C1QB_HUMAN
ID C1QB_HUMAN Reviewed; 253 AA.
AC P02746; Q5T959; Q96H17;
DT 21-JUL-1986, integrated into UniProtKB/Swiss-Prot.
DT 15-JUN-2010, sequence version 3.
DT 03-AUG-2022, entry version 221.
DE RecName: Full=Complement C1q subcomponent subunit B;
DE Flags: Precursor;
GN Name=C1QB;
OS Homo sapiens (Human).
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
OC Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae;
OC Homo.
OX NCBI_TaxID=9606;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RX PubMed=16710414; DOI=10.1038/nature04727;
RA Gregory S.G., Barlow K.F., McLay K.E., Kaul R., Swarbreck D., Dunham A.,
RA Scott C.E., Howe K.L., Woodfine K., Spencer C.C.A., Jones M.C., Gillson C.,
RA Searle S., Zhou Y., Kokocinski F., McDonald L., Evans R., Phillips K.,
RA Atkinson A., Cooper R., Jones C., Hall R.E., Andrews T.D., Lloyd C.,
RA Ainscough R., Almeida J.P., Ambrose K.D., Anderson F., Andrew R.W.,
RA Ashwell R.I.S., Aubin K., Babbage A.K., Bagguley C.L., Bailey J.,
RA Beasley H., Bethel G., Bird C.P., Bray-Allen S., Brown J.Y., Brown A.J.,
RA Buckley D., Burton J., Bye J., Carder C., Chapman J.C., Clark S.Y.,
RA Clarke G., Clee C., Cobley V., Collier R.E., Corby N., Coville G.J.,
RA Davies J., Deadman R., Dunn M., Earthrowl M., Ellington A.G., Errington H.,
RA Frankish A., Frankland J., French L., Garner P., Garnett J., Gay L.,
RA Ghori M.R.J., Gibson R., Gilby L.M., Gillett W., Glithero R.J.,
RA Grafham D.V., Griffiths C., Griffiths-Jones S., Grocock R., Hammond S.,
RA Harrison E.S.I., Hart E., Haugen E., Heath P.D., Holmes S., Holt K.,
RA Howden P.J., Hunt A.R., Hunt S.E., Hunter G., Isherwood J., James R.,
RA Johnson C., Johnson D., Joy A., Kay M., Kershaw J.K., Kibukawa M.,
RA Kimberley A.M., King A., Knights A.J., Lad H., Laird G., Lawlor S.,
RA Leongamornlert D.A., Lloyd D.M., Loveland J., Lovell J., Lush M.J.,
RA Lyne R., Martin S., Mashreghi-Mohammadi M., Matthews L., Matthews N.S.W.,
RA McLaren S., Milne S., Mistry S., Moore M.J.F., Nickerson T., O'Dell C.N.,
RA Oliver K., Palmeiri A., Palmer S.A., Parker A., Patel D., Pearce A.V.,
RA Peck A.I., Pelan S., Phelps K., Phillimore B.J., Plumb R., Rajan J.,
RA Raymond C., Rouse G., Saenphimmachak C., Sehra H.K., Sheridan E.,
RA Shownkeen R., Sims S., Skuce C.D., Smith M., Steward C., Subramanian S.,
RA Sycamore N., Tracey A., Tromans A., Van Helmond Z., Wall M., Wallis J.M.,
RA White S., Whitehead S.L., Wilkinson J.E., Willey D.L., Williams H.,
RA Wilming L., Wray P.W., Wu Z., Coulson A., Vaudin M., Sulston J.E.,
RA Durbin R.M., Hubbard T., Wooster R., Dunham I., Carter N.P., McVean G.,
RA Ross M.T., Harrow J., Olson M.V., Beck S., Rogers J., Bentley D.R.;
RT "The DNA sequence and biological annotation of human chromosome 1.";
RL Nature 441:315-321(2006).
