S3273 (e-PCR)
- UniSTS:7826

WI-8760 (e-PCR)
- UniSTS:12981

C1QA_66 (e-PCR)
- UniSTS:276167

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 more info	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

NG_007282.1 RefSeqGene

Range

5001..8058

Download

GenBank, FASTA, Sequence Viewer (Graphics), LRG_22

mRNA and Protein(s)

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)
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)
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)