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P02746

- C1QB_HUMAN

UniProt

P02746 - C1QB_HUMAN

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Protein
Complement C1q subcomponent subunit B
Gene
C1QB
Organism
Homo sapiens (Human)
Status
Reviewed - Annotation score: 5 out of 5 - Experimental evidence at protein leveli

Functioni

C1q associates with the proenzymes C1r and C1s to yield C1, the first component of the serum complement system. The collagen-like regions of C1q interact with the Ca2+-dependent C1r2C1s2 proenzyme complex, and efficient activation of C1 takes place on interaction of the globular heads of C1q with the Fc regions of IgG or IgM antibody present in immune complexes.

GO - Molecular functioni

  1. protein binding Source: IntAct

GO - Biological processi

  1. complement activation Source: Reactome
  2. complement activation, classical pathway Source: Reactome
  3. innate immune response Source: Reactome
  4. inner ear development Source: Ensembl
Complete GO annotation...

Keywords - Biological processi

Complement pathway, Immunity, Innate immunity

Enzyme and pathway databases

ReactomeiREACT_7956. Classical antibody-mediated complement activation.
REACT_8024. Initial triggering of complement.

Names & Taxonomyi

Protein namesi
Recommended name:
Complement C1q subcomponent subunit B
Gene namesi
Name:C1QB
OrganismiHomo sapiens (Human)
Taxonomic identifieri9606 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo
ProteomesiUP000005640: Chromosome 1

Organism-specific databases

HGNCiHGNC:1242. C1QB.

Subcellular locationi

GO - Cellular componenti

  1. blood microparticle Source: UniProt
  2. collagen trimer Source: UniProtKB-KW
  3. complement component C1 complex Source: ProtInc
  4. extracellular region Source: Reactome
  5. extracellular vesicular exosome Source: UniProt
Complete GO annotation...

Keywords - Cellular componenti

Secreted

Pathology & Biotechi

Involvement in diseasei

Complement component C1q deficiency (C1QD) [MIM:613652]: A disorder caused by impaired activation of the complement classical pathway. It generally leads to severe immune complex disease with features of systemic lupus erythematosus and glomerulonephritis.
Note: The disease is caused by mutations affecting the gene represented in this entry.1 Publication
Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Natural varianti42 – 421G → D in C1QD. 1 Publication
VAR_008541

Keywords - Diseasei

Disease mutation

Organism-specific databases

MIMi613652. phenotype.
Orphaneti169147. Immunodeficiency due to an early component of complement deficiency.
PharmGKBiPA25623.

PTM / Processingi

Molecule processing

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Signal peptidei1 – 27272 Publications
Add
BLAST
Chaini28 – 253226Complement C1q subcomponent subunit B
PRO_0000003521Add
BLAST

Amino acid modifications

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Modified residuei28 – 281Pyrrolidone carboxylic acid
Disulfide bondi31 – 31Interchain (with C-26 in chain A)1 Publication
Modified residuei35 – 3514-hydroxyproline
Modified residuei38 – 3814-hydroxyproline
Modified residuei41 – 4114-hydroxyproline
Modified residuei53 – 5314-hydroxyproline
Modified residuei56 – 5614-hydroxyproline
Modified residuei59 – 5915-hydroxylysine
Modified residuei62 – 6215-hydroxylysine
Modified residuei65 – 6514-hydroxyproline
Modified residuei77 – 7715-hydroxylysine
Modified residuei83 – 8314-hydroxyproline
Modified residuei86 – 8614-hydroxyproline
Modified residuei92 – 9215-hydroxylysine
Modified residuei98 – 9815-hydroxylysine
Modified residuei101 – 10114-hydroxyproline
Modified residuei104 – 10414-hydroxyproline
Modified residuei107 – 10714-hydroxyproline
Modified residuei110 – 11015-hydroxylysine

Post-translational modificationi

Hydroxylated on lysine and proline residues. Hydroxylated lysine residues can be glycosylated. Human C1Q contains up to 68.3 hydroxylysine-galactosylglucose residues and up to 2.5 hydroxylysine-galactose per molecule. Total percentage hydroxylysine residues glycosylated is 86.4%.2 Publications

Keywords - PTMi

Disulfide bond, Glycoprotein, Hydroxylation, Pyrrolidone carboxylic acid

Proteomic databases

PaxDbiP02746.
PRIDEiP02746.

