Amino Acid Transport Systems: Cellular proteins and protein complexes that transport amino acids across biological membranes.Amino Acid Transport System L: A sodium-independent neutral amino acid transporter system with specificity for large amino acids. One of the functions of the transporter system is to supply large neutral amino acids to the brain.Amino Acid Transport Systems, Basic: Amino acid transporter systems capable of transporting basic amino acids (AMINO ACIDS, BASIC).Amino Acids: Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.Biological Transport: The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.Aminoisobutyric Acids: A group of compounds that are derivatives of the amino acid 2-amino-2-methylpropanoic acid.Amino Acid Transport System A: A sodium-dependent neutral amino acid transporter that accounts for most of the sodium-dependent neutral amino acid uptake by mammalian cells. The preferred substrates for this transporter system include ALANINE; SERINE; and GLUTAMINE.Amino Acid Transport Systems, Neutral: Amino acid transporter systems capable of transporting neutral amino acids (AMINO ACIDS, NEUTRAL).Biological Transport, Active: The movement of materials across cell membranes and epithelial layers against an electrochemical gradient, requiring the expenditure of metabolic energy.Amino Acid Transport System ASC: A ubiquitous sodium-dependent neutral amino acid transporter. The preferred substrates for this transporter system include ALANINE; SERINE; and CYSTEINE.Leucine: An essential branched-chain amino acid important for hemoglobin formation.Amino Acid Transport System y+beta-Alanine: An amino acid formed in vivo by the degradation of dihydrouracil and carnosine. Since neuronal uptake and neuronal receptor sensitivity to beta-alanine have been demonstrated, the compound may be a false transmitter replacing GAMMA-AMINOBUTYRIC ACID. A rare genetic disorder, hyper-beta-alaninemia, has been reported.Antigens, CD98: A heterodimeric protein that is a cell surface antigen associated with lymphocyte activation. The initial characterization of this protein revealed one identifiable heavy chain (ANTIGENS, CD98 HEAVY CHAIN) and an indeterminate smaller light chain. It is now known that a variety of light chain subunits (ANTIGENS, CD98 LIGHT CHAINS) can dimerize with the heavy chain. Depending upon its light chain composition a diverse array of functions can be found for this protein. Functions include: type L amino acid transport, type y+L amino acid transport and regulation of cellular fusion.Amino Acids, Neutral: Amino acids with uncharged R groups or side chains.Amino Acids, Cyclic: A class of amino acids characterized by a closed ring structure.Amino Acids, Branched-Chain: Amino acids which have a branched carbon chain.Carrier Proteins: Transport proteins that carry specific substances in the blood or across cell membranes.Sodium: A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.Phenylalanine: An essential aromatic amino acid that is a precursor of MELANIN; DOPAMINE; noradrenalin (NOREPINEPHRINE), and THYROXINE.Alanine: A non-essential amino acid that occurs in high levels in its free state in plasma. It is produced from pyruvate by transamination. It is involved in sugar and acid metabolism, increases IMMUNITY, and provides energy for muscle tissue, BRAIN, and the CENTRAL NERVOUS SYSTEM.Kinetics: The rate dynamics in chemical or physical systems.Amino Acid Transport System y+LMembrane Transport Proteins: Membrane proteins whose primary function is to facilitate the transport of molecules across a biological membrane. Included in this broad category are proteins involved in active transport (BIOLOGICAL TRANSPORT, ACTIVE), facilitated transport and ION CHANNELS.4-Chloromercuribenzenesulfonate: A cytotoxic sulfhydryl reagent that inhibits several subcellular metabolic systems and is used as a tool in cellular physiology.Glutamine: A non-essential amino acid present abundantly throughout the body and is involved in many metabolic processes. It is synthesized from GLUTAMIC ACID and AMMONIA. It is the principal carrier of NITROGEN in the body and is an important energy source for many cells.Proline: A non-essential amino acid that is synthesized from GLUTAMIC ACID. It is an essential component of COLLAGEN and is important for proper functioning of joints and tendons.Cystine: A covalently linked dimeric nonessential amino acid formed by the oxidation of CYSTEINE. Two molecules of cysteine are joined together by a disulfide bridge to form cystine.Isoleucine: An essential branched-chain aliphatic amino acid found in many proteins. It is an isomer of LEUCINE. It is important in hemoglobin synthesis and regulation of blood sugar and energy levels.Fatty Acid Transport Proteins: A broad category of membrane transport proteins that specifically transport FREE FATTY ACIDS across cellular membranes. They play an important role in LIPID METABOLISM in CELLS that utilize free fatty acids as an energy source.Valine: A branched-chain essential amino acid that has stimulant activity. It promotes muscle growth and tissue repair. It is a precursor in the penicillin biosynthetic pathway.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Arginine: An essential amino acid that is physiologically active in the L-form.Lysine: An essential amino acid. It is often added to animal feed.Leucine-tRNA Ligase: An enzyme that activates leucine with its specific transfer RNA. EC 6.1.1.4.Cloning, Molecular: The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Cell Membrane: The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.Amino Acid Transport Systems, Acidic: Amino acid transporter systems capable of transporting acidic amino acids (AMINO ACIDS, ACIDIC).Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Sequence Homology, Amino Acid: The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.Hydrogen-Ion Concentration: The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Tryptophan: An essential amino acid that is necessary for normal growth in infants and for NITROGEN balance in adults. It is a precursor of INDOLE ALKALOIDS in plants. It is a precursor of SEROTONIN (hence its use as an antidepressant and sleep aid). It can be a precursor to NIACIN, albeit inefficiently, in mammals.Escherichia coli: A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.Glutamates: Derivatives of GLUTAMIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the 2-aminopentanedioic acid structure.Xenopus laevis: The commonest and widest ranging species of the clawed "frog" (Xenopus) in Africa. This species is used extensively in research. There is now a significant population in California derived from escaped laboratory animals.Substrate Specificity: A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.Oocytes: Female germ cells derived from OOGONIA and termed OOCYTES when they enter MEIOSIS. The primary oocytes begin meiosis but are arrested at the diplotene state until OVULATION at PUBERTY to give rise to haploid secondary oocytes or ova (OVUM).Histidine: An essential amino acid that is required for the production of HISTAMINE.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Taurocholic Acid: The product of conjugation of cholic acid with taurine. Its sodium salt is the chief ingredient of the bile of carnivorous animals. It acts as a detergent to solubilize fats for absorption and is itself absorbed. It is used as a cholagogue and cholerectic.Dicarboxylic AcidsRats, Inbred Strains: Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.RNA, Messenger: RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.Bacterial Proteins: Proteins found in any species of bacterium.Ethylmaleimide: A sulfhydryl reagent that is widely used in experimental biochemical studies.Large Neutral Amino Acid-Transporter 1: A CD98 antigen light chain that when heterodimerized with CD98 antigen heavy chain (ANTIGENS, CD98 HEAVY CHAIN) forms a protein that mediates sodium-independent L-type amino acid transport.Amino Acids, DiaminoCells, Cultured: Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.Glycine: A non-essential amino acid. It is found primarily in gelatin and silk fibroin and used therapeutically as a nutrient. It is also a fast inhibitory neurotransmitter.Antigens, CD98 Light Chains: A family of light chains that bind to the CD98 heavy chain (ANTIGENS, CD98 HEAVY CHAIN) to form a heterodimer. They convey functional specificity to the protein.Genes, Bacterial: The functional hereditary units of BACTERIA.Cystinuria: An inherited disorder due to defective reabsorption of CYSTINE and other BASIC AMINO ACIDS by the PROXIMAL RENAL TUBULES. This form of aminoaciduria is characterized by the abnormally high urinary levels of cystine; LYSINE; ARGININE; and ORNITHINE. Mutations involve the amino acid transport protein gene SLC3A1.Liver: A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.Antigens, CD98 Heavy Chain: A transmembrane glycoprotein subunit that can dimerize with a variety of light chain subunits (ANTIGENS, CD98 LIGHT CHAINS). This protein subunit serves a diverse array of functions including amino acid transport and cell fusion. Its function is altered depending which of the light chain subunits it interacts with.Hartnup Disease: An autosomal recessive disorder due to defective absorption of NEUTRAL AMINO ACIDS by both the intestine and the PROXIMAL RENAL TUBULES. The abnormal urinary loss of TRYPTOPHAN, a precursor of NIACIN, leads to a NICOTINAMIDE deficiency, PELLAGRA-like light-sensitive rash, CEREBELLAR ATAXIA, emotional instability, and aminoaciduria. Mutations involve the neurotransmitter transporter gene SLC6A19.Amino Acid Substitution: The naturally occurring or experimentally induced replacement of one or more AMINO ACIDS in a protein with another. If a functionally equivalent amino acid is substituted, the protein may retain wild-type activity. Substitution may also diminish, enhance, or eliminate protein function. Experimentally induced substitution is often used to study enzyme activities and binding site properties.Glucose: A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement.Dinitrophenols: Organic compounds that contain two nitro groups attached to a phenol.Carbon Radioisotopes: Unstable isotopes of carbon that decay or disintegrate emitting radiation. C atoms with atomic weights 10, 11, and 14-16 are radioactive carbon isotopes.Microvilli: Minute projections of cell membranes which greatly increase the surface area of the cell.Culture Media: Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.Methionine: A sulfur-containing essential L-amino acid that is important in many body functions.MethylglucosidesIleum: The distal and narrowest portion of the SMALL INTESTINE, between the JEJUNUM and the ILEOCECAL VALVE of the LARGE INTESTINE.Membrane Proteins: Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.Pseudomonadaceae: A family of gram-negative bacteria usually found in soil or water and including many plant pathogens and a few animal pathogens.Phenylacetates: Derivatives of phenylacetic acid. Included under this heading are a variety of acid forms, salts, esters, and amides that contain the benzeneacetic acid structure. Note that this class of compounds should not be confused with derivatives of phenyl acetate, which contain the PHENOL ester of ACETIC ACID.Methyltyrosines: A group of compounds that are methyl derivatives of the amino acid TYROSINE.Cycloheximide: Antibiotic substance isolated from streptomycin-producing strains of Streptomyces griseus. It acts by inhibiting elongation during protein synthesis.Symporters: Membrane transporters that co-transport two or more dissimilar molecules in the same direction across a membrane. Usually the transport of one ion or molecule is against its electrochemical gradient and is "powered" by the movement of another ion or molecule with its electrochemical gradient.Ion Transport: The movement of ions across energy-transducing cell membranes. Transport can be active, passive or facilitated. Ions may travel by themselves (uniport), or as a group of two or more ions in the same (symport) or opposite (antiport) directions.Sequence Alignment: The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.Protein Transport: The process of moving proteins from one cellular compartment (including extracellular) to another by various sorting and transport mechanisms such as gated transport, protein translocation, and vesicular transport.DNA, Complementary: Single-stranded complementary DNA synthesized from an RNA template by the action of RNA-dependent DNA polymerase. cDNA (i.e., complementary DNA, not circular DNA, not C-DNA) is used in a variety of molecular cloning experiments as well as serving as a specific hybridization probe.Axonal Transport: The directed transport of ORGANELLES and molecules along nerve cell AXONS. Transport can be anterograde (from the cell body) or retrograde (toward the cell body). (Alberts et al., Molecular Biology of the Cell, 3d ed, pG3)Amino Acid Transport System X-AG: A family of POTASSIUM and SODIUM-dependent acidic amino acid transporters that demonstrate a high affinity for GLUTAMIC ACID and ASPARTIC ACID. Several variants of this system are found in neuronal tissue.Monosaccharide Transport Proteins: A large group of membrane transport proteins that shuttle MONOSACCHARIDES across CELL MEMBRANES.Stereoisomerism: The phenomenon whereby compounds whose molecules have the same number and kind of atoms and the same atomic arrangement, but differ in their spatial relationships. