scholarly journals mRNA expression of amino acid transporters, aminopeptidase, and the di- and tri-peptide transporter PepT1 in the intestine and liver of posthatch broiler chicks

2015 ◽  
Vol 94 (6) ◽  
pp. 1323-1332 ◽  
Author(s):  
Katarzyna B. Miska ◽  
Raymond H. Fetterer ◽  
Eric A. Wong
Keyword(s):  
Amino Acid ◽  
Mrna Expression ◽  
Peptide Transporter ◽  
Broiler Chicks ◽  
Amino Acid Transporters

scholarly journals Delayed access to feed alters expression of genes associated with carbohydrate and amino acid utilization in newly hatched broiler chicks

2019 ◽  
Vol 317 (6) ◽  
pp. R864-R878 ◽  
Author(s):  
Jason A. Payne ◽  
Monika Proszkowiec-Weglarz ◽  
Laura E. Ellestad
Keyword(s):  
Amino Acid ◽  
Expression Patterns ◽  
Breast Muscle ◽  
Broiler Chicks ◽  
Amino Acid Transporters ◽  
Peroxisome Proliferator ◽  
Large Neutral Amino Acid ◽  
Negative Consequences ◽  
Broiler Meat ◽  
Expression Of Genes

Newly hatched chicks must transition from lipid-rich yolk to carbohydrate-rich feed as their primary nutrient source, and posthatch delays in access to feed can have long-term negative consequences on growth and metabolism. In this study, impacts of delayed access to feed at hatch on expression of genes related to nutrient uptake and utilization in two metabolically important tissues, liver and muscle, were determined in broiler (meat-type) chickens. Hatched chicks were given access to feed within 3 h (fed) or delayed access to feed for 48 h (delayed fed), and liver and breast muscle were collected from males at hatch and 4 h, 1 day, 2 days, 4 days, and 8 days posthatch for analysis of gene expression. Differential expression of carbohydrate response element-binding protein and peroxisome proliferator-activated receptor-γ in muscle and liver was observed, with results indicating a transitional delay from lipid to carbohydrate metabolism when hatched chicks were not given immediate access to feed. Extended upregulation of insulin receptor mRNA was observed in both tissues in delayed fed birds, suggesting increased sensitivity to circulating levels of the hormone. Developmental delays in expression patterns of cationic amino acid transporters 1 and 2 in both tissues and large neutral amino acid transporter 1 in muscle were also apparent when immediate feed access was prevented. These data suggest that delayed transition to carbohydrate use and altered nutrient transport and utilization within liver and breast muscle are key factors negatively affecting growth and metabolism following delayed feed access in broiler chickens.

Regulation of placental amino acid transporter activity by mammalian target of rapamycin

2009 ◽  
Vol 296 (1) ◽  
pp. C142-C150 ◽  
Author(s):  
S. Roos ◽  
Y. Kanai ◽  
P. D. Prasad ◽  
T. L. Powell ◽  
T. Jansson
Keyword(s):  
Amino Acid ◽  
Protein Expression ◽  
Mrna Expression ◽  
Mammalian Target Of Rapamycin ◽  
Amino Acid Transporter ◽  
Amino Acid Transporters ◽  
Mtor Inhibition ◽  
System A ◽  
System L ◽  
Acid Transporter

The activity of placental amino acid transporters is decreased in intrauterine growth restriction (IUGR), but the underlying regulatory mechanisms have not been established. Inhibition of the mammalian target of rapamycin (mTOR) signaling pathway has been shown to decrease the activity of the system L amino acid transporter in human placental villous fragments, and placental mTOR activity is decreased in IUGR. In the present study, we used cultured primary trophoblast cells to study mTOR regulation of placental amino acid transporters in more detail and to test the hypothesis that mTOR alters amino acid transport activity by changes in transporter expression. Inhibition of mTOR by rapamycin significantly reduced the activity of system A (−17%), system L (−28%), and taurine (−40%) amino acid transporters. mRNA expression of isoforms of the three amino acid transporter systems in response to mTOR inhibition was measured using quantitative real-time PCR. mRNA expression of l-type amino acid transporter 1 (LAT1; a system L isoform) and taurine transporter was reduced by 13% and 50%, respectively; however, mTOR inhibition did not alter the mRNA expression of system A isoforms (sodium-coupled neutral amino acid transporter-1, -2, and -4), LAT2, or 4F2hc. Rapamycin treatment did not significantly affect the protein expression of any of the transporter isoforms. We conclude that mTOR signaling regulates the activity of key placental amino acid transporters and that this effect is not due to a decrease in total protein expression. These data suggest that mTOR regulates placental amino acid transporters by posttranslational modifications or by affecting transporter translocation to the plasma membrane.