RN [2]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
RC TISSUE=Brain;
RX PubMed=15489334; DOI=10.1101/gr.2596504;
RG The MGC Project Team;
RT "The status, quality, and expansion of the NIH full-length cDNA project:
RT the Mammalian Gene Collection (MGC).";
RL Genome Res. 14:2121-2127(2004).
RN [3]
RP NUCLEOTIDE SEQUENCE [MRNA] OF 26-253.
RX PubMed=3000358; DOI=10.1042/bj2310729;
RA Reid K.B.M.;
RT "Molecular cloning and characterization of the complementary DNA and gene
RT coding for the B-chain of subcomponent C1q of the human complement
RT system.";
RL Biochem. J. 231:729-735(1985).
RN [4]
RP PROTEIN SEQUENCE OF 28-195, GLYCOSYLATION, PYROGLUTAMATE FORMATION AT
RP GLN-28, DISULFIDE BOND, AND HYDROXYLATION.
RX PubMed=708376; DOI=10.1042/bj1730863;
RA Reid K.B.M., Thompson E.O.P.;
RT "Amino acid sequence of the N-terminal 108 amino acid residues of the B
RT chain of subcomponent C1q of the first component of human complement.";
RL Biochem. J. 173:863-868(1978).
RN [5]
RP PROTEIN SEQUENCE OF 28-135, AND HYDROXYLATION AT PRO-35; PRO-38; PRO-41;
RP PRO-53; PRO-56; LYS-59; LYS-62; PRO-65; LYS-77; PRO-83; PRO-86; LYS-92;
RP LYS-98; PRO-101; PRO-104; PRO-107 AND LYS-110.
RX PubMed=486087; DOI=10.1042/bj1790367;
RA Reid K.B.M.;
RT "Complete amino acid sequences of the three collagen-like regions present
RT in subcomponent C1q of the first component of human complement.";
RL Biochem. J. 179:367-371(1979).
RN [6]
RP PROTEIN SEQUENCE OF 136-253.
RX PubMed=6981411; DOI=10.1042/bj2030559;
RA Reid K.B.M., Gagnon J., Frampton J.;
RT "Completion of the amino acid sequences of the A and B chains of
RT subcomponent C1q of the first component of human complement.";
RL Biochem. J. 203:559-569(1982).
RN [7]
RP NUCLEOTIDE SEQUENCE [MRNA] OF 226-253.
RC TISSUE=Liver;
RX PubMed=6208566; DOI=10.1098/rstb.1984.0095;
RA Reid K.B.M., Bentley D.R., Wood K.J.;
RT "Cloning and characterization of the complementary DNA for the B chain of
RT normal human serum C1q.";
RL Philos. Trans. R. Soc. Lond., B, Biol. Sci. 306:345-354(1984).
RN [8]
RP GLYCOSYLATION ON HYDROXYLYSINES.
RX PubMed=6286235; DOI=10.1016/s0174-173x(81)80015-5;
RA Yonemasu K., Shinkai H., Sasaki T.;
RT "Comparable content of hydroxylysine-linked glycosides in subcomponents C1q
RT of the first component of human, bovine and mouse complement.";
RL Coll. Relat. Res. 1:385-390(1981).
RN [9]
RP X-RAY CRYSTALLOGRAPHY (1.85 ANGSTROMS) OF 119-250.
RX PubMed=12960167; DOI=10.1074/jbc.m307764200;
RA Gaboriaud C., Juanhuix J., Gruez A., Lacroix M., Darnault C., Pignol D.,
RA Verger D., Fontecilla-Camps J.-C., Arlaud G.J.;
RT "The crystal structure of the globular head of complement protein C1q
RT provides a basis for its versatile recognition properties.";
RL J. Biol. Chem. 278:46974-46982(2003).
RN [10]
RP REVIEW ON C1Q DEFICIENCY.
RX PubMed=9777412; DOI=10.1016/s0171-2985(98)80033-8;
RA Petry F.;
RT "Molecular basis of hereditary C1q deficiency.";
RL Immunobiology 199:286-294(1998).
RN [11]
RP VARIANT C1QD ASP-42.
