Many diverse diseases arise from an excess of unfolded proteins in the endoplasmic reticulum (ER stress). ER stress induces the unfolded protein response (UPR), in which numerous protective genes are activated. It is critical to understand how the UPR defends against ER stress, and how UPR signaling affects other cellular processes. While three canonical UPR transcription factors have been identified, we have determined in C. elegans that the transcription factor SKN-1 (mammalian Nrf1/2/3) is also central to the UPR. SKN-1 has a conserved function in oxidative stress defense, and is important in longevity. We have shown that SKN-1 is regulated by the UPR, and is needed for ER stress to activate core UPR regulators, as well as downstream effector genes. Surprisingly, UPR signaling is required for SKN-1 to respond to oxidative stress, which suggests that ER signaling may broadly influence cellular stress defenses, and may regulate SKN-1 in the insulin-IGF-1-like signaling (IIS) and TOR (target of rapamycin) pathways. Using the powerful C. elegans model, this project will investigate: (1) how and in what tissues SKN-1 defends against ER stress, and how IIS and TOR might affect ER stress resistance through SKN-1, (2) how SKN-1 is regulated by the UPR during ER stress, oxidative stress, and in the context of the IIS and TOR pathways, and (3) what genes and biological processes are controlled directly by SKN-1 during the UPR. Transgenic, genetic, molecular, cell biological, and chromatin immunoprecipitation (ChIP) approaches will be used to investigate how SKN-1 functions are regulated by the UPR and contribute to ER stress resistance in vivo. A proven RNAi screening strategy will identify new regulators of SKN-1 during ER stress, and high-throughput sequencing combined with expression profiling and ChIP will be employed to identify genes and processes regulated directly by SKN-1. These studies will provide important and novel insights into how the ER defends itself against stress, and will substantially alter paradigms for understanding ER-based signaling and how it influences other cellular defense mechanisms.
Many proteins are synthesized in the endoplasmic reticulum (ER). High levels of misfolded ER proteins (ER stress) cause or exacerbate disease states as diverse as diabetes, hepatitis, and neurodegeneration. This project will use a model organism (C. elegans) to determine how a regulator of diverse cellular defenses protects against ER stress, and how signaling from the ER controls this and other functions of this regulator.
| Ewald, Collin Yvès; Hourihan, John M; Bland, Monet S et al. (2017) NADPH oxidase-mediated redox signaling promotes oxidative stress resistance and longevity through memo-1 in C. elegans. Elife 6: |
| Ewald, Collin Yvès; Hourihan, John M; Blackwell, T Keith (2017) Oxidative Stress Assays (arsenite and tBHP) in Caenorhabditis elegans. Bio Protoc 7: |
| Hourihan, John M; Moronetti Mazzeo, Lorenza E; Fernández-Cárdenas, L Paulette et al. (2016) Cysteine Sulfenylation Directs IRE-1 to Activate the SKN-1/Nrf2 Antioxidant Response. Mol Cell 63:553-566 |
| Ogawa, Takahiro; Kodera, Yukihiro; Hirata, Dai et al. (2016) Natural thioallyl compounds increase oxidative stress resistance and lifespan in Caenorhabditis elegans by modulating SKN-1/Nrf. Sci Rep 6:21611 |
| Castillo-Quan, Jorge Iván; Blackwell, T Keith (2016) Metformin: Restraining Nucleocytoplasmic Shuttling to Fight Cancer and Aging. Cell 167:1670-1671 |
| Steinbaugh, Michael J; Narasimhan, Sri Devi; Robida-Stubbs, Stacey et al. (2015) Lipid-mediated regulation of SKN-1/Nrf in response to germ cell absence. Elife 4: |
| Blackwell, T Keith; Steinbaugh, Michael J; Hourihan, John M et al. (2015) SKN-1/Nrf, stress responses, and aging in Caenorhabditis elegans. Free Radic Biol Med 88:290-301 |
| Yoon, John C; Ling, Alvin J Y; Isik, Meltem et al. (2014) GLTSCR2/PICT1 links mitochondrial stress and Myc signaling. Proc Natl Acad Sci U S A 111:3781-6 |
| Glover-Cutter, Kira M; Lin, Stephanie; Blackwell, T Keith (2013) Integration of the unfolded protein and oxidative stress responses through SKN-1/Nrf. PLoS Genet 9:e1003701 |
