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Christensen HN. Exploiting amino acid structure to learn about membrane transport. ADVANCES IN ENZYMOLOGY AND RELATED AREAS OF MOLECULAR BIOLOGY 2006; 49:41-101. [PMID: 400855 DOI: 10.1002/9780470122945.ch2] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Christensen HN. Some special kinetic problems of transport. ADVANCES IN ENZYMOLOGY AND RELATED AREAS OF MOLECULAR BIOLOGY 2006; 32:1-20. [PMID: 4892501 DOI: 10.1002/9780470122778.ch1] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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3
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Abstract
Normal fetal growth and development depend on a continuous supply of amino acids from the mother to the fetus. The placenta is responsible for the transfer of amino acids between the two circulations. The human placenta is hemomonochorial, meaning that the maternal and fetal circulations are separated by a single layer of polarized epithelium called the syncytiotrophoblast, which is in direct contact with maternal blood. Transport proteins located in the microvillous and basal membranes of the syncytiotrophoblast are the principal mechanism for transfer from maternal blood to fetal blood. Knowledge of the function and regulation of syncytiotrophoblast amino acid transporters is of great importance in understanding the mechanism of placental transport and potentially improving fetal and newborn outcomes. The development of methods for the isolation of microvillous and basal membrane vesicles from human placenta over the past two decades has contributed greatly to this understanding. Now a primary cultured trophoblast model is available to study amino acid transport and regulation as the cells differentiate. The types of amino acid transporters and their distribution between the syncytiotrophoblast microvillous and basal membranes are somewhat unique compared with other polarized epithelia. These differences may reflect the unusual circumstance of this epithelium that is exposed to blood on both sides. The current state of knowledge as to the types of transport systems present in syncytiotrophoblast, their regulation, and the effects of maternal consumption of drugs on transport are discussed.
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Affiliation(s)
- A J Moe
- Edward Mallinkrodt Department of Pediatrics, Children's Hospital, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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4
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Abstract
There is growing evidence that neurotransmitters can be released not only by exocytosis but also through the membrane carriers responsible for transmitter reuptake. Giulio Levi and Maurizio Raiteri review the in vitro and in vivo evidence supporting the existence of a carrier-mediated release for different classes of transmitters. While the physiological significance of carrier-mediated release remains speculative, widely used drugs such as sympathomimetic amines, the anorectic drug fenfluramine and some drugs of abuse act in part by stimulating monoamine carrier-mediated release. Moreover, antidepressants known to inhibit monoamine reuptake, can block carrier-mediated release. This mechanism may also come into play in pathological conditions such as ischaemia.
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Affiliation(s)
- G Levi
- Neurobiology Section, Istituto Superiore di Sanitá, Rome, Italy
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Sweiry JH, Muñoz M, Mann GE. Cis-inhibition and trans-stimulation of cationic amino acid transport in the perfused rat pancreas. THE AMERICAN JOURNAL OF PHYSIOLOGY 1991; 261:C506-14. [PMID: 1909494 DOI: 10.1152/ajpcell.1991.261.3.c506] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Transport of cationic amino acids in the isolated perfused rat pancreas was studied using dual-isotope dilution techniques. At 50 microM substrate concentration, unidirectional tracer uptakes for L-arginine (56 +/- 1%), L-lysine (49 +/- 2%), and L-ornithine (44 +/- 3%) were followed by rapid tracer efflux. In the presence of Na+, influx of L-arginine [Michaelis constant (Km) = 1.74 +/- 0.15 mM, maximum velocity (Vmax) = 1.97 +/- 0.07 mumol.min-1.g-1] and L-lysine (Km = 2.48 +/- 0.17 mM, Vmax = 2.42 +/- 0.08 mumol.min-1.g-1) was mediated by a common transport system, sensitive to cis-inhibition by L-ornithine, 2,4-L-diaminobutyric acid, D-lysine, and D-arginine. Substrates for system A [alpha-(methylamino)isobutyric acid] and an anionic carrier (L-aspartate) were poor cis-inhibitors of L-arginine entry. Removal of Na+ resulted in a 40% reduction in cationic amino acid influx. After cell loading (20 min), L-[3H]-lysine cleared predominantly from a slowly exchanging pool with a rate constant of 5.97 +/- 0.67 min. An influx/efflux permeability ratio of 14.5 +/- 1.6 was determined, and efflux of L-lysine was trans-stimulated by vascular challenges with cationic or large neutral amino acids. The specificity, relative Na+ independence, and exchange properties of this saturable cationic amino acid transporter in the pancreatic epithelium resemble those reported for system y+ in cultured fibroblasts and hepatocytes.