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)Carbon Isotopes: Stable carbon atoms that have the same atomic number as the element carbon, but differ in atomic weight. C-13 is a stable carbon isotope.Aspartic Acid: One of the non-essential amino acids commonly occurring in the L-form. It is found in animals and plants, especially in sugar cane and sugar beets. It may be a neurotransmitter.Amino Acid Transport Disorders, Inborn: Disorders characterized by defective transport of amino acids across cell membranes. These include deficits in transport across brush-border epithelial cell membranes of the small intestine (MICROVILLI) and KIDNEY TUBULES; transport across the basolateral membrane; and transport across the membranes of intracellular organelles. (From Nippon Rinsho 1992 Jul;50(7):1587-92)Amino Acids, Essential: Amino acids that are not synthesized by the human body in amounts sufficient to carry out physiological functions. They are obtained from dietary foodstuffs.Placenta: A highly vascularized mammalian fetal-maternal organ and major site of transport of oxygen, nutrients, and fetal waste products. It includes a fetal portion (CHORIONIC VILLI) derived from TROPHOBLASTS and a maternal portion (DECIDUA) derived from the uterine ENDOMETRIUM. The placenta produces an array of steroid, protein and peptide hormones (PLACENTAL HORMONES).Cyanides: Inorganic salts of HYDROGEN CYANIDE containing the -CN radical. The concept also includes isocyanides. It is distinguished from NITRILES, which denotes organic compounds containing the -CN radical.Temperature: The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.Azides: Organic or inorganic compounds that contain the -N3 group.Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Ouabain: A cardioactive glycoside consisting of rhamnose and ouabagenin, obtained from the seeds of Strophanthus gratus and other plants of the Apocynaceae; used like DIGITALIS. It is commonly used in cell biological studies as an inhibitor of the NA(+)-K(+)-EXCHANGING ATPASE.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.Glutamic Acid: A non-essential amino acid naturally occurring in the L-form. Glutamic acid is the most common excitatory neurotransmitter in the CENTRAL NERVOUS SYSTEM.Structure-Activity Relationship: The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.3-O-Methylglucose: A non-metabolizable glucose analogue that is not phosphorylated by hexokinase. 3-O-Methylglucose is used as a marker to assess glucose transport by evaluating its uptake within various cells and organ systems. (J Neurochem 1993;60(4):1498-504)Jejunum: The middle portion of the SMALL INTESTINE, between DUODENUM and ILEUM. It represents about 2/5 of the remaining portion of the small intestine below duodenum.Rabbits: The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.Mutagenesis, Site-Directed: Genetically engineered MUTAGENESIS at a specific site in the DNA molecule that introduces a base substitution, or an insertion or deletion.Cationic Amino Acid Transporter 1: A high-affinity, low capacity system y+ amino acid transporter found ubiquitously. It has specificity for the transport of ARGININE; LYSINE; and ORNITHINE. It may also act as an ecotropic leukemia retroviral receptor.Potassium: An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.Saccharomyces cerevisiae: A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.Intestinal Absorption: Uptake of substances through the lining of the INTESTINES.Plasmids: Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.Amino Acid Motifs: Commonly observed structural components of proteins formed by simple combinations of adjacent secondary structures. A commonly observed structure may be composed of a CONSERVED SEQUENCE which can be represented by a CONSENSUS SEQUENCE.Kidney: Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.Recombinant Proteins: Proteins prepared by recombinant DNA technology.Electron Transport: The process by which ELECTRONS are transported from a reduced substrate to molecular OXYGEN. (From Bennington, Saunders Dictionary and Encyclopedia of Laboratory Medicine and Technology, 1984, p270)PhloretinSerine: A non-essential amino acid occurring in natural form as the L-isomer. It is synthesized from GLYCINE or THREONINE. It is involved in the biosynthesis of PURINES; PYRIMIDINES; and other amino acids.Protein Binding: The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.Nitrogen: An element with the atomic symbol N, atomic number 7, and atomic weight [14.00643; 14.00728]. Nitrogen exists as a diatomic gas and makes up about 78% of the earth's atmosphere by volume. It is a constituent of proteins and nucleic acids and found in all living cells.Insulin: A 51-amino acid pancreatic hormone that plays a major role in the regulation of glucose metabolism, directly by suppressing endogenous glucose production (GLYCOGENOLYSIS; GLUCONEOGENESIS) and indirectly by suppressing GLUCAGON secretion and LIPOLYSIS. Native insulin is a globular protein comprised of a zinc-coordinated hexamer. Each insulin monomer containing two chains, A (21 residues) and B (30 residues), linked by two disulfide bonds. Insulin is used as a drug to control insulin-dependent diabetes mellitus (DIABETES MELLITUS, TYPE 1).ATP-Binding Cassette Transporters: A family of MEMBRANE TRANSPORT PROTEINS that require ATP hydrolysis for the transport of substrates across membranes. The protein family derives its name from the ATP-binding domain found on the protein.Taurine: A conditionally essential nutrient, important during mammalian development. It is present in milk but is isolated mostly from ox bile and strongly conjugates bile acids.Ornithine: An amino acid produced in the urea cycle by the splitting off of urea from arginine.Cysteine: A thiol-containing non-essential amino acid that is oxidized to form CYSTINE.Organic Anion Transporters: Proteins involved in the transport of organic anions. They play an important role in the elimination of a variety of endogenous substances, xenobiotics and their metabolites from the body.Chlorides: Inorganic compounds derived from hydrochloric acid that contain the Cl- ion.Deoxyglucose: 2-Deoxy-D-arabino-hexose. An antimetabolite of glucose with antiviral activity.Intestine, Small: The portion of the GASTROINTESTINAL TRACT between the PYLORUS of the STOMACH and the ILEOCECAL VALVE of the LARGE INTESTINE. It is divisible into three portions: the DUODENUM, the JEJUNUM, and the ILEUM.Anion Transport Proteins: Membrane proteins whose primary function is to facilitate the transport of negatively charged molecules (anions) across a biological membrane.Protein Conformation: The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).Genetic Complementation Test: A test used to determine whether or not complementation (compensation in the form of dominance) will occur in a cell with a given mutant phenotype when another mutant genome, encoding the same mutant phenotype, is introduced into that cell.Models, Molecular: Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.Maltose: A dextrodisaccharide from malt and starch. It is used as a sweetening agent and fermentable intermediate in brewing. (Grant & Hackh's Chemical Dictionary, 5th ed)Radioisotope Dilution Technique: Method for assessing flow through a system by injection of a known quantity of radionuclide into the system and monitoring its concentration over time at a specific point in the system. (From Dorland, 28th ed)Trophoblasts: Cells lining the outside of the BLASTOCYST. After binding to the ENDOMETRIUM, trophoblasts develop into two distinct layers, an inner layer of mononuclear cytotrophoblasts and an outer layer of continuous multinuclear cytoplasm, the syncytiotrophoblasts, which form the early fetal-maternal interface (PLACENTA).TritiumKidney Cortex: The outer zone of the KIDNEY, beneath the capsule, consisting of KIDNEY GLOMERULUS; KIDNEY TUBULES, DISTAL; and KIDNEY TUBULES, PROXIMAL.Protein Structure, Tertiary: The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.MethylglycosidesGene Expression: The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.Genes: A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.DNA Primers: Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.Depression, Chemical: The decrease in a measurable parameter of a PHYSIOLOGICAL PROCESS, including cellular, microbial, and plant; immunological, cardiovascular, respiratory, reproductive, urinary, digestive, neural, musculoskeletal, ocular, and skin physiological processes; or METABOLIC PROCESS, including enzymatic and other pharmacological processes, by a drug or other chemical.Anions: Negatively charged atoms, radicals or groups of atoms which travel to the anode or positive pole during electrolysis.Fatty Acids: Organic, monobasic acids derived from hydrocarbons by the equivalent of oxidation of a methyl group to an alcohol, aldehyde, and then acid. Fatty acids are saturated and unsaturated (FATTY ACIDS, UNSATURATED). (Grant & Hackh's Chemical Dictionary, 5th ed)Sequence Homology, Nucleic Acid: The sequential correspondence of nucleotides in one nucleic acid molecule with those of another nucleic acid molecule. Sequence homology is an indication of the genetic relatedness of different organisms and gene function.Molecular Weight: The sum of the weight of all the atoms in a molecule.Cricetinae: A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.DNA: A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).Escherichia coli Proteins: Proteins obtained from ESCHERICHIA COLI.Protein Biosynthesis: The biosynthesis of PEPTIDES and PROTEINS on RIBOSOMES, directed by MESSENGER RNA, via TRANSFER RNA that is charged with standard proteinogenic AMINO ACIDS.Lithium: An element in the alkali metals family. It has the atomic symbol Li, atomic number 3, and atomic weight [6.938; 6.997]. Salts of lithium are used in treating BIPOLAR DISORDER.Cations: Positively charged atoms, radicals or groups of atoms which travel to the cathode or negative pole during electrolysis.Iodoacetates: Iodinated derivatives of acetic acid. Iodoacetates are commonly used as alkylating sulfhydryl reagents and enzyme inhibitors in biochemical research.Membrane Potentials: The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).Intestines: The section of the alimentary canal from the STOMACH to the ANAL CANAL. It includes the LARGE INTESTINE and SMALL INTESTINE.Cattle: Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.Recombinant Fusion Proteins: Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.Neurospora: A genus of ascomycetous fungi, family Sordariaceae, order SORDARIALES, comprising bread molds. They