Unbiased Profiling of the Human Proinsulin Biosynthetic Interaction Network Reveals a Role for Peroxiredoxin 4 in Proinsulin Folding
| Autor: | Peter Arvan, Alexandre Rosa Campos, Insook Jang, Pamela Itkin-Ansari, Salvatore Loguercio, Reyhaneh Lahmy, William E. Balch, Saiful A. Mir, Kathleen M. Scully, Anita Pottekat, Ming Liu, Duc T. Tran, Randal J. Kaufman |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
0301 basic medicine
Male endocrine system Protein Folding endocrine system diseases Endocrinology Diabetes and Metabolism medicine.medical_treatment Blotting Western 030209 endocrinology & metabolism Endoplasmic Reticulum Interactome 03 medical and health sciences 0302 clinical medicine Tandem Mass Spectrometry Internal Medicine medicine Gene silencing Humans Immunoprecipitation Insulin Secretory pathway Proinsulin Peroxiredoxin-4 Chemistry nutritional and metabolic diseases Peroxiredoxins Cell biology 030104 developmental biology Diabetes Mellitus Type 2 Islet Studies Female Beta cell Peroxiredoxin hormones hormone substitutes and hormone antagonists Protein Binding |
| Zdroj: | Diabetes |
| ISSN: | 1939-327X |
| Popis: | The β-cell protein synthetic machinery is dedicated to the production of mature insulin, which requires the proper folding and trafficking of its precursor, proinsulin. The complete network of proteins that mediate proinsulin folding and advancement through the secretory pathway, however, remains poorly defined. Here we used affinity purification and mass spectrometry to identify, for the first time, the proinsulin biosynthetic interaction network in human islets. Stringent analysis established a central node of proinsulin interactions with endoplasmic reticulum (ER) folding factors, including chaperones and oxidoreductases, that is remarkably conserved in both sexes and across three ethnicities. The ER-localized peroxiredoxin PRDX4 was identified as a prominent proinsulin-interacting protein. In β-cells, gene silencing of PRDX4 rendered proinsulin susceptible to misfolding, particularly in response to oxidative stress, while exogenous PRDX4 improved proinsulin folding. Moreover, proinsulin misfolding induced by oxidative stress or high glucose was accompanied by sulfonylation of PRDX4, a modification known to inactivate peroxiredoxins. Notably, islets from patients with type 2 diabetes (T2D) exhibited significantly higher levels of sulfonylated PRDX4 than islets from healthy individuals. In conclusion, we have generated the first reference map of the human proinsulin interactome to identify critical factors controlling insulin biosynthesis, β-cell function, and T2D. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|