scholarly journals Identification and Characterization of γ-Aminobutyric Acid Uptake System GabPCg(NCgl0464) in Corynebacterium glutamicum

2012 ◽  
Vol 78 (8) ◽  
pp. 2596-2601 ◽  
Author(s):  
Zhi Zhao ◽  
Jiu-Yuan Ding ◽  
Wen-hua Ma ◽  
Ning-Yi Zhou ◽  
Shuang-Jiang Liu
Keyword(s):  
Amino Acid ◽  
Corynebacterium Glutamicum ◽  
Dry Weight ◽  
Aminobutyric Acid ◽  
Gaba Uptake ◽  
Acid Uptake ◽  
Uptake System ◽  
Content Type ◽  
Gaba Transporters ◽  
New Type

ABSTRACTCorynebacterium glutamicumis widely used for industrial production of various amino acids and vitamins, and there is growing interest in engineering this bacterium for more commercial bioproducts such as γ-aminobutyric acid (GABA). In this study, aC. glutamicumGABA-specific transporter (GabPCg) encoded byncgl0464was identified and characterized. GabPCgplays a major role in GABA uptake and is essential toC. glutamicumgrowing on GABA. GABA uptake by GabPCgwas weakly competed byl-Asn andl-Gln and stimulated by sodium ion (Na+). TheKmandVmaxvalues were determined to be 41.1 ± 4.5 μM and 36.8 ± 2.6 nmol min−1(mg dry weight [DW])−1, respectively, at pH 6.5 and 34.2 ± 1.1 μM and 67.3 ± 1.0 nmol min−1(mg DW)−1, respectively, at pH 7.5. GabPCghas 29% amino acid sequence identity to a previously and functionally identified aromatic amino acid transporter (TyrP) ofEscherichia colibut low identities to the currently known GABA transporters (17% and 15% toE. coliGabP andBacillus subtilisGabP, respectively). The mutant RES167 Δncgl0464/pGXKZ9 with the GabPCgdeletion showed 12.5% higher productivity of GABA than RES167/pGXKZ9. It is concluded that GabPCgrepresents a new type of GABA transporter and is potentially important for engineering GABA-producingC. glutamicumstrains.

scholarly journals GABA (γ-Aminobutyric Acid) Uptake Via the GABA Permease GabP Represses Virulence Gene Expression in Pseudomonas syringae pv. tomato DC3000

2016 ◽  
Vol 29 (12) ◽  
pp. 938-949 ◽  
Author(s):  
S. L. McCraw ◽  
D. H. Park ◽  
R. Jones ◽  
M. A. Bentley ◽  
A. Rico ◽  
...  
Keyword(s):  
Gene Expression ◽  
Amino Acid ◽  
Pseudomonas Syringae ◽  
Aminobutyric Acid ◽  
Gaba Uptake ◽  
Acid Uptake ◽  
Natural Setting ◽  
In Planta ◽  
Tomato Dc3000 ◽  
Virulence Gene Expression

The nonprotein amino acid γ-aminobutyric acid (GABA) is the most abundant amino acid in the tomato (Solanum lycopersicum) leaf apoplast and is synthesized by Arabidopsis thaliana in response to infection by the bacterial pathogen Pseudomonas syringae pv. tomato DC3000 (hereafter called DC3000). High levels of exogenous GABA have previously been shown to repress the expression of the type III secretion system (T3SS) in DC3000, resulting in reduced elicitation of the hypersensitive response (HR) in the nonhost plant tobacco (Nicotiana tabacum). This study demonstrates that the GABA permease GabP provides the primary mechanism for GABA uptake by DC3000 and that the gabP deletion mutant ΔgabP is insensitive to GABA-mediated repression of T3SS expression. ΔgabP displayed an enhanced ability to elicit the HR in young tobacco leaves and in tobacco plants engineered to produce increased levels of GABA, which supports the hypothesis that GABA uptake via GabP acts to regulate T3SS expression in planta. The observation that P. syringae can be rendered insensitive to GABA through loss of gabP but that gabP is retained by this bacterium suggests that GabP is important for DC3000 in a natural setting, either for nutrition or as a mechanism for regulating gene expression. [Formula: see text] Copyright © 2016 The Author(s). This is an open access article distributed under the CC BY Attribution 4.0 International license .

