Anterior Gradient Protein 3 (AGR3) Protein

Background

AGR3 is structurally related to AGR2 and also functions as a protein disulfide isomerase in the endoplasmic reticulum (ER), supporting protein folding and secretion. AGR3 is expressed predominantly in ciliated epithelial cells of tissues such as the lungs, fallopian tubes, and brain, where it is associated with cilia formation and function. Unlike AGR2, AGR3 has a more specialized role in maintaining epithelial structure and integrity. Dysregulation of AGR3 is implicated in respiratory disorders and has been linked to cancer, particularly in tumors with ciliated origins, such as certain ovarian cancers. AGR3’s role in tumorigenesis is less pronounced than AGR2, but it is being explored as a potential marker for cell differentiation and tissue-specific malignancies.