Deregulated branched-chain amino acid synthesis in a Nicotiana plumbaginifolia cell line resistant to valine

1996 ◽  
Vol 19 (3) ◽  
pp. 241-248 ◽  
Author(s):  
Giuseppe Forlani ◽  
M. Cristina Suardi ◽  
Erik Nielsen
Keyword(s):  
Amino Acid ◽  
Cell Line ◽  
Acid Synthesis ◽  
Nicotiana Plumbaginifolia ◽  
Amino Acid Synthesis ◽  
Branched Chain Amino Acid ◽  
Branched Chain

scholarly journals Mechanism of De Novo Branched-Chain Amino Acid Synthesis as an Alternative Electron Sink in Hypoxic Aspergillus nidulans Cells

2010 ◽  
Vol 76 (5) ◽  
pp. 1507-1515 ◽  
Author(s):  
Motoyuki Shimizu ◽  
Tatsuya Fujii ◽  
Shunsuke Masuo ◽  
Naoki Takaya
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Aspergillus Nidulans ◽  
De Novo ◽  
Acid Synthesis ◽  
Branched Chain Amino Acids ◽  
Amino Acid Synthesis ◽  
Lactate Dehydrogenase Activity ◽  
Branched Chain Amino Acid ◽  
Branched Chain

ABSTRACT Although branched-chain amino acids are synthesized as building blocks of proteins, we found that the fungus Aspergillus nidulans excretes them into the culture medium under hypoxia. The transcription of predicted genes for synthesizing branched-chain amino acids was upregulated by hypoxia. A knockout strain of the gene encoding the large subunit of acetohydroxy acid synthase (AHAS), which catalyzes the initial reaction of the synthesis, required branched-chain amino acids for growth and excreted very little of them. Pyruvate, a substrate for AHAS, increased the amount of hypoxic excretion in the wild-type strain. These results indicated that the fungus responds to hypoxia by synthesizing branched-chain amino acids via a de novo mechanism. We also found that the small subunit of AHAS regulated hypoxic branched-chain amino acid production as well as cellular AHAS activity. The AHAS knockout resulted in higher ratios of NADH/NAD+ and NADPH/NADP+ under hypoxia, indicating that the branched-chain amino acid synthesis contributed to NAD+ and NADP+ regeneration. The production of branched-chain amino acids and the hypoxic induction of involved genes were partly repressed in the presence of glucose, where cells produced ethanol and lactate and increased levels of lactate dehydrogenase activity. These indicated that hypoxic branched-chain amino acid synthesis is a unique alternative mechanism that functions in the absence of glucose-to-ethanol/lactate fermentation and oxygen respiration.

scholarly journals Repression of branched-chain amino acid synthesis in Staphylococcus aureus is mediated by isoleucine via CodY, and by a leucine-rich attenuator peptide

PLoS Genetics ◽  
2018 ◽  
Vol 14 (1) ◽  
pp. e1007159 ◽  
Author(s):  
Julienne C. Kaiser ◽  
Alyssa N. King ◽  
Jason C. Grigg ◽  
Jessica R. Sheldon ◽  
David R. Edgell ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Amino Acid ◽  
Acid Synthesis ◽  
Amino Acid Synthesis ◽  
Branched Chain Amino Acid ◽  
Branched Chain

scholarly journals Eucalyptus ESTs associated with resistance to herbicide inhibitors of aromatic and branched-chain amino acid synthesis

2005 ◽  
Vol 28 (3 suppl) ◽  
pp. 575-581
Author(s):  
Edivaldo Domingues Velini ◽  
Maria Lúcia Bueno Trindade ◽  
Elza Alves ◽  
Ana Catarina Catâneo ◽  
Celso Luis Marino ◽  
...  
Keyword(s):  
Amino Acid ◽  
Acid Synthesis ◽  
Amino Acid Synthesis ◽  
Branched Chain Amino Acid ◽  
Branched Chain

scholarly journals Linking Central Metabolism with Increased Pathway Flux: l-Valine Accumulation by Corynebacterium glutamicum

2002 ◽  
Vol 68 (5) ◽  
pp. 2246-2250 ◽  
Author(s):  
Eva Radmacher ◽  
Adela Vaitsikova ◽  
Udo Burger ◽  
Karin Krumbach ◽  
Hermann Sahm ◽  
...  
Keyword(s):  
Amino Acid ◽  
Corynebacterium Glutamicum ◽  
Acid Synthesis ◽  
Acetohydroxy Acid Synthase ◽  
Amino Acid Synthesis ◽  
Branched Chain Amino Acid ◽  
In The Wild ◽  
Valine Biosynthesis ◽  
Branched Chain ◽  
Pathway Flux

ABSTRACT Mutants of Corynebacterium glutamicum were made and enzymatically characterized to clone ilvD and ilvE, which encode dihydroxy acid dehydratase and transaminase B, respectively. These genes of the branched-chain amino acid synthesis were overexpressed together with ilvBN (which encodes acetohydroxy acid synthase) and ilvC (which encodes isomeroreductase) in the wild type, which does not excrete l-valine, to result in an accumulation of this amino acid to a concentration of 42 mM. Since l-valine originates from two pyruvate molecules, this illustrates the comparatively easy accessibility of the central metabolite pyruvate. The same genes, ilvBNCD, overexpressed in an ilvA deletion mutant which is unable to synthesize l-isoleucine increased the concentration of this amino acid to 58 mM. A further dramatic increase was obtained when panBC was deleted, making the resulting mutant auxotrophic for d-pantothenate. When the resulting strain, C. glutamicum 13032ΔilvAΔpanBC with ilvBNCD overexpressed, was grown under limiting conditions it accumulated 91 mM l-valine. This is attributed to a reduced coenzyme A availability and therefore reduced flux of pyruvate via pyruvate dehydrogenase enabling its increased drain-off via the l-valine biosynthesis pathway.

