Redox-dependent Regulation of Gluconeogenesis by a Novel Mechanism Mediated by a Peroxidatic Cysteine of Peroxiredoxin

Abstract

Peroxiredoxin is an abundant peroxidase, but its non-peroxidase function is also important. In this study, we discovered that Tsa1, a major peroxiredoxin of budding yeast cells, is required for the efficient flux of gluconeogenesis. We found that the suppression of pyruvate kinase (Pyk1) via the interaction with Tsa1 contributes in part to gluconeogenic enhancement. The physical interactions between Pyk1 and Tsa1 were augmented during the shift from glycolysis to gluconeogenesis. Intriguingly, a peroxidatic cysteine in the catalytic center of Tsa1 played an important role in the physical Tsa1-Pyk1 interactions. These interactions are enhanced by exogenous H2O2 and by endogenous reactive oxygen species, which is increased during gluconeogenesis. Only the peroxidatic cysteine, but no other catalytic cysteine of Tsa1, is required for efficient growth during the metabolic shift to obtain maximum yeast growth (biomass). This Tsa1 function is separable from the peroxidase function as an antioxidant. This is the first report to demonstrate that peroxiredoxin has a novel nonperoxidase function as a redox-dependent target modulator and that pyruvate kinase is modulated via an alternative mechanism.

Cysteine as a Carbon Source, a Hot Spot in Cancer Cells Survival

“…Cysteine is a glucogenic AA, as it originates pyruvate, however, as far as I know, cysteine was not yet explored as a source of glucose in cancer. Nevertheless, in other biological models cysteine has been pointed out as an important regulator of enzymes, such as peroxidases that can interact with PK and block the conversion of pyruvate into acetyl-CoA, avoiding pyruvate entrance in TCA cycle or in FA synthesis ( 68 ) and favoring its deviation into gluconeogenesis, ensuring the cell needs of glucose.…”

Immature Core protein of hepatitis C virus induces an unfolded protein response through inhibition of ERAD‐L in a yeast model system

“…Yeast lysate was separated by series of centrifugation; the precipitate was separated by 13 000 g for 10 min (P13; the microsome fraction), and the supernatant (S13) was furthermore separated by centrifuge at 100 000 g for 1 hour to the precipitate (P100) and the supernatant (S100: the cytosolic fraction). Trypsin sensitivity and Western blotting was carried out as described previously (Iwasa et al 2016b) using specific antibodies for the Core proteins (515S) (Kashiwakuma et al 1996), Kar2 (BiP; Santa Cruz, y-115) and Pyk1 (Irokawa et al 2016).…”

Comprehensive analyses of the cysteine thiol oxidation of PKM2 reveals the effects of multiple oxidation on cellular oxidative stress response

“…This reaction is irreversible and represents the final step in glycolysis. In the yeast model system, inhibition of PK activity induces metabolic change under oxidative stress (21,22). In mammalians, there are four isoforms and two genes, with each isoform expressing in different tissues.…”