scholarly journals The Tsc/Rheb signaling pathway controls basic amino acid uptake via the Cat1 permease in fission yeast

2008 ◽  
Vol 279 (5) ◽  
pp. 441-450 ◽  
Author(s):  
Paul-Joseph Aspuria ◽  
Fuyuhiko Tamanoi
Keyword(s):  
Amino Acid ◽  
Fission Yeast ◽  
Signaling Pathway ◽  
Basic Amino Acid ◽  
Amino Acid Uptake ◽  
Acid Uptake

Influence of organic cations on basic amino-acid uptake by human placental villi

1995 ◽  
Vol 7 (6) ◽  
pp. 1491
Author(s):  
RB Krishna ◽  
J Dancis ◽  
M Levitz
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Basic Amino Acid ◽  
Amino Acid Uptake ◽  
Progressive Increase ◽  
Amino Acid Transporters ◽  
Acid Uptake ◽  
Chorionic Villi ◽  
Basic Amino Acids ◽  
Kinetics Of

Human placental chorionic villi were incubated for 30 min with [3H]lysine or [3H]arginine and the distribution ratios (intracellular:extracellular concentrations) were determined. The ratios remained unchanged when Na+ in Earle's buffered salt solution was replaced with Li+. When Na+ was replaced with choline there was a significant increase is distribution ratios (lysine 1.34 +/- 0.33 v. 3.99 +/- 0.15, arginine 1.95 +/- 0.37 v. 5.05 +/- 1.16). Leucine, a neutral amino acid with a Na(+)-independent transport system, was unaffected by choline substitution. The distribution ratio for alanine, which is Na(+)-dependent, was reduced (2.50 +/- 0.41 v. 1.45 +/- 0.20). Two other quarternary amines, acetyl-beta-methylcholine and tetraethylammonium chloride (TEA) caused similar increases in the distribution ratios of the basic amino acids. Hordenine, a tertiary amine, was less effective and there was little or no effect with ephedrine, a secondary amine. The choline effect was first observable at concentrations of 105 mM. With TEA, there was a progressive increase in distribution ratios beginning at 29 mM. Lysine efflux was measured after incubation of villi with lysine in Earle's buffer or choline buffer. Lysine was rapidly released to the fresh medium with 25% more retained in choline-exposed villi. The amines may cause alterations in the kinetics of basic amino-acid transporters or may modify other aspects of placental physiology permitting an increase retention of the basic amino acids.

scholarly journals Isp7 Is a Novel Regulator of Amino Acid Uptake in the TOR Signaling Pathway

2014 ◽  
Vol 34 (8) ◽  
pp. 1535-1535
Author(s):  
D. Laor ◽  
A. Cohen ◽  
M. Pasmanik-Chor ◽  
V. Oron-Karni ◽  
M. Kupiec ◽  
...  
Keyword(s):  
Amino Acid ◽  
Signaling Pathway ◽  
Amino Acid Uptake ◽  
Acid Uptake ◽  
Tor Signaling

scholarly journals Molecular Imaging of Brain Tumor-Associated Epilepsy

Diagnostics ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1049
Author(s):  
Csaba Juhász ◽  
Sandeep Mittal
Keyword(s):  
Brain Tumor ◽  
Amino Acid ◽  
Brain Tumors ◽  
Treatment Strategies ◽  
Amino Acid Uptake ◽  
Seizure Outcome ◽  
Acid Uptake ◽  
Positron Emission ◽  
Oncology Practice ◽  
Glioneuronal Tumors

Epilepsy is a common clinical manifestation and a source of significant morbidity in patients with brain tumors. Neuroimaging has a pivotal role in neuro-oncology practice, including tumor detection, differentiation, grading, treatment guidance, and posttreatment monitoring. In this review, we highlight studies demonstrating that imaging can also provide information about brain tumor-associated epileptogenicity and assist delineation of the peritumoral epileptic cortex to optimize postsurgical seizure outcome. Most studies focused on gliomas and glioneuronal tumors where positron emission tomography (PET) and advanced magnetic resonance imaging (MRI) techniques can detect metabolic and biochemical changes associated with altered amino acid transport and metabolism, neuroinflammation, and neurotransmitter abnormalities in and around epileptogenic tumors. PET imaging of amino acid uptake and metabolism as well as activated microglia can detect interictal or peri-ictal cortical increased uptake (as compared to non-epileptic cortex) associated with tumor-associated epilepsy. Metabolic tumor volumes may predict seizure outcome based on objective treatment response during glioma chemotherapy. Advanced MRI, especially glutamate imaging, can detect neurotransmitter changes around epileptogenic brain tumors. Recently, developed PET radiotracers targeting specific glutamate receptor types may also identify therapeutic targets for pharmacologic seizure control. Further studies with advanced multimodal imaging approaches may facilitate development of precision treatment strategies to control brain tumor-associated epilepsy.

scholarly journals Polyribonucleotide Synthesis and Bacterial Amino Acid Uptake: the Work of Leon A. Heppel

2007 ◽  
Vol 282 (18) ◽  
pp. e13-e15
Author(s):  
Nicole Kresge ◽  
Robert D. Simoni ◽  
Robert L. Hill
Keyword(s):  
Amino Acid ◽  
Amino Acid Uptake ◽  
Acid Uptake

scholarly journals Amino Acid Transporters on the Guard of Cell Genome and Epigenome

Cancers ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 125
Author(s):  
Uğur Kahya ◽  
Ayşe Sedef Köseer ◽  
Anna Dubrovska
Keyword(s):  
Amino Acid ◽  
Cancer Metabolism ◽  
Tumor Imaging ◽  
Redox Homeostasis ◽  
Amino Acid Uptake ◽  
Metabolic Reprogramming ◽  
Tumor Evolution ◽  
Amino Acid Transporters ◽  
Acid Uptake ◽  
Growth And Survival

Tumorigenesis is driven by metabolic reprogramming. Oncogenic mutations and epigenetic alterations that cause metabolic rewiring may also upregulate the reactive oxygen species (ROS). Precise regulation of the intracellular ROS levels is critical for tumor cell growth and survival. High ROS production leads to the damage of vital macromolecules, such as DNA, proteins, and lipids, causing genomic instability and further tumor evolution. One of the hallmarks of cancer metabolism is deregulated amino acid uptake. In fast-growing tumors, amino acids are not only the source of energy and building intermediates but also critical regulators of redox homeostasis. Amino acid uptake regulates the intracellular glutathione (GSH) levels, endoplasmic reticulum stress, unfolded protein response signaling, mTOR-mediated antioxidant defense, and epigenetic adaptations of tumor cells to oxidative stress. This review summarizes the role of amino acid transporters as the defender of tumor antioxidant system and genome integrity and discusses them as promising therapeutic targets and tumor imaging tools.

scholarly journals Studies on Aromatic Amino Acid Uptake by Rat Brain in Vivo

1962 ◽  
Vol 237 (3) ◽  
pp. 803-806
Author(s):  
Gordon Guroff ◽  
Sidney Udenfriend
Keyword(s):  
Amino Acid ◽  
Rat Brain ◽  
Aromatic Amino Acid ◽  
Amino Acid Uptake ◽  
Acid Uptake
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