Description
S100 calcium-binding protein A7 (S100A7), also known as psoriasin, is a protein that in humans is encoded by the S100A7 gene. S100A7 is a member of the S100 family of proteins containing 2 EF-hand calcium-binding motifs. S100 proteins are localized in the cytoplasm and/or nucleus of a wide range of cells, and involved in the regulation of a number of cellular processes such as cell cycle progression and differentiation. S100A7 also displays antimicrobial properties. It is secreted by epithelial cells of the skin and is a key antimicrobial protein against Escherichia coli by disrupting their cell membranes. This is the reason that in countries with poor sanitation, human skin is exposed to E. coli strains from faecal matter but it does not usually result in an infection