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P02746

- C1QB_HUMAN

UniProt

P02746 - C1QB_HUMAN

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
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    • History
      Entry version 164 (01 Oct 2014)
      Sequence version 3 (15 Jun 2010)
      Previous versions | rss
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    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

    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

    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.1 Publication
    Note: The disease is caused by mutations affecting the gene represented in this entry.
    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 PublicationsAdd
    BLAST
    Chaini28 – 253226Complement C1q subcomponent subunit BPRO_0000003521Add
    BLAST

    Amino acid modifications

    Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
    Modified residuei28 – 281Pyrrolidone carboxylic acid1 Publication
    Disulfide bondi31 – 31Interchain (with C-26 in chain A)1 Publication
    Modified residuei35 – 3514-hydroxyproline2 Publications
    Modified residuei38 – 3814-hydroxyproline2 Publications
    Modified residuei41 – 4114-hydroxyproline2 Publications
    Modified residuei53 – 5314-hydroxyproline2 Publications
    Modified residuei56 – 5614-hydroxyproline2 Publications
    Modified residuei59 – 5915-hydroxylysine2 Publications
    Modified residuei62 – 6215-hydroxylysine2 Publications
    Modified residuei65 – 6514-hydroxyproline2 Publications
    Modified residuei77 – 7715-hydroxylysine2 Publications
    Modified residuei83 – 8314-hydroxyproline2 Publications
    Modified residuei86 – 8614-hydroxyproline2 Publications
    Modified residuei92 – 9215-hydroxylysine2 Publications
    Modified residuei98 – 9815-hydroxylysine2 Publications
    Modified residuei101 – 10114-hydroxyproline2 Publications
    Modified residuei104 – 10414-hydroxyproline2 Publications
    Modified residuei107 – 10714-hydroxyproline2 Publications
    Modified residuei110 – 11015-hydroxylysine2 Publications

    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%.3 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

    1
    253
    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.
    ModBaseiSearch...
    MobiDBiSearch...

    Miscellaneous databases

    EvolutionaryTraceiP02746.

    Family & Domainsi

    Domains and Repeats

    Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
    Domaini37 – 8650Collagen-like 1Add
    BLAST
    Domaini60 – 11455Collagen-like 2Add
    BLAST
    Domaini117 – 253137C1qPROSITE-ProRule annotationAdd
    BLAST

    Sequence similaritiesi

    Contains 1 C1q domain.PROSITE-ProRule annotation
    Contains 2 collagen-like domains.Curated

    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

    Experimental Info

    Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
    Sequence conflicti28 – 281Q → E AA sequence (PubMed:708376)Curated
    Sequence conflicti85 – 851N → D AA sequence (PubMed:708376)Curated
    Sequence conflicti100 – 1001G → P AA sequence (PubMed:708376)Curated
    Sequence conflicti100 – 1001G → P AA sequence (PubMed:486087)Curated

    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 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.
    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

    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: October 1, 2014
    This is version 164 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