Quick Order

Calreticulin  Protein, Antibody, ELISA Kit, cDNA Clone

Calreticulin Related Area

Calreticulin Related Pathways

    Calreticulin Summary & Protein Information

    Calreticulin Background

    Gene Summary: Calreticulin is a multifunctional protein that acts as a major Ca(2+)-binding (storage) protein in the lumen of the endoplasmic reticulum. It is also found in the nucleus, suggesting that it may have a role in transcription regulation. Calreticulin binds to the synthetic peptide KLGFFKR, which is almost identical to an amino acid sequence in the DNA-binding domain of the superfamily of nuclear receptors. Calreticulin binds to antibodies in certain sera of systemic lupus and Sjogren patients which contain anti-Ro/SSA antibodies, it is highly conserved among species, and it is located in the endoplasmic and sarcoplasmic reticulum where it may bind calcium. The amino terminus of calreticulin interacts with the DNA-binding domain of the glucocorticoid receptor and prevents the receptor from binding to its specific glucocorticoid response element. Calreticulin can inhibit the binding of androgen receptor to its hormone-responsive DNA element and can inhibit androgen receptor and retinoic acid receptor transcriptional activities in vivo, as well as retinoic acid-induced neuronal differentiation. Thus, calreticulin can act as an important modulator of the regulation of gene transcription by nuclear hormone receptors. Systemic lupus erythematosus is associated with increased autoantibody titers against calreticulin but calreticulin is not a Ro/SS-A antigen. Earlier papers referred to calreticulin as an Ro/SS-A antigen but this was later disproven. Increased autoantibody titer against human calreticulin is found in infants with complete congenital heart block of both the IgG and IgM classes. [provided by RefSeq, Jul 2008]
    General information above from NCBI
    Subunit structure: Monomer. Component of an EIF2 complex at least composed of CELF1/CUGBP1, CALR, CALR3, EIF2S1, EIF2S2, HSP90B1 and HSPA5. Interacts with PDIA3/ERp57 and C9orf9 (By similarity). Interacts with NR3C1 and TRIM21. Interacts with GABARAP. Interacts with PPIB. {ECO:0000250|UniProtKB:P14211, ECO:0000250|UniProtKB:P18418, ECO:0000269|PubMed:11149926, ECO:0000269|PubMed:19154346, ECO:0000269|PubMed:20801878, ECO:0000269|PubMed:21423620, ECO:0000269|PubMed:8666824}.
    Domain: Can be divided into a N-terminal globular domain, a proline-rich P-domain forming an elongated arm-like structure and a C-terminal acidic domain. The P-domain binds one molecule of calcium with high affinity, whereas the acidic C-domain binds multiple calcium ions with low affinity.; The interaction with glycans occurs through a binding site in the globular lectin domain.; The zinc binding sites are localized to the N-domain.; Associates with PDIA3 through the tip of the extended arm formed by the P-domain.
    Subcellular location: Endoplasmic reticulum lumen. Cytoplasm, cytosol. Secreted, extracellular space, extracellular matrix. Cell surface. Sarcoplasmic reticulum lumen {ECO:0000250}. Note=Also found in cell surface (T cells), cytosol and extracellular matrix. Associated with the lytic granules in the cytolytic T-lymphocytes.
    Sequence similarity: Belongs to the calreticulin family. {ECO:0000305}.
    General information above from UniProt

    Calreticulin is a multifunctional protein. It acts as a main Ca(2+)-binding (storage) protein in the lumen of the endoplasmic reticulum. Calreticulin binds Ca2+ ions (a second messenger in signal transduction), rendering it inactive. The Ca2+ is bound with low affinity, but high capacity, and can be released on a signal. Located in storage compartments associated with the endoplasmic reticulum, calreticulin also binds to misfolded proteins and prevents them from being exported from the endoplasmic reticulum to the golgi apparatus. The amino terminus of calreticulin interacts with the DNA-binding domain of the glucocorticoid receptor and prevents the receptor from binding to its specific glucocorticoid response element. Calreticulin reduces the binding of androgen receptor to its hormone-responsive DNA element and inhibits androgen receptor and retinoic acid receptor transcriptional activities in vivo, as well as retinoic acid-induced neuronal differentiation. Therefore, calreticulin acts as a significant modulator of the regulation of gene transcription by nuclear hormone receptors.

    Calreticulin Alternative Name

    RO,CRT,SSA,cC1qR,HEL-S-99n, [homo-sapiens]
    CALR,calregulin,Calreticulin,calreticulin),cC1qR,CRP55,CRT,endoplasmic reticulum resident protein 60,ERp60,grp60,HACBP,RO,Sicca syndrome antigen A (autoantigen Ro,SSA, [human]
    Calr,Calregulin,Calreticulin,CRP55,CRT,endoplasmic reticulum resident protein 60,ERp60,HACBP, [mouse]
    CRT,Calregulin, [mus-musculus]

    Calreticulin Related Studies

  • Michalak M, et al. (2002) Calreticulin in cardiac development and pathology. Biochim Biophys Acta. 1600(1-2):32-7.
  • Chao MP, et al. (2010) Calreticulin is the dominant pro-phagocytic signal on multiple human cancers and is counterbalanced by CD47. Sci Transl Med. 2(63):63ra94.
  • Andrin, C, et al. (1998) Interaction between a Ca2+-binding protein calreticulin and perforin, a component of the cytotoxic T-cell granules. Biochemistry. 37(29):10386-94.
  • Please note: All products are "FOR RESEARCH USE ONLY AND ARE NOT INTENDED FOR DIAGNOSTIC OR THERAPEUTIC USE"