ヒトGRP78を定量するELISAキット Human GRP78(Glucose-Regulated Protein 78) ELISA

Human Glucose Regulated Protein 78 (GRP78) also known as BiP (immunoglobulin heavy-chain binding protein) or HSPA5 is a constitutively expressed protein from the HSP70 heat-shock protein family. It exists in two isoforms, the standard isoform of 78 kDa constituted of 636 amino acids and the short GRP78 isoform of 62 kDa.Human GRP78 is a multifunctional protein involved in protein folding, calcium binding in the endoplasmic reticulum (ER), cellular defense mechanism, and antiapoptotic response of cells. It was reported to function as a cell-surface receptor in some cells. It is predominantly expressed in the ER, but it has also been found in other cellular compartments and in extracellular fluids. The expression of GRP78 is not tissue-specific. It is induced by hypoglycemia, hypoxia and some other cytotoxic stresses. Accordingly, elevated expression of GRP78 was reported under pathological conditions in tissues with insufficient blood supply (e.g. myocardial infarction, pre-eclampsia, tumors), but also different nephropathies, neuropathies or atherosclerosis. It is believed to be one of the key regulators of cellular invasion and angioneogenesis in developing precancerous and cancerous tissues, and it has also been detected in the extracellular microenvironment of these tissues. Experiments in mouse models revealed that it is also required for optimal metabolic turnover of lipids and glucose.