Cloning and Functional Expression of ATA1, a Subtype of Amino Acid Transporter A, from Human Placenta

2000 ◽  
Vol 273 (3) ◽  
pp. 1175-1179 ◽  
Author(s):  
Haiping Wang ◽  
Wei Huang ◽  
Mitsuru Sugawara ◽  
Lawrence D. Devoe ◽  
Frederick H. Leibach ◽  
...  
Keyword(s):  
Amino Acid ◽  
Human Placenta ◽  
Functional Expression ◽  
Amino Acid Transporter ◽  
Acid Transporter

scholarly journals SNAT4 isoform of system A amino acid transporter is expressed in human placenta

2006 ◽  
Vol 290 (1) ◽  
pp. C305-C312 ◽  
Author(s):  
M. Desforges ◽  
H. A. Lacey ◽  
J. D. Glazier ◽  
S. L. Greenwood ◽  
K. J. Mynett ◽  
...  
Keyword(s):  
Amino Acid ◽  
Protein Expression ◽  
Western Blot ◽  
Human Placenta ◽  
Blot Analysis ◽  
First Trimester ◽  
Amino Acid Transporter ◽  
Full Term ◽  
System A ◽  
Acid Transporter

The system A amino acid transporter is encoded by three members of the Slc38 gene family, giving rise to three subtypes: Na+-coupled neutral amino acid transporter (SNAT)1, SNAT2, and SNAT4. SNAT2 is expressed ubiquitously in mammalian tissues; SNAT1 is predominantly expressed in heart, brain, and placenta; and SNAT4 is reported to be expressed solely by the liver. In the placenta, system A has an essential role in the supply of neutral amino acids needed for fetal growth. In the present study, we examined expression and localization of SNAT1, SNAT2, and SNAT4 in human placenta during gestation. Real-time quantitative PCR was used to examine steady-state levels of system A subtype mRNA in early (6–10 wk) and late (10–13 wk) first-trimester and full-term (38–40 wk) placentas. We detected mRNA for all three isoforms from early gestation onward. There were no differences in SNAT1 and SNAT2 mRNA expression with gestation. However, SNAT4 mRNA expression was significantly higher early in the first trimester compared with the full-term placenta ( P < 0.01). We next investigated SNAT4 protein expression in human placenta. In contrast to the observation for gene expression, Western blot analysis revealed that SNAT4 protein expression was significantly higher at term compared with the first trimester ( P < 0.05). Immunohistochemistry and Western blot analysis showed that SNAT4 is localized to the microvillous and basal plasma membranes of the syncytiotrophoblast, suggesting a role for this isoform of system A in amino acid transport across the placenta. This study therefore provides the first evidence of SNAT4 mRNA and protein expression in the human placenta, both at the first trimester and at full term.

scholarly journals Cloning, functional expression and dietary regulation of the mouse neutral and basic amino acid transporter (NBAT)

1997 ◽  
Vol 328 (2) ◽  
pp. 657-664 ◽  
Author(s):  
Hiroko SEGAWA ◽  
Ken-ichi MIYAMOTO ◽  
Yoshio OGURA ◽  
Hiromi HAGA ◽  
Kyoko MORITA ◽  
...  
Keyword(s):  
Amino Acid ◽  
Xenopus Oocytes ◽  
Physiological Role ◽  
Basic Amino Acid ◽  
Functional Expression ◽  
Amino Acid Transporter ◽  
Amino Acid Transporters ◽  
Transport Activity ◽  
Acid Transporter ◽  
Mouse Ileum

The Na+-independent dibasic and neutral amino acid transporter NBAT is among the least hydrophobic of mammalian amino acid transporters. The transporter contains one to four transmembrane domains and induces amino acid transport activity via a b0,+-like system when expressed in Xenopus oocytes. However, the physiological role of NBAT remains unclear. Complementary DNA clones encoding mouse NBAT have now been isolated. The expression of mouse NBAT in Xenopus oocytes also induced an obligatory amino acid exchange activity similar to that of the b0,+-like system. The amount of NBAT mRNA in mouse kidney increased during postnatal development, consistent with the increase in renal cystine and dibasic transport activity. Dietary aspartate induced a marked increase in cystine transport via the b0,+ system in mouse ileum. A high-aspartate diet also increased the amount of NBAT mRNA in mouse ileum. In the ileum of mice fed on the aspartate diet, the extent of cystine transport was further increased by preloading brush border membrane vesicles with lysine. Hybrid depletion of NBAT mRNA from ileal polyadenylated RNA revealed that the increase in cystine transport activity induced by the high-aspartate diet, as measured in Xenopus oocytes, was attributable to NBAT. These results demonstrate that mouse NBAT has an important role in cystine transport.

scholarly journals SorCS2 Controls Functional Expression of Amino Acid Transporter EAAT3 and Protects Neurons from Oxidative Stress and Epilepsy-Induced Pathology

Cell Reports ◽  
2019 ◽  
Vol 26 (10) ◽  
pp. 2792-2804.e6 ◽  
Author(s):  
Anna R. Malik ◽  
Kinga Szydlowska ◽  
Karolina Nizinska ◽  
Antonino Asaro ◽  
Erwin A. van Vliet ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Amino Acid ◽  
Functional Expression ◽  
Amino Acid Transporter ◽  
Acid Transporter

scholarly journals DNA methylation of amino acid transporter genes in the human placenta

Placenta ◽  
2017 ◽  
Vol 60 ◽  
pp. 64-73 ◽  
Author(s):  
C. Simner ◽  
B. Novakovic ◽  
K.A. Lillycrop ◽  
C.G. Bell ◽  
N.C. Harvey ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Amino Acid ◽  
Human Placenta ◽  
Amino Acid Transporter ◽  
Acid Transporter

scholarly journals SorCS2 controls functional expression of amino acid transporter EAAT3 to protect neurons from oxidative stress and epilepsy-induced pathology

2018 ◽  
Author(s):  
Anna R. Malik ◽  
Kinga Szydlowska ◽  
Karolina Nizinska ◽  
Antonino Asaro ◽  
Erwin A. van Vliet ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Death ◽  
Amino Acid ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Functional Expression ◽  
Amino Acid Transporter ◽  
Protective Role ◽  
The Family ◽  
Acid Transporter

SUMMARYThe family of VPS10P domain receptors emerges as central regulator of intracellular protein sorting in neurons with relevance for various brain pathologies. Here, we identified a unique role for the family member SorCS2 in protection of neurons from oxidative stress and from epilepsy-induced cell death. We show that SorCS2 acts as sorting receptor that targets the neuronal amino acid transporter EAAT3 to the plasma membrane to facilitate import of cysteine, required for synthesis of the reactive oxygen species scavenger glutathione. Absence of SorCS2 activity causes aberrant transport of EAAT3 to lysosome for catabolism and impairs cysteine uptake. As a consequence, SorCS2-deficient mice exhibit oxidative brain damage that coincides with enhanced neuronal cell death and increased mortality during epilepsy. Our findings highlight a protective role for SorCS2 in neuronal stress response and provide an explanation for upregulation of the receptor seen in surviving neurons of the human epileptic brain.

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