P4HB Protein, Mouse (HEK293, His)

P4HB Protein, a versatile and multifunctional entity, orchestrates the catalysis of disulfide bond formation, breakage, and rearrangement. Positioned at the cell surface, it exhibits reductase activity, cleaving disulfide bonds of proteins attached to the cell and potentially inducing structural modifications in exofacial proteins. Within the cellular interior, P4HB plays a role in forming and rearranging disulfide bonds in nascent proteins. At elevated concentrations, and upon phosphorylation by FAM20C, it transforms into a chaperone that inhibits the aggregation of misfolded proteins, whereas at lower concentrations, it facilitates aggregation, showcasing anti-chaperone activity. Furthermore, P4HB may collaborate with other chaperones in modifying the structure of the thyroglobulin precursor during hormone biogenesis. Additionally, it serves as a structural subunit for various enzymes, including prolyl 4-hydroxylase and microsomal triacylglycerol transfer protein MTTP. Notably, P4HB also functions as a receptor for LGALS9, with this interaction impacting its localization on the cell surface, enhancing disulfide reductase activity, altering the plasma membrane redox state, and promoting cell migration.