Skip Header

You are using a version of browser that may not display all the features of this website. Please consider upgrading your browser.
Protein

Complement C1q subcomponent subunit B

Gene

C1qb

Organism
Rattus norvegicus (Rat)
Status
Reviewed-Annotation score: 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 - Biological processi

  • aging Source: RGD
  • brain development Source: RGD
  • complement activation, classical pathway Source: UniProtKB-KW
  • immune response Source: RGD
  • innate immune response Source: UniProtKB-KW
  • response to glucocorticoid Source: RGD
  • response to organic substance Source: RGD
Complete GO annotation...

Keywords - Biological processi

Complement pathway, Immunity, Innate immunity

Names & Taxonomyi

Protein namesi
Recommended name:
Complement C1q subcomponent subunit B
Gene namesi
Name:C1qb
OrganismiRattus norvegicus (Rat)
Taxonomic identifieri10116 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresGliresRodentiaSciurognathiMuroideaMuridaeMurinaeRattus
Proteomesi
  • UP000002494 Componenti: Unplaced

Organism-specific databases

RGDi2229. C1qb.

Subcellular locationi

GO - Cellular componenti

  • collagen trimer Source: UniProtKB-KW
  • complement component C1 complex Source: RGD
Complete GO annotation...

Keywords - Cellular componenti

Secreted

PTM / Processingi

Molecule processing

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Signal peptidei1 – 2525By similarityAdd
BLAST
Chaini26 – 253228Complement C1q subcomponent subunit BPRO_0000003523Add
BLAST

Amino acid modifications

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Modified residuei26 – 261Pyrrolidone carboxylic acidBy similarity
Disulfide bondi29 – 29Interchain (with C-26 in chain A)
Modified residuei33 – 3314-hydroxyprolineBy similarity
Modified residuei36 – 3614-hydroxyprolineBy similarity
Modified residuei39 – 3914-hydroxyprolineBy similarity
Modified residuei51 – 5114-hydroxyprolineBy similarity
Modified residuei54 – 5414-hydroxyprolineBy similarity
Modified residuei57 – 5715-hydroxylysineBy similarity
Modified residuei60 – 6015-hydroxylysineBy similarity
Modified residuei63 – 6314-hydroxyprolineBy similarity
Modified residuei75 – 7515-hydroxylysineBy similarity
Modified residuei81 – 8114-hydroxyprolineBy similarity
Modified residuei84 – 8414-hydroxyprolineBy similarity
Modified residuei90 – 9015-hydroxylysineBy similarity
Modified residuei96 – 9615-hydroxylysineBy similarity
Modified residuei99 – 9914-hydroxyprolineBy similarity
Modified residuei102 – 10214-hydroxyprolineBy similarity
Modified residuei108 – 10815-hydroxylysineBy similarity

Post-translational modificationi

Hydroxylated on lysine and proline residues. Hydroxylated lysine residues can be glycosylated.

Keywords - PTMi

Disulfide bond, Glycoprotein, Hydroxylation, Pyrrolidone carboxylic acid

Proteomic databases

PaxDbiP31721.
PRIDEiP31721.

PTM databases

iPTMnetiP31721.
PhosphoSiteiP31721.

Expressioni

Tissue specificityi

Highest levels in spleen, lung and brain. Weaker expression in kidney and liver. In the spleen, localized mainly to the red pulp, in cells mainly of monocyte-macrophage lineage. In white pulp, localized in specific dendritic cells such as those from the periarteriolar lymphatic sheath (PALS).1 Publication

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. In addition to the major A:B and C:C dimer bands, rat, unlike human C1q, contained minor dimer species.

Protein-protein interaction databases

BioGridi248307. 1 interaction.
STRINGi10116.ENSRNOP00000017060.

Structurei

3D structure databases

ProteinModelPortaliP31721.
SMRiP31721. Positions 116-250.
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Domains and Repeats

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Domaini29 – 11284Collagen-likeAdd
BLAST
Domaini115 – 253139C1qPROSITE-ProRule annotationAdd
BLAST

Sequence similaritiesi

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

Keywords - Domaini

Collagen, Repeat, Signal

Phylogenomic databases

eggNOGiENOG410IWVM. Eukaryota.
ENOG4111MQB. LUCA.
HOGENOMiHOG000085653.
HOVERGENiHBG108220.
InParanoidiP31721.
KOiK03987.
PhylomeDBiP31721.

Family and domain databases

Gene3Di2.60.120.40. 1 hit.
InterProiIPR001073. C1q_dom.
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.

