“…All three are up‐regulated at protein level and down‐regulated at mRNA level. A similar tendency was observed for MetB (cystathionine γ‐synthase), MetE (homocysteine methyltransferase), and MetY (O‐acetylhomoserine‐thiol lyase), which are involved in methionine synthesis 58. MetB forms the intermediate cystathionine 59, 60, MetY subsequently the interstage homocysteine 61, and MetE finally forms methionine 32.…”
Section: Discussionsupporting
confidence: 63%
“…3C). CysI (ferredoxin‐sulfite reductase), CysJ (also Fpr2: Ferredoxin‐NADP + reductase), and CysK (O‐acetylserine‐thiol lyase) are enzymes involved in cysteine synthesis 57, whereby CysI and CysJ are responsible for sulphur reduction and CysK for the final synthesis step of L ‐cysteine 58. All three are up‐regulated at protein level and down‐regulated at mRNA level.…”
Corynebacterium glutamicum is one of the biotechnologically most important microorganisms because of its ability to enrich amino acids extracellularly. Hence, C. glutamicum requires effective adaptation strategies against both hypo- and hyperosmotic stress. We give a comprehensive and coherent outline about the quantitative dynamics of C. glutamicum during adaptation to hyperosmotic stress at the transcript and protein levels. The osmolyte carrier ProP, playing a pivotal role in hyperosmotic stress defence, exhibits the strongest up-regulation of all proteins. A conspicuously regulated group comprises proteins involved in lipid biosynthesis of the cell envelope. This is in accordance with our observation of a more viscous and stickier cell envelope, which is supported by the findings of an altered lipid composition. Together with our results, showing that several transporters were down-regulated, this membrane adaptation appears to be one of C. glutamicum's major protection strategies against hyperosmotic stress. In addition, we demonstrate that no oxidative stress and no iron limitation occur during salt stress contrary to former postulations. Ultimately, it is remarkable that various proteins with divergent mRNA-protein dynamics and regulation have been observed. This leads to the assumption that there are still unknown mechanisms in between the bacterial transcription, translation and post-translation and that these are waiting to be unravelled.
“…All three are up‐regulated at protein level and down‐regulated at mRNA level. A similar tendency was observed for MetB (cystathionine γ‐synthase), MetE (homocysteine methyltransferase), and MetY (O‐acetylhomoserine‐thiol lyase), which are involved in methionine synthesis 58. MetB forms the intermediate cystathionine 59, 60, MetY subsequently the interstage homocysteine 61, and MetE finally forms methionine 32.…”
Section: Discussionsupporting
confidence: 63%
“…3C). CysI (ferredoxin‐sulfite reductase), CysJ (also Fpr2: Ferredoxin‐NADP + reductase), and CysK (O‐acetylserine‐thiol lyase) are enzymes involved in cysteine synthesis 57, whereby CysI and CysJ are responsible for sulphur reduction and CysK for the final synthesis step of L ‐cysteine 58. All three are up‐regulated at protein level and down‐regulated at mRNA level.…”
Corynebacterium glutamicum is one of the biotechnologically most important microorganisms because of its ability to enrich amino acids extracellularly. Hence, C. glutamicum requires effective adaptation strategies against both hypo- and hyperosmotic stress. We give a comprehensive and coherent outline about the quantitative dynamics of C. glutamicum during adaptation to hyperosmotic stress at the transcript and protein levels. The osmolyte carrier ProP, playing a pivotal role in hyperosmotic stress defence, exhibits the strongest up-regulation of all proteins. A conspicuously regulated group comprises proteins involved in lipid biosynthesis of the cell envelope. This is in accordance with our observation of a more viscous and stickier cell envelope, which is supported by the findings of an altered lipid composition. Together with our results, showing that several transporters were down-regulated, this membrane adaptation appears to be one of C. glutamicum's major protection strategies against hyperosmotic stress. In addition, we demonstrate that no oxidative stress and no iron limitation occur during salt stress contrary to former postulations. Ultimately, it is remarkable that various proteins with divergent mRNA-protein dynamics and regulation have been observed. This leads to the assumption that there are still unknown mechanisms in between the bacterial transcription, translation and post-translation and that these are waiting to be unravelled.
“…CAS activity was measured with cysteine as substrate while CYS activity was measured with O -acetylserine as substrate. Data for the plants A. thaliana and G. max were obtained in Yamaguchi et al (2000) and Yi et al (2012), respectively, while data for the bacteria C. glutamaticum and L. casei were retrieved from Wada et al (2004) and Bogicevic et al (2012), respectively.10.7554/eLife.02365.012Figure 7.Panel A: Formation and accumulation of β-cyanoalanine by recombinant Tu-CAS as visualized by TLC analysis.Controls; C1: no cysteine control, C2: no cyanide control, C3: no enzyme control. Time course 0–60 min after adding 3.75 µg of recombinant Tu-CAS.…”
Cyanogenic glucosides are among the most widespread defense chemicals of plants. Upon plant tissue disruption, these glucosides are hydrolyzed to a reactive hydroxynitrile that releases toxic hydrogen cyanide (HCN). Yet many mite and lepidopteran species can thrive on plants defended by cyanogenic glucosides. The nature of the enzyme known to detoxify HCN to β-cyanoalanine in arthropods has remained enigmatic. Here we identify this enzyme by transcriptome analysis and functional expression. Phylogenetic analysis showed that the gene is a member of the cysteine synthase family horizontally transferred from bacteria to phytophagous mites and Lepidoptera. The recombinant mite enzyme had both β-cyanoalanine synthase and cysteine synthase activity but enzyme kinetics showed that cyanide detoxification activity was strongly favored. Our results therefore suggest that an ancient horizontal transfer of a gene originally involved in sulfur amino acid biosynthesis in bacteria was co-opted by herbivorous arthropods to detoxify plant produced cyanide.DOI:
http://dx.doi.org/10.7554/eLife.02365.001
“…B). A strong protein band around 34.5 kDa, the molecular weight of CysK was observed in whole proteins from IWJ001/pDXW‐8‐ cysK cells, but not in the control IWJ001/pDXW‐8 cells. This “first slow then fast” growth mode could also be observed when CysK was overexpressed in Desulfovibrio piger Vib‐7 and E. coli BL21 .…”
Cysteine synthase A (CysK) catalyzes the last reaction of L-cysteine synthesis in bacteria, but its moonlighting functions have been revealed recently. In this study, CysK was overexpressed in Corynebacterium glutamicum IWJ001, an L-isoleucine producer. Compared with the control IWJ001/pDXW-8, IWJ001/pDXW-8-cysK cells grew fast during log phase, and produced 26.5% more L-isoleucine in flask fermentation and 23.5% more L-isoleucine in fed-batch fermentation. The key genes aspC, lysC, hom, thrB, ilvA, and ilvBN involved in L-isoleucine biosynthesis were all upregulated in IWJ001/pDXW-8-cysK, compared with IWJ001/pDXW-8. In addition, IWJ001/pDXW-8-cysK cells were longer and thicker than IWJ001/pDXW-8 cells. Compared with IWJ001/pDXW-8, the membrane permeability increased 15.8% and biofilm formation ability decreased 71.3% for IWJ001/pDXW-8-cysK cells. The results demonstrate that CysK overexpression in C. glutamicum is a good approach to enhance L-isoleucine production.
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