scholarly journals Role of the DksA-Like Protein in the Pathogenesis and Diverse Metabolic Activity of Campylobacter jejuni

2008 ◽  
Vol 190 (13) ◽  
pp. 4512-4520 ◽  
Author(s):  
Jiae Yun ◽  
Byeonghwa Jeon ◽  
Yi-Wen Barton ◽  
Paul Plummer ◽  
Qijing Zhang ◽  
...  
Keyword(s):  
Amino Acid ◽  
Campylobacter Jejuni ◽  
Pathogenic Bacteria ◽  
Acid Metabolism ◽  
Acid Synthesis ◽  
Regulatory Role ◽  
Intestinal Cells ◽  
Amino Acid Synthesis ◽  
Metabolic Reactions

ABSTRACT DksA is well known for its regulatory role in the transcription of rRNA and genes involved in amino acid synthesis in many bacteria. DksA has also been reported to control expression of virulence genes in pathogenic bacteria. Here, we elucidated the roles of a DksA-like protein (CJJ81176_0160, Cj0125c) in the pathogenesis of Campylobacter jejuni. As in other bacteria, transcription of stable RNA was repressed by the DksA-like protein under stress conditions in C. jejuni. Transcriptomic and proteomic analyses of C. jejuni 81-176 and an isogenic mutant lacking the DksA-like protein showed differential expression of many genes involved in amino acid metabolism, iron-related metabolism, and other metabolic reactions. Also, the C. jejuni DksA-like protein mutant exhibited a decreased ability to invade intestinal cells and induce release of interleukin-8 from intestinal cells. These results suggest that the DksA-like protein plays an important regulatory role in diverse metabolic events and the virulence of C. jejuni.

Role of O-acetylhomoserine sulfhydrylase in sulfur amino acid synthesis in various yeasts

Yeast ◽  
1993 ◽  
Vol 9 (12) ◽  
pp. 1335-1342 ◽  
Author(s):  
Jerzy Brzywczy ◽  
Andrzej Paszewski
Keyword(s):  
Amino Acid ◽  
Acid Synthesis ◽  
Sulfur Amino Acid ◽  
Amino Acid Synthesis

scholarly journals Effect of IGF-I on serine metabolism in fetal sheep

2000 ◽  
Vol 165 (2) ◽  
pp. 261-269 ◽  
Author(s):  
EC Jensen ◽  
P van Zijl ◽  
PC Evans ◽  
JE Harding
Keyword(s):  
Amino Acid ◽  
Amino Acid Metabolism ◽  
Acid Metabolism ◽  
Amino Acid Uptake ◽  
Acid Synthesis ◽  
Acid Oxidation ◽  
Acid Uptake ◽  
Amino Acid Synthesis ◽  
Fetal Sheep ◽  
Igf I

Acute infusion of IGF-I to the fetus has been shown to inhibit amino acid oxidation and appears to increase fetoplacental amino acid uptake. This study was designed to investigate further the effects of IGF-I on fetal amino acid metabolism. Radiolabeled serine was used to test the hypothesis that fetal IGF-I infusion enhances serine uptake into the fetus and/or placenta and inhibits serine oxidation. Eight fetal sheep were studied at 127 days of gestation before and during a 4-h infusion of IGF-I (50 microg/h per kg). During the infusion there was no change in uptake of serine or its oxidation by fetus or placenta. However, both uptake and oxidation of serine and glycine decreased in the fetal carcass. There was also a decrease in fetal blood serine and glycine concentrations which could indicate a decrease in protein breakdown, although reduced amino acid synthesis cannot be excluded. Thus IGF-I appeared to influence the distribution of these amino acids as oxidative substrates between different fetal tissues. In addition, fetal IGF-I infusion increased the conversion of serine to glycine which is likely to have increased the availability of one-carbon groups for biosynthesis. Our data provide further evidence that IGF-I plays a role in the regulation of fetoplacental amino acid metabolism.

scholarly journals The Role of the Tricarboxylic Acid Cycle in Amino Acid Synthesis in Escherichia Coli

1953 ◽  
Vol 39 (10) ◽  
pp. 1013-1019 ◽  
Author(s):  
R. B. Roberts ◽  
D. B. Cowie ◽  
R. Britten ◽  
E. Bolton ◽  
P. H. Abelson
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Tricarboxylic Acid Cycle ◽  
Acid Synthesis ◽  
Tricarboxylic Acid ◽  
Amino Acid Synthesis ◽  
Acid Cycle

Roles and regulation of the glutamate racemase isogenes, racE and yrpC, in Bacillus subtilis

Microbiology ◽  
2004 ◽  
Vol 150 (9) ◽  
pp. 2911-2920 ◽  
Author(s):  
Keitarou Kimura ◽  
Lam-Son Phan Tran ◽  
Yoshifumi Itoh
Keyword(s):  
Bacillus Subtilis ◽  
Amino Acid ◽  
Minimal Medium ◽  
Degradation Products ◽  
Acid Synthesis ◽  
Rich Medium ◽  
Amino Acid Synthesis ◽  
Double Mutation ◽  
Glutamate Racemase

