Human Calreticulin, 0.05 mg Recombinant Protein

FOR RESEARCH USE ONLY.

Related Product Names:
- CALR protein; CALR; CRTC; RO; SSA; cC1qR; FLJ26680; Human Calreticulin
- CRP55; Calregulin; HACBP; ERp60; grp60; Calreticulin

Fusion: His-tag at N-terminus.
Source/Host: E Coli
Purity/Purification: 90%
Crossreactivity: human
Format: 10 mM Tris-HCl, pH 8.0, 0.1 mM DTT, 5% Glycerol
Storage: -70 degree C. Avoid frequent freeze and thaw.
Stability: 6-12 months at -70 degree C.
Shipping: Products may be shipped on ice pack or dry ice.

Synonym Names for CALR protein: CALR; CRTC; RO; SSA; cC1qR; FLJ26680; CRP55; Calregulin; HACBP; ERp60; grp60; Calreticulin

Function: Molecular calcium binding chaperone promoting folding, oligomeric assembly and quality control in the ER via the calreticulin/calnexin cycle. This lectin interacts transiently with almost all of the monoglucosylated glycoproteins that are synthesized in the ER. Interacts with the DNA-binding domain of NR3C1 and mediates its nuclear export.

Subunit: Monomer. Interacts with GRP58 (ERp57) and with NR3C1 (By similarity).

Subcellular Location: Endoplasmic reticulum; endoplasmic reticulum lumen. Cytoplasm; cytosol. Secreted protein; extracellular space; extracellular matrix. Cell surface. Also found in cell surface (T cells), cytosol and extracellular matrix. Associated with the lytic granules in the cytolytic T-lymphocytes.

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.

Domain: The interaction with glycans occurs through a binding site in the globular lectin domain.

Domain: The zinc binding sites are localized to the N-domain.

Domain: Associates with ERp57 through the tip of the extended arm formed by the P-domain.

Mass Spectrometry: MW=46879; METHOD=MALDI; RANGE=18-417; NOTE=Ref.16.

Similarity: Belongs to the calreticulin family.

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.

Human Calreticulin reacts with human.

OMIM: 109091; gene. [NCBI / EBI]

Pathways:
KEGG pathway: Antigen processing and presentation 04612