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Protein

Complement component 1 Q subcomponent-binding protein, mitochondrial

Gene

C1QBP

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

Functioni

Is believed to be a multifunctional and multicompartmental protein involved in inflammation and infection processes, ribosome biogenesis, protein synthesis in mitochondria, regulation of apoptosis, transcriptional regulation and pre-mRNA splicing. At the cell surface is thought to act as an endothelial receptor for plasma proteins of the complement and kallikrein-kinin cascades. Putative receptor for C1q; specifically binds to the globular "heads" of C1q thus inhibiting C1; may perform the receptor function through a complex with C1qR/CD93. In complex with cytokeratin-1/KRT1 is a high affinity receptor for kininogen-1/HMWK. Can also bind other plasma proteins, such as coagulation factor XII leading to its autoactivation. May function to bind initially fluid kininogen-1 to the cell membrane. The secreted form may enhance both extrinsic and intrinsic coagulation pathways. It is postulated that the cell surface form requires docking with transmembrane proteins for downstream signaling which might be specific for a cell-type or response. By acting as C1q receptor is involved in chemotaxis of immature dendritic cells and neutrophils and is proposed to signal through CD209/DC-SIGN on immature dendritic cells, through integrin alpha-4/beta-1 during trophoblast invasion of the decidua, and through integrin beta-1 during endothelial cell adhesion and spreading. Signaling involved in inhibition of innate immune response is implicating the PI3K-AKT/PKB pathway. Required for protein synthesis in mitochondria (PubMed:28942965). In mitochondrial translation may be involved in formation of functional 55S mitoribosomes; the function seems to involve its RNA-binding activity. May be involved in the nucleolar ribosome maturation process; the function may involve the exchange of FBL for RRP1 in the association with pre-ribosome particles. Involved in regulation of RNA splicing by inhibiting the RNA-binding capacity of SRSF1 and its phosphorylation. Is required for the nuclear translocation of splicing factor U2AF1L4. Involved in regulation of CDKN2A- and HRK-mediated apoptosis. Stabilizes mitochondrial CDKN2A isoform smARF. May be involved in regulation of FOXC1 transcriptional activity and NFY/CCAAT-binding factor complex-mediated transcription. May play a role in antibacterial defense as it can bind to cell surface hyaluronan and inhibit Streptococcus pneumoniae hyaluronate lyase. May be involved in modulation of the immune response; ligation by HCV core protein is resulting in suppression of interleukin-12 production in monocyte-derived dendritic cells. Involved in regulation of antiviral response by inhibiting DDX58- and IFIH1-mediated signaling pathways probably involving its association with MAVS after viral infection.20 Publications
(Microbial infection) Involved in HIV-1 replication, presumably by contributing to splicing of viral RNA.1 Publication
(Microbial infection) In infection processes acts as an attachment site for microbial proteins, including Listeria monocytogenes internalin B and Staphylococcus aureus protein A.2 Publications
(Microbial infection) Involved in replication of Rubella virus.1 Publication

Caution

The subcellular location has been matter of debate. After being reported to be exclusively localized to mitochondria, demonstrations of promiscuous associations and locations have been rather considered as artifactual due to the extremely acidic character and the use of different tagged versions of the protein (PubMed:9305894, PubMed:11493647). However, by now the location to multiple compartments linked to diverse functions is accepted. The N-termini of the surface and secreted forms are identical to the reported processed mitochondrial form.2 Publications

GO - Molecular functioni

  • adrenergic receptor binding Source: UniProtKB
  • complement component C1q binding Source: UniProtKB
  • hyaluronic acid binding Source: UniProtKB
  • kininogen binding Source: UniProtKB
  • mitochondrial ribosome binding Source: UniProtKB
  • mRNA binding Source: UniProtKB
  • protein kinase C binding Source: Ensembl
  • transcription corepressor activity Source: UniProtKB
  • transcription factor binding Source: UniProtKB