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Affiliation(s)
- J H Sweiry
- Biomedical Sciences Division, King's College London, United Kingdom
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Stewart BH, Collarini EJ, Pisoni RL, Christensen HN. Separate and shared lysosomal transport of branched and aromatic dipolar amino acids. BIOCHIMICA ET BIOPHYSICA ACTA 1989; 987:145-53. [PMID: 2605258 DOI: 10.1016/0005-2736(89)90537-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Transport systems analogous to the T and L carriers for aromatic and bulky dipolar amino acids in plasma membranes have been characterized in the membranes of intact lysosomes isolated from human fetal skin fibroblasts. While system L appears ubiquitous in plasma membranes, system T has previously been discriminated only in the plasmalemma of human red blood cells and freshly isolated rat hepatocytes. Our findings with the lysosomal systems, provisionally designated t and l, reveal both shared and dissimilar properties with the plasma membrane systems. These properties include a lack of dependency on extralysosomal Na+, differential sensitivities to the classical system L analog, 2-aminobicyclo[2.2.1]heptane-2-carboxylic acid (BCH), and the system T analog, D-tryptophan, as well as susceptibility to thiol modification at the membrane by reactivity with N-ethylmaleimide. A transport system in lysosomes from the FRTL-5 rat thyroid cell line has been described by Bernar et al. ((1986) J. Biol. Chem. 261, 17107-17112) resembles a composite of both carrier systems reported in this work.
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Affiliation(s)
- B H Stewart
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor
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Handlogten ME, Kilberg MS. Growth-dependent regulation of system A in SV40-transformed fetal rat hepatocytes. THE AMERICAN JOURNAL OF PHYSIOLOGY 1988; 255:C261-70. [PMID: 2844092 DOI: 10.1152/ajpcell.1988.255.3.c261] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Fetal RLA209-15 hepatocytes, transformed with a temperature-sensitive SV40 mutant, behave like fully differentiated cells at the growth-restrictive temperature of 40 degrees C. Conversely, incubation at the growth-permissive temperature of 33 degrees C results in a transformed phenotype characterized by rapid cell division and decreased production of liver-specific proteins. The results presented here demonstrate that the cells at 33 degrees C exhibited high rates of system A transport, but transfer to 40 degrees C reduced the activity greater than 50% within 24 h. This decline in transport was independent of cell density, although the basal rate of uptake was inversely proportional to cell density in rapidly dividing cells. Transfer of cells from 40 to 33 degrees C resulted in an enhancement of system A activity that was blocked by tunicamycin. Plasma membrane vesicles from cells maintained at either 33 or 40 degrees C retained uptake rates proportional to those in the intact cells; this difference in transport activity could also be demonstrated after detergent solubilization and reconstitution. Collectively, these data indicate that de novo synthesis of the system A carrier is regulated in conjunction with temperature-dependent cell growth in RLA209-15 hepatocytes.
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Affiliation(s)
- M E Handlogten
- Department of Biochemistry and Molecular Biology, University of Florida School of Medicine, Gainesville 32610
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Wheatley DN, Inglis MS, Malone PC. The concept of the intracellular amino acid pool and its relevance in the regulation of protein metabolism, with particular reference to mammalian cells. CURRENT TOPICS IN CELLULAR REGULATION 1986; 28:107-82. [PMID: 3539533 DOI: 10.1016/b978-0-12-152828-7.50005-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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10
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Thoene JG, Forster S, Lloyd JB. The role of pinocytosis in the cellular uptake of an amino acid. Biochem Biophys Res Commun 1985; 127:733-8. [PMID: 3985954 DOI: 10.1016/s0006-291x(85)80004-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Uptake of L- and D-alanine by the rat visceral yolk sac has been studied in vitro in incubations of short duration. It is concluded that much of the uptake of D-alanine is due to fluid-phase pinocytosis and that the plasma membrane L-alanine porter is more stereospecific than has hitherto been supposed.
