AGR2 was initially discovered in the African clawed frog, Xenopus laevis. In Xenopus, AGR2 is involved in the differentiation of the cement gland, a mucus-secreting organ essential for the frog’s early development . The gene has since been identified in other species, including humans and mice, where it performs similar functions .
AGR2 is a member of the protein disulfide isomerase (PDI) family, which is involved in the formation and rearrangement of disulfide bonds in proteins. This activity is crucial for the proper folding and stability of many proteins . In mice, AGR2 is expressed in various tissues, including the stomach, colon, and nasal epithelium .
One of the most significant aspects of AGR2 is its role in cancer. AGR2 is overexpressed in several types of human cancers, including those of the esophagus, pancreas, breast, prostate, and lung . High levels of AGR2 are associated with the downregulation of the p53 response, a critical pathway for cell cycle regulation and apoptosis . This makes AGR2 a potential biomarker for cancer diagnosis and prognosis .
Recombinant AGR2, particularly the mouse variant, is widely used in research to study its functions and interactions. The recombinant protein is produced using various expression systems, including bacterial and mammalian cells, to ensure proper folding and activity . Researchers use recombinant AGR2 to investigate its role in protein folding, cancer progression, and potential therapeutic applications .