GO - Biological processi

  • apoptotic process Source: UniProtKB-KW
  • blood coagulation, intrinsic pathway Source: Reactome
  • complement activation, classical pathway Source: UniProtKB-KW
  • immune response Source: ProtInc
  • innate immune response Source: UniProtKB-KW
  • mature ribosome assembly Source: UniProtKB
  • mRNA processing Source: UniProtKB-KW
  • negative regulation of defense response to virus Source: UniProtKB
  • negative regulation of interferon-gamma production Source: UniProtKB
  • negative regulation of interleukin-12 production Source: UniProtKB
  • negative regulation of MDA-5 signaling pathway Source: UniProtKB
  • negative regulation of mRNA splicing, via spliceosome Source: UniProtKB
  • negative regulation of RIG-I signaling pathway Source: UniProtKB
  • negative regulation of transcription by RNA polymerase II Source: UniProtKB
  • phosphatidylinositol 3-kinase signaling Source: UniProtKB
  • positive regulation of apoptotic process Source: UniProtKB
  • positive regulation of cell adhesion Source: UniProtKB
  • positive regulation of dendritic cell chemotaxis Source: UniProtKB
  • positive regulation of mitochondrial translation Source: UniProtKB
  • positive regulation of neutrophil chemotaxis Source: UniProtKB
  • positive regulation of protein kinase B signaling Source: UniProtKB
  • positive regulation of substrate adhesion-dependent cell spreading Source: UniProtKB
  • positive regulation of trophoblast cell migration Source: UniProtKB
  • regulation of complement activation Source: UniProtKB
  • RNA splicing Source: UniProtKB-KW
  • transcription, DNA-templated Source: UniProtKB-KW
  • viral process Source: UniProtKB-KW

Keywordsi

Biological processAdaptive immunity, Apoptosis, Complement pathway, Host-virus interaction, Immunity, Innate immunity, mRNA processing, mRNA splicing, Ribosome biogenesis, Transcription, Transcription regulation

Enzyme and pathway databases

ReactomeiR-HSA-140837 Intrinsic Pathway of Fibrin Clot Formation
SIGNORiQ07021

Protein family/group databases

TCDBi9.B.103.1.1 the putative ca(2+) uniporter (gc1qr) family

Names & Taxonomyi

Protein namesi
Recommended name:
Complement component 1 Q subcomponent-binding protein, mitochondrial
Alternative name(s):
ASF/SF2-associated protein p32
Glycoprotein gC1qBP
Short name:
C1qBP
Hyaluronan-binding protein 1
Mitochondrial matrix protein p32
gC1q-R protein
p33
Gene namesi
Name:C1QBP
Synonyms:GC1QBP, HABP1, SF2P32
OrganismiHomo sapiens (Human)
Taxonomic identifieri9606 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo
Proteomesi
  • UP000005640 Componenti: Chromosome 17

Organism-specific databases

EuPathDBiHostDB:ENSG00000108561.8
HGNCiHGNC:1243 C1QBP
MIMi601269 gene
neXtProtiNX_Q07021

Subcellular locationi

Extracellular region or secreted Cytosol Plasma membrane Cytoskeleton Lysosome Endosome Peroxisome ER Golgi apparatus Nucleus Mitochondrion Manual annotation Automatic computational assertionGraphics by Christian Stolte; Source: COMPARTMENTS

Keywords - Cellular componenti

Cell membrane, Cytoplasm, Membrane, Mitochondrion, Nucleus, Secreted

Pathology & Biotechi

Involvement in diseasei

Combined oxidative phosphorylation deficiency 33 (COXPD33)1 Publication
The disease is caused by mutations affecting the gene represented in this entry.
Disease descriptionAn autosomal recessive disorder caused by multiple mitochondrial respiratory chain defects and impaired mitochondrial energy metabolism. Clinical manifestations are highly variable. Affected infants present with cardiomyopathy accompanied by multisystemic features involving liver, kidney, and brain. Death in infancy is observed in some patients. Children and adults present with myopathy and progressive external ophthalmoplegia.
See also OMIM:617713
Feature keyPosition(s)DescriptionActionsGraphical viewLength
Natural variantiVAR_080391186C → S in COXPD33; unknown pathological significance. 1 PublicationCorresponds to variant dbSNP:rs748497469EnsemblClinVar.1
Natural variantiVAR_080392188Missing in COXPD33; unknown pathological significance. 1 Publication1
Natural variantiVAR_080393204F → L in COXPD33; unknown pathological significance. 1 PublicationCorresponds to variant dbSNP:rs767427194EnsemblClinVar.1
Natural variantiVAR_080394247G → W in COXPD33. 1 Publication1
Natural variantiVAR_080395275L → F in COXPD33; unknown pathological significance. 1 Publication1
Natural variantiVAR_080396275L → P in COXPD33. 1 Publication1

Mutagenesis

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Mutagenesisi107G → D: Impairs HIV RNA splicing in mouse cells. 1 Publication1

