Cal reticulum also known as Calregulin, CRP55, CAP3, Cal sequestrin like protein, and endoplasmic reticulum resident protein 60 is a protein that in humans is encoded by the calurgine. Cal reticulum is a multifunctional soluble protein that binds CO2 plus ions, rendering it inactive. The CO2 plus is bound with low affinity, but high capacity, and can be released on a signal. Cal reticulum is located in storage compartments associated with the endoplasmic reticulum and is considered an ER resident protein. The term mobile ferron is considered to be the same as Cal reticulum by some sources. Cal reticulum binds to misfolded proteins and prevents them from being exported from the endoplasmic reticulum to the Golgi apparatus. A similar quality control molecular chaperone, Calnexin, performs the same service for soluble proteins as does Cal reticulum, however it is a membrane-bound protein. Both proteins, Calnexin and Cal reticulum have the function of binding to oligosaccharides containing terminal glucose residues, thereby targeting them for degradation. Cal reticulum and Calnexin's ability to bind carbohydrates associates them with electin protein family. In normal cellular function, trimming of glucose residues off the core oligosaccharide added during n-linked glycosolation is a part of protein processing. If overseer enzymes note that residues are misfolded, proteins within the row will re-adglucose residues so that other Cal reticulants slash Calnexin combine to these proteins and prevent them from proceeding to the Golgi. This leads these apparently folded proteins down a pathway by their targeted for degradation. Studies on transgenic mice reveal that Cal reticulum is a cardiac embryonic gene that is essential during development. Cal reticulum and Calnexin are also integral proteins in the production of MHC-classi proteins. As newly synthesized MHC-classi alpha chains enter the endoplasmic reticulum, Calnexin binds onto them retaining them in a partly folded state. After the beta-2 micro-blobulane binds to the peptide loading complex, Cal reticulum takes over the job of shaperoning. The MHC-classi protein while the tapison links the complex to the transporter associated with antigen processing complex. This association prepares the MHC-classi for binding an antigen for presentation on the cell surface. Cal reticulum is also found in the nucleus, suggesting that it may have a role in transcription regulation. Cal reticulum binds to the synthetic peptide KLGFF-AR, which is almost identical to an amino acid sequence in the DNA binding domain of the superfamily of nuclear receptors. The amino terminus of Cal reticulum interacts with the DNA binding domain of the glucocorticoid receptor and prevents the receptor from binding to its specific glucocorticoid response element. Cal reticulum 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 Cal reticulum can act as an important modulator of the regulation of gene transcription by nuclear hormone receptors. Cal reticulum binds to antibodies in certain area of systemic lupus and churgrin patients that contain anti-roslash-SSA antibodies. Systemic lupus erythematosis is associated with increased auto-antibody titers against Cal reticulum, but Cal reticulum is not a roslash-SSA antigen. Earlier papers referred to Cal reticulum as in roslash-SSA antigen, but this was later disproven. Increased auto-antibody titer against human Cal reticulum is found in infants with complete congenital heart block of both the Iganon classes. In 2013, two groups detected Cal reticulum mutations in a majority of Jack-2-negative-slash-MPL negative patients with essential thrombosythemia and primary myelophybrosis, which makes Cal reticulum mutations the second most common in myeloproliferative neoplasms. All mutations affected the last exon, generating a reading frame shift of the resulting protein, that creates a novel terminal peptide and causes a loss of endoplasmic reticulum-catal retention signal. Cal reticulum is expressed in many cancer cells and plays a role to promote macrophages to engulf hazardous cancerous cells. The reason why most of the cells are not destroyed is the presence of another molecule with signal CD47, which blocks CRT. Hens antibodies that block CD47 might be useful as a cancer treatment. In mice models of myeloid leukemia and non-Hodgkin lymphoma, anti-CD47 were effective in clearing cancer cells while normal cells were unaffected. Cal reticulum has been shown to interact with perform and NK-2 homeobox-1. Thanks for watching!