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Phenotypic and Transcriptomic Characterization of ElyC-Defective Escherichia coli Under Optimal and Stress-inducing Temperatures

ABSTRACT: The bacterial cell envelope is a primary defense mechanism, protecting cells from environmental and intrinsic stressors and ensuring homeostasis. Understanding the molecular pathways involved in envelope biology is critical for both basic and translational research. Peptidoglycan (PG), a key structural component of the envelope, protects bacteria from mechanical and osmotic stress, and maintains cell shape and integrity. We previously identified the Escherichia coli ElyC protein, which contains a conserved domain of unknown function, as essential for envelope integrity at low temperatures. ElyC is required for PG assembly at 21°C and for lipid carrier metabolism in the membrane-associated biosynthesis of PG and other envelope polysaccharides. In ElyC-defective cells at 21°C, PG assembly is blocked, leading to cell lysis. The physiological role of ElyC at 37°C remained unexplored. We performed phenotypic characterization and transcriptomic profiling of ΔelyC mutant cells grown at 37°C and 21°C, compared to wild-type cells. Although ΔelyC mutants grow similarly to wild-type cells at 37°C, they exhibit altered morphology. PG quantification revealed significant inhibition of PG biosynthesis in the absence of ElyC at 37°C. Moreover, these cells show increased sensitivity to PG-targeting β-lactam antibiotics. RNA-Seq analysis revealed that the loss of ElyC leads to a defective cellular envelope at 21°C, whereas at 37°C, the response is more moderate. While PG defects in ElyC-deficient cells are lethal at 21°C, these cells retain sufficient PG integrity at 37°C to survive. However, they are morphologically defective, under envelope stress, and more sensitive to antibiotics. Our findings highlight ElyC’s critical role in the metabolic regulation of PG biosynthesis at both optimal and suboptimal temperatures. These results underscore the importance of ElyC in maintaining cell envelope integrity and its potential as a target for antibiotic development.

ORGANISM(S): Escherichia coli

PROVIDER: GSE141694 | GEO | 2020/03/20

REPOSITORIES: GEO

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Phenotypic and Transcriptomic Characterization of ElyC-Defective Escherichia coli Under Optimal and Stress-inducing Temperatures

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