Wiktionary
calreticulin
n. (context protein English) A multifunctional protein that binds calcium ions
Wikipedia
Calreticulin
Calreticulin also known as calregulin, CRP55, CaBP3, calsequestrin-like protein, and endoplasmic reticulum resident protein 60 (ERp60) is a protein that in humans is encoded by the CALR gene.
Calreticulin is a multifunctional protein that binds Ca ions (a second messenger in signal transduction), rendering it inactive. The Ca is bound with low affinity, but high capacity, and can be released on a signal (see inositol triphosphate). Calreticulin is located in storage compartments associated with the endoplasmic reticulum.
The term "Mobilferrin" is considered to be the same as calreticulin by some sources.