RX PubMed=9476130; DOI=10.1016/s0162-3109(97)00065-9;
RA Petry F., Hauptmann G., Goetz J., Grosshans E., Loos M.;
RT "Molecular basis of a new type of C1q-deficiency associated with a non-
RT functional low molecular weight (LMW) C1q: parallels and differences to
RT other known genetic C1q-defects.";
RL Immunopharmacology 38:189-201(1997).
RN [12]
RP VARIANT [LARGE SCALE ANALYSIS] THR-123.
RX PubMed=16959974; DOI=10.1126/science.1133427;
RA Sjoeblom T., Jones S., Wood L.D., Parsons D.W., Lin J., Barber T.D.,
RA Mandelker D., Leary R.J., Ptak J., Silliman N., Szabo S., Buckhaults P.,
RA Farrell C., Meeh P., Markowitz S.D., Willis J., Dawson D., Willson J.K.V.,
RA Gazdar A.F., Hartigan J., Wu L., Liu C., Parmigiani G., Park B.H.,
RA Bachman K.E., Papadopoulos N., Vogelstein B., Kinzler K.W.,
RA Velculescu V.E.;
RT "The consensus coding sequences of human breast and colorectal cancers.";
RL Science 314:268-274(2006).
CC -!- FUNCTION: C1q associates with the proenzymes C1r and C1s to yield C1,
CC the first component of the serum complement system. The collagen-like
CC regions of C1q interact with the Ca(2+)-dependent C1r(2)C1s(2)
CC proenzyme complex, and efficient activation of C1 takes place on
CC interaction of the globular heads of C1q with the Fc regions of IgG or
CC IgM antibody present in immune complexes.
CC -!- SUBUNIT: C1 is a calcium-dependent trimolecular complex of C1q, c1r and
CC C1s in the molar ration of 1:2:2. C1q subcomponent is composed of nine
CC subunits, six of which are disulfide-linked dimers of the A and B
CC chains, and three of which are disulfide-linked dimers of the C chain.
CC {ECO:0000269|PubMed:708376}.
CC -!- INTERACTION:
CC P02746; P02745: C1QA; NbExp=4; IntAct=EBI-2813376, EBI-1220209;
CC P02746; PRO_0000018590 [Q07021]: C1QBP; NbExp=4; IntAct=EBI-2813376, EBI-14032968;
CC P02746; Q9UHD9: UBQLN2; NbExp=3; IntAct=EBI-2813376, EBI-947187;
CC -!- SUBCELLULAR LOCATION: Secreted.
CC -!- PTM: Hydroxylated on lysine and proline residues. Hydroxylated lysine
CC residues can be glycosylated. Human C1Q contains up to 68.3
CC hydroxylysine-galactosylglucose residues and up to 2.5 hydroxylysine-
CC galactose per molecule. Total percentage hydroxylysine residues
CC glycosylated is 86.4%. {ECO:0000269|PubMed:486087,
CC ECO:0000269|PubMed:6286235, ECO:0000269|PubMed:708376}.
CC -!- DISEASE: Complement component C1q deficiency (C1QD) [MIM:613652]: A
CC disorder caused by impaired activation of the complement classical
CC pathway. It generally leads to severe immune complex disease with
CC features of systemic lupus erythematosus and glomerulonephritis.
CC {ECO:0000269|PubMed:9476130}. Note=The disease is caused by variants
CC affecting the gene represented in this entry.
CC -!- WEB RESOURCE: Name=C1QBbase; Note=C1QB mutation db;
CC URL="http://structure.bmc.lu.se/idbase/C1QBbase/";
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DR EMBL; AL158086; -; NOT_ANNOTATED_CDS; Genomic_DNA.
DR EMBL; BC008983; AAH08983.1; -; mRNA.
DR EMBL; X03084; CAA26880.1; -; mRNA.
DR EMBL; M36278; AAC41692.1; -; mRNA.
DR CCDS; CCDS228.1; -.
DR PIR; B23422; C1HUQB.
