scholarly journals The protein disulphide-isomerase family: unravelling a string of folds

1999 ◽  
Vol 339 (1) ◽  
pp. 1-10 ◽  
Author(s):  
David M. FERRARI ◽  
Hans-Dieter SÖLING
Keyword(s):  
Amino Acids ◽  
Endoplasmic Reticulum ◽  
Cell Adhesion ◽  
Peptide Binding ◽  
Secretory Proteins ◽  
Cytoplasmic Protein ◽  
Protein Disulphide Isomerase ◽  
Redox Active ◽  
Binding Cell ◽  
Mammalian Protein

The mammalian protein disulphide-isomerase (PDI) family encompasses several highly divergent proteins that are involved in the processing and maturation of secretory proteins in the endoplasmic reticulum. These proteins are characterized by the presence of one or more domains of roughly 95–110 amino acids related to the cytoplasmic protein thioredoxin. All but the PDI-D subfamily are composed entirely of repeats of such domains, with at least one domain containing and one domain lacking a redox-active -Cys-Xaa-Xaa-Cys- tetrapeptide. In addition to their known roles as redox catalysts and isomerases, the last few years have revealed additional functions of the PDI proteins, including peptide binding, cell adhesion and perhaps chaperone activities. Attention is now turning to the non-redox-active domains of the PDIs, which may play an important role in all of the known activities of these proteins. Thus the presence of both redox-active and -inactive domains within these proteins portends a complexity of functions differentially accommodated by the various family members.

scholarly journals Two Pairs of Conserved Cysteines Are Required for the Oxidative Activity of Ero1p in Protein Disulfide Bond Formation in the Endoplasmic Reticulum

2000 ◽  
Vol 11 (9) ◽  
pp. 2833-2843 ◽  
Author(s):  
Alison R. Frand ◽  
Chris A. Kaiser
Keyword(s):  
Endoplasmic Reticulum ◽  
Disulfide Bond ◽  
Mutational Analysis ◽  
Bond Formation ◽  
Secretory Proteins ◽  
Disulfide Bond Formation ◽  
Major Pathway ◽  
Disulfide Exchange ◽  
Redox Active ◽  
Protein Disulfide

In the major pathway for protein disulfide-bond formation in the endoplasmic reticulum (ER), oxidizing equivalents flow from the conserved ER-membrane protein Ero1p to secretory proteins via protein disulfide isomerase (PDI). Herein, a mutational analysis of the yeast ERO1 gene identifies two pairs of conserved cysteines likely to form redox-active disulfide bonds in Ero1p. Cys100, Cys105, Cys352, and Cys355 of Ero1p are important for oxidative protein folding and for cell viability, whereas Cys90, Cys208, and Cys349 are dispensable for these functions. Substitution of Cys100 with alanine impedes the capture of Ero1p-Pdi1p mixed-disulfide complexes from yeast, and also blocks oxidation of Pdi1p in vivo. Cys352 and Cys355 are required to maintain the fully oxidized redox state of Ero1p, and also play an auxiliary role in thiol–disulfide exchange with Pdi1p. These results suggest a model for the function of Ero1p wherein Cys100 and Cys105 form a redox-active disulfide bond that engages directly in thiol–disulfide exchange with ER oxidoreductases. The Cys352–Cys355 disulfide could then serve to reoxidize the Cys100–Cys105 cysteine pair, possibly through an intramolecular thiol–disulfide exchange reaction.

scholarly journals Preparation and characterization of dog pancreas microsomal membranes specifically depleted of protein disulphide-isomerase

1989 ◽  
Vol 257 (3) ◽  
pp. 657-663 ◽  
Author(s):  
J L Paver ◽  
H C Hawkins ◽  
R B Freedman
Keyword(s):  
Endoplasmic Reticulum ◽  
Rat Liver ◽  
Enzyme Assay ◽  
Experimental System ◽  
Secretory Proteins ◽  
Immunoblotting Analysis ◽  
Protein Disulphide Isomerase ◽  
Microsomal Membranes ◽  
Dog Pancreas

1. The selective release of protein disulphide-isomerase from dog pancreas and rat liver microsomal membranes was studied to throw light on the mechanisms of retention of this enzyme within the endoplasmic reticulum, and in order to prepare microsomal membranes specifically depleted of the enzyme. 2. Protein disulphide-isomerase was quantitatively released from dog pancreas microsomal membranes by washing at pH 9 and above, as demonstrated both by enzyme assay and by immunoblotting analysis. 3. Integral membrane proteins implicated in the process of translocation and segregation of secretory proteins were retained in pH 9-washed dog pancreas microsomal membranes. 4. After pH 9 washing, dog pancreas microsomal membranes were fully active in the translocation, segregation and processing of nascent secretory proteins; these membranes therefore provide a useful experimental system for testing the action of protein disulphide-isomerase on nascent secretory proteins. 5. Protein disulphide-isomerase was not released from rat liver microsomal membranes by pH 9 washing, and was much less readily released from these membranes by sonication, washing etc. than from dog pancreas microsomal membranes. 6. The mechanism of retention of protein disulphide-isomerase, and of other resident proteins of the lumen of the endoplasmic reticulum, is discussed in the light of these findings.

