The CREC family, a novel family of multiple EF-hand, low-affinity Ca2+-binding proteins localised to the secretory pathway of mammalian cells

The CREC family consists of a number of recently discovered multiple (up to seven) EF-hand proteins that localise to the secretory pathway of mammalian cells. At present, the family includes reticulocalbin, ERC-55/TCBP-49/E6BP, Cab45, calumenin and crocalbin/CBP-50, Similar proteins are found in quite diverse invertebrate organisms such as DCB-45 and SCF in Drosophila melanogaster, SCF in Bombyx mori, CCB-39 in Caenorhabditis elegans and Pfs40/PfERC in Plasmodium falciparum. The Ca2+ affinity is rather low with dissociation constants around 10(-4)-10(-3) M, The proteins may participate in Ca2+-regulated activities. Recent evidence has been obtained that some CREC family members are involved in pathological activities such as malignant cell transformation, mediation of the toxic effects of snake venom toxins and putative participation in amyloid formation. (C) 2000 Federation of European Biochemical Societies.