are capable of converting tryptophan to nicotinic acid and are used extensively in genetic and enzyme research. (Dorland, 27th ed)Organic Anion Transporters, Sodium-Dependent: A subclass of ORGANIC ANION TRANSPORTERS whose transport of organic anions is driven either directly or indirectly by a gradient of sodium ions.Threonine: An essential amino acid occurring naturally in the L-form, which is the active form. It is found in eggs, milk, gelatin, and other proteins.Coenzyme A Ligases: Enzymes that catalyze the formation of acyl-CoA derivatives. EC 6.2.1.Adenosine Triphosphate: An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.Bile Acids and Salts: Steroid acids and salts. The primary bile acids are derived from cholesterol in the liver and usually conjugated with glycine or taurine. The secondary bile acids are further modified by bacteria in the intestine. They play an important role in the digestion and absorption of fat. They have also been used pharmacologically, especially in the treatment of gallstones.Bile Canaliculi: Minute intercellular channels that occur between liver cells and carry bile towards interlobar bile ducts. Also called bile capillaries.Chromosome Mapping: Any method used for determining the location of and relative distances between genes on a chromosome.Binding, Competitive: The interaction of two or more substrates or ligands with the same binding site. The displacement of one by the other is used in quantitative and selective affinity measurements.Restriction Mapping: Use of restriction endonucleases to analyze and generate a physical map of genomes, genes, or other segments of DNA.Tissue Distribution: Accumulation of a drug or chemical substance in various organs (including those not relevant to its pharmacologic or therapeutic action). This distribution depends on the blood flow or perfusion rate of the organ, the ability of the drug to penetrate organ membranes, tissue specificity, protein binding. The distribution is usually expressed as tissue to plasma ratios.Gene Library: A large collection of DNA fragments cloned (CLONING, MOLECULAR) from a given organism, tissue, organ, or cell type. It may contain complete genomic sequences (GENOMIC LIBRARY) or complementary DNA sequences, the latter being formed from messenger RNA and lacking intron sequences.Transfection: The uptake of naked or purified DNA by CELLS, usually meaning the process as it occurs in eukaryotic cells. It is analogous to bacterial transformation (TRANSFORMATION, BACTERIAL) and both are routinely employed in GENE TRANSFER TECHNIQUES.Erythrocytes: Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.Species Specificity: The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.Peptide Fragments: Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.Osmolar Concentration: The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent.Glutamate Plasma Membrane Transport Proteins: A family of plasma membrane neurotransmitter transporter proteins that couple the uptake of GLUTAMATE with the import of SODIUM ions and PROTONS and the export of POTASSIUM ions. In the CENTRAL NERVOUS SYSTEM they regulate neurotransmission through synaptic reuptake of the excitatory neurotransmitter glutamate. Outside the central nervous system they function as signal mediators and regulators of glutamate metabolism.Carcinoma, Ehrlich Tumor: A transplantable, poorly differentiated malignant tumor which appeared originally as a spontaneous breast carcinoma in a mouse. It grows in both solid and ascitic forms.Amino Acids, Aromatic: Amino acids containing an aromatic side chain.Periplasmic Binding Proteins: Periplasmic proteins that scavenge or sense diverse nutrients. In the bacterial environment they usually couple to transporters or chemotaxis receptors on the inner bacterial membrane.Blood-Brain Barrier: Specialized non-fenestrated tightly-joined ENDOTHELIAL CELLS with TIGHT JUNCTIONS that form a transport barrier for certain substances between the cerebral capillaries and the BRAIN tissue.Intestinal Mucosa: Lining of the INTESTINES, consisting of an inner EPITHELIUM, a middle LAMINA PROPRIA, and an outer MUSCULARIS MUCOSAE. In the SMALL INTESTINE, the mucosa is characterized by a series of folds and abundance of absorptive cells (ENTEROCYTES) with MICROVILLI.Electrophoresis, Polyacrylamide Gel: Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.Membrane Glycoproteins: Glycoproteins found on the membrane or surface of cells.Peptides: Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Tyrosine: A non-essential amino acid. In animals it is synthesized from PHENYLALANINE. It is also the precursor of EPINEPHRINE; THYROID HORMONES; and melanin.Blotting, Northern: Detection of RNA that has been electrophoretically separated and immobilized by blotting on nitrocellulose or other type of paper or nylon membrane followed by hybridization with labeled NUCLEIC ACID PROBES.Epithelium: One or more layers of EPITHELIAL CELLS, supported by the basal lamina, which covers the inner or outer surfaces of the body.Succinates: Derivatives of SUCCINIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain a 1,4-carboxy terminated aliphatic structure.Cell Membrane Permeability: A quality of cell membranes which permits the passage of solvents and solutes into and out of cells.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.MethylgalactosidesXenopus: An aquatic genus of the family, Pipidae, occurring in Africa and distinguished by having black horny claws on three inner hind toes.Proteins: Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.Gene Expression Regulation: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.RNA, Complementary: Synthetic transcripts of a specific DNA molecule or fragment, made by an in vitro transcription system. This cRNA can be labeled with radioactive uracil and then used as a probe. (King & Stansfield, A Dictionary of Genetics, 4th ed)Cation Transport Proteins: Membrane proteins whose primary function is to facilitate the transport of positively charged molecules (cations) across a biological membrane.Sodium-Potassium-Exchanging ATPase: An enzyme that catalyzes the active transport system of sodium and potassium ions across the cell wall. Sodium and potassium ions are closely coupled with membrane ATPase which undergoes phosphorylation and dephosphorylation, thereby providing energy for transport of these ions against concentration gradients.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.
A novel system A isoform mediating Na+/neutral amino acid cotransport. (1/100)
A cDNA clone encoding a plasma membrane alanine-preferring transporter (SAT2) has been isolated from glutamatergic neurons in culture and represents the second member of the system A family of neutral amino acid transporters. SAT2 displays a widespread distribution and is expressed in most tissues, including heart, adrenal gland, skeletal muscle, stomach, fat, brain, spinal cord, colon, and lung, with lower levels detected in spleen. No signal is detected in liver or testis. In the central nervous system, SAT2 is expressed in neurons. SAT2 is significantly up-regulated during differentiation of cerebellar granule cells and is absent from astrocytes in primary culture. The functional properties of SAT2, examined using transfected fibroblasts and in cRNA-injected voltage-clamped Xenopus oocytes, show that small aliphatic neutral amino acids are preferred substrates and that transport is voltage- and Na(+)-dependent (1:1 stoichiometry), pH-sensitive, and inhibited by alpha-(methylamino)isobutyric acid (MeAIB), a specific inhibitor of system A. Kinetic analyses of alanine and MeAIB uptake by SAT2 are saturable, with Michaelis constants (K(m)) of 200-500 microm. In addition to its ubiquitous role as a substrate for oxidative metabolism and a major vehicle of nitrogen transport, SAT2 may provide alanine to function as the amino group donor to alpha-ketoglutarate to provide an alternative source for neurotransmitter synthesis in glutamatergic neurons. (+info)Subcellular localization and adaptive up-regulation of the System A (SAT2) amino acid transporter in skeletal-muscle cells and adipocytes. (2/100)
The recently cloned amino acid transporter SAT2 is ubiquitously expressed and confers Na(+)-dependent transport of short-chain neutral amino acids, characteristics of the functionally defined System A transporter. Here we report the presence of SAT2 mRNA and protein in both skeletal muscle and adipocytes, and the characterization of polyclonal antibodies directed against this transporter. SAT2 protein was present in both plasma-membrane and internal-membrane fractions derived from rat skeletal muscle and adipose tissue, L6 myotubes and 3T3-L1 adipocytes, having a localization similar to that of the glucose transporter GLUT4. Moreover, consistent with the adaptive up-regulation of System A activity following chronic amino acid deprivation, a time-dependent increase in SAT2 protein abundance was observed in amino-acid-deprived L6 myotubes and 3T3-L1 adipocytes. These studies provide the first evidence regarding the subcellular distribution and adaptive up-regulation of SAT2 protein and the characterization of molecular probes for this physiologically important transporter, the function of which is altered in several disease states. (+info)Characterization of an N-system amino acid transporter expressed in retina and its involvement in glutamine transport. (3/100)
We report here on the characterization of a mouse N-system amino acid transporter protein, which is involved in the transport of glutamine. This protein of 485 amino acids shares 52% sequence homology with an N-system amino acid transporter, mouse N-system amino acid transporter (mNAT) and its orthologs. Because this protein shares a high degree of sequence homology and functional similarity to mNAT, we named it mNAT2. mNAT2 is predominately expressed in the retina and to a slightly lesser extent in the brain. In the retina, it is located in the axons of ganglion cells in the nerve fiber layer and in the bundles of the optic nerve. Functional analysis of mNAT2 expressed in Xenopus oocytes revealed that the strongest transport activities were specific for l-glutamine. In addition, mNAT2 is a Na(+)- and pH-dependent, high affinity transporter and partially tolerates substitution of Na(+) by Li(+). Additionally, mNAT2 functions as a carrier-mediated transporter that facilitates efflux. The unique expression pattern and selective glutamine transport properties of mNAT2 suggest that it plays a specific role in the uptake of glutamine involved in the generation of the neurotransmitter glutamate in retina. (+info)Transforming growth factor-beta 1 stimulates vascular smooth muscle cell L-proline transport by inducing system A amino acid transporter 2 (SAT2) gene expression. (4/100)
Transforming growth factor-beta1 (TGF-beta 1) is a multifunctional cytokine that contributes to arterial remodelling by stimulating vascular smooth muscle cell (SMC) growth and collagen synthesis at sites of vascular injury. Since l-proline is essential for the synthesis of collagen, we examined whether TGF-beta 1 regulates the transcellular transport of l-proline by vascular SMCs. l-Proline uptake by vascular SMCs was primarily sodium-dependent, pH-sensitive, blocked by neutral amino acids and alpha-(methylamino)isobutyric acid, and exhibited trans-inhibition. Treatment of SMCs with TGF-beta 1 stimulated l-proline transport in a concentration- and time-dependent manner. The TGF-beta 1-mediated l-proline uptake was inhibited by cycloheximide or actinomycin D. Kinetic studies indicated that TGF-beta 1-induced l-proline transport was mediated by an increase in transport capacity independent of any changes in the affinity for l-proline. TGF-beta 1 stimulated the expression of system A amino acid transporter 2 (SAT2) mRNA in a time-dependent fashion that paralleled the increase in l-proline transport. Reverse transcriptase PCR failed to detect the presence of SAT1 or amino acid transporter 3 (ATA3) in either untreated or TGF-beta 1-treated SMCs. These results demonstrate that l-proline transport by vascular SMCs is mediated predominantly by the SAT and that TGF-beta 1 stimulates SMC l-proline uptake by inducing the expression of the SAT2 gene. The ability of TGF-beta 1 to induce SAT2 expression may function to provide SMCs with the necessary levels of l-proline required for collagen synthesis and cell growth. (+info)Physiological importance of system A-mediated amino acid transport to rat fetal development. (5/100)
