Family of vertebrate proteins involved in cell division and inflammation
The S100 proteins are a family of low molecular-weight proteins found in vertebrates characterized by two calcium-binding sites that have helix-loop-helix ("EF-hand-type") conformation. At least 21 different S100 proteins are known.[1] They are encoded by a family of genes whose symbols use the S100 prefix, for example, S100A1, S100A2, S100A3.
They are also considered as damage-associated molecular pattern molecules (DAMPs), and knockdown of aryl hydrocarbon receptor downregulates the expression of S100 proteins in THP-1 cells.[2]