Calreticulin Mouse, Unlabeled, Clone: 16, BD

Proteins undergo numerous modifications, including folding, translocation, and degradation. During such modifications, polypeptides are rarely in a native, stable state. Molecular chaperones are a diverse group of proteins that modulate polypeptide stability through ATP-dependent folding. Many chaperone proteins are found in the endoplasmic reticulum (ER). Calreticulin is a luminal ER protein that is 39% homologous to the ER chaperone protein, calnexin. Calreticulin contains a C-terminal KDEL ER retention signal, and can bind Ca²⁺;, Zn²⁺, ATP, and the proteins, ERp57 and protein disulfide isomerase. The molecular chaperone activities of calreticulin may include folding of both Asn-linked glycoproteins and non-glycosylated proteins. In addition, calreticulin is a component of MHC I/transporter associated with Ag presentation (TAP) complex where it may function in peptide assembly onto nascent class I molecules. Calreticulin may also function in integrin signaling, since it binds a3-integrin subunits and regulates integrin-mediated metalloprotease secretion. Thus, calreticulin may be involved in Ca²⁺; storage, cell adhesion, and protein folding.

Immunofluorescence, Western Blotting