PSK1 coordinates glucose metabolism and utilization and regulates energy‐metabolism oscillation in Saccharomyces cerevisiae

Abstract

Energy‐metabolism oscillations (EMO) are ultradian biological rhythms observed in in aerobic chemostat cultures of Saccharomyces cerevisiae. EMO regulates energy metabolism such as glucose, carbohydrate storage, O2 uptake, and CO2 production. PSK1 is a nutrient responsive protein kinase involved in regulation of glucose metabolism, sensory response to light, oxygen, and redox state. The aim of this investigation was to assess the function of PSK1 in regulation of EMO. The mRNA levels of PSK1 fluctuated in concert with EMO, and deletion of PSK1 resulted in unstable EMO with disappearance of the fluctuations and reduced amplitude, compared with the wild type. Furthermore, the mutant PSK1Δ showed downregulation of the synthesis and breakdown of glycogen with resultant decrease in glucose concentrations. The redox state represented by NADH also decreased in PSK1Δ compared with the wild type. These data suggest that PSK1 plays an important role in the regulation of energy metabolism and stabilizes ultradian biological rhythms. These results enhance our understanding of the mechanisms of biorhythms in the budding yeast.

Validation of Appropriate Reference Genes for qRT–PCR Normalization in Oat (Avena sativa L.) under UV-B and High-Light Stresses

“…PSK is a novel plant peptide growth regulator discovered in recent years that has a very wide range of biological activities and effects. It has been reported that PSK genes promote cell division, cell differentiation, and somatic cell formation, coordinate the metabolism and utilization of glucose, help resist oxidative stress, increase chlorophyll contents, improve salt tolerance and high-temperature tolerance of Arabidopsis, and promote the development of pear pollen tubes, and these genes are considered chemical caretakers of plant cell development processes [ 38 , 39 , 40 ]. A combined analysis of all the samples in the current study indicated that PSKS1 was the most stably expressed candidate reference gene and that VBP was the least stably expressed candidate reference gene.…”