Fetal growth and development are dependent on the delivery of amino acids from maternal amino acid pools to the fetal blood. This is accomplished via transfer across the apical and basal plasma membrane of the placental syncytiotrophoblast. The aim of this study was to determine whether inhibition of system A (amino acid transporter) was associated with a decrease in fetal weight in the rat. System A is a ubiquitous Na(+)-dependent amino acid transporter that actively transports small zwitterionic amino acids. In brief, system A was inhibited by infusing a nonmetabolizable synthetic amino acid analog, 2-(methylamino)isobutyric acid from days 7-20 of gestation. On day 20, the rats were killed and tissues (maternal liver, fetuses, and placentas) were collected for analysis. The degree of system A inhibition was determined, as was the impact of said inhibition on fetal and maternal weights, system A-mediated placental transport, and placental system A-mediated transporter expression. Our results suggest that when system A is inhibited, fetal weight is diminished [control group: -3.55 +/- 0.04 g (n = 113), experimental group: -3.29 +/- 0.04 g (n = 128)], implying an integral role for system A transport in fetal growth and development in the rat. (+info)Glutamine uptake by neurons: interaction of protons with system a transporters. (6/100)
Astrocytes provide the glutamine required by neurons to synthesize glutamate and GABA. However, the mechanisms involved in glutamine transfer from glia to neurons have remained poorly understood. Recent work has implicated the System N transporter SN1 in the efflux of glutamine from astrocytes and the very closely related System A transporters SA1 and SA2 in glutamine uptake by neurons. To understand how these closely related proteins mediate flux in different directions, we have examined their ionic coupling. In contrast to the electroneutral exchange of H+ for Na+ and neutral amino acid catalyzed by SN1, we now show that SA1 and SA2 do not couple H+ movement to amino acid flux. As a result, SA1 and SA2 are electrogenic and do not mediate flux reversal as readily as SN1. Differences between System N and A transporters in coupling to H+ thus contribute to the delivery of glutamine from glia to neurons. Nonetheless, although they are not transported, H+ inhibit SA1 and SA2 by competing with Na+. (+info)Localization and functional relevance of system a neutral amino acid transporters in cultured hippocampal neurons. (7/100)
Glutamine and alanine are important precursors for the synthesis of glutamate. Provided to neurons by neighboring astrocytes, these amino acids are internalized by classical system A amino acid carriers. In particular, System A transporter (SAT1) is a highly efficient glutamine transporter, whereas SAT2 exhibits broad specificity for neutral amino acids with a preference for alanine. We investigated the localization and the functional relevance of SAT1 and SAT2 in primary cultures of hippocampal neurons. Both carriers have been expressed since early developmental stages and are uniformly distributed throughout all neuronal processes. However, whereas SAT1 is present in axonal growth cones and can be detected at later developmental stages at the sites of synaptic contacts, SAT2 does not appear to be significantly expressed in these compartments. The non-metabolizable amino acid analogue alpha-(methylamino)-isobutyric acid, a competitive inhibitor of system A carriers, significantly reduced miniature excitatory postsynaptic current amplitude in neurons growing on top of astrocytes, being ineffective in pure neuronal cultures. alpha-(Methylamino)-isobutyric acid did not alter neuronal responsitivity to glutamate, thus excluding a postsynaptic effect. These data indicate that system A carriers are expressed with a different subcellular distribution in hippocampal neurons and play a crucial role in controlling the astrocyte-mediated supply of glutamatergic neurons with neurotransmitter precursors. (+info)Insulin promotes the cell surface recruitment of the SAT2/ATA2 system A amino acid transporter from an endosomal compartment in skeletal muscle cells. (8/100)
SAT1-3 comprise members of the recently cloned family of System A transporters that mediate the sodium-coupled uptake of short chain neutral amino acids, and their activity is regulated extensively by stimuli such as insulin, growth factors, and amino acid availability. In skeletal muscle, insulin stimulates System A activity rapidly by a presently ill-defined mechanism. Here we demonstrate that insulin induces an increase in the plasma membrane abundance of SAT2 in a phosphatidylinositol 3-kinase-dependent manner and that this increase is derived from an endosomal compartment that is required for the hormonal activation of System A. Chloroquine, an acidotropic weak base that impairs endosomal recycling of membrane proteins, induced a complete inhibition in the insulin-mediated stimulation of System A, which was associated with a loss in SAT2 recruitment to the plasma membrane. The failure to stimulate System A and recruit SAT2 to the cell surface could not be attributed to a block in insulin signaling, as chloroquine had no effect on the insulin-mediated phosphorylation of protein kinase B or glycogen synthase kinase 3 or upon insulin-stimulated GLUT4 translocation and glucose transport. Our data indicate strongly that insulin increases System A transport in L6 cells by stimulating the exocytosis of SAT2 carriers from a chloroquine-sensitive endosomal compartment. (+info)Peptide and amino acid uptake. Peptidases in the glycocalyx cleave proteins to amino acids or small peptides. Enteropeptidase ( ... Galactose uses the same transport system. Fructose, on the other hand, crosses the apical membrane of the enterocyte, using ... Smaller lipids are transported into intestinal capillaries, while larger lipids are processed by the Golgi and smooth ... Microvilli on the apical surface increase surface area for the digestion and transport of molecules from the intestinal lumen. ...
Peptide and amino acid uptake. Peptidases in the glycocalyx cleave proteins to amino acids or small peptides. Enteropeptidase ( ... Galactose uses the same transport system. Fructose, on the other hand, crosses the apical membrane of the enterocyte, using ... Histology image: 11706loa - Histology Learning System at Boston University - "Digestive System: Alimentary Canal - jejunum, ... This typically occurs through active transport.. *Water uptake. This follows the osmotic gradient established by Na+/K+ ATPase ...
Serotonin is synthesized from an amino acid called L-tryptophan. Active transport system regulates the uptake of tryptophan ... The same motif can be found in reboxetine where it is constrained in a morpholine ring system. Some studies have been made ... 150 mg/day), it acts on serotonergic and noradrenergic systems, whereas at high doses (>300 mg/day), it also affects ... Although the perception and transmission of pain stimuli in the central nervous system have not been fully elucidated, ...
Cysteine is a sulfur-containing amino acid, hence the name "-thionein". However, the participation of inorganic sulfide and ... Metallothioneins likely participate in the uptake, transport, and regulation of zinc in biological systems. Mammalian MT binds ... In this way the thionein-metallothionein becomes a key component of the zinc signaling system in cells. This system is ... of its constituent amino acid residues. MT was discovered in 1957 by Vallee and Margoshe from purification of a Cd-binding ...
The plants are slowly starved of these amino acids and eventually DNA synthesis stops. ESPS Inhibitors affect grasses and ... They are medically important by interfering with components of the nervous system affecting membrane transport, protein ... ALS Inhibitors affect grasses and dicots by inhibiting the first step in some amino acid synthesis, acetolactate synthesis. ... Alkaloids are derived from amino acids, and contain nitrogen. ...
"Coupled and uncoupled proton movement by amino acid transport system N". EMBO Journal. 20 (24): 7041-51. doi:10.1093/emboj/ ... Since Systems A are electrogenic which Systems N are not, the amino acid:cation stoichiometries may differ. Fischer, WN; Loo, ... "Low and high affinity amino acid H+-cotransporters for cellular import of neutral and charged amino acids". Plant Journal. 29 ( ... Six AAAPs in A. thaliana are well characterized and transport neutral and charged amino acids with varying specificities and ...
P. aeruginosa contain 13 RND transport systems, including one HME-RND and the remaining HAE-RNDs. Among the best identified are ... RND proteins are large and can include more than 1000 amino acid residues. They are generally composed of two homologous ... Most of the RND superfamily transport systems are made of large polypeptide chains. RND proteins exist primarily in gram- ... The RND protein dictates the substrate for the completed transport systems including: metal ions, xenobiotics or drugs. ...
In this system, the anionic form of cystine is transported in exchange for glutamate. Cystine is quickly reduced to cysteine.[ ... Cystine is the oxidized dimer form of the amino acid cysteine and has the formula (SCH2CH(NH2)CO2H)2. It is a white solid that ... This transport system, which is highly specific for cystine and glutamate, increases the concentration of cystine inside the ... The presence of cystine in urine is often indicative of amino acid reabsorption defects. Cystinuria has been reported to occur ...
Amino acid synthesis. Chloroplasts alone make almost all of a plant cell's amino acids in their stroma[158] except the sulfur- ... Chloroplasts can pump K+ and H+ ions in and out of themselves using a poorly understood light-driven transport system.[156] ... Chloroplasts carry out a number of other functions, including fatty acid synthesis, much amino acid synthesis, and the immune ... Chloroplasts synthesize all the fatty acids in a plant cell[145][147]-linoleic acid, a fatty acid, is a precursor to jasmonate. ...
The bacteria synthesise amino acids, vitamins, and haem for the protozoan. In return the protozoan offers its enzymes for the ... The bacteria are known to provide essential nutrients to the host, and provide electron transport system for the production of ... the genomic cooperation between bacterium and host in the synthesis of essential amino acids is heavily influenced by multiple ... complete metabolic pathways for the biosysnthesis of amino acids, lipids and nucleotides, that are absent in the bacterium. ...
... is a member of a heterodimeric Na+-independent anionic amino acid transport system highly specific for cystine and ... the amino acid transport activity system xc-". Pflugers Archiv. 442 (2): 286-96. doi:10.1007/s004240100537. PMID 11417227. ... the light chain of amino acid transport system xc-". Antioxidants & Redox Signaling. 2 (4): 665-71. doi:10.1089/ars.2000.2.4- ... "Entrez Gene: SLC7A11 solute carrier family 7, (cationic amino acid transporter, y+ system) member 11". Lutgen V, Resch J, ...
... encodes a protein similar to certain nuclear transport proteins of Xenopus and human. The predicted amino acid sequence shows ... The similarities among these proteins suggests that karyopherin alpha-3 may be involved in the nuclear transport system. KPNA3 ... Most nuclear proteins contain short basic amino acid sequences known as nuclear localization signals (NLSs). KPNA3, ... The transport of molecules between the nucleus and the cytoplasm in eukaryotic cells is mediated by the nuclear pore complex ( ...