Keywords - Diseasei

Disease mutation, Primary mitochondrial disease

Organism-specific databases

DisGeNETi708
MalaCardsiC1QBP
MIMi617713 phenotype
OpenTargetsiENSG00000108561
PharmGKBiPA25624

Chemistry databases

DrugBankiDB08818 Hyaluronic acid

Polymorphism and mutation databases

BioMutaiC1QBP
DMDMi730772

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Transit peptidei1 – 73MitochondrionCombined sources2 PublicationsAdd BLAST73
ChainiPRO_000001859074 – 282Complement component 1 Q subcomponent-binding protein, mitochondrialAdd BLAST209

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Modified residuei87PhosphoserineCombined sources1
Modified residuei91N6-acetyllysineCombined sources1
Modified residuei188PhosphotyrosineCombined sources1
Modified residuei201PhosphoserineCombined sources1
Modified residuei205PhosphoserineCombined sources1
Modified residuei214PhosphothreonineCombined sources1

Keywords - PTMi

Acetylation, Phosphoprotein

Proteomic databases

EPDiQ07021
MaxQBiQ07021
PaxDbiQ07021
PeptideAtlasiQ07021
PRIDEiQ07021
ProteomicsDBi58500
TopDownProteomicsiQ07021

2D gel databases

DOSAC-COBS-2DPAGEiQ07021
OGPiQ07021

PTM databases

iPTMnetiQ07021
PhosphoSitePlusiQ07021
SwissPalmiQ07021

Miscellaneous databases

PMAP-CutDBiQ07021

Expressioni

Tissue specificityi

Expressed on cell surface of peripheral blood cells (at protein level); Surface expression is reported for macrophages and monocyte-derived dendritic cells.2 Publications

Inductioni

Enhanced cell surface expression upon platelet and monocyte activation.2 Publications

Gene expression databases

BgeeiENSG00000108561
CleanExiHS_C1QBP
ExpressionAtlasiQ07021 baseline and differential
GenevisibleiQ07021 HS

Organism-specific databases

HPAiHPA026483

Interactioni

Subunit structurei

Homotrimer; three monomers form a donut-shaped structure with an unusually asymmetric charge distribution on the surface. Interacts with CDK13, HRK, VTN, NFYB, ADRA1B, FOXC1, DDX21, DDX50, NCL, SRSF1, SRSF9 and CDKN2A isoform smARF. Interacts with CD93; the association may represent a cell surface C1q receptor. Interacts with KRT1; the association represents a cell surface kininogen receptor. Interacts with CD209; the interaction is indicative for a C1q:C1QBP:CD209 signaling complex. Interacts with FBL and RRP1; the respective interactions with C1QBP are competetive. Probably associates with the mitoribosome. Interacts with MAVS; the interaction occurs upon viral transfection. Interacts with PPIF. Interacts with U2AF1L4.By similarity14 Publications
(Microbial infection) Interacts with Rubella virus capsid protein; the interaction occurs in mitochondria. Interacts with Rubella virus protease p150.3 Publications
(Microbial infection) Interacts with Staphylococcus aureus protein A/spa.1 Publication
(Microbial infection) Interacts with Staphylococcus aureus protein A/spa, HIV-1 Tat and HCV core protein.1 Publication
(Microbial infection) Interacts with HIV-1 Tat and HCV core protein.1 Publication

Binary interactionsi

Show more details

GO - Molecular functioni

  • adrenergic receptor binding Source: UniProtKB
  • complement component C1q binding Source: UniProtKB
  • kininogen binding Source: UniProtKB
  • protein kinase C binding Source: Ensembl
  • transcription factor binding Source: UniProtKB

Protein-protein interaction databases

BioGridi107169, 329 interactors
CORUMiQ07021
DIPiDIP-31164N
IntActiQ07021, 110 interactors
MINTiQ07021
STRINGi9606.ENSP00000225698

Structurei

Secondary structure

1282
Legend: HelixTurnBeta strandPDB Structure known for this area
Show more details
Feature keyPosition(s)DescriptionActionsGraphical viewLength
Helixi77 – 96Combined sources20
Turni106 – 108Combined sources3
Beta strandi110 – 114Combined sources5
Beta strandi117 – 124Combined sources8
Beta strandi127 – 134Combined sources8
Beta strandi168 – 174Combined sources7
Helixi175 – 177Combined sources3
Beta strandi180 – 187Combined sources8
Beta strandi205 – 213Combined sources9
Beta strandi225 – 228Combined sources4
Helixi233 – 244Combined sources12
Turni245 – 247Combined sources3
Helixi250 – 280Combined sources31

3D structure databases

ProteinModelPortaliQ07021
SMRiQ07021
ModBaseiSearch...
MobiDBiSearch...

