Cg Hog1-Mediated Cg Rds2 Phosphorylation Alters Glycerophospholipid Composition To Coordinate Osmotic Stress in Candida glabrata

Abstract

Under stress conditions, Hog1 is required for cell survival through transiently phosphorylating downstream targets and reprogramming gene expression. Here, we report that Candida glabrata Hog1 (CgHog1) interacts with and phosphorylates CgRds2, a zinc cluster transcription factor, in response to osmotic stress. Additionally, we found that deletion of CgRDS2 led to decreases in cell growth and cell survival by 23.4% and 39.6%, respectively, at 1.5 M NaCl, compared with levels of the wild-type strain. This is attributed to significant downregulation of the expression levels of glycerophospholipid metabolism genes. As a result, the content of total glycerophospholipid decreased by 30.3%. Membrane integrity also decreased 47.6% in the Cgrds2Δ strain at 1.5 M NaCl. In contrast, overexpression of CgRDS2 increased the cell growth and cell survival by 10.2% and 6.3%, respectively, owing to a significant increase in the total glycerophospholipid content and increased membrane integrity by 27.2% and 12.1%, respectively, at 1.5 M NaCl, compared with levels for the wild-type strain. However, a strain in which the CgRDS2 gene encodes the replacement of Ser64 and Thr97 residues with alanines (Cgrds22A), harboring a CgRds2 protein that was not phosphorylated by CgHog1, failed to promote glycerophospholipid metabolism and membrane integrity at 1.5 M NaCl. Thus, the above results demonstrate that CgHog1-mediated CgRds2 phosphorylation enhanced glycerophospholipid composition and membrane integrity to resist osmotic stress in C. glabrata. IMPORTANCE This study explored the role of CgHog1-mediated CgRds2 phosphorylation in response to osmotic stress in Candida glabrata. CgHog1 interacts with and phosphorylates CgRds2, a zinc cluster transcription factor, under osmotic stress. Phosphorylated CgRds2 plays an important role in increasing glycerophospholipid composition and membrane integrity, thereby enhancing cell growth and survival.

Engineering of membrane phospholipid component enhances salt stress tolerance in Saccharomyces cerevisiae

“…PssA overexpression increases PE zwitterionic phospholipid content (Tan et al, ). Other methods of regulating membrane lipids include transcription factors such as Rds2 and Crz1 (Wu et al, ; Yan et al, ) and mediators such as Med15B (Qi, Liu, Yu, Chen, & Liu, ), which are applied to manipulate gene transcription level. These approaches do not directly engineer cell membranes and are not strongly dependent on phospholipid pathways.…”

“…Many efforts to increase membrane integrity have been reported. They include changes in membrane lipid composition (Lima et al, ), regulation of transcription factors (Wu et al, ), and increased expression of multiple antibiotic resistance operons (Sharma et al, ). In this study, redistributed membrane phospholipid driven by the module assembly of cds1 and cho1 contributed to the increase in membrane potential and membrane integrity, which significantly enhanced salt stress tolerance.…”

“…The phospholipid extractions of harvested cells were carried out as described previously (Deranieh, Joshi, & Greenberg, 2013). Samples of phospholipids were analyzed by electrospray ionization mass spectrometry (Wu et al, 2019).…”

“…Other methods of regulating membrane lipids include transcription factors such as Rds2 and Crz1 (Wu et al, 2019;Yan et al, 2016) and mediators such as Med15B (Qi, Liu, Yu, Chen, & Liu, 2017), which are applied to manipulate gene transcription level.…”

Sml1 Inhibits the DNA Repair Activity of Rev1 in Saccharomyces cerevisiae during Oxidative Stress

“…Alkaline phosphatase treatment. The alkaline phosphatase treatment method was performed as in a previous study with a slight modification (51). Yeast cells were cultivated to the logarithmic phase, and total proteins were extracted.…”