S100P Human, His

S100 Calcium Binding Protein P (S100P) is a member of the S100 family of proteins, which are characterized by their ability to bind calcium ions through EF-hand motifs. These proteins are involved in a variety of cellular processes, including cell cycle progression, differentiation, and signal transduction .

S100P contains two EF-hand calcium-binding motifs, which are helix-loop-helix structural domains capable of binding calcium ions. This protein is localized in the cytoplasm and/or nucleus of a wide range of cells. In addition to binding calcium, S100P can also bind zinc and magnesium ions .

The primary function of S100P is to act as a calcium sensor and modulator, contributing to cellular calcium signaling. It interacts with other proteins in a calcium-dependent manner, such as EZR and PPP5C, and indirectly plays a role in physiological processes like the formation of microvilli in epithelial cells .

S100P is widely expressed in both normal and malignant tissues. Among normal tissues, the highest levels of S100P mRNA are observed in the placenta and esophagus, with moderate levels in the stomach, duodenum, large intestine, prostate, and leukocytes. At the protein level, the highest reactions for S100P are seen in the placenta and stomach .

S100P is overexpressed in a variety of cancers, including breast, colon, prostate, pancreatic, and lung carcinomas. Its overexpression has been functionally implicated in carcinogenic processes. For instance, in pancreatic cancer, S100P is overexpressed due to hypomethylation of its gene. In prostate cancer, its expression is regulated by androgens and interleukin-6 .

Recombinant S100P with a His tag is a form of the protein that has been genetically engineered to include a polyhistidine tag. This tag facilitates the purification of the protein using metal affinity chromatography. The recombinant form is often used in research to study the protein’s structure, function, and interactions.