Tescalcin (TESC)

Tescalcin (TESC) is a small, 24-kDa calcium-binding protein belonging to the EF-hand domain–containing family, closely related to calcineurin homologous proteins. It contains a single functional EF-hand motif, enabling Ca²⁺-sensing activity central to its function. TESC plays multiple critical cellular roles, including regulation of the plasma membrane Na⁺/H⁺ exchanger 1 (NHE1), which is vital for controlling intracellular pH and ion homeostasis. Beyond ion transport, tescalcin interacts with and modulates key signaling proteins such as glycogen synthase kinase 3 (GSK3), the COP9 signalosome subunit CSN4, and the c-Src/IGF1Rβ/STAT3 axis, thereby influencing processes like cell proliferation, differentiation, epithelial–mesenchymal transition, and cancer stem cell properties. TESC is overexpressed in several cancer types (notably colorectal, lung, gastric, and liver cancers) and acts as both a diagnostic biomarker and a potential therapeutic target. Its regulation of major signaling cascades links it to tumorigenesis and radioresistance, especially through the maintenance of cancer stem cell–like phenotypes in solid tumors.

Other names

Calcineurin B homologous protein 3CHP3TSCFLJ20607Calcineurin-like EF hand protein 3

Modulation of intracellular signaling pathways such as Akt–NF-κB, STAT3, MAPK/ERK. Regulation of Na⁺/H⁺ exchanger degradation and surface stability. Calcium-dependent protein–protein interactions. Regulation of kinase (e.g., GSK3) phosphorylation and activity. Interaction with COP9 signalosome components.