The ins and outs of calreticulin: from the ER lumen to the extracellular space

Trends Cell Biol. 2001 Mar;11(3):122-9. doi: 10.1016/s0962-8924(01)01926-2.


Calreticulin was first isolated 26 years ago. Since its discovery as a minor Ca(2+)-binding protein of the sarcoplasmic reticulum, the appreciation of its importance has grown, and it is now recognized to be a multifunctional protein, most abundant in the endoplasmic reticulum (ER). The protein has well-recognized physiological roles in the ER as a molecular chaperone and Ca(2+)-signalling molecule. However, it has also been found in other membrane-bound organelles, at the cell surface and in the extracellular environment, where it has recently been shown to exert a number of physiological and pathological effects. Here, we will focus on these less-well-characterized functions of calreticulin.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Bodily Secretions / metabolism
  • Calcium Signaling / physiology*
  • Calcium-Binding Proteins / metabolism*
  • Calreticulin
  • Cell Adhesion / physiology
  • Disease Progression
  • Endoplasmic Reticulum / metabolism*
  • Extracellular Space / metabolism
  • Homeostasis / physiology
  • Humans
  • Molecular Chaperones / metabolism*
  • Organelles / metabolism
  • Ribonucleoproteins / metabolism*


  • Calcium-Binding Proteins
  • Calreticulin
  • Molecular Chaperones
  • Ribonucleoproteins