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11
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Bannai S. Transport of cystine and cysteine in mammalian cells. BIOCHIMICA ET BIOPHYSICA ACTA 1984; 779:289-306. [PMID: 6383474 DOI: 10.1016/0304-4157(84)90014-5] [Citation(s) in RCA: 236] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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12
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Miller JG, Schultz GA. Properties of amino acid transport in preimplantation rabbit embryos. THE JOURNAL OF EXPERIMENTAL ZOOLOGY 1983; 228:511-25. [PMID: 6663263 DOI: 10.1002/jez.1402280311] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The kinetics, specificity, time dependency, Na+ dependency, and exchange behavior of the uptake of methionine, as a model for the uptake of the neutral amino acids, was investigated in rabbit eggs, morulae, and 6-day blastocysts. Uptake by the blastocyst was physically resolved into components representing uptake into the cellular and cavity compartments. The kinetic data for all material, except the cellular compartment of the blastocyst, could be described mathematically by the parallel activity of a saturable and a linear transport system. The Km decreased from 91 microM in the unfertilized egg to 38 microM in the fertilized egg to 13 microM in the 69-hr morula. The Km of uptake into blastocysts was 131 microM. The Vmax of uptake into the whole blastocyst was calculated to be about 5000 times that of uptake into the egg. Competition of methionine uptake by other amino acids indicated that the egg had somewhat more "L-like" transport specificity than subsequent developmental stages, while the system(s) in the blastocyst were reactive with most neutral amino acids. Uptake into the egg, 69-hr morula, and the cellular compartment of the blastocyst reached a steady state with time, in contrast to uptake into the 76-hr morula and the cavity compartment of the blastocyst. Compatible with this, was the observation that eggs and 69-hr morula, but not blastocysts, exhibited considerable efflux into amino acid-containing media. The cavity compartment of the blastocyst may, however, act as a reservoir of amino acids for the cellular compartment. The Na+ dependency of transport was unchanged throughout the developmental period studied in this investigation.
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White MF, Christensen HN. Simultaneous regulation of amino acid influx and efflux by system A in the hepatoma cell HTC. Ouabain simulates the starvation-induced derepression of system A amino acid transport. J Biol Chem 1983. [DOI: 10.1016/s0021-9258(20)82023-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Malik JK, Schwarz LR, Wiebel FJ. Assessment of membrane damage in continuous cultures of mammalian cells. Chem Biol Interact 1983; 45:29-42. [PMID: 6872098 DOI: 10.1016/0009-2797(83)90040-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The present studies were aimed at evaluating procedures for assessing the effect of chemicals on the integrity of the plasma membrane in continuous cell cultures. The degree of membrane damage was monitored by determining the 'leakage' of alpha-[3H]aminoisobutyric acid ([3H]AIB) and [14C]deoxy-2-fluoro-D-glucose ([14C]FdG) from the prelabelled cells. These parameters were compared to the loss of lactate dehydrogenase (LDH) from the cells and the decrease in the intracellular level of K+. Triton X-100, sodium dodecylsulfate (SDS), phospholipase C and nystatin which are known to affect membranes by different mechanisms served as test agents. In parallel, we monitored the effects of the chemicals on the viability of the cells. The following results were obtained: (1) The two radioactive markers [3H]AIB and [14C]FdG were found to be suitable to probe for damages of the plasma membrane in a variety of continuous cell lines which differ widely in their phenotype, rate of growth and degree of differentiation. (2) The leakage of the two markers could conveniently be monitored by double labelling techniques. (3) The loss from the cells of the 3 markers of smaller molecular size, K+, [3H]AIB, [14C]FdG, differed considerably depending on the test agent used. (4) Intracellular K+ level and [3H]AIB leakage generally appeared to follow a similar pattern, whereas [14C]FdG leakage may have shown a distinctly different response. (5) The leakage of LDH was an insensitive indicator for membrane damage. (6) No clear relationship was detectable between a particular leakage pattern of the markers and the loss of cellular viability.
