AMPK and vacuole-associated Atg14p orchestrate μ-lipophagy for energy production and long-term survival under glucose starvation

Autor: Arnold Y Seo, Pick-Wei Lau, Daniel Feliciano, Prabuddha Sengupta, Mark A Le Gros, Bertrand Cinquin, Carolyn A Larabell, Jennifer Lippincott-Schwartz
Jazyk: angličtina
Rok vydání: 2017
Předmět:
Zdroj: eLife, Vol 6 (2017)
Druh dokumentu: article
ISSN: 2050-084X
DOI: 10.7554/eLife.21690
Popis: Dietary restriction increases the longevity of many organisms, but the cell signaling and organellar mechanisms underlying this capability are unclear. We demonstrate that to permit long-term survival in response to sudden glucose depletion, yeast cells activate lipid-droplet (LD) consumption through micro-lipophagy (µ-lipophagy), in which fat is metabolized as an alternative energy source. AMP-activated protein kinase (AMPK) activation triggered this pathway, which required Atg14p. More gradual glucose starvation, amino acid deprivation or rapamycin did not trigger µ-lipophagy and failed to provide the needed substitute energy source for long-term survival. During acute glucose restriction, activated AMPK was stabilized from degradation and interacted with Atg14p. This prompted Atg14p redistribution from ER exit sites onto liquid-ordered vacuole membrane domains, initiating µ-lipophagy. Our findings that activated AMPK and Atg14p are required to orchestrate µ-lipophagy for energy production in starved cells is relevant for studies on aging and evolutionary survival strategies of different organisms.
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