Miscellaneous databases

EvolutionaryTraceiQ07021

Family & Domainsi

Region

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Regioni76 – 93C1q bindingAdd BLAST18
Regioni168 – 213Interaction with MAVS1 PublicationAdd BLAST46

Sequence similaritiesi

Belongs to the MAM33 family.Curated

Keywords - Domaini

Transit peptide

Phylogenomic databases

eggNOGiKOG4024 Eukaryota
ENOG4111G4Z LUCA
GeneTreeiENSGT00390000018406
HOGENOMiHOG000046272
HOVERGENiHBG000914
InParanoidiQ07021
KOiK15414
OMAiATHYEHS
OrthoDBiEOG091G0IZD
PhylomeDBiQ07021
TreeFamiTF315160

Family and domain databases

Gene3Di3.10.280.10, 1 hit
InterProiView protein in InterPro
IPR003428 MAM33
IPR036561 MAM33_sf
PANTHERiPTHR10826 PTHR10826, 1 hit
PfamiView protein in Pfam
PF02330 MAM33, 1 hit
SUPFAMiSSF54529 SSF54529, 1 hit

Sequencei

Sequence statusi: Complete.

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

Q07021-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MLPLLRCVPR VLGSSVAGLR AAAPASPFRQ LLQPAPRLCT RPFGLLSVRA
60 70 80 90 100
GSERRPGLLR PRGPCACGCG CGSLHTDGDK AFVDFLSDEI KEERKIQKHK
110 120 130 140 150
TLPKMSGGWE LELNGTEAKL VRKVAGEKIT VTFNINNSIP PTFDGEEEPS
160 170 180 190 200
QGQKVEEQEP ELTSTPNFVV EVIKNDDGKK ALVLDCHYPE DEVGQEDEAE
210 220 230 240 250
SDIFSIREVS FQSTGESEWK DTNYTLNTDS LDWALYDHLM DFLADRGVDN
260 270 280
TFADELVELS TALEHQEYIT FLEDLKSFVK SQ
Length:282
Mass (Da):31,362
Last modified:February 1, 1995 - v1
Checksum:i2F747FA73BB1314B
GO

Natural variant

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Natural variantiVAR_080391186C → S in COXPD33; unknown pathological significance. 1 PublicationCorresponds to variant dbSNP:rs748497469EnsemblClinVar.1
Natural variantiVAR_080392188Missing in COXPD33; unknown pathological significance. 1 Publication1
Natural variantiVAR_080393204F → L in COXPD33; unknown pathological significance. 1 PublicationCorresponds to variant dbSNP:rs767427194EnsemblClinVar.1
Natural variantiVAR_080394247G → W in COXPD33. 1 Publication1
Natural variantiVAR_080395275L → F in COXPD33; unknown pathological significance. 1 Publication1
Natural variantiVAR_080396275L → P in COXPD33. 1 Publication1

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
L04636 mRNA Translation: AAA16315.1
X75913 mRNA Translation: CAA53512.1
AF338439 Genomic DNA Translation: AAK26580.1
BT019898 mRNA Translation: AAV38701.1
BT019899 mRNA Translation: AAV38702.1
DQ372108 Genomic DNA Translation: ABC79624.1
BC000435 mRNA Translation: AAH00435.1
BC013731 mRNA Translation: AAH13731.1
M69039 mRNA Translation: AAA73055.1
AF275902 mRNA Translation: AAF78763.1
CCDSiCCDS11071.1
PIRiJT0762
RefSeqiNP_001203.1, NM_001212.3
UniGeneiHs.555866

Genome annotation databases

EnsembliENST00000225698; ENSP00000225698; ENSG00000108561
GeneIDi708
KEGGihsa:708
UCSCiuc002gby.2 human

Similar proteinsi

Entry informationi

Entry nameiC1QBP_HUMAN
AccessioniPrimary (citable) accession number: Q07021
Secondary accession number(s): Q2HXR8, Q9NNY8
Entry historyiIntegrated into UniProtKB/Swiss-Prot: February 1, 1995
Last sequence update: February 1, 1995
Last modified: July 18, 2018
This is version 186 of the entry and version 1 of the sequence. See 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 17
    Human chromosome 17: 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

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