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Weigensberg AM, Johnstone RM, Blostein R. Reversal of Na+-dependent glycine transport in sheep reticulocyte membrane vesicles. J Bioenerg Biomembr 1982; 14:335-45. [PMID: 7161278 DOI: 10.1007/bf00743062] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Inside-out membrane vesicles have been prepared from sheep reticulocytes. With these vesicles, Na+-dependent glycine uptake and net accumulation have been demonstrated to occur in reverse, i.e., from extravesicular (normal cytoplasmic) to intravesicular (normal extravesicular) surface. Uptake and accumulation are inhibited by energization of the sodium pump by ATP whereby the Na+ electrochemical gradient is dissipated. Glycine-dependent Na+ uptake was also observed, providing evidence that Na+-dependent glycine influx into these vesicles, equivalent to normal efflux, is characterized by Na+-glycine co-transport.
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White MF, Christensen HN. The two-way flux of cationic amino acids across the plasma membrane of mammalian cells is largely explained by a single transport system. J Biol Chem 1982. [DOI: 10.1016/s0021-9258(18)33986-3] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Bannai S, Ishii T. Transport of cystine and cysteine and cell growth in cultured human diploid fibroblasts: effect of glutamate and homocysteate. J Cell Physiol 1982; 112:265-72. [PMID: 6126484 DOI: 10.1002/jcp.1041120216] [Citation(s) in RCA: 107] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Human diploid fibroblasts take up cystine in the culture medium and the cystine is immediately reduced to cysteine in the cells. It is found that cysteine thus formed is rapidly released from the cells into the medium and accumulates there. The system transporting cysteine is convincingly similar to the ASC system described by Christensen et al. (1967). Since cysteine in the medium is sensitive to autoxidation and readily changes back to cystine, the uptake of cystine seems crucial to the cells. Inhibitors of cystine uptake, such as glutamate and homocysteate, potently reduce the intracellular and extracellular levels of cysteine. These inhibitors modify the cell growth depending upon the cystine concentration is physiological. An excessive concentration of cystine is in itself inhibitory action is antagonized by glutamate or homocysteate.
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Johnstone RM, Laris PC. Bimodal effects of cellular amino acids on Na+-dependent amino acid transport in Ehrlich cells. BIOCHIMICA ET BIOPHYSICA ACTA 1980; 599:715-30. [PMID: 7407111 DOI: 10.1016/0005-2736(80)90212-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Cells depleted of amino acids show lower rates of glycine or aminoisobutyric acid uptake than do freshly isolated cells. In the amino acid-depleted cells, addition of valinomycin stimulates amino acid influx at least to the level observed in freshly isolated cells. In cells containing high levels of cellular amino acids, valinomycin has little effect on influx of amino acids. It is concluded that the transport of amino acids in freshly isolated cells is elevated compared to depleted cells because the cells are hyperpolarized by the continuous loss of cellular amino acids during the transport assay. During this hyperpolarization by amino acid loss, transport of amino acids is not further stimulated by valinomycin at low external [K+] (10 mM +/- 5 mM). With the exception of preloading with glycine, cells preloaded with a single amino acid to a concentration greater than 20 mM show reduced rates of glycine and aminoisobutyric acid influx at early times (less than 15 min) compared to amino acid-depleted cells. The reduction of influx is transient and by 30 min, influx is greater in preloaded than in amino acid-depleted cells. Knowing that increases and decreases in the membrane potential are achieved by using varying external [K+] in the presence of valinomycin and propranolol, and using amino acid-depleted cells, it can be shown that an increased membrane potential increases the V for glycine and aminoisobutyric acid influx. A decrease in the potential difference results in a decreased V. Changes in Km also occur when the membrane potential is varied.