Jones HN, Ashworth CJ, Page KR, McArdle HJ (2006). "Cortisol stimulates system A amino acid transport and SNAT2 expression in a ... "Transcriptional control of the human sodium-coupled neutral amino acid transporter system A gene by amino acid availability is ... 2006). "Amino acid starvation induces the SNAT2 neutral amino acid transporter by a mechanism that involves eukaryotic ... 2006). "Characterization of the amino acid response element within the human sodium-coupled neutral amino acid transporter 2 ( ...
... is a member of the system y+ family of transporters characterized by sodium-independent transport of cationic amino acids.[ ... "Entrez Gene: SLC7A3 solute carrier family 7 (cationic amino acid transporter, y+ system), member 3". Hosokawa H, Sawamura T, ... Cationic amino acid transporter 3 is a protein that in humans is encoded by the SLC7A3 gene. SLC7A3 ... Ito K, Groudine M (1997). "A new member of the cationic amino acid transporter family is preferentially expressed in adult ...
"Characterization of an N-system amino acid transporter expressed in retina and its involvement in glutamine transport". J. Biol ... Sodium-coupled neutral amino acid transporter 1 is a protein that in humans is encoded by the SLC38A1 gene. Amino acid ... 2007). "Activation of a system A amino acid transporter, ATA1/SLC38A1, in human hepatocellular carcinoma and preneoplastic ... a subtype of amino acid transporter A, from human placenta". Biochem Biophys Res Commun. 273 (3): 1175-9. doi:10.1006/bbrc. ...
"Molecular cloning of mouse amino acid transport system B0, a neutral amino acid transporter related to Hartnup disorder". J. ... SLC6A19 is a system B(0) transporter that mediates epithelial resorption of neutral amino acids across the apical membrane in ... Solute carrier family 6 member 19 also known as the sodium-dependent neutral amino acid transporter B(0)AT1 or system B(0) ... Bröer S (January 2008). "Amino acid transport across mammalian intestinal and renal epithelia". Physiol. Rev. 88 (1): 249-286. ...
... via the bile acid transport system, where most is stored; though some remains in the blood stream and may contaminate tissue. ... Microcystins contain several uncommon non-proteinogenic amino acids such as dehydroalanine derivatives and the uncommon β-amino ... The impact of exposure to microcystin by patients with a compromised immune system is not yet fully known, but is starting to ... Some evidence shows the toxin can be transported by irrigation into the food chain, Microcystins are chemically stable over a ...
... but often the various transport systems can handle unnatural amino acids with apolar side-chains. In the second case, a ... while the added amino acids are called non-standard amino acids (NSAAs), or unnatural amino acids (uAAs; term not used in ... or non-canonical amino acids. The first element of the system is the amino acid that is added to the genetic code of a certain ... An amino acid auxotrophic expression host is supplemented with an amino acid analog during target protein expression. This ...
Amino acid-based hormones (amines and peptide or protein hormones) are water-soluble and act on the surface of target cells via ... are water-soluble and are thus readily transported through the circulatory system. Other hormones, including steroid and ... Peptides composed of scores or hundreds of amino acids are referred to as proteins. Examples of protein hormones include ... Vertebrate hormones fall into three main chemical classes: Amino acid derived - Examples include melatonin and thyroxine. ...
Glutamate (the conjugate base of glutamic acid) is abundant in the human body, but particularly in the nervous system and ... However, there is a possibility that two human-specific "fixed" amino acid substitutions, D71G in GRIN3A and R727H in GRIN3B, ... Weaver CD, Gundersen V, Verdoorn TA (January 1998). "A high affinity glutamate/aspartate transport system in pancreatic islets ... Meldrum B (1993). "Amino acids as dietary excitotoxins: a contribution to understanding neurodegenerative disorders". Brain Res ...
Amino acid-based hormones (amines and peptide or protein hormones) are water-soluble and act on the surface of target cells via ... A hormone is any member of a class of signaling molecules produced by glands in multicellular organisms that are transported by ... Female endocrine system. Male endocrine system Endocrine disease Endocrinology Exocrine gland Neuroendocrinology Nervous system ... The human endocrine system consists of several systems that operate via feedback loops. Several important feedback systems are ...
The amino-acid sequence identity can go down to 15% between ParM and other actin-like ATPase. The mechanism of partition ... The net result being transport of partition complex to the cell pole. The partition system of the plasmid R388 has been found ... Amino-acid sequence identity can go down to 21% for TubZ proteins. The mechanism is similar to a treadmill mechanism: Multiple ... This system has been proposed to be the type IV partition system. It is thought to be a derivative of the type I partition ...
This transport system normally removes cysteine from the fluid destined to become urine and returns this essential amino acid ... such as glucose or amino acids. When the lipid bilayer is impermeable to the molecule needing transport, active transport is ... Excitatory amino acid transporters (EAATs) EAAT1 EAAT2 EAAT3 EAAT4 EAAT5 Glucose transporter Monoamine transporters, including ... Unlike channel proteins which only transport substances through membranes passively, carrier proteins can transport ions and ...
The transport mechanism for tryptophan is shared with the branched chain amino acids (BCAAs), leucine, isoleucine, and valine. ... amino acid and carbohydrate supplementation on the exercise-induced change in plasma and muscle concentration of amino acids in ... Branch-chained amino acid supplementation has proven to have little to no effect on performance. There has been little success ... Amino acids, brain neurotransmitters and a functional link between muscle and brain that is important in sustained exercise. In ...
Kudo Y, Boyd CA (August 2002). "Changes in expression and function of syncytin and its receptor, amino acid transport system B( ... Neutral amino acid transporter B(0) is a protein that in humans is encoded by the SLC1A5 gene. Glutamate transporter Solute ... "Entrez Gene: SLC1A5 solute carrier family 1 (neutral amino acid transporter), member 5". Tailor CS, Nouri A, Zhao Y, Takeuchi Y ... Uchiyama T, Matsuda Y, Wada M, Takahashi S, Fujita T (April 2005). "Functional regulation of Na+-dependent neutral amino acid ...
... rich in hydroxylated amino acids such as serine, threonine, and proline, and poor in acidic amino acids like aspartic acid and ... 4.2 Phosphorylation, chaperones, and transport. *4.3 The translocon on the outer chloroplast membrane (TOC) *4.3.1 Toc34 and 33 ... the new chloroplast host had to develop a unique protein targeting system to avoid having chloroplast proteins being sent to ... Chloroplast transit peptides exhibit huge variation in length and amino acid sequence.[42] They can be from 20-150 amino acids ...
Classical amino acid transport System A accounts for most of the Na+-dependent neutral amino acid uptake by mammalian cells. ... unlike System ASC, System L does not depend on Na+. Thus, two of the three general amino acid transport systems mediate ... Amino acid transport System A resembles System N in sequence but differs in mechanism. Richard J. Reimer, Farrukh A. Chaudhry, ... Transport mediated by SA1 is also electrogenic. Amino acid transport Systems A and N thus appear closely related in function as ...
... is a member of the heterodimeric amino acid transporter family. Proteins within this family are linked to one another via a ... xCT: Amino Acid Transport and Disorders of the Central Nervous System. Fri, 09/06/2013 - 13:53 ... Home » xCT: Amino Acid Transport and Disorders of the Central Nervous System ... an amino acid that is found only at very low levels in plasma and cerebrospinal fluid. The cysteine is subsequently transported ...
What is Amino acid transport systems, neutral? Meaning of Amino acid transport systems, neutral as a finance term. What does ... Amino acid transport systems, neutral mean in finance? ... Definition of Amino acid transport systems, neutral in the ... Amino acid transport systems, neutral financial definition of Amino acid transport systems, neutral https://financial- ... redirected from Amino acid transport systems, neutral). Also found in: Dictionary, Thesaurus, Medical, Encyclopedia. neutral. ...
Inhibition of amino acid transport system xc- in human SNB19 cells assessed as [3H]L-glutamate uptake at 500 uM by liquid ...
The rBAT gene is responsible for L-cystine uptake via the b0,(+)-like amino acid transport system in a "renal proximal tubular ... like amino acid transport system in a "renal proximal tubular" cell line (OK cells). Journal of Biological Chemistry, 271(18): ... We have also examined transport of l-cystine in OK cells and found characteristics very similar to the amino acid exchanger ... We have also examined transport of l-cystine in OK cells and found characteristics very similar to the amino acid exchanger ...
Renal transport of neutral amino acids. Tubular localization of Na+-dependent phenylalanine- and glucose-transport systems. U ... Renal transport of neutral amino acids. Tubular localization of Na+-dependent phenylalanine- and glucose-transport systems ... Renal transport of neutral amino acids. Tubular localization of Na+-dependent phenylalanine- and glucose-transport systems ... Renal transport of neutral amino acids. Tubular localization of Na+-dependent phenylalanine- and glucose-transport systems ...
The general amino acid transport system of Saccharomyces cerevisiae functions in the uptake of neutral, basic, and acidic amino ... "The general amino acid transport system of Saccharomyces cerevisiae functions in the uptake of neutral, basic, and acidic amino ... The general amino acid transport system of Saccharomyces cerevisiae functions in the uptake of neutral, basic, and acidic amino ... The general amino acid transport system of Saccharomyces cerevisiae functions in the uptake of neutral, basic, and acidic amino ...
Adenosine induces system A amino acid transport in cultured rat hepatocytes. In: Journal of Biochemistry. 1991 ; Vol. 110, No. ... Adenosine induces system A amino acid transport in cultured rat hepatocytes. Journal of Biochemistry. 1991 Jul;110(1):9-11. ... Adenosine induces system A amino acid transport in cultured rat hepatocytes. Hiroaki Kiyokawa, Hiroyuki Fukui, Hiroyuki ... Adenosine induces system A amino acid transport in cultured rat hepatocytes. / Kiyokawa, Hiroaki; Fukui, Hiroyuki; Mizuguchi, ...
... ... chemiosmotic coupling hypothesis has been proposed as a model for the coupling of energy metabolism with amino acid transport ... Although this model has been extensively studied in procaryotic systems, it has not been well characterized in eucaryotic ... systems. Isolation of a mutant yeast strain with altered plasma membrane ATPase activity and the preparation of spheroplasts ...
Jones, C. R., Srinivas, S. R., Devoe, L. D., Ganapathy, V., & Prasad, P. D. (2002). Inhibition of system A amino acid transport ... Inhibition of system A amino acid transport activity by ethanol in BeWo choriocarcinoma cells. American journal of obstetrics ... Inhibition of system A amino acid transport activity by ethanol in BeWo choriocarcinoma cells. / Jones, Chandra R.; Srinivas, ... Jones, CR, Srinivas, SR, Devoe, LD, Ganapathy, V & Prasad, PD 2002, Inhibition of system A amino acid transport activity by ...
