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Nutrients including glucose, nitrogen, sulfur, zinc, and iron are involved in the regulation of chronological lifespan (CLS) of yeast, which serves as a model of the lifespan of differentiated cells of higher organisms. Herein, we show that magnesium (Mg 2+ ) depletion extends CLS of the fission yeast Schizosaccharomyces pombe through a mechanism involving the Ecl1 gene family. We discovered that ecl1 + expression, which extends CLS, responds to Mg 2+ depletion. Therefore, we investigated the underlying intracellular responses. In amino acid auxotrophic strains, Mg 2+ depletion robustly induces ecl1 + expression through the activation of the general amino acid control (GAAC) pathway-the equivalent of the amino acid response of mammals. Polysome analysis indicated that the expression of Ecl1 family genes was required for regulating ribosome amount when cells were starved, suggesting that Ecl1 family gene products control the abundance of ribosomes, which contributes to longevity through the activation of the evolutionarily conserved GAAC pathway. The present study extends our understanding of the cellular response to Mg 2+ depletion and its influence on the mechanism controlling longevity., (© 2021 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.) more...

The ε subunit of F o F 1 -ATPase/synthase (F o F 1 ) plays a crucial role in regulating F obscript> F 1 activity. To understand the physiological significance of the ε subunit-mediated regulation of F o F 1 in Bacillus subtilis, we constructed and characterized a mutant harboring a deletion in the C-terminal regulatory domain of the ε subunit (ε ∆C ). Analyses using inverted membrane vesicles revealed that the ε ∆C mutation decreased ATPase activity and the ATP-dependent H + -pumping activity of F o F 1 . To enhance the effects of ε ∆C mutation, this mutation was introduced into a ∆rrn8 strain harboring only two of the 10 rrn (rRNA) operons (∆rrn8 ε ∆C mutant strain). Interestingly, growth of the ∆rrn8 ε ∆C mutant stalled at late-exponential phase. During the stalled growth phase, the membrane potential of the ∆rrn8 ε ∆C mutant cells was significantly reduced, which led to a decrease in the cellular level of 70S ribosomes. The growth stalling was suppressed by adding glucose into the culture medium. Our findings suggest that the C-terminal region of the ε subunit is important for alleviating the temporal reduction in the membrane potential, by enhancing the ATP-dependent H + -pumping activity of F o F 1 ., (© 2019 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.) more...