Systemic CI-966, a new γ-aminobutyric acid uptake blocker, enhances γ-aminobutyric acid action in CA1 pyramidal layer in situ

1990 ◽  
Vol 68 (9) ◽  
pp. 1194-1199 ◽  
Author(s):  
U. Ebert ◽  
K. Krnjević
Keyword(s):  
Aminobutyric Acid ◽  
Gaba Uptake ◽  
Acid Uptake ◽  
Sprague Dawley ◽  
Nipecotic Acid ◽  
Ca1 Region ◽  
Stratum Pyramidale ◽  
Sprague Dawley Rats ◽  
Pyramidal Layer ◽  
Urethane Anaesthesia

A new potent, blood–brain barrier permeable γ-aminobutyric acid (GABA) uptake blocker, 1-[2-[bis[4-(trifluoromethyl)-phenyl]methoxy]ethyl]-1,2,5,6-tetrahydro-3-pyridinecarboxylic acid (CI-966) was administered systemically by i.p. injection (5 mg/kg) in Sprague–Dawley rats under urethane anaesthesia. Twenty to thirty minutes after injection there was a highly variable, but overall significant, enhancement of the inhibition of hippocampal population spikes by GABA applied by microiontophoresis in the CA1 region. Like the effect of nipecotic acid (applied locally by iontophoresis), the potentiation by CI-966 was clearest when GABA was applied in or near the stratum pyramidale where its action normally is weakest and shows the most pronounced fading. This change in GABA potency is most simply explained by a reduction in GABA uptake.Key words: GABA, muscimol, nipecotic acid, GABA-uptake blocker, epilepsy.

scholarly journals The Paralogous Transcription Factors Stp1 and Stp2 of Candida albicans Have Distinct Functions in Nutrient Acquisition and Host Interaction

2020 ◽  
Vol 88 (5) ◽  
Author(s):  
Pedro Miramón ◽  
Andrew W. Pountain ◽  
Ambro van Hoof ◽  
Michael C. Lorenz
Keyword(s):  
Candida Albicans ◽  
Transcription Factors ◽  
Amino Acid ◽  
Cell Damage ◽  
Nutrient Acquisition ◽  
Acid Uptake ◽  
Content Type ◽  
Host Interaction ◽  
Amino Acid Utilization

ABSTRACT Nutrient acquisition is a central challenge for all organisms. For the fungal pathogen Candida albicans, utilization of amino acids has been shown to be critical for survival, immune evasion, and escape, while the importance of catabolism of host-derived proteins and peptides in vivo is less well understood. Stp1 and Stp2 are paralogous transcription factors (TFs) regulated by the Ssy1-Ptr3-Ssy5 (SPS) amino acid sensing system and have been proposed to have distinct, if uncertain, roles in protein and amino acid utilization. We show here that Stp1 is required for proper utilization of peptides but has no effect on amino acid catabolism. In contrast, Stp2 is critical for utilization of both carbon sources. Commensurate with this observation, we found that Stp1 controls a very limited set of genes, while Stp2 has a much more extensive regulon that is partly dependent on the Ssy1 amino acid sensor (amino acid uptake and catabolism) and partly Ssy1 independent (genes associated with filamentous growth, including the regulators UME6 and SFL2). The ssy1Δ/Δ and stp2Δ/Δ mutants showed reduced fitness in a gastrointestinal (GI) colonization model, yet induced greater damage to epithelial cells and macrophages in a manner that was highly dependent on the growth status of the fungal cells. Surprisingly, the stp1Δ/Δ mutant was better able to colonize the gut but the mutation had no effect on host cell damage. Thus, proper protein and amino acid utilization are both required for normal host interaction and are controlled by an interrelated network that includes Stp1 and Stp2.

scholarly journals PII Signal Transduction Protein GlnK Alleviates Feedback Inhibition of N-Acetyl-L-Glutamate Kinase by L-Arginine in Corynebacterium glutamicum