Amino acid transport systems, neutral explanation free. What is Amino acid transport systems, neutral? Meaning of Amino acid ... transport systems, neutral medical term. What does Amino acid transport systems, neutral mean? ... Looking for online definition of Amino acid transport systems, neutral in the Medical Dictionary? ... Amino acid transport systems, neutral , definition of Amino acid transport systems, neutral by Medical dictionary https:// ...
A reduced activity of LAT1 remains the primary hypothesis possibly due to a modification of intracellular amino acid content ... relation to genotype and amino acid transport system L Chloé C Feral 1 , Floriane S Tissot 1 , Lionel Tosello 1 , Nicolas ... relation to genotype and amino acid transport system L Chloé C Feral et al. Eur J Nucl Med Mol Imaging. 2017 May. . ... Fluorine-18 labeled amino acids for tumor PET/CT imaging. Qi Y, Liu X, Li J, Yao H, Yuan S. Qi Y, et al. Oncotarget. 2017 Aug 4 ...
Cystinuria is an autosomal-recessive defect in reabsorptive transport of cystine and the dibasic amino acids ornithine, ... Amino acid transport system. Localization in proximal converted tubule. S3. S1, S2 ... Cloning and chromosomal localization of a human kidney cDNA involved in cystine, dibasic, and neutral amino acid transport. J ... Amino acid metabolism in cystinuria. Q J Med New Series. 1974. 214:507-12. ...
series parallel diagram single cell analysis of kynurenine and system l amino acid transport in t cells nature communications. ... Piezo Controllers Drivers For Nanopositioning Systems Series Parallel Diagram Position Control Electronics Optimizes System ...
We investigated the molecular mechanism involved in the adaptive regulation of the amino acid transport system A, a process in ... N2 - We investigated the molecular mechanism involved in the adaptive regulation of the amino acid transport system A, a ... AB - We investigated the molecular mechanism involved in the adaptive regulation of the amino acid transport system A, a ... abstract = "We investigated the molecular mechanism involved in the adaptive regulation of the amino acid transport system A, a ...
Cloning and functional characterization of a new subtype of the amino acid transport system N. ... Cloning and functional characterization of a new subtype of the amino acid transport system N. Together they form a unique ...
... a branched-chain amino acid transport system II carrier protein) contributed to Erava heteroresistance in S. aureus. Genetic ... Furthermore, two efflux pump family proteins encoded by USA300HOU_RS01625 (a branched-chain amino acid transport system II ... encodes a branched-chain amino acid transport system II carrier protein), USA300HOU_RS03535 and USA300HOU_Tet(K), each into ... and branched-chain amino acid transport system II carrier protein, Na/Pi cotransporter family protein in Staphylococcus aureus ...
... and the ability to take up one or more of the 20 common L-alpha-amino acids was studied in order to obtain a complete picture … ... All known amino-acid permeases (AAPs) in Saccharomyces cerevisiae belong to a single family of homologous proteins. Genes of 15 ... Amino Acid Transport Systems * Amino Acids / metabolism* * Amino Acids / pharmacokinetics * DNA-Binding Proteins / genetics ... Radiolabelled amino-acid uptake measurements showed that Agp1p is a general permease for most uncharged amino acids (Ala, Gly, ...
... in the vertebrate nervous system. The process by which developing neurons select between these two cell fates is poorly ... Vesicular Transport Proteins* * gamma-Aminobutyric Acid / metabolism* Substances * Amino Acid Transport Systems ... in the vertebrate nervous system. The process by which developing neurons select between these two cell fates is poorly ... Gad1/2 and Viaat that regulate GABA synthesis and transport, and the kainate receptors Grik2/3. Third, ectopic expression of ...
AMINO ACIDS AS CENTRAL NERVOUS TRANSMITTERS: THE INFLUENCE OF IONS, AMINO ACID ANALOGUES, AND ONTOGENY ON TRANSPORT SYSTEMS for ... AMINO ACIDS AS CENTRAL NERVOUS TRANSMITTERS: THE INFLUENCE OF IONS, AMINO ACID ANALOGUES, AND ONTOGENY ON TRANSPORT SYSTEMS for ... AMINO ACIDS AS CENTRAL NERVOUS TRANSMITTERS : THE INFLUENCE OF IONS, AMINO ACID ANALOGUES, AND ONTOGENY ON TRANSPORT SYSTEMS ... AMINO ACIDS AS CENTRAL NERVOUS TRANSMITTERS: THE INFLUENCE OF IONS, AMINO ACID ANALOGUES, AND ONTOGENY ON TRANSPORT SYSTEMS for ...
Double mutants deficient in transport of both these amino acids still possess the general amino acid transport system, a third ... system which was described previously. Evidence for additional amino acid transport systems in Chlorella is discussed. ... Six amino acids are transported at high rates across the plasmalemma of Chlorella vulgaris only after the induction of two ... List of Publication » Selection and characterization of chlorella mutants deficient in amino Acid transport : further evidence ...
branched-chain amino acid transport system substrate-binding protein Aromatic compound transport protein 1076 ... Putative branched-chain amino acid transport system substrate-binding protein 1076 4 3UKJ 1 A Extracellular ligand-binding ... Putative branched-chain amino acid transport system substrate-binding protein 1076 7 4EYQ 1 A Extracellular ligand-binding ... Putative branched-chain amino acid transport system substrate-binding protein UNP residues 27-385 1076 ...
Amino acid transport system xc xCT antibody. *Amino acid transport system xc- ... Belongs to the amino acid-polyamine-organocation (APC) superfamily. L-type amino acid transporter (LAT) (TC 2.A.3.8) family. ... Solute carrier family 7 (anionic amino acid transporter light chain, xc- system), member 11 ... Solute carrier family 7, (cationic amino acid transporter, y+ system) member 11 ...
1990) The identification of neutral amino acid transport systems. Exp Physiol 75(1):3-26. ... The 2-amino-4-methyl-3-cyanato-5-thiophenecarboxylate ethyl ester was obtained from Life Chemicals. Cyanoacetic acid was ... The genetic evidence pointing to the importance of the amino acid serine in tumorigenesis is striking. The gene encoding the ... At the cellular level, serine can be imported from the extracellular space via amino acid transporters (6, 7). Alternatively, ...
... accounts for the activity of transport system A for neutral amino acids in most mammalian tissues. As the transport process ... Sodium-dependent neutral amino acid transporter-2 (SNAT2), the ubiquitous member of SLC38 family, ... Amino Acid Transport System A / physiology*. Amino Acids, Neutral / metabolism*. Biological Transport. Cell Membrane / ... 0/Amino Acid Transport System A; 0/Amino Acids, Neutral; 0/Hypertonic Solutions; 0/RNA, Small Interfering; 0/SLC38A2 protein, ...
ProteinSubstratesMetabolismTryptophanFingerprintCysteineGlutamineExtracellular amino acidsCationic amino acidsAlanineGeneral amino-acid permeaseRatsGlutamateInhibitionSpecificityGlycineNitrogenMetabolicPermeaseHigh affinitySaccharomycesCharacterizationCell membranesPlacentaMechanismsNeutral amino acid transportHeteromericMethylaminoTransporters playSubstancesMammalian aminoNeuronsInsulinPlacentalNutrientMolecularStarvationBrain interstitialInduces systemMoleculesSubtypeGene expressionAffinityNucleic AcidsMechanism
- Because System A also catalyzes Na + -dependent amino acid transport sensitive to low pH, we considered that the protein(s) responsible might belong to the same family as VGAT and, in particular, SN1. (pnas.org)
- To demonstrate that the rBAT protein is functionally related to this transport activity, we have transfected OK cells with human rBAT antisense and sense sequences. (uzh.ch)
- In contrast, the chronic phase is associated with an induction of ata2 gene expression as evidenced from the increase in the steady-state levels of ATA2 mRNA, restoration of the intracellular pool of ATA2 protein, and blockade of the induction by cycloheximide and actinomycin D. The increase in system A activity induced by amino acid starvation is blocked specifically by system A substrates, including the non-metabolizable α-(methylamino)isobutyric acid. (elsevier.com)
- RT-qPCR analysis and the in vitro overexpression experiments indicated that USA300HOU_RS00550 (an Na/Pi cotransporter family protein) and USA300HOU_RS01625 (a branched-chain amino acid transport system II carrier protein) contributed to Erava heteroresistance in S. aureus . (biomedcentral.com)
- Mechanistically, genetic studies in Drosophila, along with cellular and biophysical studies in mammalian systems, demonstrate the dominant negative effect exerted by the mutant on the wild-type (WT) protein, which explains dominant inheritance. (bireme.br)
- The nuclear transport activity of various mutants was estimated by analyzing the proportion of protein localized in the nucleus. (bireme.br)
- RESULTS In the absence of insulin, gAd stimulated AMPK Thr172 phosphorylation, SNAT2 protein expression, and system A activity. (diabetesjournals.org)
- Cyanobacteria produce a range of secondary metabolites, one being the neurotoxic non-protein amino acid β- N -methylamino-L-alanine (BMAA), proposed to be a causative agent of human neurodegeneration. (mdpi.com)
- For instance, BMAA is a small non-protein amino acid that appears to be synthesized by the entire cyanobacterial phylum [ 5 , 6 ], suggesting that BMAA is a fundamental cellular metabolite in cyanobacteria. (mdpi.com)
- Note: Tryptophan and Phenylalanine are amino acids commonly found in protein-rich foods such a meat, nuts, and legumes. (amazonaws.com)
- The heteromeric amino acid transporters are composed of a type II glycoprotein and a non‐glycosylated polytopic membrane protein. (embopress.org)
- Plasma concentrations of amino acids are frequently elevated in insulin-resistant states, and a protein-enriched diet can impair glucose metabolism. (diabetesjournals.org)
- Plasma concentrations of alanine and particularly branched-chain amino acids (AAs) are elevated in insulin-resistant states such as obesity ( 1 , 2 ), and high dietary protein intake impairs glucose metabolism mainly by changing the utilization of gluconeogenic precursors ( 3 - 6 ). (diabetesjournals.org)
- Identification and functional analysis of fructosyl amino acid-binding protein from Gram-positive bacterium Arthrobacter sp. (semanticscholar.org)
- Characterization of the binding protein-dependent cellobiose and cellotriose transport system of the cellulose degrader Streptomyces reticuli. (semanticscholar.org)
- A protein chain can consist of anything from ten to tens of thousands of amino acids. (nobelprize.org)
- Some antibiotics inhibit the monitoring mechanism of the molecular ruler (see illustration above), others hinder the formation of the connection between amino acids or block the tunnel through which the emerging protein chain leaves the ribosome. (nobelprize.org)
- Induction of AGP1 by amino acids also requires Grr1p, the F-box protein of the SCF Grr1 ubiquitin-protein ligase complex also required for transduction of the glucose signal generated by the Snf3p and Rgt2p glucose sensors. (asm.org)
- The essential role of Grr1p in this amino acid signaling pathway lends further support to the hypothesis that this protein participates in integrating nutrient availability with the cell cycle. (asm.org)
- Protein and Amino Acid Metabolism 16. (whsmith.co.uk)