PTM databases

PhosphoSiteiP02746.

Expressioni

Gene expression databases

ArrayExpressiP02746.
BgeeiP02746.
CleanExiHS_C1QB.
GenevestigatoriP02746.

Organism-specific databases

HPAiHPA052116.

Interactioni

Subunit structurei

C1 is a calcium-dependent trimolecular complex of C1q, c1r and C1s 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.1 Publication

Binary interactionsi

WithEntry#Exp.IntActNotes
C1QAP027454EBI-2813376,EBI-1220209

Protein-protein interaction databases

BioGridi107174. 5 interactions.
IntActiP02746. 7 interactions.
MINTiMINT-6629999.
STRINGi9606.ENSP00000313967.

Structurei

Secondary structure

Legend: HelixTurnBeta strand
Show more details
Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Beta strandi123 – 1275
Beta strandi144 – 1496
Turni155 – 1573
Beta strandi159 – 1613
Beta strandi166 – 17813
Beta strandi180 – 19011
Beta strandi192 – 1998
Beta strandi202 – 2043
Beta strandi206 – 21611
Beta strandi221 – 23010
Beta strandi241 – 2499

3D structure databases

Select the link destinations:
PDBe
RCSB PDB
PDBj
Links Updated
EntryMethodResolution (Å)ChainPositionsPDBsum
1PK6X-ray1.85B119-250[»]
2JG8X-ray2.05B/E118-253[»]
2JG9X-ray1.90B/E118-253[»]
2WNUX-ray2.30B/E118-253[»]
2WNVX-ray1.25B/E118-253[»]
ProteinModelPortaliP02746.
SMRiP02746. Positions 119-250.

Miscellaneous databases

EvolutionaryTraceiP02746.

Family & Domainsi

Domains and Repeats

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Domaini37 – 8650Collagen-like 1
Add
BLAST
Domaini60 – 11455Collagen-like 2
Add
BLAST
Domaini117 – 253137C1q
Add
BLAST

Sequence similaritiesi

Contains 1 C1q domain.

Keywords - Domaini

Collagen, Repeat, Signal

Phylogenomic databases

eggNOGiNOG115400.
HOGENOMiHOG000085653.
HOVERGENiHBG108220.
InParanoidiP02746.
KOiK03987.
OMAiNLMRGRE.
PhylomeDBiP02746.
TreeFamiTF329591.

Family and domain databases

Gene3Di2.60.120.40. 1 hit.
InterProiIPR001073. C1q.
IPR008160. Collagen.
IPR008983. Tumour_necrosis_fac-like_dom.
[Graphical view]
PfamiPF00386. C1q. 1 hit.
PF01391. Collagen. 2 hits.
[Graphical view]
PRINTSiPR00007. COMPLEMNTC1Q.
SMARTiSM00110. C1Q. 1 hit.
[Graphical view]
SUPFAMiSSF49842. SSF49842. 1 hit.
PROSITEiPS50871. C1Q. 1 hit.
[Graphical view]

Sequencei

Sequence statusi: Complete.

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

P02746-1 [UniParc]FASTAAdd to Basket

« Hide

MMMKIPWGSI PVLMLLLLLG LIDISQAQLS CTGPPAIPGI PGIPGTPGPD    50
GQPGTPGIKG EKGLPGLAGD HGEFGEKGDP GIPGNPGKVG PKGPMGPKGG 100
PGAPGAPGPK GESGDYKATQ KIAFSATRTI NVPLRRDQTI RFDHVITNMN 150
NNYEPRSGKF TCKVPGLYYF TYHASSRGNL CVNLMRGRER AQKVVTFCDY 200
AYNTFQVTTG GMVLKLEQGE NVFLQATDKN SLLGMEGANS IFSGFLLFPD 250
MEA 253
Length:253
Mass (Da):26,722
Last modified:June 15, 2010 - v3
Checksum:iD80C753C0D430EDC
GO

Natural variant

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Natural varianti42 – 421G → D in C1QD. 1 Publication
VAR_008541
Natural varianti123 – 1231A → T in a breast cancer sample; somatic mutation. 1 Publication
VAR_035551

