Interplays of AMPK and TOR in Autophagy Regulation in Yeast

Abstract

Cells survey their environment and need to balance growth and anabolism with stress programmes and catabolism towards maximum cellular bioenergetics economy and survival. Nutrient-responsive pathways, such as the mechanistic target of rapamycin (mTOR) interact and cross-talk, continuously, with stress-responsive hubs such as the AMP-activated protein kinase (AMPK) to regulate fundamental cellular processes such as transcription, protein translation, lipid and carbohydrate homeostasis. Especially in nutrient stresses or deprivations, cells tune their metabolism accordingly and, crucially, recycle materials through autophagy mechanisms. It has now become apparent that autophagy is pivotal in lifespan, health and cell survival as it is a gatekeeper of clearing damaged macromolecules and organelles and serving as quality assurance mechanism within cells. Autophagy is hard-wired with energy and nutrient levels as well as with damage-response, and yeasts have been instrumental in elucidating such connectivities. In this review, we briefly outline cross-talks and feedback loops that link growth and stress, mainly, in the fission yeast Schizosaccharomyces pombe, a favourite model in cell and molecular biology.

Shikonin promotes hypertrophic scar repair by autophagy of hypertrophic scar-derived fibroblasts

“…Some reports suggested that the AMPK/mTOR signaling pathway was implicated in the regulation of autophagy 33 , 34 . Under stress conditions such as energy starvation, AMPK is activated as a sensor of energy molecules to regulate autophagy 35 and is a positive regulator of autophagy that actively regulates autophagy by inhibiting mTOR activity 36 . The mTOR is a negative regulator of autophagy that inhibits autophagy by phosphorylating ULK1 to maintain it in an inactive state 37 .…”

Advances in the study of autophagy in breast cancer

“…The occurrence of cellular autophagy can be divided into four distinct stages: autophagic vesicle precursor formation, auto phagosome membrane formation and extension, lysosome closure and fusion, and intracapsular degradation [ 14 ]. While the majority of our understanding of autophagy has been gleaned from studies in yeast, where approximately 30 autophagy-related genes have been identified, it is important to note that the autophagic process involves a complex interplay of signaling molecules and pathways [ 15 ].…”

ecl family genes: Factors linking starvation and lifespan extension in Schizosaccharomyces pombe

“…The regulation of TORC1 signaling pathway is involved in lifespan extension in various species, such as yeast, nematode, fly, and mammals (Bjedov & Rallis, 2020; Fontana et al, 2010; Santos et al, 2016). Similar to other organisms, in fission yeast, the inhibition of TORC1 results in lifespan extension, and it is thought that decreased translation level, increased translational fidelity, and induction of autophagy are involved in the longevity mechanism (Alao et al, 2023; Martinez‐Miguel et al, 2021; Rodríguez‐López et al, 2020). Additionally, some phenotypes of the TORC1 inhibition, including CLS extension and sexual differentiation, are observed during the overexpression of Ecl family genes (Ohtsuka, Imada, et al, 2022; Ohtsuka et al, 2021a; Otsubo et al, 2017).…”