scholarly journals A Relaxed Specificity in Interchain Disulfide Bond Formation Characterizes the Assembly of a Low-Molecular-Weight Glutenin Subunit in the Endoplasmic Reticulum

2008 ◽  
Vol 149 (1) ◽  
pp. 412-423 ◽  
Author(s):  
Alessio Lombardi ◽  
Alessandra Barbante ◽  
Pietro Della Cristina ◽  
Daniele Rosiello ◽  
Chiara Lara Castellazzi ◽  
...  
mAbs ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 1829333
Author(s):  
Zhijun Tan ◽  
Vivekh Ehamparanathan ◽  
Tingwei Ren ◽  
Peifeng Tang ◽  
Laurel Hoffman ◽  
...  

2008 ◽  
Vol 190 (17) ◽  
pp. 5738-5745 ◽  
Author(s):  
Sumarin Soonsanga ◽  
Jin-Won Lee ◽  
John D. Helmann

ABSTRACTOhrR proteins can be divided into two groups based on their inactivation mechanism: 1-Cys (represented byBacillus subtilisOhrR) and 2-Cys (represented byXanthomonas campestrisOhrR). A conserved cysteine residue near the amino terminus is present in both groups of proteins and is initially oxidized to the sulfenic acid. TheB. subtilis1-Cys OhrR protein is subsequently inactivated by formation of a mixed-disulfide bond with low-molecular-weight thiols or by cysteine overoxidation to sulfinic and sulfonic acids. In contrast, theX. campestris2-Cys OhrR is inactivated when the initially oxidized cysteine sulfenate forms an intersubunit disulfide bond with a second Cys residue from the other subunit of the protein dimer. Here, we demonstrate that the 1-CysB. subtilisOhrR can be converted into a 2-Cys OhrR by introducing another cysteine residue in either position 120 or position 124. Like theX. campestrisOhrR protein, these mutants (G120C and Q124C) are inactivated by intermolecular disulfide bond formation. Analysis of oxidized 2-Cys variants both in vivo and in vitro indicates that intersubunit disulfide bond formation can occur simultaneously at both active sites in the protein dimer. Rapid formation of intersubunit disulfide bonds protects OhrR against irreversible overoxidation in the presence of strong oxidants much more efficiently than do the endogenous low-molecular-weight thiols.


2000 ◽  
Vol 11 (9) ◽  
pp. 2833-2843 ◽  
Author(s):  
Alison R. Frand ◽  
Chris A. Kaiser

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.


2012 ◽  
Vol 102 ◽  
pp. S185-S186
Author(s):  
M. Koritzinsky ◽  
T. Van den Beucken ◽  
K. Chu ◽  
P.C. Boutros ◽  
I. Braakman ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document