Sequence conflict

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Sequence conflicti28 – 281Q → E AA sequence 1 Publication
Sequence conflicti85 – 851N → D AA sequence 1 Publication
Sequence conflicti100 – 1001G → P AA sequence 1 Publication
Sequence conflicti100 – 1001G → P AA sequence 1 Publication

Sequence databases

Select the link destinations:
EMBL
GenBank
DDBJ
Links Updated
AL158086 Genomic DNA. Translation: CAI22896.1.
BC008983 mRNA. Translation: AAH08983.1.
X03084 mRNA. Translation: CAA26880.1.
M36278 mRNA. Translation: AAC41692.1.
CCDSiCCDS228.1.
PIRiB23422. C1HUQB.
RefSeqiNP_000482.3. NM_000491.3.
XP_005246039.1. XM_005245982.1.
UniGeneiHs.8986.

Genome annotation databases

EnsembliENST00000314933; ENSP00000313967; ENSG00000173369.
GeneIDi713.
KEGGihsa:713.
UCSCiuc001bgd.3. human.

Polymorphism databases

DMDMi298286922.

Keywords - Coding sequence diversityi

Polymorphism

Cross-referencesi

Web resourcesi

C1QBbase

C1QB mutation db

Sequence databases

Select the link destinations:
EMBL
GenBank
DDBJ
Links Updated
AL158086 Genomic DNA. Translation: CAI22896.1 .
BC008983 mRNA. Translation: AAH08983.1 .
X03084 mRNA. Translation: CAA26880.1 .
M36278 mRNA. Translation: AAC41692.1 .
CCDSi CCDS228.1.
PIRi B23422. C1HUQB.
RefSeqi NP_000482.3. NM_000491.3.
XP_005246039.1. XM_005245982.1.
UniGenei Hs.8986.

3D structure databases

Select the link destinations:
PDBe
RCSB PDB
PDBj
Links Updated
Entry Method Resolution (Å) Chain Positions PDBsum
1PK6 X-ray 1.85 B 119-250 [» ]
2JG8 X-ray 2.05 B/E 118-253 [» ]
2JG9 X-ray 1.90 B/E 118-253 [» ]
2WNU X-ray 2.30 B/E 118-253 [» ]
2WNV X-ray 1.25 B/E 118-253 [» ]
ProteinModelPortali P02746.
SMRi P02746. Positions 119-250.
ModBasei Search...
MobiDBi Search...

Protein-protein interaction databases

BioGridi 107174. 5 interactions.
IntActi P02746. 7 interactions.
MINTi MINT-6629999.
STRINGi 9606.ENSP00000313967.

Chemistry

DrugBanki DB00054. Abciximab.
DB00051. Adalimumab.
DB00092. Alefacept.
DB00087. Alemtuzumab.
DB00074. Basiliximab.
DB00112. Bevacizumab.
DB00002. Cetuximab.
DB00111. Daclizumab.
DB00095. Efalizumab.
DB00005. Etanercept.
DB00056. Gemtuzumab ozogamicin.
DB00078. Ibritumomab.
DB00028. Immune globulin.
DB00075. Muromonab.
DB00108. Natalizumab.
DB00110. Palivizumab.
DB00073. Rituximab.
DB00081. Tositumomab.
DB00072. Trastuzumab.

PTM databases

PhosphoSitei P02746.

Polymorphism databases

DMDMi 298286922.

Proteomic databases

PaxDbi P02746.
PRIDEi P02746.

Protocols and materials databases

DNASUi 713.
Structural Biology Knowledgebase Search...

Genome annotation databases

Ensembli ENST00000314933 ; ENSP00000313967 ; ENSG00000173369 .
GeneIDi 713.
KEGGi hsa:713.
UCSCi uc001bgd.3. human.

Organism-specific databases

CTDi 713.
GeneCardsi GC01P022979.
HGNCi HGNC:1242. C1QB.
HPAi HPA052116.
MIMi 120570. gene.
613652. phenotype.
neXtProti NX_P02746.
Orphaneti 169147. Immunodeficiency due to an early component of complement deficiency.
PharmGKBi PA25623.
GenAtlasi Search...

