How do yeast sense mitochondrial dysfunction?

Abstract

Apart from energy transformation, mitochondria play important signaling roles. In yeast, mitochondrial signaling relies on several molecular cascades. However, it is not clear how a cell detects a particular mitochondrial malfunction. The problem is that there are many possible manifestations of mitochondrial dysfunction. For example, exposure to the specific antibiotics can either decrease (inhibitors of respiratory chain) or increase (inhibitors of ATP-synthase) mitochondrial transmembrane potential. Moreover, even in the absence of the dysfunctions, a cell needs feedback from mitochondria to coordinate mitochondrial biogenesis and/or removal by mitophagy during the division cycle. To cope with the complexity, only a limited set of compounds is monitored by yeast cells to estimate mitochondrial functionality. The known examples of such compounds are ATP, reactive oxygen species, intermediates of amino acids synthesis, short peptides, Fe-S clusters and heme, and also the precursor proteins which fail to be imported by mitochondria. On one hand, the levels of these molecules depend not only on mitochondria. On the other hand, these substances are recognized by the cytosolic sensors which transmit the signals to the nucleus leading to general, as opposed to mitochondria-specific, transcriptional response. Therefore, we argue that both ways of mitochondria-to-nucleus communication in yeast are mostly (if not completely) unspecific, are mediated by the cytosolic signaling machinery and strongly depend on cellular metabolic state.

Alkylimidazolium Ionic Liquids as Antifungal Alternatives: Antibiofilm Activity Against Candida albicans and Underlying Mechanism of Action

“…Generation and accumulation of intracellular ROS was prominent in C. albicans 10231 cells treated with [C 16 MIM][Cl] (Figure 7). In yeasts, ROS are majorly produced in the mitochondria (Knorre et al, 2016). High ROS levels are detrimental as they cause oxidative damage to intracellular molecules and cell membrane lipids .…”

“…High ROS levels are detrimental as they cause oxidative damage to intracellular molecules and cell membrane lipids . Interestingly, ROS production is one of the mechanisms by which yeast cells senses mitochondrial dysfunction (Knorre et al, 2016). The mitochondrial dysfunction in C. albicans 10231 cells was assessed by ψ m and dehydrogenases activity.…”

Insights into the respiratory chain and oxidative stress

“…Consequently, a Cys–SOH chaperone, Ybp1, brings together Orp1 and Yap1 into a ternary complex that selectively activates condensation of the Orp1 to provide specificity in the transfer of oxidising equivalents by a reactive sulphenic acid species [ 105 ]. In yeast, respiratory complex III deficiencies could then be compensated by a ROS modulation of the Yap1 signalling process [ 106 ].…”

Cellular mechanism for the improvement of multiple stress tolerance in brewer's yeast by potassium ion supplementation

“…The maximum ATP content of yeast in the hyperosmotic medium with 4 g L −1 KCl addition occurred at metaphase, with 168.45% of control, while with 10% (v v −1 ) ethanol present, 10 g L −1 KCl addition led to the maximum ATP content, with 201.64% of control. The result indicated that KCl supplementation could promote ATP synthesis and then improve functionality of mitochondrial, which could enable the cells to resist stress from hyperosmotic or ethanol stress (Knorre et al , ). It also should be noted that 4 or 10 g L −1 KCl, rather than a higher concentration, exhibited the best promotion activity, which probably because that KCl could not absorb into cells completely (Casey et al , ).…”