Structural highlights
Function
[PDIA1_HUMAN] This multifunctional protein catalyzes the formation, breakage and rearrangement of disulfide bonds. At the cell surface, seems 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, seems 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.[1] [2]
Publication Abstract from PubMed
Protein disulfide isomerases (PDIs) are responsible for catalyzing the proper oxidation and isomerization of disulfide bonds of newly synthesized proteins in the endoplasmic reticulum (ER). Here, it is shown that human PDI (PDIA1) dimerizes in vivo and proposed that the dimerization of PDI has physiological relevance by autoregulating its activity. The crystal structure of the dimeric form of noncatalytic bb' domains of human PDIA1 determined to 2.3 A resolution revealed that the formation of dimers occludes the substrate binding site and may function as a mechanism to regulate PDI activity in the ER.
Structural insight into the dimerization of human protein disulfide isomerase.,Bastos-Aristizabal S, Kozlov G, Gehring K Protein Sci. 2014 Feb 18. doi: 10.1002/pro.2444. PMID:24549644[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Mezghrani A, Courageot J, Mani JC, Pugniere M, Bastiani P, Miquelis R. Protein-disulfide isomerase (PDI) in FRTL5 cells. pH-dependent thyroglobulin/PDI interactions determine a novel PDI function in the post-endoplasmic reticulum of thyrocytes. J Biol Chem. 2000 Jan 21;275(3):1920-9. PMID:10636893
- ↑ Lumb RA, Bulleid NJ. Is protein disulfide isomerase a redox-dependent molecular chaperone? EMBO J. 2002 Dec 16;21(24):6763-70. PMID:12485997
- ↑ Bastos-Aristizabal S, Kozlov G, Gehring K. Structural insight into the dimerization of human protein disulfide isomerase. Protein Sci. 2014 Feb 18. doi: 10.1002/pro.2444. PMID:24549644 doi:http://dx.doi.org/10.1002/pro.2444
