This multifunctional protein catalyzes the formation, breakage and rearrangent of disulfide bonds. At the cell surface, ses to act as a reductase that cleaves disulfide bonds of proteins attached to the cell. May therefore cause structural modifications of exofacial proteins. Inside the cell, ses to form,rearrange disulfide bonds of nascent proteins. At high concentrations, functions as a chaperone that inhibits aggregation of misfolded proteins. At low concentrations, facilitates aggregation (anti-chaperone activity). May be involved with other chaperones in the structural modification of the TG precursor in hormone biogenesis. Also acts a structural subunit of various enzymes such as prolyl 4-hydroxylase and microsomal triacylglycerol transfer protein MTTP.
Molecular cloning of the beta-subunit of human prolyl 4-hydroxylase. This subunit and protein disulphide isomerase are products of the same gene.Pihlajaniemi T., Helaakoski T., Tasanen K., Myllylae R., Huhtala M.-L., Koivu J., Kivirikko K.I.EMBO J. 6:643-649(1987)
Research Topic:Cancer