A large family of calcium-binding proteins that contain an EF-hand. S100A1 (94 aa, a dimer with three forms, αα, αβ, ββ) is produced by a wide variety of normal and neoplastic cells of mesodermal, neuroectodermal, and epithelial origin. It improves cardiac contractile performance by regulating sarcoplasmic reticulum calcium ion handling and myofibrillar calcium ion responsiveness. S100A4 (placental calcium-binding protein, Mts1, metastasin, p9Ka, pEL98, CAPL, calvasculin, Fsp-1) is found in placenta, uterus, and the vasculature and its expression is upregulated in various pathological conditions. It apparently contributes to tumour cell motility and metastasis. S100A6 is calcyclin. Calprotectin is a heterodimer composed of S100A8 (calgranulin A) and S100A9 (calgranulin B) and is a major calcium- and zinc-binding protein in the cytosol of neutrophils, monocytes, and keratinocytes. S100A10 is the light chain of calpactin, S100A12 is calgranulin C. S100β has neurotrophic and mitogenic activity. Other members of the family include calmodulin and troponin.
Subjects: Medicine and Health.