DR RefSeq; NP_000482.3; NM_000491.4.
DR RefSeq; XP_011540361.1; XM_011542059.2.
DR PDB; 1PK6; X-ray; 1.85 A; B=119-250.
DR PDB; 2JG8; X-ray; 2.05 A; B/E=118-253.
DR PDB; 2JG9; X-ray; 1.90 A; B/E=118-253.
DR PDB; 2WNU; X-ray; 2.30 A; B/E=118-253.
DR PDB; 2WNV; X-ray; 1.25 A; B/E=118-253.
DR PDB; 5HKJ; X-ray; 1.35 A; A=117-253.
DR PDB; 5HZF; X-ray; 1.55 A; A=117-253.
DR PDB; 6FCZ; EM; 10.00 A; B=119-250.
DR PDB; 6Z6V; X-ray; 2.19 A; B/E=119-253.
DR PDBsum; 1PK6; -.
DR PDBsum; 2JG8; -.
DR PDBsum; 2JG9; -.
DR PDBsum; 2WNU; -.
DR PDBsum; 2WNV; -.
DR PDBsum; 5HKJ; -.
DR PDBsum; 5HZF; -.
DR PDBsum; 6FCZ; -.
DR PDBsum; 6Z6V; -.
DR AlphaFoldDB; P02746; -.
DR SASBDB; P02746; -.
DR SMR; P02746; -.
DR BioGRID; 107174; 97.
DR ComplexPortal; CPX-1919; Complement component C1q complex.
DR CORUM; P02746; -.
DR IntAct; P02746; 21.
DR MINT; P02746; -.
DR STRING; 9606.ENSP00000313967; -.
DR DrugBank; DB00112; Bevacizumab.
DR DrugBank; DB00002; Cetuximab.
DR DrugBank; DB00111; Daclizumab.
DR DrugBank; DB00005; Etanercept.
DR DrugBank; DB00110; Palivizumab.
DR DrugBank; DB01593; Zinc.
DR DrugBank; DB14487; Zinc acetate.
DR DrugBank; DB14533; Zinc chloride.
DR DrugBank; DB14548; Zinc sulfate, unspecified form.
DR iPTMnet; P02746; -.
DR PhosphoSitePlus; P02746; -.
DR BioMuta; C1QB; -.
DR DMDM; 298286922; -.
DR CPTAC; non-CPTAC-1101; -.
DR jPOST; P02746; -.
DR MassIVE; P02746; -.
DR PaxDb; P02746; -.
DR PeptideAtlas; P02746; -.
DR PRIDE; P02746; -.
DR ProteomicsDB; 51562; -.
DR DNASU; 713; -.
DR GeneID; 713; -.
DR KEGG; hsa:713; -.
DR UCSC; uc001bgd.3; human.
DR CTD; 713; -.
DR DisGeNET; 713; -.
DR GeneCards; C1QB; -.
DR HGNC; HGNC:1242; C1QB.
DR MalaCards; C1QB; -.
DR MIM; 120570; gene.
DR MIM; 613652; phenotype.
DR neXtProt; NX_P02746; -.
DR Orphanet; 169147; Immunodeficiency due to a classical component pathway complement deficiency.
DR PharmGKB; PA25623; -.
DR eggNOG; ENOG502RYR2; Eukaryota.
DR InParanoid; P02746; -.
DR OrthoDB; 1258047at2759; -.
DR PhylomeDB; P02746; -.
DR TreeFam; TF329591; -.
DR PathwayCommons; P02746; -.
DR Reactome; R-HSA-166663; Initial triggering of complement.
DR Reactome; R-HSA-173623; Classical antibody-mediated complement activation.
DR Reactome; R-HSA-977606; Regulation of Complement cascade.
DR SignaLink; P02746; -.
DR SIGNOR; P02746; -.
DR BioGRID-ORCS; 713; 11 hits in 1076 CRISPR screens.
DR ChiTaRS; C1QB; human.
DR EvolutionaryTrace; P02746; -.
DR GenomeRNAi; 713; -.