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Ohsawa M, Kilberg MS, Kimmel G, Christensen HN. Energization of amino acid transport in energy-depleted Ehrlich cells and plasma membrane vesicles. BIOCHIMICA ET BIOPHYSICA ACTA 1980; 599:175-90. [PMID: 7397146 DOI: 10.1016/0005-2736(80)90066-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
We redirect attention to contributions to the energization, of the active transport of amino acids in the Ehrlich cell, beyond the known energization, by down-gradient comigration of Na+, beyond possible direct energization by coupling to ATP breakdown, and beyond known energization by exchange with prior accumulations of amino acids. We re-emphasize the uphill operation of System L, and by prior depletion of cellular amino acids show that this system must receive energy beyond that made available by their coupled exodus. After this depletion the Na+-indepdendent accumulation of the norbornane amino acid, 2-aminobicycloheptane-2-carboxylic acid becomes strongly subject to stimulation by incubation with glucose. Energy transfer between Systems A and L through the mutual substrate action of ordinary amino acids was minimized although not entirely avoided by the use of amino acid analogs specific to each system. When 2,4-dinitrophenol was included in the depleting treatment, and pyruvate, phenazine methosulfate, or glucose used for restoration, recovery of uptake of the norbornane amino acid was independent of external Na+ or K+ levels. Restoration or the uptake of 2-(methylamino)isobutyric acid was, however, decreased by omission of external K+. Contrary to an earlier finding, restoration of uptake of each of these amino acids was associated with distinct and usually correlated rises in cellular ATP levels. ATP addition failed to stimulate exodus of the norbornane amino acid from plasma membrane vesicles, although either NADH or phenazine methosulfate did stimulate exodus. ATP production and use is thus associated with transport energization although evidence for a direct role failed to appear.
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Kilberg MS, Christensen HN. The relation between membrane potential and the transport activity of system A and L in plasma membrane vesicles of the Ehrlich cell. MEMBRANE BIOCHEMISTRY 1980; 3:155-68. [PMID: 7432185 DOI: 10.3109/09687688009063883] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Plasma membrane vesicles isolated from Ehrlich ascites tumor cells have been used to investigate the role of the transmembrane potential in the energetics of Systems A and L. As expected, Na+ -dependent System A was responsive to changes in membrane potential. System L activity, as measured by transport of 2-amino-norbornane-2-carboxylic acid (BCH), was shown to be Na+ -independent and was not altered by changes in the membrane potential. The combination of valinomycin and nigericin decreased accumulation of MeAIB but not that of BCH. The presence of nigericin alone caused a significant decrease in uptake by System A and a decrease in uptake by System L to a lesser degree. The inhibitory action of nigericin might reflect its ability to dissipate the Na+ gradient rather than an effect on K+ or H+ flows. The results indicate that modes of energization not produced through the transmembrane potential must account for any uphill operation of System L.
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Im WB, Deutchler JT, Spector AA. Effects of membrane fatty acid composition on sodium-independent phenylalanine transport in Ehrlich cells. Lipids 1979; 14:1003-8. [PMID: 529997 DOI: 10.1007/bf02533437] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Christensen HN, Handlogten ME. Interaction between parallel transport systems examined with tryptophan and related amino acids. JOURNAL OF NEURAL TRANSMISSION. SUPPLEMENTUM 1979:1-13. [PMID: 290747 DOI: 10.1007/978-3-7091-2243-3_1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Most of the neutral amino acids are transported across the plasma membrane by two or more parallel transport systems. In this study, we have limited transport interactions to System A and L by studying amino acids not transported by System ASC. Results are presented to emphasize that such amino acids as leucine, phenylalanine and tryptophan do enter the Ehrlich cell to substantial degrees by System A. We show how the phenomenon of competitive stimulation presents a strong argument that these systems operate between the same two compartments, extracellular and cellular. To discover what is needed to bring two amino acids into the transport relation shown by tryptophan and methionine, we arbitrarily set up two classes of amino acids: (1) those whose steady-state gradients will be increased when System L is deleted; (2) those whose gradients will instead be decreased. On blockading System L with 2-aminorbornane-2-carboxylic acid applied in symmetry to the two sides of the plasma membrane, we show as predicted that the gradient maintained for methionine is strongly increased, that for trypotphan decreased. The initial rate of uptake of all the amino acids mentioned is highly sensitive to the nature of the cellular amino acid pool. A high influx by exchange, relative to net influx, appears to characterize the amino acids that respond to competitive stimulation. Albumin-bound tryptophan appears not directly accessible to the tested carriers.