Phylogenomic databases

eggNOGi NOG115400.
HOGENOMi HOG000085653.
HOVERGENi HBG108220.
InParanoidi P02746.
KOi K03987.
OMAi NLMRGRE.
PhylomeDBi P02746.
TreeFami TF329591.

Enzyme and pathway databases

Reactomei REACT_7956. Classical antibody-mediated complement activation.
REACT_8024. Initial triggering of complement.

Miscellaneous databases

ChiTaRSi C1QB. human.
EvolutionaryTracei P02746.
GenomeRNAii 713.
NextBioi 2898.
PROi P02746.
SOURCEi Search...

Gene expression databases

ArrayExpressi P02746.
Bgeei P02746.
CleanExi HS_C1QB.
Genevestigatori P02746.

Family and domain databases

Gene3Di 2.60.120.40. 1 hit.
InterProi IPR001073. C1q.
IPR008160. Collagen.
IPR008983. Tumour_necrosis_fac-like_dom.
[Graphical view ]
Pfami PF00386. C1q. 1 hit.
PF01391. Collagen. 2 hits.
[Graphical view ]
PRINTSi PR00007. COMPLEMNTC1Q.
SMARTi SM00110. C1Q. 1 hit.
[Graphical view ]
SUPFAMi SSF49842. SSF49842. 1 hit.
PROSITEi PS50871. C1Q. 1 hit.
[Graphical view ]
ProtoNeti Search...