scholarly journals Ssy1p and Ptr3p Are Plasma Membrane Components of a Yeast System That Senses Extracellular Amino Acids

1999 ◽  
Vol 19 (8) ◽  
pp. 5405-5416 ◽  
Author(s):  
Hanna Klasson ◽  
Gerald R. Fink ◽  
Per O. Ljungdahl
Keyword(s):  
Amino Acids ◽  
Plasma Membrane ◽  
Amino Acid ◽  
Genetic Selection ◽  
Functional Expression ◽  
Subcellular Fractionation ◽  
Peptide Transporter ◽  
Amino Acid Transporters ◽  
Amino Acid Permease ◽  
Membrane Components

ABSTRACT Mutations in SSY1 and PTR3 were identified in a genetic selection for components required for the proper uptake and compartmentalization of histidine in Saccharomyces cerevisiae. 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. Both Ssy1p and Ptr3p have previously been implicated in relaying signals regarding the presence of extracellular amino acids. We have found that ssy1 andptr3 mutants belong to the same epistasis group; single andssy1 ptr3 double-mutant strains exhibit indistinguishable phenotypes. Mutations in these genes cause the nitrogen-regulated general amino acid permease gene (GAP1) to be abnormally expressed and block the nonspecific induction of arginase (CAR1) and the peptide transporter (PTR2).ssy1 and ptr3 mutations manifest identical differential effects on the functional expression of multiple specific amino acid transporters. ssy1 and ptr3 mutants have increased vacuolar pools of histidine and arginine and exhibit altered cell growth morphologies accompanied by exaggerated invasive growth. 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. These findings suggest that Ssy1p and Ptr3p function in the PM as components of a sensor of extracellular amino acids.

scholarly journals Pulmonary alveolar epithelial uptake of S-nitrosothiols is regulated by L-type amino acid transporter

2008 ◽  
Vol 295 (1) ◽  
pp. L38-L43 ◽  
Author(s):  
Olivia M. Granillo ◽  
Mulugu V. Brahmajothi ◽  
Sheng Li ◽  
A. Richard Whorton ◽  
S. Nicholas Mason ◽  
...  
Keyword(s):  
Amino Acid ◽  
Epithelial Cells ◽  
Biological Effects ◽  
Cell Types ◽  
Alveolar Epithelial Cells ◽  
Peptide Transporter ◽  
Amino Acid Transporters ◽  
No Donor ◽  
Alveolar Epithelial ◽  
System L

Nitric oxide (NO) effects are often mediated via S-nitrosothiol (SNO) formation; SNO uptake has recently been shown to be mediated in some cell types via system L-type amino acid transporters (LAT-1, 2). Inhaled NO therapy may exert some biological effects via SNO formation. We therefore sought to determine if pulmonary epithelial SNO uptake depended on LAT or peptide transporter 2 (PEPT2). Both LAT-1 and PEPT2 proteins were detected by immunoblot and immunocytochemistry in L2 cells and rat lung. We tested SNO uptake through the transporters by exposing rat alveolar epithelial cells (L2 and type II) to RSNOs: S-nitrosoglutathione, S-nitrosocysteinylglycine (SNO-Cys-Gly), S-nitrosocysteine (CSNO), and to NO donor diethylamine NONOate (DEA-NONOate). SNO was detected in cell lysates by ozone chemiluminescence. NO uptake was detected by fluorescence in alveolar epithelial cells loaded with 4-amino-5-methylamino-2′,7′-difluorofluorescein (DAF-FM) diacetate cultured in submersion and exposed to RSNOs and DEA NONOate. Addition of l-Cys but not d-Cys to RSNOs or DEA NONOate increased SNO and DAF-FM signal that was inhibited by coincubation with LAT competitors. Incubation of cells with PEPT2 substrate SNO-Cys-Gly showed no increase in SNO or DAF-FM signal unless incubated with l-Cys. This was unaffected by PEPT2 inhibition. We conclude that RSNOs (thionitrites, S-nitrosothiols) and NO enter alveolar epithelial cells predominantly by S-nitrosation of l-Cys, which is then imported through LAT.

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