DR Pharos; P02746; Tbio.
DR PRO; PR:P02746; -.
DR Proteomes; UP000005640; Chromosome 1.
DR RNAct; P02746; protein.
DR Genevisible; P02746; HS.
DR GO; GO:0072562; C:blood microparticle; HDA:UniProtKB.
DR GO; GO:0005581; C:collagen trimer; IEA:UniProtKB-KW.
DR GO; GO:0062023; C:collagen-containing extracellular matrix; HDA:BHF-UCL.
DR GO; GO:0005602; C:complement component C1 complex; TAS:ProtInc.
DR GO; GO:0062167; C:complement component C1q complex; IPI:ComplexPortal.
DR GO; GO:0005576; C:extracellular region; IDA:ComplexPortal.
DR GO; GO:0098794; C:postsynapse; ISS:ARUK-UCL.
DR GO; GO:0045202; C:synapse; ISS:ARUK-UCL.
DR GO; GO:0006956; P:complement activation; TAS:ProtInc.
DR GO; GO:0006958; P:complement activation, classical pathway; IDA:ComplexPortal.
DR GO; GO:0045087; P:innate immune response; IEA:UniProtKB-KW.
DR GO; GO:0098883; P:synapse pruning; ISS:ARUK-UCL.
DR Gene3D; 2.60.120.40; -; 1.
DR InterPro; IPR001073; C1q_dom.
DR InterPro; IPR008160; Collagen.
DR InterPro; IPR037573; Complement_C1qB.
DR InterPro; IPR008983; Tumour_necrosis_fac-like_dom.
DR PANTHER; PTHR15427:SF18; PTHR15427:SF18; 1.
DR Pfam; PF00386; C1q; 1.
DR Pfam; PF01391; Collagen; 2.
DR PRINTS; PR00007; COMPLEMNTC1Q.
DR SMART; SM00110; C1Q; 1.
DR SUPFAM; SSF49842; SSF49842; 1.
DR PROSITE; PS50871; C1Q; 1.
PE 1: Evidence at protein level;
KW 3D-structure; Collagen; Complement pathway; Direct protein sequencing;
KW Disease variant; Disulfide bond; Glycoprotein; Hydroxylation; Immunity;
KW Innate immunity; Pyrrolidone carboxylic acid; Reference proteome; Repeat;
KW Secreted; Signal.
FT SIGNAL 1..27
FT /evidence="ECO:0000269|PubMed:486087,
FT ECO:0000269|PubMed:708376"
FT CHAIN 28..253
FT /note="Complement C1q subcomponent subunit B"
FT /id="PRO_0000003521"
FT DOMAIN 37..86
FT /note="Collagen-like 1"
FT DOMAIN 60..114
FT /note="Collagen-like 2"
FT DOMAIN 117..253
FT /note="C1q"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00368"
FT REGION 38..115
FT /note="Disordered"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT MOD_RES 28
FT /note="Pyrrolidone carboxylic acid"
FT /evidence="ECO:0000269|PubMed:708376"
FT MOD_RES 35
FT /note="4-hydroxyproline"
FT /evidence="ECO:0000269|PubMed:486087"
FT MOD_RES 38
FT /note="4-hydroxyproline"
FT /evidence="ECO:0000269|PubMed:486087"
FT MOD_RES 41
FT /note="4-hydroxyproline"
FT /evidence="ECO:0000269|PubMed:486087"
FT MOD_RES 53
FT /note="4-hydroxyproline"
FT /evidence="ECO:0000269|PubMed:486087"
FT MOD_RES 56
FT /note="4-hydroxyproline"
FT /evidence="ECO:0000269|PubMed:486087"
FT MOD_RES 59
FT /note="5-hydroxylysine"
