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Symbol CALR contributors: mct/shn - updated : 02-05-2015
HGNC name calreticulin
HGNC id 1455
Location 19p13.2      Physical location : 13.049.413 - 13.055.304
Synonym name
  • SS-A/Ro autoantigen elevated in Sjögren syndrome
  • calregulin
  • autoantigen Ro
  • endoplasmic reticulum resident protein 60
  • sicca syndrome antigen A (autoantigen Ro; calreticulin)
  • Synonym symbol(s) SSA, RO, cC1qR, CRT, FLJ26680, HACBP, grp60, CRP55, ERp60, CRTC
    TYPE functioning gene
    STRUCTURE 5.89 kb     9 Exon(s)
    10 Kb 5' upstream gene genomic sequence study
    regulatory sequence Binding site
    text structure an ER stress response element (ERSE)
    MAPPING cloned Y linked N status confirmed
    Map pter - D19S221 - D19S914 - CALR - D19S840 - D19S892 - cen
    TRANSCRIPTS type messenger
    identificationnb exonstypebpproduct
    ProteinkDaAAspecific expressionYearPubmed
    9 - 1929 46 417 - 1990 2332496
    Type widely
       expressed in (based on citations)
    SystemOrgan level 1Organ level 2Organ level 3Organ level 4LevelPubmedSpeciesStageRna symbol
    Cardiovascularheart   highly
    Digestiveintestinesmall intestine  highly
    Endocrinethyroid   highly
    Reproductivefemale systemovary  highly
    SystemTissueTissue level 1Tissue level 2LevelPubmedSpeciesStageRna symbol
    cell lineage
    cell lines
    fluid/secretion increased in peripheral maternal blood early in pregnancy and remaining elevated throughout normal gestation
    at STAGE
    physiological period embryo
    Text highly at early stages of cardiac development
    PHYSICAL PROPERTIES acid ,globular
  • a globular zinc binding sites at the N terminus
  • a central proline-rich P domain forming an elongated arm-like structure, binding one molecule of calcium with high affinity
  • a C-terminal acidic binding multiple calcium ions with low affinity, partly responsible for the ER retention of calreticulin, and thus, disruption of the conformation of this domain could reduce the effectiveness of the retention mechanism
  • conjugated GlycoP
    mono polymer monomer
    interspecies ortholog to Calr, Mus musculus
    ortholog to Calr, Rattus norvegicus
    ortholog to calr, Danio rerio
    ortholog to CALR, Pan troglodytes
  • calreticulin family
  • CATEGORY chaperone/stress , antigen
    intracellular,cytoplasm,organelle,endoplasmic reticulum
  • calcium binding protein of endoplasmic and sarcoplasmic reticulum
  • also found in cell surface (T cells), cytosol and in the exracellular matrix
  • associated with the lytic granules in the cytolytic T-lymphocytes
  • basic FUNCTION
  • involved in the regulation of intracellular Ca2+ homeostasis and endoplasmic reticulum (ER) Ca2+ storage capacity (
  • involved in the synthesis (folding) of many proteins (lectin-like chaperone)
  • key upstream regulator of calcineurin-dependent pathways during cardiac development
  • inhibiting activity of glucocorticoid and other nuclear hormone receptors
  • playing a role which involves chromatin dynamics on the surface of mitotic chromosomes and posible role as histone chaperone
  • negatively regulating the cell surface expression of cystic fibrosis transmembrane conductance regulator
  • having functions in Ca(2+) homeostasis of myocardiac disease
  • can act as an important modulator of the regulation of gene transcription by nuclear hormone receptors (
  • can inhibit AR and RAR transcriptional activities as well as RA-induced neuronal differentiation
  • important modulator of the regulation of gene transcription by nuclear hormone receptors
  • playing a key role in determining anticancer immune responses
  • a receptor for nuclear export and may regulate the transcriptional activity of steroid hormone receptors (
  • role in thrombospondin signaling (
  • deglycosylated major histocompatibility complex class I heavy chains (
  • essential in early cardiac development and plays an important role in autoimmunity and cancer (
  • promotes cell motility and enhances resistance to anoikis through STAT3-CTTN-Akt pathway in esophageal squamous cell carcinoma
  • enhancing B2 bradykinin receptor maturation and homodimerization
  • may inhibit growth and/or metastasis of prostate cancer cells
  • enhancing gastric cancer cell proliferation and migration
  • enhancing BDKRB2 maturation and heterodimerization with AGT
  • plays an important role in the MHC class I assembly pathway
  • can regulate CD1D expression
  • CALR levels could potentially regulate CD1D-mediated stimulation of NKT cells
  • key role in the quality control of class I-peptide complexes
  • functions as a calcium buffer in the ER
  • calcium-binding role in thick ascending limb of Henle's loop adaptation and survival under osmotic stress
  • soluble placental CNX may have a physiological chaperone function similar to that of CALR
  • CELLULAR PROCESS protein, post translation, folding
    a component
  • component of an EIF2 complex
  • hYRNA, the RNA backbone of the Ro/SS-A RNP particle (
  • C/EBPalpha and C/EBPbeta mRNAs (
  • 5' region of p21 mRNA (
  • small molecule metal binding, other,
  • Ca2+ binding
  • lectin binding
  • Zn2+ binding
  • protein
  • integrin alpha 3 and alpha 5 subunits (
  • fibrinogen B beta chain, FGB (
  • C1q-R, C1q, and mannan-binding protein (
  • glucocorticoid receptor (
  • protein disulfide isomerase, PDI (
  • newly synthesized human immunodeficiency virus type 1 envelope glycoprotein and gp160 (
  • glucose transporter type 1, Glut1 (
  • MHC class I-beta 2 microglobulin, beta 2m (
  • tissue-type plasminogen activator, tPA (
  • coagulation factor VIII and factor V (
  • Perforin (
  • thyroid transcription factor-1, TTF-1 (
  • apolipoprotein B, ApoB (
  • carboxy-terminal fibrillin-1, FBN1 (
  • von Willebrand factor, VWF (
  • beta-amyloid precursor protein, APP (
  • H glycoprotein (
  • monoglucosylated oligosaccharides of the form Glc(1)Man(5-9)GlcNAc(2), thiol oxidoreductase and ERp57 (
  • thrombospondin (
  • CD1d (
  • thyrotropin receptor, TSHR (
  • Lipoprotein lipase, LPL (
  • low-density lipoprotein receptor-related protein, LRP (
  • MPO is chaperoned by calreticulin (CALR) in the endoplasmic reticulum
  • cell & other
  • synthetic peptide KLGFFKR (
    activated by the transcription factor CSX
    corresponding disease(s)
    Other morbid association(s)
    TypeGene ModificationChromosome rearrangementProtein expressionProtein Function
    constitutional     --over  
    in Sjögren syndrome
    tumoral germinal mutation      
    are frequently found in patients with myelofibrosis (MF) and essential thrombocythemia and patients with homozygous CALR mutations had reduced MPO protein, but normal MPO messenger RNA (mRNA) levels(ET)
    Variant & Polymorphism
    Candidate gene
  • angiogenic regulator in gastric cancer, can serve as a prognosis marker
  • Therapy target