Calumenin (CALU)

Calumenin (CALU) is a secreted, multifunctional calcium-binding protein with six EF-hand domains, predominantly localized in the endoplasmic reticulum and sarcoplasmic reticulum of mammalian cells. It plays critical roles in protein folding, sorting, and handling Ca²⁺ within cells. CALU also influences the activity of vitamin K-dependent proteins, cardiac Ca²⁺ cycling, cell migration, tumor progression, immune responses, and coagulation. Genetic variants in CALU are associated with variation in warfarin dose requirements and its expression may serve as a biomarker in certain cardiovascular and cancer settings. Its widespread physiological functions make it a possible therapeutic target, though interventions must consider the risk of broad systemic effects.

Other names

CALUCrocalbinIEF SSP 9302CalumeninCrocalbin-like proteinMultiple EF-hand proteinFLJ90608

Modulation of vitamin K–dependent carboxylation (alters γ-carboxylase activity); Influences ERK1/2 signaling pathways in cancer, stabilizes matrix components (e.g., fibulin-1); Interaction with SERCA2 modulates intracellular calcium cycling; Interacts with thrombospondin-1 in platelets, affecting hemostasis.