Enhanced multi-stress tolerance and glucose utilization of Saccharomyces cerevisiae by overexpression of the SNF1 gene and varied beta isoform of Snf1 dominates in stresses

Lu Meng,Hui-Ling Liu,Kun-Ru Teng,Xue Lin,Xiao-Ping Hu,Si-Xin Liu

doi:10.1186/s12934-020-01391-4

Abstract

BackgroundThe Saccharomyces cerevisiae Snf1 complex is a member of the AMP-activated protein kinase family and plays an important role in response to environmental stress. The α catalytic subunit Snf1 regulates the activity of the protein kinase, while the β regulatory subunits Sip1/Sip2/Gal83 specify substrate preferences and stress response capacities of Snf1. In this study, we aim to investigate the effects of SNF1 overexpression on the cell tolerance and glucose consumption of S. cerevisiae in high glucose, ethanol, and heat stresses and to explore the valid Snf1 form in the light of β subunits in these stresses.ResultsThe results suggest that overexpression of SNF1 is effective to improve cell resistance and glucose consumption of S. cerevisiae in high glucose, ethanol, and heat stresses, which might be related to the changed accumulation of fatty acids and amino acids and altered expression levels of genes involved in glucose transport and glycolysis. However, different form of β regulatory subunits dominated in stresses with regard to cell tolerance and glucose utilization. The Sip1 isoform was more necessary to the growth and glucose consumption in ethanol stress. The glucose uptake largely depended on the Sip2 isoform in high sugar and ethanol stresses. The Gal83 isoform only contributed inferior effect on the growth in ethanol stress. Therefore, redundancy and synergistic effect of β subunits might occur in high glucose, ethanol, and heat stresses, but each subunit showed specificity under various stresses.ConclusionsThis study enriches the understanding of the function of Snf1 protein kinase and provides an insight to breed multi-stress tolerant yeast strains.

Highlights

The Saccharomyces cerevisiae Snf1 complex is a member of the AMP-activated protein kinase family and plays an important role in response to environmental stress
Growth property To investigate the influence of SNF1/SIP1/SIP2/GAL83 overexpression on the general growth property of S. cerevisiae, the growth curves of the strains were measured in Yeast extract peptone dextrose (YEPD) medium (Fig. 1)
The transformant α + K, which was used as a blank control to demonstrate any possible effects of an empty vector showed similar results to the parental strain. These findings demonstrate that overexpression of SNF1 did not influence the growth property of the S. cerevisiae strain used in the present study in a standard glucose growth condition (2% glucose), but any of the Snf1 complex dominated by only one β isoform served as a negative contributor

Summary

Introduction

The Saccharomyces cerevisiae Snf complex is a member of the AMP-activated protein kinase family and plays an important role in response to environmental stress. The α catalytic subunit Snf regulates the activity of the protein kinase, while the β regulatory subunits Sip1/Sip2/Gal specify substrate preferences and stress response capacities of Snf. The S. cerevisiae Snf complex is a member of the AMP-activated protein kinase family and plays a critical role in a series of cellular activities, such as meiosis, aging, autophagy, and the responses to the limited glucose, nitrogen, and other environmental stresses [5, 6]. The β subunits, which are required for the assemblage and intracellular localization of the protein kinase complex specify substrate preferences and stress response abilities of Snf1 [5, 10]

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