Conserved Site

Calreticulin/calnexin, conserved site (IPR018124)

Short name: Calret/calnex_CS


Synonym(s): Calregulin, CRP55, HACBP

Calreticulin [PMID: 1497605] is a high-capacity calcium-binding protein which is present in most tissues and located at the periphery of the endoplasmic (ER) and the sarcoplamic reticulum (SR) membranes. It probably plays a role in the storage of calcium in the lumen of the ER and SR and it may well have other important functions.

Structurally, calreticulin is a protein of about 400 amino acid residues consisting of three domains:

  • An N-terminal, probably globular, domain of about 180 amino acid residues (N-domain).
  • A central domain of about 70 residues (P-domain) which contains three repeats of an acidic 17 amino acid motif. This region binds calcium with a low-capacity, but a high-affinity.
  • A C-terminal domain rich in acidic residues and in lysine (C-domain). This region binds calcium with a high-capacity but a low-affinity.

Calreticulin is evolutionarily related to several other calcium-binding proteins, including Onchocerca volvulus antigen RAL-1, calnexin [PMID: 8203019] and calmegin [PMID: 8126001].

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0005509 calcium ion binding

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PROSITE patterns
PROSITE patterns
PROSITE patterns