Many bacteria, including Escherichia coli, have a unique gene that encodes glutamate racemase. This enzyme catalyses the formation of d-glutamate, which is necessary for cell wall peptidoglycan synthesis. However, Bacillus subtilis has two glutamate racemase genes, named racE and yrpC. Since racE appears to be indispensable for growth in rich medium, the role of yrpC in d-amino acid synthesis is vague. Experiments with racE- and yrpC-knockout mutants confirmed that racE is essential for growth in rich medium but showed that this gene was dispensable for growth in minimal medium, where yrpC executes the anaplerotic role of racE. LacZ fusion assays demonstrated that racE was expressed in both types of media but yrpC was expressed only in minimal medium, which accounted for the absence of yrpC function in rich medium. Neither racE nor yrpC was required for B. subtilis cells to synthesize poly-γ-dl-glutamate (γ-PGA), a capsule polypeptide of d- and l-glutamate linked through a γ-carboxylamide bond. Wild-type cells degraded the capsule during the late stationary phase without accumulating the degradation products, d-glutamate and l-glutamate, in the medium. In contrast, racE or yrpC mutant cells accumulated significant amounts of d- but not l-glutamate. Exogenous d-glutamate utilization was somewhat defective in the mutants and the double mutation of race and yrpc severely impaired d-amino acid utilization. Thus, both racemase genes appear necessary to complete the catabolism of exogenous d-glutamate generated from γ-PGA.

scholarly journals Petasis vs. Strecker Amino Acid Synthesis: Convergence, Divergence and Opportunities in Organic Synthesis

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1707
Author(s):  
Wayiza Masamba
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Organic Synthesis ◽  
Acid Synthesis ◽  
Physical Sciences ◽  
Amino Acid Synthesis

α-Amino acids find widespread applications in various areas of life and physical sciences. Their syntheses are carried out by a multitude of protocols, of which Petasis and Strecker reactions have emerged as the most straightforward and most widely used. Both reactions are three-component reactions using the same starting materials, except the nucleophilic species. The differences and similarities between these two important reactions are highlighted in this review.

scholarly journals Identification and characterization of early Fusarium wilt responsive mRNAs and long non-coding RNAs in banana root using high-throughput sequencing

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chunzhen Cheng ◽  
Fan Liu ◽  
Na Tian ◽  
Raphael Anue Mensah ◽  
Xueli Sun ◽  
...  
Keyword(s):  
Fusarium Wilt ◽  
Acid Metabolism ◽  
Function Analysis ◽  
Regulatory Role ◽  
Novel Genes ◽  
Root Transcriptome ◽  
Qrt Pcr ◽  
Non Coding Rnas ◽  
Infection Stage

AbstractFusarium wilt disease, caused by Fusarium oxysporum f.sp. cubense (Foc), has been recognized as the most devastating disease to banana. The regulatory role of long non-coding RNAs (lncRNAs) in plant defense has been verified in many plant species. However, the understanding of their role during early FocTR4 (Foc tropical race 4) infection stage is very limited. In this study, lncRNA sequencing was used to reveal banana root transcriptome profile changes during early FocTR4 infection stages. Quantitative real time PCR (qRT-PCR) was performed to confirm the expression of eight differentially expressed (DE) lncRNAs (DELs) and their predicted target genes (DETs), and three DE genes (DEGs). Totally, 12,109 lncRNAs, 36,519 mRNAs and 2642 novel genes were obtained, of which 1398 (including 78 DELs, 1220 DE known genes and 100 DE novel genes) were identified as FocTR4 responsive DE transcripts. Gene function analysis revealed that most DEGs were involved in biosynthesis of secondary metabolites, plant–pathogen interaction, plant hormone signal transduction, phenylalanine metabolism, phenylpropanoid biosynthesis, alpha-linolenic acid metabolism and so on. Coincidently, many DETs have been identified as DEGs in previous transcriptome studies. Moreover, many DETs were found to be involved in ribosome, oxidative phosphorylation, lipoic acid metabolism, ubiquitin mediated proteolysis, N-glycan biosynthesis, protein processing in endoplasmic reticulum and DNA damage response pathways. QRT-PCR result showed the expression patterns of the selected transcripts were mostly consistent with our lncRNA sequencing data. Our present study showed the regulatory role of lncRNAs on known biotic and abiotic stress responsive genes and some new-found FocTR4 responsive genes, which can provide new insights into FocTR4-induced changes in the banana root transcriptome during the early pathogen infection stage.

scholarly journals Enzymatic cascade systems for D-amino acid synthesis: progress and perspectives

2021 ◽  
Author(s):  
Anwen Fan ◽  
Jiarui Li ◽  
Yangqing Yu ◽  
Danping Zhang ◽  
Yao Nie ◽  
...  
Keyword(s):  
Amino Acid ◽  
Acid Synthesis ◽  
Amino Acid Synthesis ◽  
Cascade Systems
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