- "Quantitative phosphoproteomic analysis of T cell receptor signaling reveals system-wide modulation of protein-protein interactions. (tcdb.org)
- Phylogenetic characterization of novel transport protein families revealed by genome analyses. (antievolution.org)
- Tracing pathways of transport protein evolution. (antievolution.org)
- Ssy1p is a unique member of the amino acid permease gene family, and Ptr3p is predicted to be a hydrophilic protein that lacks known functional homologs. (asm.org)
- Subcellular fractionation experiments reveal that both Ssy1p and Ptr3p are localized to the plasma membrane (PM). Ssy1p requires the endoplasmic reticulum protein Shr3p, the amino acid permease-specific packaging chaperonin, to reach the PM, whereas Ptr3p does not. (asm.org)
- As the transport process performed by SNAT2 is highly energized, system A substrates, such as glutamine, glycine, proline and alanine, reach high transmembrane gradients and constitute major components of the intracellular amino acid pool. (biomedsearch.com)
- For less permeable substrates the placenta possesses both passive and active transport mechanisms. (hindawi.com)
- Changes in energy availability or ion gradients can profoundly influence net transfer of substrates transported by active mechanisms. (hindawi.com)
- b o,+ AT‐reconstituted systems from HeLa or MDCK cells catalysed transport of arginine that was totally dependent on the presence of one of the b o,+ substrates inside the liposomes. (embopress.org)
- At the cellular level, availability of substrates for energy production, such as AAs and free fatty acids (FFAs), may play an important role in modulating the response to insulin ( 7 ). (diabetesjournals.org)
- It also mediates an anion leak conductance that is differentially inhibited by transported substrates ( Zhang and Grewer, 2007 ). (tcdb.org)
- The chemiosmotic coupling hypothesis has been proposed as a model for the coupling of energy metabolism with amino acid transport in S. cerevisiae. (kzoo.edu)
- This is mainly because a standard methodology for extracting functional category information, such as individual metabolism, energy generation and transportation systems, has not yet been fully established. (biomedcentral.com)
- Well-known examples include insulin, which comprises 51 amino acid building blocks and controls the metabolism of sugar, or cyclosporine, an eleven amino acid-peptide that has been proven to suppress organ rejection after transplants. (eurekalert.org)
- Carbohydrate Metabolism I: Glycolysis and the Tricarboxylic Acid Cycle 13. (whsmith.co.uk)
- Endocrine Metabolism V: Reproductive System 33. (whsmith.co.uk)
- The word metabolism can also refer to the sum of all chemical reactions that occur in living organisms, including digestion and the transport of substances into and between different cells, in which case the set of reactions within the cells is called intermediary metabolism or intermediate metabolism. (wikipedia.org)
- Amino acids also contribute to cellular energy metabolism by providing a carbon source for entry into the citric acid cycle (tricarboxylic acid cycle), especially when a primary source of energy, such as glucose, is scarce, or when cells undergo metabolic stress. (wikipedia.org)
- l-Tryptophan, which is transported exclusively by the general transport system, was used as a substrate. (umn.edu)
- In the presence of glucose as an energy source, NCAO inhibited tryptophan transport competitively (Ki=80 μM) during short time intervals (1-2 min), but adding 100 μM NCAO to a yeast cell suspension resulted in a time-dependent activation of tryptophan transport during the first 15 min of treatment. (umn.edu)
- Following the activation a time-dependent decay of tryptophan transport activity occurred. (umn.edu)
- When a yeast cell suspension was treated with NCAO in the absence of an energy source, an 80% inactivation of tryptophan transport occurred in 90 min. (umn.edu)
- Addition of a fivefold excess of L-lysine during NCAO treatment or prevented inactivation of tryptophan transport. (umn.edu)
- The amino-acids tryptophan, phenylalanine and tyrosine seem to play an important role in the pathophysiology of depressive disorders. (nature.com)
- Both neurotransmitters are synthesized from aromatic amino-acids, i.e. serotonin from tryptophan, and noradrenalin from tyrosine or its precursor phenylalanine. (nature.com)
- Taken together, different classes of NVU-AATs constitute an integrated dynamic system controlling the homeostasis of AAs such as large neutral amino acids (LNAAs: L-tyrosine, L-leucine, L-isoleucine, L-phenylalanine, L-histidine, L-valine, L-tryptophan, and L-methionine) in the brain interstitial fluid (ISF). (frontiersin.org)
- A number of members of the medical profession have observed that high doses of the trace element selenium, and of the amino acids cysteine, tryptophan, and glutamine can together rapidly reverse the symptoms of AIDS, as predicted by Dr. Harold D. Foster's nutritional hypothesis. (newmediaexplorer.org)
- Fingerprint Dive into the research topics of 'Cloning and functional characterization of a new subtype of the amino acid transport system N'. Together they form a unique fingerprint. (elsevier.com)
- System ASC preferentially transports alanine, serine, and cysteine but also recognizes other aliphatic amino acids ( 3 ). (pnas.org)
- The cysteine is subsequently transported in to neurons, where it supports glutathione production. (novusbio.com)
- MTs have the capacity to bind both physiological (such as zinc, copper, selenium) and xenobiotic (such as cadmium, mercury, silver, arsenic) heavy metals through the thiol group of its cysteine residues, which represent nearly 30% of its constituent amino acid residues. (wikipedia.org)
- Their production is dependent on availability of the dietary minerals such as zinc, copper, and selenium, as well as the amino acids histidine and cysteine. (wikipedia.org)
- The three amino acids comprising glutathione are glutamate, cysteine, and glycine. (asnjournals.org)
- When taken in a form of capsule of tablet, L-glutamine can give protection to your muscles during rigorous workouts and can also enhance your immune system to make it more likely to increase muscle mass. (archive.org)
- Plant roots incorporate inorganic nitrogen into the amino acids glutamine, glutamic acid, asparagine and aspartic acid, which together serve as the primary metabolites of nitrogen transport to other tissues. (biologists.org)
- Aspartic acid aminotransferase and asparagine synthase use glutamic acid and glutamine, respectively, as nitrogen donors to produce aspartic acid and asparagine. (biologists.org)
- It is the sole system that transports glutamate and glutamine, but it can also transport aspartate and asparagine ( Singh and Röhm 2008 ). (tcdb.org)
- System A function also varies inversely with the concentration of extracellular amino acids as part of adaptive regulation and up-regulates with cell proliferation and hypertonic shock, suggesting additional homeostatic roles. (pnas.org)
- Both Ssy1p and Ptr3p have previously been implicated in relaying signals regarding the presence of extracellular amino acids. (asm.org)
- These findings suggest that Ssy1p and Ptr3p function in the PM as components of a sensor of extracellular amino acids. (asm.org)
- while Can1p, Lyp1p and the previously uncharacterized Alp1p are specific for the cationic amino acids. (nih.gov)
- hATB(0+) was found to transport both neutral and cationic amino acids, with the highest affinity for hydrophobic amino acids and the lowest affinity for proline. (tcdb.org)
- The Na-dependent alanine/α-(methylamino) isobutyric acid-transporting system A, ATA3 or SNAT4. (tcdb.org)
- It comprised six molecules of the simplest amino acid, alanine. (eurekalert.org)
- These findings modify the prevalent view that S. cerevisiae only contains one general amino-acid permease, Gap1p, and a number of permeases that are specific for a single or a few amino acids. (nih.gov)
- Sialic acid supplementation ameliorates puromycin aminonucleoside nephrosis in rats. (nih.gov)
- In this study, we investigated PGB transport in rats, mammalian cell lines, and Xenopus laevis oocytes. (aspetjournals.org)
- Sodium-independent, high-affinity exchange of anionic amino acids with high specificity for anionic form of cystine and glutamate. (abcam.com)
- For example, in the central nervous system, glutamate transporters are critically important in maintaining the extracellular glutamate concentration below neurotoxic levels, and defects of the human D2 gene have been shown to account for the formation of kidney stones in patients with cystinuria. (biologists.org)
- Taurine is a potent antioxidant and anti-inflammatory semi-essential amino acid extensively involved in neurological activities, acting as neurotrophic factor, binding to GABA A/glycine receptors and blocking the excitotoxicity glutamate-induced pathway leading to be a neuroprotective effect and neuromodulation. (mdpi.com)
- Transport by System N also depends on Na + but shows a striking sensitivity to inhibition by low external pH. (pnas.org)
- However, the mutual inhibition alone is insufficient to conclude which specific transport system is involved in PGB transport in the ileum. (aspetjournals.org)
- Pharmacological inhibition of system Xc causes a rapid depletion of intracellular glutathione, resulting in decreased cell growth. (freepatentsonline.com)
- It was trans-stimulated by amino acids with the same specificity as rBAT-induced transport activity in oocytes. (uzh.ch)
- Genes of 15 AAPs were overexpressed in different strains, and the ability to take up one or more of the 20 common L-alpha-amino acids was studied in order to obtain a complete picture of the substrate specificity for these permeases. (nih.gov)
- Amino acids are taken up by different transport systems with overlapping substrate specificity. (aspetjournals.org)
- The inhibitory effects of 5-hydroxytryptophan and 4-aminomethylbenzoic acid were additive, demonstrating that both PAT1 and PepT1 contribute to intestinal transport of ALA. This is the first demonstration of overlap in substrate specificity between these distinct transporters for amino acids and dipeptides. (aspetjournals.org)
- We show here that SSY1 is required for transcriptional induction, in response to multiple amino acids, of the AGP1 gene encoding a low-affinity, broad-specificity amino acid permease. (asm.org)
- Developmental studies revealed GABA and l‐glutamic acid to have absolute sodium requirements for cortical synaptosomal accumulation from the 16th gestational day through adulthood, with glycine accumulation showing a decreasing sodium requirement as maturation proceeded over this period. (elsevier.com)
- Cyclic hexapeptide in its bioactive form with the integrin-binding tripeptide sequence arginine-glycine-aspartic acid: Green spheres represent carbon atoms, red oxygen atoms, blue nitrogen atoms and white hydrogen atoms. (eurekalert.org)
- A sequence of the three amino acids arginine, glycine and aspartic acid is the key to the docking at these receptors. (eurekalert.org)
- All four permeases are transcriptionally induced by an extracellular amino acid, but differ in expression with respect to the nitrogen source. (nih.gov)
