| Autor: |
Freije BJ; Biochemistry & Molecular Biology Program, Departments of Biology and Chemistry, The College of Wooster, Wooster, Ohio 44691, United States., Freije WM; Biochemistry & Molecular Biology Program, Departments of Biology and Chemistry, The College of Wooster, Wooster, Ohio 44691, United States., Do TU; Biochemistry & Molecular Biology Program, Departments of Biology and Chemistry, The College of Wooster, Wooster, Ohio 44691, United States., Adkins GE; Biochemistry & Molecular Biology Program, Departments of Biology and Chemistry, The College of Wooster, Wooster, Ohio 44691, United States., Bruch A; Fachgebiet Mikrobiologie, Institut für Biologie, Universität Kassel, Kassel 34132, Germany., Hurtig JE; Biochemistry & Molecular Biology Program, Departments of Biology and Chemistry, The College of Wooster, Wooster, Ohio 44691, United States.; Department of Microbiology & Molecular Genetics, McGovern Medical School, University of Texas at Houston, Houston, Texas 77030, United States., Morano KA; Department of Microbiology & Molecular Genetics, McGovern Medical School, University of Texas at Houston, Houston, Texas 77030, United States., Schaffrath R; Fachgebiet Mikrobiologie, Institut für Biologie, Universität Kassel, Kassel 34132, Germany., West JD; Biochemistry & Molecular Biology Program, Departments of Biology and Chemistry, The College of Wooster, Wooster, Ohio 44691, United States. |
| Abstrakt: |
Protein disulfide isomerases (PDIs) function in forming the correct disulfide bonds in client proteins, thereby aiding the folding of proteins that enter the secretory pathway. Recently, several PDIs have been identified as targets of organic electrophiles, yet the client proteins of specific PDIs remain largely undefined. Here, we report that PDIs expressed in Saccharomyces cerevisiae are targets of divinyl sulfone (DVSF) and other thiol-reactive protein cross-linkers. Using DVSF, we identified the interaction partners that were cross-linked to Pdi1 and Eug1, finding that both proteins form cross-linked complexes with other PDIs, as well as vacuolar hydrolases, proteins involved in cell wall biosynthesis and maintenance, and many ER proteostasis factors involved ER stress signaling and ER-associated protein degradation (ERAD). The latter discovery prompted us to examine the effects of DVSF on ER quality control, where we found that DVSF inhibits the degradation of the ERAD substrate CPY*, in addition to covalently modifying Ire1 and blocking the activation of the unfolded protein response. Our results reveal that DVSF targets many proteins within the ER proteostasis network and suggest that these proteins may be suitable targets for covalent therapeutic development in the future. |