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Guidotti GG, Borghetti AF, Gazzola GC. The regulation of amino acid transport in animal cells. BIOCHIMICA ET BIOPHYSICA ACTA 1978; 515:329-66. [PMID: 365236 DOI: 10.1016/0304-4157(78)90009-6] [Citation(s) in RCA: 393] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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25
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Johnstone RM. The basic asymmetry of Na+-dependent glycine transport in Ehrlich cells. BIOCHIMICA ET BIOPHYSICA ACTA 1978; 512:199-213. [PMID: 698214 DOI: 10.1016/0005-2736(78)90230-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Influx and efflux of glycine have been examined as a function of external and internal Na+ concentrations, respectively, when : formula: (see text) = O. With : formula: (see text) = O it was found that at comparable external and cellular Na+ levels, the Km for efflux was larger by an order of magnitude than the value for influx and the V for efflux was several times greater than the V for influx. For both fluxes the major effect of Na+ was to decrease the Km value. The observations are consistent with the conclusion that the Na+-dependent transport system is asymmetric per se. Influx and efflux of glycine were increased in a near linear manner by increasing the Na+ concentration from 13 to 100 mM, the half-time for glycine equilibration being a funcion of the Na+ concentration in absence of an electrochemical potential difference for Na+. In Na+-free media ([Na+] less than 5 mM) equilibration of glycine between cells and medium was not achieved after 60 min at 25 degrees C. With : formula: (see text) = O, efflux (or uptake) of glycine was not affected by internal (or external) K+ between 20 and 120 mM suggesting that K+ plays no direct role in Na+-dependent transport of glycine in Ehrlich cells.
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Blackman MS, McDaniel CN. Amino acid transport in suspension cultured plant cells: I. Methods and kinetics of L-leucine uptake. ACTA ACUST UNITED AC 1978. [DOI: 10.1016/0304-4211(78)90061-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Ruzycki SM, Kelley LK, Smith CH. Placental amino acid uptake. IV. Transport microvillous membrane vesicles. THE AMERICAN JOURNAL OF PHYSIOLOGY 1978; 234:C27-35. [PMID: 623238 DOI: 10.1152/ajpcell.1978.234.1.c27] [Citation(s) in RCA: 69] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The recent characterization of a vesicular microvillous plasma membrane preparation from human placenta has made possible study of the characteristics of amino acid transport by the isolated membrane. Variation of medium osmolality demonstrated that alpha-aminoisobutyric acid (AIB) is taken up virtually entirely into a vesicular space. Vesicular volume was determined from equilibrium uptake of three dissimilar nonamino acid substrates, all of which gave a common value. Temperature dependence, saturability, specificity, and similarity of kinetic constants all indicated that AIB uptake by the vesicles resembles that by whole villous tissue. AIB uptake was stimulated specifically by an inward sodium gradient and unaffected by an outward potassium gradient. The persistence of stimulation up to 2 h after the gradient was established could be correlated with the slow equilibration of sodium across the membrane. AIB exodus could be studied with minimal problems of substrate recapture by using preloaded membrane vesicles bound tightly to cellulose ester filters to facilitate transfer to fresh medium. The exodus process was saturable with a Km considerably greater than that for entry.
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Christensen HN, Handlogten ME. Does the non-saturable cell entry apply to the charge-free form of amino acids? BIOCHIMICA ET BIOPHYSICA ACTA 1977; 469:216-20. [PMID: 561617 DOI: 10.1016/0005-2736(77)90184-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The slow cellular entry shown by neutral alpha-amino acids at very high concentrations appears not to arise from diffusion of the totally uncharged species through the plasma membrane of the Ehrlich cell, judging from a similarity of the rates observed for the two conformational isomers of 1-amino-2-hydroxy-cyclohexane-carboxylic acid. One of these isomers provides in neutral solution 4 times as large a proportion of the charge-free species as the other, and 5 times the proportion calculated for alanine.