2020 ◽  
Vol 86 (8) ◽  
Author(s):  
Meijuan Xu ◽  
Mi Tang ◽  
Jiamin Chen ◽  
Taowei Yang ◽  
Xian Zhang ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Corynebacterium Glutamicum ◽  
Feedback Inhibition ◽  
Amino Acid Biosynthesis ◽  
Arginine Biosynthesis ◽  
Acid Biosynthesis ◽  
Content Type ◽  
Pii Protein

ABSTRACT PII signal transduction proteins are ubiquitous and highly conserved in bacteria, archaea, and plants and play key roles in controlling nitrogen metabolism. However, research on biological functions and regulatory targets of PII proteins remains limited. Here, we illustrated experimentally that the PII protein Corynebacterium glutamicum GlnK (CgGlnK) increased l-arginine yield when glnK was overexpressed in Corynebacterium glutamicum. Data showed that CgGlnK regulated l-arginine biosynthesis by upregulating the expression of genes of the l-arginine metabolic pathway and interacting with N-acetyl-l-glutamate kinase (CgNAGK), the rate-limiting enzyme in l-arginine biosynthesis. Further assays indicated that CgGlnK contributed to alleviation of the feedback inhibition of CgNAGK caused by l-arginine. In silico analysis of the binding interface of CgGlnK-CgNAGK suggested that the B and T loops of CgGlnK mainly interacted with C and N domains of CgNAGK. Moreover, F11, R47, and K85 of CgGlnK were identified as crucial binding sites that interact with CgNAGK via hydrophobic interaction and H bonds, and these interactions probably had a positive effect on maintaining the stability of the complex. Collectively, this study reveals PII-NAGK interaction in nonphotosynthetic microorganisms and further provides insights into the regulatory mechanism of PII on amino acid biosynthesis in corynebacteria. IMPORTANCE Corynebacteria are safe industrial producers of diverse amino acids, including l-glutamic acid and l-arginine. In this study, we showed that PII protein GlnK played an important role in l-glutamic acid and l-arginine biosynthesis in C. glutamicum. Through clarifying the molecular mechanism of CgGlnK in l-arginine biosynthesis, the novel interaction between CgGlnK and CgNAGK was revealed. The alleviation of l-arginine inhibition of CgNAGK reached approximately 48.21% by CgGlnK addition, and the semi-inhibition constant of CgNAGK increased 1.4-fold. Furthermore, overexpression of glnK in a high-yield l-arginine-producing strain and fermentation of the recombinant strain in a 5-liter bioreactor led to a remarkably increased production of l-arginine, 49.978 g/liter, which was about 22.61% higher than that of the initial strain. In conclusion, this study provides a new strategy for modifying amino acid biosynthesis in C. glutamicum.

scholarly journals Concurrent acetylcholinesterase staining and gamma-aminobutyric acid uptake of cortical neurons in culture.

1981 ◽  
Vol 29 (2) ◽  
pp. 306-308 ◽  
Author(s):  
M M Mesulam ◽  
M Dichter
Keyword(s):  
Tissue Culture ◽  
Cortical Neurons ◽  
Gabaergic Neurons ◽  
Aminobutyric Acid ◽  
Gaba Uptake ◽  
Acid Uptake ◽  
Gamma Aminobutyric Acid ◽  
Acetylcholinesterase Staining ◽  
Culture Positive

Gamma-aminobutyric acid (GABA) uptake and acetylcholinesterase (AChE) content were demonstrated concurrently in cortical neurons grown in tissue culture. Positive reactions either for GABA uptake or for AChE content were encountered in pyramidal and stellate, as well as spindle-shaped neurons. Neither reaction was confined to a specific morphological subtype. Nearly half the neurons were negative for either reaction. Most of the remaining neurons were positive only for GABA or only for AChE. However, a subpopulation of neurons showed not only a high AChE content, but also an avid GABA uptake. Thus, four types of neurons could be identified on the basis of these two reactions. The high AChE content in some of the cortical neurons that also showed GABA uptake indicates that there are at least two distinct types of GABAergic neurons.

