C3AR1

Protein identityUniProt · HPA

UniProt accession

Q16581

Gene

C3AR1

Ensembl

ENSG00000171860

Chromosome

12

Canonical length

482 aa

Protein class

G-protein coupled receptors, Predicted membrane proteins

OverviewNCBI Gene

C3a is an anaphylatoxin released during activation of the complement system. The protein encoded by this gene is an orphan G protein-coupled receptor for C3a. Binding of C3a by the encoded receptor activates chemotaxis, granule enzyme release, superoxide anion production, and bacterial opsonization. [provided by RefSeq, May 2016]

Canonical amino-acid sequenceUniProt

482 residues, UniProt reviewed canonical sequence.

>Q16581|C3AR1
     1  MASFSAETNS TDLLSQPWNE PPVILSMVIL SLTFLLGLPG NGLVLWVAGL KMQRTVNTIW
    61  FLHLTLADLL CCLSLPFSLA HLALQGQWPY GRFLCKLIPS IIVLNMFASV FLLTAISLDR
   121  CLVVFKPIWC QNHRNVGMAC SICGCIWVVA FVMCIPVFVY REIFTTDNHN RCGYKFGLSS
   181  SLDYPDFYGD PLENRSLENI VQPPGEMNDR LDPSSFQTND HPWTVPTVFQ PQTFQRPSAD
   241  SLPRGSARLT SQNLYSNVFK PADVVSPKIP SGFPIEDHET SPLDNSDAFL STHLKLFPSA
   301  SSNSFYESEL PQGFQDYYNL GQFTDDDQVP TPLVAITITR LVVGFLLPSV IMIACYSFIV
   361  FRMQRGRFAK SQSKTFRVAV VVVAVFLVCW TPYHIFGVLS LLTDPETPLG KTLMSWDHVC
   421  IALASANSCF NPFLYALLGK DFRKKARQSI QGILEAAFSE ELTRSTHCPS NNVISERNST
   481  TV

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against C3AR1 can act on the native protein depends on physical access: surface and secreted proteins are reachable by circulating antibodies, intracellular proteins usually are not.

Antibody reachability

Cell surface

Secreted

No

Transmembrane segments

7

Mean surface accessibility (rSASA)

0.43

Highest tissue expression

38 nTPM

Expression across tissuesHPA

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about C3AR1.

Disease | GeneticClinVar

1 pathogenic / likely-pathogenic of 82 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

• Hemolytic uremic syndrome, atypical, susceptibility to, 1

ReferencesPubMed · IEDB

Publications for C3AR1 from three distinct lines of evidence, kept separate because they answer different questions: whether antibodies are directed at the protein, whether a B-cell epitope has been mapped on it, and whether a T-cell epitope has. Each is labelled with its source.

Sources: PubMed — antigen-level antibody evidence from a custom retrieval. Records matching a controlled set of autoantibody terms (the MeSH descriptors Autoantibodies and Autoantigens, with title and abstract term variants) were obtained through NCBI E-utilities, and their titles and abstracts parsed for constructions that direct an antibody at a named protein rather than for co-occurrence. Captured names were resolved against UniProt nomenclature and each antigen adjudicated individually against the source text. Bibliographic records from PubMed and MeSH, U.S. National Library of Medicine; citation metrics from NIH iCite (Hutchins et al., PLoS Biology 2016). Titles link to PubMed; abstracts are not reproduced here. The NLM does not endorse this analysis.

Genetic constraint and essentialitygnomAD · DepMap

Does the body need this protein intact? Low LOEUF or a strong DepMap dependency means loss or blockade of the protein is likely to be felt.

gnomAD LOEUF (loss-of-function intolerance)

1.59

gnomAD pLI

0

gnomAD missense Z

-0.3

DepMap mean gene effect

0

DepMap dependency class

none

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 4% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

• adenylate cyclase-inhibiting G protein-coupled receptor signaling pathway
• blood circulation
• calcium-mediated signaling
• chemotaxis
• complement receptor mediated signaling pathway
• G protein-coupled receptor signaling pathway
• inflammatory response
• phospholipase C-activating G protein-coupled receptor signaling pathway
• positive regulation of angiogenesis
• positive regulation of cytosolic calcium ion concentration
• positive regulation of macrophage chemotaxis
• positive regulation of neutrophil chemotaxis
• positive regulation of vascular endothelial growth factor production

Molecular functions

• complement component C5a receptor activity
• G protein-coupled receptor activity
• complement component C3a receptor activity

Cellular components

• azurophil granule membrane
• plasma membrane
• specific granule membrane

Protein domainsUniProt · Pfam · InterPro

• G protein-coupled receptor, rhodopsin-like
• Formyl peptide receptor-related
• Anaphylatoxin chemotactic receptor, C3a/C5a1/C5a2
• GPCR, rhodopsin-like, 7TM
• 7 transmembrane receptor (rhodopsin family)
• C3a anaphylatoxin chemotactic receptor

KeywordsUniProt

• Cell membrane
• Chemotaxis
• Disulfide bond
• G-protein coupled receptor
• Glycoprotein
• Membrane
• Phosphoprotein
• Receptor
• Sulfation
• Transducer
• Transmembrane
• Transmembrane helix

InteractionsUniProt · HPA

Protein binding partners of C3AR1 in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

• VGF