Anti-S100A3 pAb

The S100 proteins comprise a family of 25 small acidic proteins (9–13 kDa) that are characterized by the presence of two calcium-binding EF-hand motifs. Among the different human S100 genes, 22 are clustered at chromosome locus 1q21 (3), a region frequently involved in chromosomal rearrangement in cancers. Thirteen S100 proteins (S100A2, S100A3, S100A4, S100A6, S100A7, S100A8, S100A9, S100A10, S100A11, S100A12, S100A15, S100B, and S100P) are expressed in normal and/or diseased epidermis. The protein S100A3, formerly called S100E, was recognized for the first time as the product of one of the tightest gene clusters discovered in the human genome located on chromosome 1q21 (1) The S100A3 gene shows a low but general transcription level in diaphragm, heart, skeletal muscle, stomach, lung, liver, fat tissue, and placenta. S100A3 shows a remarkably narrow tissue- and cell-specific expression pattern. It is highly expressed in hair root cells (2-4) and some astrocytomas (5). Because both cell types are characterized by high proliferation rates S100A3 is supposed to be involved in cell cycle progression. Within the S100 subfamily S100A3 is unique for the exceptionally high number of Cys residues. Despite the Cys frequency, S100A3 does not display the classical zinc-binding motifs seen in metallothioneins (6), DNA-binding proteins (7), or protein kinase C (8).