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Ruderman NB, Schmahl FW, Goodman MN. Regulation of alanine formation and release in rat muscle in vivo: effect of starvation and diabetes. THE AMERICAN JOURNAL OF PHYSIOLOGY 1977; 233:E109-14. [PMID: 888947 DOI: 10.1152/ajpendo.1977.233.2.e109] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Lindqvist I, Nilsson O, Ronquist G. Preferential uptake of 14c-alpha-aminoisobuturic acid into mouse uterine tissue during early pregnancy. ACTA PHYSIOLOGICA SCANDINAVICA 1977; 99:37-41. [PMID: 842363 DOI: 10.1111/j.1748-1716.1977.tb10349.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The uptake of 14C-AIB into uterine tissue and some other organs was studied during early implantation. Mice in experimentally delayed implantation were given estrogen and 14C-AIB at different time intervals. Mice in delayed implantation given only 14C-AIB displayed a low transport rate into the uterine tissue, comparable with that for the diaphragm muscle. However, if the estrogen injection preceeded that of the 14C-AIB by 4 to 8 h the transport capacity increased by a factor of at least 4 times while the uptake for the diaphargm muscle remained low. Under such conditions 14C-AIB-accumulation into uterine tissue was favoured for at least 4 h of in vivo incubation with the labeled amino acid.
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Christensen HN. Amino acid transport systems in animal cells: interrelations and energization. JOURNAL OF SUPRAMOLECULAR STRUCTURE 1977; 6:205-13. [PMID: 20537 DOI: 10.1002/jss.400060206] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Im WB, Christensen HN. Heterogeneity of histidine transport in the Ehrlich cell. BIOCHIMICA ET BIOPHYSICA ACTA 1976; 455:144-51. [PMID: 11000 DOI: 10.1016/0005-2736(76)90159-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
We have reexamined the heterogeneity shown by histidine in its uptake by the Ehrlich ascites tumor cell, in the face of a contradiction of our earlier interpretation. We again find the fraction of histidine uptake at neutral pH inhibitable by the model substrate for System A, 2-(methylamino)-isobutyric acid, to be fully dependent on the presence of Na+ or Li+. The small Na+ -independent component not attributable to System L can be identified with System Ly+ through its inhibitability by homoarginine. This component increases as the pH is lowered with an apparent pK' a of 6.1. The simultaneous decrease in the uptake by the neutral systems could be identified, for System L, with the same titration of histidine to its cationic form, but for System A the sharp decrease is identified with the protonation of a structure on the membrane rather than one on the substrate. The action of H+ in the latter case proved approximately non-competitive with Na+ when tested with ordinary substrates.
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Ronquist G, Agren G, Ponten J, Westermark B. Alpha-aminoisobutyric acid transport into human glia and glioma cells in culture. J Cell Physiol 1976; 89:433-9. [PMID: 977662 DOI: 10.1002/jcp.1040890309] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The AIB transport into human glia and glioma cells in culture has been studied. Because of the high affinity of AIB to the plastic culture dishes, a special washing technique had to be developed. With this technique, it was possible to perform transport experiments in a single plate containing about one million cells. The cells were viable, intact and adhered to the supporting medium throughout the experiment. The AIB transport into both types of cells was Na+-dependent and showed saturation kinetics when the small component of the transport due to diffusion had been subtracted. The AIB transport capacity of neoplastic glioma cells was 3.6 times higher than that of glia cells. This difference was related to the Vmax-values for the two types of cells. The apparent Km-values were the same. Inhibition experiments with other amino acids support the view that AIB is transported via System A in both glia and glioma cells. Sulfhydryl reagents (ethacrynic acid and NEM) and cytochalasin B clearly inhibited the AIB transport into glia cells whereas the effect on glioma cells was minimal.
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Ames A, Parks JM, Nesbett FB. Transport of leucine and sodium in central nervous tissue: studies on retina in vitro. J Neurochem 1976; 27:999-1015. [PMID: 12170629 DOI: 10.1111/j.1471-4159.1976.tb00302.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Unidirectional leucine fluxes were measured in isolated rabbit retina maintained under steady state conditions in medium resembling CSF but with leucine varied from 2 to 20,000 microM. At physiological leucine concentration (11 microM), 1/2 time for outward transport was 88 s and intracellular fluid was cleared of isotopically labelled leucine at 2.3 ml/g dry wt./min; 1/2 time for inward transport was 16 s and interstitial fluid was cleared at 7.5 ml/g dry wt./min. The rate of leucine influx corresponded quite well with its rate of disappearance from the intracellular fluid, over a wide range of concentrations. Exchange diffusion was demonstrated for transport in both directions. There was competition by other amino acids, but no interaction between Na+ and leucine transport could be demonstrated. Kinetic analysis indicated the presence of more than one transport system for leucine. There was an unexpected fall in the efflux coefficient, with reduction in leucine concentration at the lower end of the concentration range, for which an explanation is proposed. Under control conditions, 1/2 time for efflux of intracellular 24Na+ was about 0.9 min. With intracellular Na+ increased 4 fold, 1/2 time for efflux was slightly reduced. Problems encountered in measuring fluxes in organized tissue are discussed.
