The Impact of ackA, pta, and ackA-pta Mutations on Growth, Gene Expression and Protein Acetylation in Escherichia coli K-12

Heart disease is the number one cause of death in developed countries. Metabolic diseases influence the severity of heart disease linked to risk factors which are thought to alter epigenetic mechanisms. Pyruvate dehydrogenase (PDH) kinases (PDK), which phosphorylate and reduce the activity of PDH the nexus of glucose oxidation and fatty acid oxidation are sensitive to metabolic status. Four isozymes of PDK (PDK1-4) exist with PDK2 and PDK4 as the major regulators in cardiac tissue. Owing to the role of PDH in regulating pyruvate to acetyl-CoA, we hypothesized that PDK inhibition may regulate protein acetylation through increasing acetyl-CoA because of PDH activation leading to post-translational modifications both directly to proteins in metabolic pathways as well as to histones associated with the genes encoding them. To test this, we utilized PDK2 germline knockout mice (P2KO), PDK4 germline knockout mice (P4KO), and PDK2 and PDK4 double knockout (DKO) mice for molecular analysis. Our results identify a novel increase in whole-cell protein acetylation in P2KO left ventricle tissue (LV). However, protein acetylation in P4KO LV was not changed compared to WT mice. The most robust protein acetylation was observed in the DKO LV. Furthermore, when we explored sub-cellular distribution of protein acetylation, the greatest increases were found on cytoplasmic proteins, with moderate changes in mitochondrial proteins. We also found PDK2 ablation induces histone H3 acetylation, which may also lead to changes in gene expression. Moreover, this protein acetylation in P2KO and DKO was not seen in other tissues examined (e.g., liver, skeletal muscle). The hyperacetylation is robust in male LV compared to female LV. In conclusion, our study supports a novel protein acetylation mechanism that is both tissue and PDK isozyme specific highlighting the role of PDK2, which is relatively understudied compared to PDK4 in heart disease. Further study will evaluate if the hyperacetylation has a beneficial effect in various heart disease settings as well as identify the impact on changes in gene expression. This study supports PDK isozyme-specific inhibition strategies will be required to develop therapeutic targets of cardiovascular disease with metabolic inflexibility.

Download Full-text

Role of the purine repressor in the regulation of pyrimidine gene expression in Escherichia coli K-12.

Journal of Bacteriology ◽

10.1128/jb.172.6.3208-3213.1990 ◽

1990 ◽

Vol 172 (6) ◽

pp. 3208-3213 ◽

Cited By ~ 20

Author(s):

H R Wilson ◽

C L Turnbough

Keyword(s):

Gene Expression ◽

Escherichia Coli ◽

Expression In Escherichia Coli ◽

K 12

Download Full-text

Global gene expression analysis of Escherichia coli K-12 DH5α after exposure to 2.4 GHz wireless fidelity radiation

Scientific Reports ◽

10.1038/s41598-019-51046-7 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 2

Author(s):

Ilham H. Said-Salman ◽

Fatima A. Jebaii ◽

Hoda H. Yusef ◽

Mohamed E. Moustafa

Keyword(s):

Gene Expression ◽

Escherichia Coli ◽

Cell Adhesion ◽

Metabolic Pathways ◽

Enrichment Analysis ◽

Global Gene Expression ◽

Enrichment Score ◽

Pcr Analysis ◽

Radiofrequency Radiation ◽

K 12

Abstract This study investigated the non-thermal effects of Wi-Fi radiofrequency radiation of 2.4 GHz on global gene expression in Escherichia coli K-12 DH5α. High-throughput RNA-sequencing of 2.4 GHz exposed and non-exposed bacteria revealed that 101 genes were differentially expressed (DEGs) at P ≤ 0.05. The up-regulated genes were 52 while the down-regulated ones were 49. QRT-PCR analysis of pgaD, fliC, cheY, malP, malZ, motB, alsC, alsK, appB and appX confirmed the RNA-seq results. About 7% of DEGs are involved in cellular component organization, 6% in response to stress stimulus, 6% in biological regulation, 6% in localization, 5% in locomotion and 3% in cell adhesion. Database for annotation, visualization and integrated discovery (DAVID) functional clustering revealed that DEGs with high enrichment score included genes for localization of cell, locomotion, chemotaxis, response to external stimulus and cell adhesion. Kyoto encyclopedia of genes and genomes (KEGG) pathways analysis showed that the pathways for flagellar assembly, chemotaxis and two-component system were affected. Go enrichment analysis indicated that the up-regulated DEGs are involved in metabolic pathways, transposition, response to stimuli, motility, chemotaxis and cell adhesion. The down-regulated DEGs are associated with metabolic pathways and localization of ions and organic molecules. Therefore, the exposure of E. coli DH5α to Wi-Fi radiofrequency radiation for 5 hours influenced several bacterial cellular and metabolic processes.

Download Full-text

Nitrate regulation of anaerobic respiratory gene expression in narX deletion mutants of Escherichia coli K-12.

Journal of Bacteriology ◽

10.1128/jb.172.9.5020-5029.1990 ◽

1990 ◽

Vol 172 (9) ◽

pp. 5020-5029 ◽

Cited By ~ 20

Author(s):

S M Egan ◽

V Stewart

Keyword(s):

Gene Expression ◽

Escherichia Coli ◽

Deletion Mutants ◽

K 12

Download Full-text

Role of Escherichia coli O157:H7 Virulence Factors in Colonization at the Bovine Terminal Rectal Mucosa

Infection and Immunity ◽

10.1128/iai.00406-06 ◽

2006 ◽

Vol 74 (8) ◽

pp. 4685-4693 ◽

Cited By ~ 87

Author(s):

Haiqing Sheng ◽

Ji Youn Lim ◽

Hannah J. Knecht ◽

Jie Li ◽

Carolyn J. Hovde

Keyword(s):

Escherichia Coli ◽

Virulence Factors ◽

Clinical Manifestations ◽

Rectal Mucosa ◽

Wild Type ◽

E Coli ◽

Healthy Cattle ◽

Life Threatening ◽

K 12 ◽

The Impact

ABSTRACT The human pathogen Escherichia coli O157:H7 causes hemorrhagic colitis and life-threatening sequelae and transiently colonizes healthy cattle at the terminal rectal mucosa. This study analyzed virulence factors important for the clinical manifestations of human E. coli O157:H7 infection for their contribution to the persistence of E. coli in cattle. The colonizing ability of E. coli O157:H7 was compared with those of nonpathogenic E. coli K-12 and isogenic deletion mutants missing Shiga toxin (Stx), the adhesin intimin, its receptor Tir, hemolysin, or the ∼92-kb pO157. Fully ruminant steers received a single rectal application of one E. coli strain so that effects of mucosal attachment and survival at the terminal rectum could be measured without the impact of bacterial passage through the entire gastrointestinal tract. Colonization was monitored by sensitive recto-anal junction mucosal swab culture. Nonpathogenic E. coli K-12 did not colonize as well as E. coli O157:H7 at the bovine terminal rectal mucosa. The E. coli O157:H7 best able to persist had intimin, Tir, and the pO157. Strains missing even one of these factors were recovered in lower numbers and were cleared faster than the wild type. In contrast, E. coli O157:H7 strains that were missing Stx or hemolysin colonized like the wild type. For these three strains, the number of bacteria increased between days 1 and 4 postapplication and then decreased slowly. In contrast, the numbers of noncolonizing strains (K-12, Δtir, and Δeae) decreased from the day of application. These patterns consistently predicted long-term colonization or clearance of the bacteria from the bovine terminal rectal mucosa.

Download Full-text