Publicationsi

« Hide 'large scale' publications
  1. "The DNA sequence and biological annotation of human chromosome 1."
    Gregory S.G., Barlow K.F., McLay K.E., Kaul R., Swarbreck D., Dunham A., Scott C.E., Howe K.L., Woodfine K., Spencer C.C.A., Jones M.C., Gillson C., Searle S., Zhou Y., Kokocinski F., McDonald L., Evans R., Phillips K.
    , Atkinson A., Cooper R., Jones C., Hall R.E., Andrews T.D., Lloyd C., Ainscough R., Almeida J.P., Ambrose K.D., Anderson F., Andrew R.W., Ashwell R.I.S., Aubin K., Babbage A.K., Bagguley C.L., Bailey J., Beasley H., Bethel G., Bird C.P., Bray-Allen S., Brown J.Y., Brown A.J., Buckley D., Burton J., Bye J., Carder C., Chapman J.C., Clark S.Y., Clarke G., Clee C., Cobley V., Collier R.E., Corby N., Coville G.J., Davies J., Deadman R., Dunn M., Earthrowl M., Ellington A.G., Errington H., Frankish A., Frankland J., French L., Garner P., Garnett J., Gay L., Ghori M.R.J., Gibson R., Gilby L.M., Gillett W., Glithero R.J., Grafham D.V., Griffiths C., Griffiths-Jones S., Grocock R., Hammond S., Harrison E.S.I., Hart E., Haugen E., Heath P.D., Holmes S., Holt K., Howden P.J., Hunt A.R., Hunt S.E., Hunter G., Isherwood J., James R., Johnson C., Johnson D., Joy A., Kay M., Kershaw J.K., Kibukawa M., Kimberley A.M., King A., Knights A.J., Lad H., Laird G., Lawlor S., Leongamornlert D.A., Lloyd D.M., Loveland J., Lovell J., Lush M.J., Lyne R., Martin S., Mashreghi-Mohammadi M., Matthews L., Matthews N.S.W., McLaren S., Milne S., Mistry S., Moore M.J.F., Nickerson T., O'Dell C.N., Oliver K., Palmeiri A., Palmer S.A., Parker A., Patel D., Pearce A.V., Peck A.I., Pelan S., Phelps K., Phillimore B.J., Plumb R., Rajan J., Raymond C., Rouse G., Saenphimmachak C., Sehra H.K., Sheridan E., Shownkeen R., Sims S., Skuce C.D., Smith M., Steward C., Subramanian S., Sycamore N., Tracey A., Tromans A., Van Helmond Z., Wall M., Wallis J.M., White S., Whitehead S.L., Wilkinson J.E., Willey D.L., Williams H., Wilming L., Wray P.W., Wu Z., Coulson A., Vaudin M., Sulston J.E., Durbin R.M., Hubbard T., Wooster R., Dunham I., Carter N.P., McVean G., Ross M.T., Harrow J., Olson M.V., Beck S., Rogers J., Bentley D.R.
    Nature 441:315-321(2006) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
  2. "The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC)."
    The MGC Project Team
    Genome Res. 14:2121-2127(2004) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
    Tissue: Brain.
  3. "Molecular cloning and characterization of the complementary DNA and gene coding for the B-chain of subcomponent C1q of the human complement system."
    Reid K.B.M.
    Biochem. J. 231:729-735(1985) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [MRNA] OF 26-253.
  4. "Amino acid sequence of the N-terminal 108 amino acid residues of the B chain of subcomponent C1q of the first component of human complement."
    Reid K.B.M., Thompson E.O.P.
    Biochem. J. 173:863-868(1978) [PubMed] [Europe PMC] [Abstract]
    Cited for: PROTEIN SEQUENCE OF 28-195, GLYCOSYLATION, PYROGLUTAMATE FORMATION AT GLU-28, DISULFIDE BOND, HYDROXYLATION.
  5. "Complete amino acid sequences of the three collagen-like regions present in subcomponent C1q of the first component of human complement."
    Reid K.B.M.
    Biochem. J. 179:367-371(1979) [PubMed] [Europe PMC] [Abstract]
    Cited for: PROTEIN SEQUENCE OF 28-135, HYDROXYLATION AT PRO-35; PRO-38; PRO-41; PRO-53; PRO-56; LYS-59; LYS-62; PRO-65; LYS-77; PRO-83; PRO-86; LYS-92; LYS-98; PRO-101; PRO-104; PRO-107 AND LYS-110.
  6. "Completion of the amino acid sequences of the A and B chains of subcomponent C1q of the first component of human complement."
    Reid K.B.M., Gagnon J., Frampton J.
    Biochem. J. 203:559-569(1982) [PubMed] [Europe PMC] [Abstract]
    Cited for: PROTEIN SEQUENCE OF 136-253.
  7. "Cloning and characterization of the complementary DNA for the B chain of normal human serum C1q."
    Reid K.B.M., Bentley D.R., Wood K.J.
    Philos. Trans. R. Soc. Lond., B, Biol. Sci. 306:345-354(1984) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [MRNA] OF 226-253.
    Tissue: Liver.
  8. "Comparable content of hydroxylysine-linked glycosides in subcomponents C1q of the first component of human, bovine and mouse complement."
    Yonemasu K., Shinkai H., Sasaki T.
    Coll. Relat. Res. 1:385-390(1981) [PubMed] [Europe PMC] [Abstract]
    Cited for: GLYCOSYLATION ON HYDROXYLYSINES.
  9. "The crystal structure of the globular head of complement protein C1q provides a basis for its versatile recognition properties."
    Gaboriaud C., Juanhuix J., Gruez A., Lacroix M., Darnault C., Pignol D., Verger D., Fontecilla-Camps J.-C., Arlaud G.J.
    J. Biol. Chem. 278:46974-46982(2003) [PubMed] [Europe PMC] [Abstract]
    Cited for: X-RAY CRYSTALLOGRAPHY (1.85 ANGSTROMS) OF 119-250.
  10. "Molecular basis of hereditary C1q deficiency."
    Petry F.
    Immunobiology 199:286-294(1998) [PubMed] [Europe PMC] [Abstract]
    Cited for: REVIEW ON C1Q DEFICIENCY.
  11. "Molecular basis of a new type of C1q-deficiency associated with a non-functional low molecular weight (LMW) C1q: parallels and differences to other known genetic C1q-defects."
    Petry F., Hauptmann G., Goetz J., Grosshans E., Loos M.
    Immunopharmacology 38:189-201(1997) [PubMed] [Europe PMC] [Abstract]
    Cited for: VARIANT C1QD ASP-42.
  12. Cited for: VARIANT [LARGE SCALE ANALYSIS] THR-123.

Entry informationi

Entry nameiC1QB_HUMAN
AccessioniPrimary (citable) accession number: P02746
Secondary accession number(s): Q5T959, Q96H17
Entry historyi
Integrated into UniProtKB/Swiss-Prot: July 21, 1986
Last sequence update: June 15, 2010
Last modified: September 3, 2014
This is version 163 of the entry and version 3 of the sequence. [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 1
    Human chromosome 1: 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

External Data

Dasty 3

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