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Affiliation(s)
- A Ames
- Neurosurgical Service, Massachusetts General Hospital, Boston, MA 02114, USA
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36
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Wade LA, Katzman R. Synthetic amino acids and the nature of L-DOPA transport at the blood-brain barrier. J Neurochem 1975; 25:837-42. [PMID: 1206400 DOI: 10.1111/j.1471-4159.1975.tb04415.x] [Citation(s) in RCA: 139] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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37
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Harrison LI, Christensen HN. Simulation of differential effects on rates in membrane transport. J Theor Biol 1975; 49:439-59. [PMID: 1121190 DOI: 10.1016/0022-5193(75)90185-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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38
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Harrison LI, Christensen HN. Simulation of differential effects on rates in membrane transport. J Theor Biol 1975. [DOI: 10.1016/s0022-5193(75)80047-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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39
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Recognition Sites for Material Transport and Information Transfer. ACTA ACUST UNITED AC 1975. [DOI: 10.1016/s0070-2161(08)60105-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Johnstone RM. Role of ATP on the initial rate of amino acid uptake in Ehrlich ascites cells. BIOCHIMICA ET BIOPHYSICA ACTA 1974; 356:319-30. [PMID: 4858486 DOI: 10.1016/0005-2736(74)90272-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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42
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Christensen HN, De Cespedes C, Handlogten ME, Ronquist G. Modified transport substrates as probes for intramembrane gradients. Ann N Y Acad Sci 1974; 227:355-79. [PMID: 4133305 DOI: 10.1111/j.1749-6632.1974.tb14400.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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43
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Christensen HN, de Cespedes C, Handlogten ME, Ronquist G. Energization of amino acid transport, studied for the Ehrlich ascites tumor cell. BIOCHIMICA ET BIOPHYSICA ACTA 1973; 300:487-522. [PMID: 4130564 DOI: 10.1016/0304-4157(73)90017-8] [Citation(s) in RCA: 124] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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44
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Gazzola GC, Franchi-Gazzola R, Ronchi P, Guidotti GG. Regulation of amino acid transport in chick embryo heart cells. 3. Formal identification of the A mediation as an adaptive transport system. BIOCHIMICA ET BIOPHYSICA ACTA 1973; 311:292-301. [PMID: 4736914 DOI: 10.1016/0005-2736(73)90275-7] [Citation(s) in RCA: 63] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Battistin L, Piccoli F, Lajtha A. Heteroexchange of amino acids in incubated slices of brain. Arch Biochem Biophys 1972; 151:102-11. [PMID: 5044511 DOI: 10.1016/0003-9861(72)90478-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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47
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Levi G. Transport systems for GABA and for other amino acids in incubated chick brain tissue during development. Arch Biochem Biophys 1972; 151:8-21. [PMID: 5044528 DOI: 10.1016/0003-9861(72)90466-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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48
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Cass CE. Density-dependent fluctuations in membrane permeability in logarithmically growing cell cultures. Exp Cell Res 1972; 73:140-4. [PMID: 5036981 DOI: 10.1016/0014-4827(72)90111-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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49
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Coben LA, Cotlier E, Beaty C, Becker B. Transport of amino acids by rabbit choroid plexus in vitro. Brain Res 1971; 30:67-82. [PMID: 5092631 DOI: 10.1016/0006-8993(71)90006-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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50
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Manchester KL, Guidotti GG, Borghetti AF, Lüneburg B. Evaluation of kinetic parameters for uptake of amino acids by cells: effect of insulin on the accumulation of aminoisobutyrate and cycloleucine by isolated rat diaphragm muscle and chick embryo hearts. BIOCHIMICA ET BIOPHYSICA ACTA 1971; 241:226-41. [PMID: 5125248 DOI: 10.1016/0005-2736(71)90319-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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