Prevalence of the pit and antipit in the genus Glycine

1987 ◽  
Vol 45 ◽  
pp. 986-987
Author(s):  
R. W. Yaklich ◽  
E. L. Vigil ◽  
W. P. Wergin
Keyword(s):  
Amino Acids ◽  
Endoplasmic Reticulum ◽  
Glycine Max ◽  
Seed Coat ◽  
Cell Types ◽  
Abaxial Surface ◽  
Legume Seed ◽  
Initial Report ◽  
Cone Cells ◽  
Glycine Max L

The legume seed coat is the site of sucrose unloading and the metabolism of imported ureides and synthesis of amino acids for the developing embryo. The cell types directly responsible for these functions in the seed coat are not known. We recently described a convex layer of tissue on the inside surface of the soybean (Glycine max L. Merr.) seed coat that was termed “antipit” because it was in direct opposition to the concave pit on the abaxial surface of the cotyledon. Cone cells of the antipit contained numerous hypertrophied Golgi apparatus and laminated rough endoplasmic reticulum common to actively secreting cells. The initial report by Dzikowski (1936) described the morphology of the pit and antipit in G. max and found these structures in only 68 of the 169 seed accessions examined.

Common modifications of selenocysteine in selenoproteins

2019 ◽  
Vol 64 (1) ◽  
pp. 45-53 ◽  
Author(s):  
Elias S.J. Arnér
Keyword(s):  
Amino Acids ◽  
Covalent Binding ◽  
Physicochemical Characteristics ◽  
Redox Active

Abstract Selenocysteine (Sec), the sulfur-to-selenium substituted variant of cysteine (Cys), is the defining entity of selenoproteins. These are naturally expressed in many diverse organisms and constitute a unique class of proteins. As a result of the physicochemical characteristics of selenium when compared with sulfur, Sec is typically more reactive than Cys while participating in similar reactions, and there are also some qualitative differences in the reactivities between the two amino acids. This minireview discusses the types of modifications of Sec in selenoproteins that have thus far been experimentally validated. These modifications include direct covalent binding through the Se atom of Sec to other chalcogen atoms (S, O and Se) as present in redox active molecular motifs, derivatization of Sec via the direct covalent binding to non-chalcogen elements (Ni, Mb, N, Au and C), and the loss of Se from Sec resulting in formation of dehydroalanine. To understand the nature of these Sec modifications is crucial for an understanding of selenoprotein reactivities in biological, physiological and pathophysiological contexts.

Secretory proteins move through the endoplasmic reticulum membrane via an aqueous, gated pore

Cell ◽  
1994 ◽  
Vol 78 (3) ◽  
pp. 461-471 ◽  
Author(s):  
Kathleen S. Crowley ◽  
Shuren Liao ◽  
Veronica E. Worrell ◽  
Gregory D. Reinhart ◽  
Arthur E. Johnson
Keyword(s):  
Endoplasmic Reticulum ◽  
Secretory Proteins ◽  
Endoplasmic Reticulum Membrane

scholarly journals The unfolded protein response coordinates the production of endoplasmic reticulum protein and endoplasmic reticulum membrane.

1997 ◽  
Vol 8 (9) ◽  
pp. 1805-1814 ◽  
Author(s):  
J S Cox ◽  
R E Chapman ◽  
P Walter
Keyword(s):  
Endoplasmic Reticulum ◽  
Unfolded Protein Response ◽  
Secretory Pathway ◽  
Lipid Synthesis ◽  
Secretory Proteins ◽  
Endoplasmic Reticulum Membrane ◽  
Yeast Saccharomyces Cerevisiae ◽  
Unfolded Protein ◽  
The Unfolded Protein Response ◽  
Protein Response

The endoplasmic reticulum (ER) is a multifunctional organelle responsible for production of both lumenal and membrane components of secretory pathway compartments. Secretory proteins are folded, processed, and sorted in the ER lumen and lipid synthesis occurs on the ER membrane itself. In the yeast Saccharomyces cerevisiae, synthesis of ER components is highly regulated: the ER-resident proteins by the unfolded protein response and membrane lipid synthesis by the inositol response. We demonstrate that these two responses are intimately linked, forming different branches of the same pathway. Furthermore, we present evidence indicating that this coordinate regulation plays a role in ER biogenesis.

Negatively-charged amino acids at the peptide-binding pocket of HLA-DPB1 alleles are associated with susceptibility to anti-topoisomerase I-positive systemic sclerosis

2016 ◽  
Vol 77 (7) ◽  
pp. 550-554 ◽  
Author(s):  
Jeong Seok Lee ◽  
Jin Kyun Park ◽  
Heung Jae Kim ◽  
Hyung Ki Lee ◽  
Yeong Wook Song ◽  
...  
Keyword(s):  
Amino Acids ◽  
Systemic Sclerosis ◽  
Topoisomerase I ◽  
Peptide Binding ◽  
Binding Pocket ◽  
Charged Amino Acids
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