Fine tuning of the UPR by the ubiquitin ligases Siah1/2.
| Autor: | Marzia Scortegagna, Hyungsoo Kim, Jian-Liang Li, Hang Yao, Laurence M Brill, Jaeseok Han, Eric Lau, David Bowtell, Gabriel Haddad, Randal J Kaufman, Ze'ev A Ronai |
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| Jazyk: | angličtina |
| Rok vydání: | 2014 |
| Předmět: | |
| Zdroj: | PLoS Genetics, Vol 10, Iss 5, p e1004348 (2014) |
| Druh dokumentu: | article |
| ISSN: | 1553-7390 1553-7404 |
| DOI: | 10.1371/journal.pgen.1004348 |
| Popis: | The endoplasmic reticulum (ER) responds to changes in intracellular homeostasis through activation of the unfolded protein response (UPR). Yet, it is not known how UPR-signaling coordinates adaptation versus cell death. Previous studies suggested that signaling through PERK/ATF4 is required for cell death. We show that high levels of ER stress (i.e., ischemia-like conditions) induce transcription of the ubiquitin ligases Siah1/2 through the UPR transducers PERK/ATF4 and IRE1/sXBP1. In turn, Siah1/2 attenuates proline hydroxylation of ATF4, resulting in its stabilization, thereby augmenting ER stress output. Conversely, ATF4 activation is reduced upon Siah1/2 KD in cultured cells, which attenuates ER stress-induced cell death. Notably, Siah1a(+/-)::Siah2(-/-) mice subjected to neuronal ischemia exhibited smaller infarct volume and were protected from ischemia-induced death, compared with the wild type (WT) mice. In all, Siah1/2 constitutes an obligatory fine-tuning mechanism that predisposes cells to death under severe ER stress conditions. |
| Databáze: | Directory of Open Access Journals |
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