ERp57 (Endoplasmic Reticulum Protein 57), also known as PDIA3 or GRP58. is a member of the protein disulfide isomerase (PDI) family. It localizes primarily within the endoplasmic reticulum (ER) and plays a critical role in protein quality control by catalyzing disulfide bond formation, isomerization, and assisting in the folding of nascent glycoproteins. ERp57 interacts with lectin chaperones calnexin and calreticulin, forming a complex that ensures proper folding of MHC class I molecules and other glycoproteins. Beyond its canonical role, ERp57 has been implicated in diverse cellular processes, including calcium homeostasis, cell adhesion, and immune response regulation.
Dysregulation of ERp57 is linked to various diseases. Overexpression is observed in cancers, correlating with tumor progression, drug resistance, and poor prognosis. Conversely, reduced ERp57 activity is associated with neurodegenerative disorders like Alzheimer’s disease, possibly due to impaired protein folding. ERp57 also participates in viral infection mechanisms, aiding in the processing of viral glycoproteins.
ERp57 antibodies are essential tools for studying its expression, localization, and function. They are widely used in techniques such as Western blotting, immunohistochemistry, and immunofluorescence to investigate ERp57’s role in physiological and pathological contexts. Specific antibodies help identify its interaction partners and post-translational modifications, contributing to therapeutic research targeting ERp57-related pathways. However, antibody specificity must be validated due to structural similarities among PDI family members.