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Webster CM, Pino EC, Carr CE, Wu L, Zhou B, Cedillo L, Kacergis MC, Curran SP, Soukas AA. Genome-wide RNAi Screen for Fat Regulatory Genes in C. elegans Identifies a Proteostasis-AMPK Axis Critical for Starvation Survival. Cell Rep 2018; 20:627-640. [PMID: 28723566 DOI: 10.1016/j.celrep.2017.06.068] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 05/11/2017] [Accepted: 06/22/2017] [Indexed: 12/26/2022] Open
Abstract
Organisms must execute metabolic defenses to survive nutrient deprivation. We performed a genome-wide RNAi screen in Caenorhabditis elegans to identify fat regulatory genes indispensable for starvation resistance. Here, we show that opposing proteostasis pathways are principal determinants of starvation survival. Reduced function of cytoplasmic aminoacyl tRNA synthetases (ARS genes) increases fat mass and extends starvation survival, whereas reduced proteasomal function reduces fat and starvation survival. These opposing pathways converge on AMP-activated protein kinase (AMPK) as the critical effector of starvation defenses. Extended starvation survival in ARS deficiency is dependent upon increased proteasome-mediated activation of AMPK. When the proteasome is inhibited, neither starvation nor ARS deficiency can fully activate AMPK, leading to greatly diminished starvation survival. Thus, activity of the proteasome and AMPK are mechanistically linked and highly correlated with starvation resistance. Conversely, aberrant activation of the proteostasis-AMPK axis during nutritional excess may have implications for obesity and cardiometabolic diseases.
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Affiliation(s)
- Christopher M Webster
- Department of Medicine, Center for Genomic Medicine and Diabetes Unit, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Medicine, Harvard Medical School, Boston, MA 02114, USA
| | - Elizabeth C Pino
- Department of Medicine, Center for Genomic Medicine and Diabetes Unit, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Medicine, Harvard Medical School, Boston, MA 02114, USA
| | - Christopher E Carr
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Lianfeng Wu
- Department of Medicine, Center for Genomic Medicine and Diabetes Unit, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Medicine, Harvard Medical School, Boston, MA 02114, USA
| | - Ben Zhou
- Department of Medicine, Center for Genomic Medicine and Diabetes Unit, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Medicine, Harvard Medical School, Boston, MA 02114, USA
| | - Lucydalila Cedillo
- Department of Medicine, Center for Genomic Medicine and Diabetes Unit, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Medicine, Harvard Medical School, Boston, MA 02114, USA; Graduate Program in Biomedical and Biological Sciences, Harvard Medical School, Boston, MA 02115, USA
| | - Michael C Kacergis
- Department of Medicine, Center for Genomic Medicine and Diabetes Unit, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Medicine, Harvard Medical School, Boston, MA 02114, USA
| | - Sean P Curran
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089, USA
| | - Alexander A Soukas
- Department of Medicine, Center for Genomic Medicine and Diabetes Unit, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Medicine, Harvard Medical School, Boston, MA 02114, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
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