P31721-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MKTQWSEILT PLLLLLLGLL HVSWAQSSCT GSPGIPGVPG IPGVPGSDGK
60 70 80 90 100
PGTPGIKGEK GLPGLAGDHG ELGEKGDAGI PGIPGKVGPK GPVGPKGAPG
110 120 130 140 150
PPGPRGPKGG SGDYKATQKV AFSALRTVNS ALRPNQAIRF EKVITNVNDN
160 170 180 190 200
YEPRSGKFTC KVPGLYYFTY HASSRGNLCV NIVRGRDRDR MQKVLTFCDY
210 220 230 240 250
AQNTFQVTTG GVVLKLEQEE VVHLQATDKN SLLGVEGANS IFTGFLLFPD

MDV
Length:253
Mass (Da):26,589
Last modified:November 1, 1995 - v2
Checksum:i1CB40622571BFC9B
GO

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
X71127 mRNA. Translation: CAA50440.1.
PIRiS49158.
RefSeqiNP_062135.1. NM_019262.1.
UniGeneiRn.6702.

Genome annotation databases

GeneIDi29687.
KEGGirno:29687.

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
X71127 mRNA. Translation: CAA50440.1.
PIRiS49158.
RefSeqiNP_062135.1. NM_019262.1.
UniGeneiRn.6702.

3D structure databases

ProteinModelPortaliP31721.
SMRiP31721. Positions 116-250.
ModBaseiSearch...
MobiDBiSearch...

Protein-protein interaction databases

BioGridi248307. 1 interaction.
STRINGi10116.ENSRNOP00000017060.

PTM databases

iPTMnetiP31721.
PhosphoSiteiP31721.

Proteomic databases

PaxDbiP31721.
PRIDEiP31721.

Protocols and materials databases

Structural Biology KnowledgebaseSearch...

Genome annotation databases

GeneIDi29687.
KEGGirno:29687.

Organism-specific databases

CTDi713.
RGDi2229. C1qb.

Phylogenomic databases

eggNOGiENOG410IWVM. Eukaryota.
ENOG4111MQB. LUCA.
HOGENOMiHOG000085653.
HOVERGENiHBG108220.
InParanoidiP31721.
KOiK03987.
PhylomeDBiP31721.

Miscellaneous databases

PROiP31721.

Family and domain databases

Gene3Di2.60.120.40. 1 hit.
InterProiIPR001073. C1q_dom.
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]
ProtoNetiSearch...

Publicationsi

  1. "Follicular dendritic cells, interdigitating cells, and cells of the monocyte-macrophage lineage are the C1q-producing sources in the spleen. Identification of specific cell types by in situ hybridization and immunohistochemical analysis."
    Schwaeble W., Schaefer M.K.-H., Petry F., Fink T., Knebel D., Weihe E., Loos M.
    J. Immunol. 155:4971-4978(1995) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [MRNA], TISSUE SPECIFICITY.
    Strain: Sprague-Dawley.
    Tissue: Spleen.
  2. "Rapid isolation and biochemical characterization of rat C1 and C1q."
    Wing M.G., Seilly D.J., Bridgman D.J., Harrison R.A.
    Mol. Immunol. 30:433-440(1993) [PubMed] [Europe PMC] [Abstract]
    Cited for: PROTEIN SEQUENCE OF 71-79 AND 141-146.

Entry informationi

Entry nameiC1QB_RAT
AccessioniPrimary (citable) accession number: P31721
Entry historyi
Integrated into UniProtKB/Swiss-Prot: July 1, 1993
Last sequence update: November 1, 1995
Last modified: June 8, 2016
This is version 115 of the entry and version 2 of the sequence. [Complete history]
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programChordata Protein Annotation Program

Miscellaneousi

Keywords - Technical termi

Complete proteome, Direct protein sequencing, Reference proteome

Documents

  1. SIMILARITY comments
    Index of protein domains and families

Similar proteinsi

Links to similar proteins from the UniProt Reference Clusters (UniRef) at 100%, 90% and 50% sequence identity:
100%UniRef100 combines identical sequences and sub-fragments with 11 or more residues from any organism into one UniRef entry.
90%UniRef90 is built by clustering UniRef100 sequences that have at least 90% sequence identity to, and 80% overlap with, the longest sequence (a.k.a seed sequence).
50%UniRef50 is built by clustering UniRef90 seed sequences that have at least 50% sequence identity to, and 80% overlap with, the longest sequence in the cluster.