- or γ- 15 N). The metabolic fate of the dietary 15 N and 13 C was traced using gas chromatography-mass spectrometry (GC-MS). Nitrogen was the major contributor to the observed amino acid isotopomers with one additional unit mass (M+1). (biologists.org)
- However, there was differential incorporation, with the amine nitrogen of asparagine being incorporated into other amino acids more efficiently than the amide nitrogen. (biologists.org)
- Hilger, D. 2007-04-06 00:00:00 Amino acid transport is a ubiquitous phenomenon and serves a variety of functions in prokaryotes, including supply of carbon and nitrogen for catabolic and anabolic processes, pH homeostasis, osmoprotection, virulence, detoxification, signal transduction and generation of electrochemical ion gradients. (deepdyve.com)
- The volume further deals with the metabolic engineering of microorganisms for the biotechnological production of amino acids for use as pharmaceuticals and, particularly, as food and feed additives. (springer.com)
- Maternal diet and obesity impact fuels, hormones, and inflammation with powerful effects on fetal metabolic systems. (diabetesjournals.org)
- The acquired form of 5-oxoproline (pyroglutamic acid) metabolic acidosis was first described in 1989 and its relationship to chronic acetaminophen ingestion was proposed the next year. (asnjournals.org)
- Both diffusion and carrier mediated transport mechanisms which facilitate molecular trafficking through transcellular route to maintain influx and outflux of important nutrients and metabolic substances are elucidated. (hindawi.com)
- The metabolic system of a particular organism determines which substances it will find nutritious and which poisonous. (wikipedia.org)
- The availability of both a positive selection technique and an extensive nutritional screening system has enabled the identification of fourteen spontaneous deletion mutations, recognized as extending into the prn B gene, specifying the principal L-proline permease, and into at least one other prn gene. (cambridge.org)
- Systematic analysis of amino acid permease genes showed that Ssy1p is involved in transcriptional induction of at least five genes in addition to AGP1 . (asm.org)
- Our results show that the amino acid permease homologue Ssy1p is a sensor of external amino acids, coupling availability of amino acids to transcriptional events. (asm.org)
- By contrast, in the outer-medullary preparation, L-phenylalanine transport occurred via two transport systems, namely a high-affinity system with K1A congruent to 0.33 mM and a low-affinity system with K2A congruent to 7 mM respectively. (biochemj.org)
- The physiological importance of the arrangement of low-affinity and high-affinity transport systems along the kidney proximal tubule is discussed. (biochemj.org)
- The majority of other AAP family members are low-capacity, high-affinity amino acid permeases, each exhibiting characteristic narrow substrate specificities ( 31 ). (asm.org)
- Larimore, FS & Roon, RJ 1978, ' Possible Site-Specific Reagent for the General Amino Acid Transport System of Saccharomyces cerevisiae ', Biochemistry , vol. 17, no. 3, pp. 431-436. (umn.edu)
- Saccharomyces cerevisiae provides an attractive model system for studying adhesion in yeast because of its well-characterized genetics and gene expression systems and the conservation of signal transduction pathways among the yeasts. (asm.org)
- The SSY1 gene of Saccharomyces cerevisiae encodes a member of a large family of amino acid permeases. (asm.org)
- Amino acids are transported into the yeast Saccharomyces cerevisiae by both general and specific transport systems. (asm.org)
- Selection and characterization of chlorella mutants deficient in amino Acid transport : further evidence for three independent systems. (fau.de)
- The characterization of the control mechanisms of amino acid biosynthesis has revealed insights into principles of genetic and biochemical regulation, such as transcriptional regulators and a new class of regulatory elements, the riboswitch. (springer.com)
- These heterodimers facilitate the transport of amino acids across cell membranes. (novusbio.com)
- Numerous solutes move across the NVU cell membranes with various transport mechanisms. (frontiersin.org)
- frequently occurs by way of active transport within cell membranes, an excess of one nutrient (A) may inhibit absorption of a second nutrient (B), if they share the same absorption pathway. (britannica.com)
- Fetal growth is dependent on nutrient availability, which in turn is related to the capacity of the placenta to transport these nutrients. (hindawi.com)
- Furthermore, the placenta with its nutrient transport functions is increasingly seen as being the mediator of maternal nutrition effects on the lifelong health consequences for the child [ 8 - 10 ]. (hindawi.com)
- A wide range of nutrients (e.g., amino acids, phosphorus, and lactate) are transported across the placenta mediated by secondary active transport, utilizing energy provided by ion gradients such as sodium, chloride, and protons [ 14 - 16 ]. (hindawi.com)
- Their function as exchangers presumably relies on the active accumulation of amino acids through other mechanisms. (pnas.org)
- Animals that feed on nutritionally unbalanced resources such as phloem sap, which typically has sub-optimal amounts of essential amino acids, have evolved mechanisms for acquiring or synthesizing these amino acids. (biologists.org)
- The mechanisms that independently control or modulate Ure2p in response to ammonium and Nil2p activity in response to amino acids have not been elucidated. (asm.org)
- The neutral amino acid transport system of larval midgut has been studied most extensively. (biologists.org)
- PDF] Heteromeric amino acid transporters: biochemistry, genetics, and physiology. (semanticscholar.org)
- The heteromeric amino acid transporters (HATs) are composed of two polypeptides: a heavy subunit (HSHAT) and a light subunit (LSHAT) linked by a disulfide bridge. (semanticscholar.org)
- The function of system A was monitored by the transport of α-(methylamino)isobutyric acid. (elsevier.com)
- System-L amino acid transporters play a key role in pancreatic β-cell signalling and function. (nih.gov)
- This work has furthermore advanced our understanding of the roles these transporters play in amino acid homeostasis and in various pathologies. (biologists.org)
- Organic anion-transporting polypeptide (OATP)1B1, OATP1B3, and OATP2B1 transporters play an important role in hepatic drug disposition. (aspetjournals.org)
- Present review paper highlights role of BBB in endothelial transport of various substances into the brain. (hindawi.com)
- HATs represent several of the classic mammalian amino acid transport systems (e.g. (semanticscholar.org)
- Glutamatergic and GABAergic neurons mediate much of the excitatory and inhibitory neurotransmission, respectively, in the vertebrate nervous system. (nih.gov)
- The BBB endothelium together with the astrocytes and neurons are the fundamental elements of the neurovascular unit (NVU) system. (frontiersin.org)
- When combined with insulin, gAd did not affect system A activity or SNAT expression. (diabetesjournals.org)
- In contrast, fAd abolished insulin-stimulated AKT Thr308 and IRS-1 Tyr612 phosphorylation, system A activity, and SNAT2 expression. (diabetesjournals.org)
- As a result, fAd inhibits insulin-stimulated amino acid transport, which may have important implications for placental nutrient transport and fetal growth in pregnancy complications associated with altered maternal adiponectin levels. (diabetesjournals.org)
- Ive been told by some people to add BCAA's and some insulin spiking amino acids to this shake. (exrx.net)
- We hypothesized that adiponectin regulates placental amino acid transport. (diabetesjournals.org)
- however, the primary determinant of fetal growth is nutrient supply, which is dependent on placental nutrient transport. (diabetesjournals.org)
- Obesity in pregnancy ( 9 , 10 ) and gestational diabetes mellitus ( 11 ) are associated with low maternal circulating levels of adiponectin, but the impact of adiponectin on placental nutrient transport functions is unknown. (diabetesjournals.org)
- The activity of a range of nutrient transporters has been reported to be decreased in placentas of growth restricted fetuses, whereas at least some studies indicate that placental nutrient transport is upregulated in fetal overgrowth. (hindawi.com)
- These findings suggest that changes in placental nutrient transport may directly contribute to the development of abnormal fetal growth. (hindawi.com)
- Fetal growth is largely determined by nutrient supply, which is dependent upon placental nutrient transport. (hindawi.com)
- This suggests that changes in placental nutrient transport directly contribute to altered fetal growth. (hindawi.com)
- What circulatory systems are involved in nutrient absorption and transport? (studystack.com)
- We investigated the molecular mechanism involved in the adaptive regulation of the amino acid transport system A, a process in which amino acid starvation induces the transport activity. (elsevier.com)
- Molecular characteristics of mammalian and insect amino acid transporters: implications for amino acid homeostasis. (biologists.org)
- Using similar approaches, we are investigating the molecular characteristics of K(+)-coupled amino acid transporters in the larval lepidopteran insect midgut. (biologists.org)
- Dr Julian Dow Laboratory of Cell Biology, Division of Cellular and Molecular Biology, Institute of Biomedical and Life Sciences, University of Glasgow: Genetic analysis of epithelial transport in Drosophila. (bio.net)
- however, the molecular basis for this transport system is still unknown. (tcdb.org)
- Similarly, expression of most genes encoding amino acid biosynthetic enzymes is stimulated severalfold in response to starvation for any one of several amino acids ( 35 , 45 ). (asm.org)
- The homeostatic regulation of large neutral amino acid (LNAA) concentration in the brain interstitial fluid (ISF) is essential for proper brain function. (frontiersin.org)
- These findings suggest that adenosine induces System A amino acid transport in a transcription-dependent manner, and that P,-purinergic receptors are mainly involved in this action of the nucleoside. (elsevier.com)
- Microvilli on the apical surface increase surface area for the digestion and transport of molecules from the intestinal lumen . (wikipedia.org)
- In addition, roles of various receptors, ATP powered pumps, channels, and transporters in transport of vital molecules in maintenance of homeostasis and normal body functions have been described in detail. (hindawi.com)
- Carbohydrates are the most abundant biological molecules, and fill numerous roles, such as the storage and transport of energy (starch, glycogen) and structural components (cellulose in plants, chitin in animals). (wikipedia.org)
- "Structure and function of ATA3, a new subtype of amino acid transport system A, primarily expressed in the liver and skeletal muscle. (tcdb.org)
- Multiple hormones increase System A function acutely through changes in the driving force for transport as well as through longer-term changes in gene expression. (pnas.org)
- They can function by either a channel-type or a carrier-type mechanism, and in the latter case, they are frequently energized by coupling solute transport to the flux of an ion down its electrochemical gradient. (antievolution.org)