Iron–sulfur protein NFU2 is required for branched-chain amino acid synthesis in Arabidopsis roots

2019 ◽  
Vol 70 (6) ◽  
pp. 1875-1889 ◽  
Author(s):  
Brigitte Touraine ◽  
Florence Vignols ◽  
Jonathan Przybyla-Toscano ◽  
Till Ischebeck ◽  
Tiphaine Dhalleine ◽  
...  
Keyword(s):  
Amino Acid ◽  
Acid Synthesis ◽  
Amino Acid Synthesis ◽  
Branched Chain Amino Acid ◽  
Iron Sulfur ◽  
Sulfur Protein ◽  
Iron Sulfur Protein ◽  
Branched Chain

scholarly journals Induction of alternative oxidase synthesis by herbicides inhibiting branched-chain amino acid synthesis

1997 ◽  
Vol 11 (4) ◽  
pp. 649-657 ◽  
Author(s):  
Serge Aubert ◽  
Richard Bligny ◽  
David A. Day ◽  
James Whelan ◽  
Roland Douce
Keyword(s):  
Amino Acid ◽  
Alternative Oxidase ◽  
Acid Synthesis ◽  
Amino Acid Synthesis ◽  
Branched Chain Amino Acid ◽  
Branched Chain

scholarly journals Pantothenate auxotrophy inZymomonas mobilisZM4 is due to a lack of aspartate decarboxylase activity

2017 ◽  
Author(s):  
J. R. Gliessman ◽  
T. A. Kremer ◽  
A. A. Sangani ◽  
S. E. Jones-Burrage ◽  
J. B. McKinlay
Keyword(s):  
Growth Medium ◽  
Genetic Basis ◽  
Single Gene ◽  
Cost Effective ◽  
Acid Synthesis ◽  
Decarboxylase Activity ◽  
Amino Acid Synthesis ◽  
Branched Chain Amino Acid ◽  
Branched Chain ◽  
Effective Growth

AbstractThe bacteriumZymomonas mobilisnaturally produces ethanol at near theoretical maximum yields, making it of interest for industrial ethanol production.Z. mobilisrequires the vitamin pantothenate for growth. Here we characterized the genetic basis for theZ. mobilispantothenate auxotrophy. We found that this auxotrophy is due to the absence of a single gene,panD, encoding aspartate-decarboxylase. Heterologous expression ofEscherichia coliPanD inZ. mobilisor supplementation of the growth medium with the product of PanD activity, β-alanine, eliminated the need for exogenous pantothenate. We also determined that IlvC, an enzyme better known for branched-chain amino acid synthesis, is required for pantothenate synthesis inZ. mobilis, as it compensates for the absence of PanE, another pantothenate synthesis pathway enzyme. In addition to contributing to an understanding of the nutritional requirements ofZ. mobilis, our results have led to the design of a more cost-effective growth medium.

Nitrogen in dietary glutamate is utilized exclusively for the synthesis of amino acids in the rat intestine

2013 ◽  
Vol 304 (1) ◽  
pp. E100-E108 ◽  
Author(s):  
Hidehiro Nakamura ◽  
Yasuko Kawamata ◽  
Tomomi Kuwahara ◽  
Kunio Torii ◽  
Ryosei Sakai
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Portal Vein ◽  
Acid Synthesis ◽  
Male Rats ◽  
Isotopic Enrichment ◽  
Amino Acid Synthesis ◽  
Quantitative Evidence ◽  
Branched Chain ◽  
Net Release

Although previous studies have shown that virtually the entire carbon skeleton of dietary glutamate (glutamate-C) is metabolized in the gut for energy production and amino acid synthesis, little is known regarding the fate of dietary glutamate nitrogen (glutamate-N). In this study, we hypothesized that dietary glutamate-N is an effective nitrogen source for amino acid synthesis and investigated the fate of dietary glutamate-N using [15N]glutamate. Fischer male rats were given hourly meals containing [U-13C]- or [15N]glutamate. The concentration and isotopic enrichment of several amino acids were measured after 0–9 h of feeding, and the net release of each amino acid into the portal vein was calculated. Most of the dietary glutamate-C was metabolized into CO2, lactate, or alanine (56, 13, and 12% of the dietary input, respectively) in the portal drained viscera (PDV). Most of the glutamate-N was utilized for the synthesis of other amino acids such as alanine and citrulline (75 and 3% of dietary input, respectively) in the PDV, and only minor amounts were released into the portal vein in the form of ammonia and glutamate (2 and 3% of the dietary input, respectively). Substantial incorporation of 15N into systemic amino acids such as alanine, glutamine, and proline, amino acids of the urea cycle, and branched-chain amino acids was also evident. These results provide quantitative evidence that dietary glutamate-N distributes extensively to amino acids synthesized in the PDV and, consequently, to circulating amino acids.

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