STC 2 Human, His

Stanniocalcin-2 (STC2) is a secreted glycoprotein hormone that belongs to the stanniocalcin family. This family of proteins was first discovered in the corpuscles of Stannius, which are endocrine glands located on the surface of the fish kidney . The human orthologs of these proteins, STC1 and STC2, have been identified and studied for their various biological functions and potential therapeutic applications.

STC2 was identified by searching the Expressed Sequence Tag (EST) database related to STC1 . It shares 34% identity with human STC1 and eel STC based on sequencing analysis . Phylogenetically, STC2 is highly conserved across vertebrates, including common animal models such as Danio rerio (zebrafish), Xenopus tropicalis (frog), Mus musculus (mouse), and Rattus norvegicus (rat) . This conservation suggests that STC2 plays an important role in species preservation during evolution.

Human STC2 is a disulfide-linked homodimeric glycoprotein hormone. It has 10 of its 15 cysteine residues conserved among stanniocalcin family members and is phosphorylated by casein kinase 2 . The recombinant form of STC2, often tagged with a His (histidine) tag for purification purposes, is expressed in various systems, including HEK293 cells . The His tag facilitates the purification of the protein using affinity chromatography techniques.

STC2 is involved in several physiological processes. It is broadly expressed in human tissues, including the kidney, ovary, bone, prostate, thyroid, neuron, and muscle . Biologically, STC2 helps cells cope with stress conditions such as endoplasmic reticulum (ER) stress, hypoxia, and nutrient deprivation . It prevents apoptosis and promotes cell proliferation, migration, and immune response . These properties make STC2 a potential biomarker and therapeutic target, especially in the context of cancer .

The overexpression of STC2 has been positively correlated with tumor growth, invasion, metastasis, and patients’ prognosis . It is significantly stimulated under various stress conditions and helps in the development of acquired resistance to chemo- and radio-therapies . Therefore, STC2 is considered a universal tumor biomarker and a potential therapeutic target .

Recombinant human STC2 with a His tag is produced in various expression systems, including mouse myeloma cell lines and HEK293 cells . The His tag allows for easy purification and is often used in research to study the protein’s functions and interactions. The recombinant protein is typically lyophilized and can be reconstituted in PBS for use in various assays .