CALR Gene

The CALR gene, located on chromosome 19p13.13, encodes calreticulin, a highly conserved chaperone protein found primarily in the endoplasmic reticulum and involved in a variety of cellular processes, including cell adhesion. It is also involved in protein folding quality control and calcium homeostasis. Calreticulin is also found in the nucleus, suggesting that it may play a role in transcriptional regulation.

Systemic lupus erythematosus is associated with elevated autoantibody titers to calreticulin. Mutations in calreticulin have been associated with various neoplasms.

Furthermore, mutations of the CALR gene have been described in patients with essential thrombocythemia (ET) and primary myelofibrosis (PMF). These CALR mutations are found in approximately 70 to 84% of ET and PMF cases that did not have a JAK2 mutation.

1. Araki M et al (2020) The role of calreticulin mutations in myeloproliferative neoplasms. Int J Hematol 111:200-205.
2. Araki M et al (2017) Novel molecular mechanism of cellular transformation by a mutant molecular chaperone in myeloproliferative neoplasms. Cancer Sci 108:1907-1912.
3. Chao MPet al. (2010) Calreticulin is the dominant pro-phagocytic signal on multiple human cancers and is counterbalanced by CD47. Science Translational Medicine 2: 63ra94.
4. Fucikova J et al (2021) Calreticulin and cancer. Cell Res 31:5-16.