FT /evidence="ECO:0000269|PubMed:486087"
FT MOD_RES 62
FT /note="5-hydroxylysine"
FT /evidence="ECO:0000269|PubMed:486087"
FT MOD_RES 65
FT /note="4-hydroxyproline"
FT /evidence="ECO:0000269|PubMed:486087"
FT MOD_RES 77
FT /note="5-hydroxylysine"
FT /evidence="ECO:0000269|PubMed:486087"
FT MOD_RES 83
FT /note="4-hydroxyproline"
FT /evidence="ECO:0000269|PubMed:486087"
FT MOD_RES 86
FT /note="4-hydroxyproline"
FT /evidence="ECO:0000269|PubMed:486087"
FT MOD_RES 92
FT /note="5-hydroxylysine"
FT /evidence="ECO:0000269|PubMed:486087"
FT MOD_RES 98
FT /note="5-hydroxylysine"
FT /evidence="ECO:0000269|PubMed:486087"
FT MOD_RES 101
FT /note="4-hydroxyproline"
FT /evidence="ECO:0000269|PubMed:486087"
FT MOD_RES 104
FT /note="4-hydroxyproline"
FT /evidence="ECO:0000269|PubMed:486087"
FT MOD_RES 107
FT /note="4-hydroxyproline"
FT /evidence="ECO:0000269|PubMed:486087"
FT MOD_RES 110
FT /note="5-hydroxylysine"
FT /evidence="ECO:0000269|PubMed:486087"
FT DISULFID 31
FT /note="Interchain (with C-26 in chain A)"
FT /evidence="ECO:0000269|PubMed:708376"
FT VARIANT 42
FT /note="G -> D (in C1QD)"
FT /evidence="ECO:0000269|PubMed:9476130"
FT /id="VAR_008541"
FT VARIANT 123
FT /note="A -> T (in a breast cancer sample; somatic mutation;
FT dbSNP:rs776292843)"
FT /evidence="ECO:0000269|PubMed:16959974"
FT /id="VAR_035551"
FT CONFLICT 28
FT /note="Q -> E (in Ref. 4; AA sequence)"
FT /evidence="ECO:0000305"
FT CONFLICT 85
FT /note="N -> D (in Ref. 4; AA sequence)"
FT /evidence="ECO:0000305"
FT CONFLICT 100
FT /note="G -> P (in Ref. 4; AA sequence and 5; AA sequence)"
FT /evidence="ECO:0000305"
FT HELIX 118..120
FT /evidence="ECO:0007829|PDB:5HKJ"
FT STRAND 123..127
FT /evidence="ECO:0007829|PDB:2WNV"
FT STRAND 144..149
FT /evidence="ECO:0007829|PDB:2WNV"
FT TURN 155..157
FT /evidence="ECO:0007829|PDB:2WNV"
FT STRAND 159..161
FT /evidence="ECO:0007829|PDB:1PK6"
FT STRAND 166..178
FT /evidence="ECO:0007829|PDB:2WNV"
FT STRAND 180..190
FT /evidence="ECO:0007829|PDB:2WNV"
FT STRAND 192..199
FT /evidence="ECO:0007829|PDB:2WNV"
FT STRAND 202..204
FT /evidence="ECO:0007829|PDB:2WNV"
FT STRAND 206..216
FT /evidence="ECO:0007829|PDB:2WNV"
FT STRAND 221..230
FT /evidence="ECO:0007829|PDB:2WNV"
FT STRAND 241..249
FT /evidence="ECO:0007829|PDB:2WNV"
SQ SEQUENCE 253 AA; 26722 MW; D80C753C0D430EDC CRC64;
MMMKIPWGSI PVLMLLLLLG LIDISQAQLS CTGPPAIPGI PGIPGTPGPD GQPGTPGIKG
EKGLPGLAGD HGEFGEKGDP GIPGNPGKVG PKGPMGPKGG PGAPGAPGPK GESGDYKATQ
KIAFSATRTI NVPLRRDQTI RFDHVITNMN NNYEPRSGKF TCKVPGLYYF TYHASSRGNL
CVNLMRGRER AQKVVTFCDY AYNTFQVTTG GMVLKLEQGE NVFLQATDKN SLLGMEGANS
IFSGFLLFPD MEA
