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FLASH GENE
Symbol CR1 contributors: mct - updated : 28-05-2014
HGNC name complement component (3b/4b) receptor 1, including Knops blood group system
HGNC id 2334
Corresponding disease
KPN Knops blood group system
Location 1q32.1      Physical location : 207.669.472 - 207.815.109
Synonym name
  • cell differentiation antigen CD35,C3b/C4b receptor, identified by monoclonal antibodies TO5, E11, J3B11, CB04, J3D3
  • CD35 antigen
  • C3b/C4b receptor
  • C3-binding protein
  • Knops blood group antigen
  • Synonym symbol(s) C3BR, CD35, KN, C4BR
    EC.number 2.7.1.-
    DNA
    TYPE functioning gene
    STRUCTURE 145.64 kb     39 Exon(s)
    Genomic sequence alignment details
    10 Kb 5' upstream gene genomic sequence study
    MAPPING cloned Y linked Y status confirmed
    RNA
    TRANSCRIPTS type messenger
    identificationnb exonstypebpproduct
    ProteinkDaAAspecific expressionYearPubmed
    39 - 8629 223 2039 - 1993 8245463
    variant F
    49 - 9979 272 2489 - 1993 8245463
  • variant S
  • including an additional 8 exons in the coding region
  • EXPRESSION
    Type
       expressed in (based on citations)
    organ(s)
    SystemOrgan level 1Organ level 2Organ level 3Organ level 4LevelPubmedSpeciesStageRna symbol
    Urinarykidneynephronrenal capsuleglomerulus 
    cells
    SystemCellPubmedSpeciesStageRna symbol
    Urinarypodocyte
    cell lineage hematopoietic cells
    cell lines
    fluid/secretion
    at STAGE
    PROTEIN
    PHYSICAL PROPERTIES
    STRUCTURE
    motifs/domains
  • 30 short consensus repeats
  • sushi structure (see F13B, SRCP1), arranged in four longer regions(LHRD, LHRC, LHRB, LHRA)
  • conjugated GlycoP
    mono polymer monomer
    isoforms Precursor
    HOMOLOGY
    interspecies homolog to dog loc609328
    Homologene
    FAMILY complement receptor family
    CATEGORY regulatory , antigen , receptor
    SUBCELLULAR LOCALIZATION extracellular
        plasma membrane
        intracellular
    intracellular,cytoplasm,cytosolic,vesicle
    basic FUNCTION
  • enhancing phagocytosis of particles opsonized by C3b
  • binding immune complexes bearing C3b and transporting them to the reticulo-endothelial system
  • mediating cellular binding of particles and immune complexes that have activated complement
  • cofactor of the mediated cleavage of the C3b to iC3b
  • playing a role in severity of malarial infection
  • mediates inhibitory signals in human T-lymphocytes
  • protein that clears complement-tagged inflammatory
  • particles from the circulation, influences interindividual variation in erythrocyte sedimentation rate (ESR)
  • mediating inhibitory signals in human T-lymphocytes
  • constitutively dispersed on the surface of circulating red blood cells (RBC)
  • ATP release by RBC following CR1 ligation increases the efficiency of the immune-transfer process from RBC to the effector phagocytic cells
  • CELLULAR PROCESS
    PHYSIOLOGICAL PROCESS immunity/defense
    PATHWAY
    metabolism
    signaling signal transduction
    a component
    INTERACTION
    DNA
    RNA
    small molecule
    protein
  • RUNX1 (ETS binding site)
  • C3b primary ligand also binding C4b
  • is an EBV receptor with a salient role in primary infection (pMID: 23416052)
  • ABCC1 plays a role in mediating, either directly or indirectly the CR1-mediated ATP release in red blood cells
  • cell & other
    REGULATION
    activated by RUNX1
    ASSOCIATED DISORDERS
    corresponding disease(s) KPN
    related resource Blood Group Antigen Mutation Database
    Other morbid association(s)
    TypeGene ModificationChromosome rearrangementProtein expressionProtein Function
    constitutional       loss of function
    patients with systemic lupus erythematosus (SLE) have relative deficiencies of the C3b/C4b receptor (CR1) on erythrocytes (E)
    Susceptibility
  • to late-onset Alzheimer's disease (LOAD) (pMID: 24794147)
  • to cerebral amyloid angiopathy (CAA) with intracerebral hemorrhage (ICH) in elderly individuals
  • Variant & Polymorphism other
  • rs3818361 single nucleotide polymorphism in CR1 is associated with increased risk of Alzheimer disease (AD)
  • CR1 variant rs6656401 influences risk and recurrence of CAA-ICH, as well as the severity of vascular amyloid deposition
  • Candidate gene
    Marker
    Therapy target
    ANIMAL & CELL MODELS
  • Cr1-deficient (Cr1KO) mice develop normal B1 and B2 immature and mature B cell subsets and have normal levels of naive serum Abs but altered levels of natural