scholarly journals LOCALIZATION OF THE SITES OF γ-AMINOBUTYRIC ACID (GABA) UPTAKE IN LOBSTER NERVE-MUSCLE PREPARATIONS

1971 ◽  
Vol 49 (1) ◽  
pp. 75-89 ◽  
Author(s):  
Paula M. Orkand ◽  
Edward A. Kravitz
Keyword(s):  
Amino Acid ◽  
Connective Tissue ◽  
Electron Micrographs ◽  
Aminobutyric Acid ◽  
Gaba Uptake ◽  
Tissue Cell ◽  
Connective Tissue Cell ◽  
Cell Cytoplasm ◽  
Nerve Muscle

The principal sites of γ-aminobutyric acid (GABA) uptake in lobster nerve-muscle preparations have been determined with radioautographic techniques after binding of the amino acid to proteins by aldehyde fixation. Semiquantitative studies showed that about 30% of the radioactive GABA taken into the tissue was bound to protein by fixation. Both light and electron micrographs showed dense accumulations of label over Schwann and connective tissue cell cytoplasm; muscle was lightly labeled, but axons and terminals were almost devoid of label. The possible role of Schwann and connective tissue cells in the inactivation of GABA released from inhibitory axons is discussed.

Characterization of l-arginine transport in adrenal cells: effect of ACTH

2006 ◽  
Vol 291 (2) ◽  
pp. E291-E297 ◽  
Author(s):  
Esteban M. Repetto ◽  
Vanesa Pannunzio ◽  
Francisco Astort ◽  
Camila Martinez Calejman ◽  
Marcos Besio Moreno ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Amino Acid ◽  
Transport System ◽  
Zona Fasciculata ◽  
Acid Uptake ◽  
Uptake System ◽  
Amino Acid Transport System ◽  
Cationic Amino Acid ◽  
Arginine Transport

Nitric oxide synthesis depends on the availability of its precursor l-arginine, which could be regulated by the presence of a specific uptake system. In the present report, the characterization of the l-arginine transport system in mouse adrenal Y1 cells was performed. l-arginine transport was mediated by the cationic/neutral amino acid transport system y+L and the cationic amino acid transporter (CAT) y+ in Y1 cells. These Na+-independent transporters were identified by their selectivity for neutral amino acids in both the presence and absence of Na+ and by the effect of N-ethylmaleimide. Transport data correlated to expression of genes encoding for CAT-1, CAT-2, CD-98, and y+LAT-2. A similar expression profile was detected in rat adrenal zona fasciculata. In addition, cationic amino acid uptake in Y1 cells was upregulated by ACTH and/or cAMP with a concomitant increase in nitric oxide (NO) production.

Structure–activity studies on the inhibition of γ-aminobutyric acid uptake in brain slices by compounds related to nipecotic acid

1979 ◽  
Vol 57 (6) ◽  
pp. 581-585 ◽  
Author(s):  
J. D. Wood ◽  
D. Tsui ◽  
J. W. Phillis
Keyword(s):  
Cortical Neurons ◽  
Therapeutic Potential ◽  
Brain Slices ◽  
Aminobutyric Acid ◽  
Gaba Uptake ◽  
Acid Uptake ◽  
Nipecotic Acid ◽  
Depressant Action ◽  
Methyl Derivatives ◽  
Derivatives Of

Various N-methyl derivatives of nipecotic acid and related compounds were tested as inhibitors of γ-aminobutyric acid (GABA) uptake into mini slices. N-Methylnipecotic acid, N,N-dimethyinipecotic acid, N-methylguvacine, and N-methylnicotinic acid were effective inhibitors. None of them, however, were as potent as nipecotic acid itself. All the effective inhibitors, including nipecotic acid, also inhibited the uptake of L-proline, but to a much lesser extent. Four of the test compounds produced a depressant action on cerebral cortical neurons, but even N-methylisoguvacine, the most potent in this respect, was considerably less active than GABA. None of the test compounds caused any clearly discernible changes in the gross behaviour or appearance of mice in the 1-h period following intramuscular injection. It was concluded that methylation of the N atom of nipecotic acid and its derivatives was unlikely to lead to the development of agents with greater experimental or therapeutic potential than that of nipecotic acid itself, if the action of the agent was dependent on its effects on GABA uptake.

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