Evidence for a high affinity, Na+-dependent glutamate transport system in lactating rat mammary tissue

1995 ◽  
Vol 23 (4) ◽  
pp. 567S-567S
Author(s):  
I.D. MILLAR ◽  
D.T. CALVERT ◽  
M.A. LOMAX ◽  
D.B. SHENNAN
Keyword(s):  
Transport System ◽  
Glutamate Transport ◽  
Mammary Tissue ◽  
High Affinity

Identification of a high affinity taurine transporter which is not dependent on chloride

1995 ◽  
Vol 15 (4) ◽  
pp. 231-239 ◽  
Author(s):  
D. B. Shennan
Keyword(s):  
Amino Acids ◽  
Transport System ◽  
Niflumic Acid ◽  
Cell Swelling ◽  
Mammary Tissue ◽  
Taurine Transporter ◽  
Taurine Transport ◽  
High Affinity ◽  
Taurine Uptake

Taurine transport by lactating gerbil mammary tissue has been examined. Taurine uptake is, mediated by a high-affinity system which is specific for β-amino acids. The uptake of taurine is Na+-dependent but appears not to be obligatorly dependent upon Cl−. Thus, replacing Na+ with choline almost abolished taurine uptake. Substituting Cl− with NO3− had no effect whereas SCN− induced a small but significant increase in taurine influx. Taurine uptake was Na+-dependent under conditions where Cl− had been replaced with NO3−. However, it is apparent that the Na+-dependent taurine transport system requires the presence of a permeable anion because replacing Cl− with gluconate markedly reduced taurine uptake. Cell-swelling, induced by a hyposmotic challenge, increased the efflux of taurine from gerbil mammary tissue via a pathway sensitive to niflumic acid.

scholarly journals Induction of the high-affinity Na+-dependent glutamate transport system XAG- by hypertonic stress in the renal epithelial cell line NBL-1

1995 ◽  
Vol 310 (2) ◽  
pp. 689-692 ◽  
Author(s):  
A Ferrer-Martinez ◽  
A Felipe ◽  
B Nicholson ◽  
J Casado ◽  
M Pastor-Anglada ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Cell Line ◽  
Transport System ◽  
Glutamate Transport ◽  
Transport Systems ◽  
Epithelial Cell Line ◽  
Renal Epithelial Cell ◽  
Hypertonic Stress ◽  
High Affinity ◽  
Renal Epithelial Cell Line

The high-affinity Na(+)-dependent glutamate transport system XAG- is induced (threefold increase in Vmax. with no change in Km) by hypertonicity in the renal epithelial cell line NBL-1. This effect is dependent on protein synthesis and glycosylation and is accompanied by an increase in EAAC1 mRNA levels. Other Na(+)-dependent transport systems in this cell line do not respond to hypertonic stress. In contrast to recent findings [Ruiz-Montasell, Gomez-Angelats, Casado, Felipe, McGivan and Pastor-Anglada (1994) Proc. Natl. Acad. Sci. U.S.A. 91, 9569-9573] showing that increased system A activity after hyperosmotic shock results from induction of a regulatory protein, this is the first demonstration that hypertonicity may increase the expression of the gene for an amino acid transport protein itself.

Regulation of the High-Affinity Nitrate Transport System in Wheat Roots by Exogenous Abscisic Acid and Glutamine

2007 ◽  
Vol 49 (12) ◽  
pp. 1719-1725 ◽  
Author(s):  
Chao Cai ◽  
Xue-Qiang Zhao ◽  
Yong-Guan Zhu ◽  
Bin Li ◽  
Yi-Ping Tong ◽  
...  
Keyword(s):  
Abscisic Acid ◽  
Transport System ◽  
Nitrate Transport ◽  
Wheat Roots ◽  
High Affinity

scholarly journals RCO-3 and COL-26 form an external-to-internal module that regulates the dual-affinity glucose transport system in Neurospora crassa

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Jinyang Li ◽  
Qian Liu ◽  
Jingen Li ◽  
Liangcai Lin ◽  
Xiaolin Li ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Neurospora Crassa ◽  
Glucose Transport ◽  
Transport System ◽  
Rational Design ◽  
Glucose Sensor ◽  
Glucose Transporters ◽  
Glucose Fluctuation ◽  
High Affinity ◽  
Glucose Transport System

Abstract Background Low- and high-affinity glucose transport system is a conserved strategy of microorganism to cope with environmental glucose fluctuation for their growth and competitiveness. In Neurospora crassa, the dual-affinity glucose transport system consists of a low-affinity glucose transporter GLT-1 and two high-affinity glucose transporters HGT-1/HGT-2, which play diverse roles in glucose transport, carbon metabolism, and cellulase expression regulation. However, the regulation of this dual-transporter system in response to environmental glucose fluctuation is not yet clear. Results In this study, we report that a regulation module consisting of a downstream transcription factor COL-26 and an upstream non-transporting glucose sensor RCO-3 regulates the dual-affinity glucose transport system in N. crassa. COL-26 directly binds to the promoter regions of glt-1, hgt-1, and hgt-2, whereas RCO-3 is an upstream factor of the module whose deletion mutant resembles the Δcol-26 mutant phenotypically. Transcriptional profiling analysis revealed that Δcol-26 and Δrco-3 mutants had similar transcriptional profiles, and both mutants had impaired response to a glucose gradient. We also showed that the AMP-activated protein kinase (AMPK) complex is involved in regulation of the glucose transporters. AMPK is required for repression of glt-1 expression in starvation conditions by inhibiting the activity of RCO-3. Conclusions RCO-3 and COL-26 form an external-to-internal module that regulates the glucose dual-affinity transport system. Transcription factor COL-26 was identified as the key regulator. AMPK was also involved in the regulation of the dual-transporter system. Our findings provide novel insight into the molecular basis of glucose uptake and signaling in filamentous fungi, which may aid in the rational design of fungal strains for industrial purposes.

scholarly journals Functional Characterization of a High-Affinity Choline Transport System in Human Keratinocytes

2002 ◽  
Vol 119 (1) ◽  
pp. 118-121 ◽  
Author(s):  
Kathrin Hoffmann ◽  
Franziska Grafe ◽  
Wolfgang Wohlrab ◽  
Reinhard H. Neubert ◽  
Matthias Brandsch
Keyword(s):  
Transport System ◽  
Functional Characterization ◽  
Human Keratinocytes ◽  
Choline Transport ◽  
High Affinity

scholarly journals Corrigendum to: A high affinity nitrate transport system from Chlamydomonas requires two gene products (FEBS 23233)

FEBS Letters ◽  
2000 ◽  
Vol 481 (1) ◽  
pp. 88-88
Author(s):  
Jing-Jiang Zhou ◽  
Emilio Fernández ◽  
Aurora Galván ◽  
Anthony J. Miller
Keyword(s):  
Transport System ◽  
Nitrate Transport ◽  
Gene Products ◽  
High Affinity

scholarly journals High-affinity maltose/trehalose transport system in the hyperthermophilic archaeon Thermococcus litoralis.

1996 ◽  
Vol 178 (16) ◽  
pp. 4773-4777 ◽  
Author(s):  
K B Xavier ◽  
L O Martins ◽  
R Peist ◽  
M Kossmann ◽  
W Boos ◽  
...  
Keyword(s):  
Transport System ◽  
Thermococcus Litoralis ◽  
Hyperthermophilic Archaeon ◽  
High Affinity
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