scholarly journals Glucocorticoid Regulates the Synthesis of Porcine Muscle Protein through m6A Modified Amino Acid Transporter SLC7A7

2022 ◽  
Vol 23 (2) ◽  
pp. 661
Author(s):  
Wei-Jing Xu ◽  
Kai Guo ◽  
Jia-Li Shi ◽  
Chang-Tong Guo ◽  
Jia-Le Xu ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Stress Response ◽  
Muscle Protein ◽  
Stress Hormones ◽  
Muscle Growth ◽  
Amino Acid Transporter ◽  
Acid Transporter ◽  
Livestock Productivity ◽  
Prolonged Stress

The occurrence of stress is unavoidable in the process of livestock production, and prolonged stress will cause the decrease of livestock productivity. The stress response is mainly regulated by the hypothalamic-pituitary-adrenal axis (HPA axis), which produces a large amount of stress hormones, namely glucocorticoids (GCs), and generates a severe impact on the energy metabolism of the animal body. It is reported that m6A modification plays an important role in the regulation of stress response and also participates in the process of muscle growth and development. In this study, we explored the effect of GCs on the protein synthesis procession of porcine skeletal muscle cells (PSCs). We prove that dexamethasone affects the expression of SLC7A7, a main amino acid transporter for protein synthesis by affecting the level of m6A modification in PSCs. In addition, we find that SLC7A7 affects the level of PSC protein synthesis by regulating the conduction of the mTOR signaling pathway, which indicates that the reduction of SLC7A7 expression may alleviate the level of protein synthesis under stress conditions.

Influence of nutrient ingestion on amino acid transporters and protein synthesis in human skeletal muscle after sprint exercise

2017 ◽  
Vol 123 (6) ◽  
pp. 1501-1515 ◽  
Author(s):  
Håkan C. Rundqvist ◽  
Mona Esbjörnsson ◽  
Olav Rooyackers ◽  
Ted Österlund ◽  
Marcus Moberg ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Resistance Exercise ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Amino Acid Transporter ◽  
Mtor Signaling ◽  
Sprint Exercise ◽  
Phosphorylated Akt ◽  
Acid Transporter

Nutrient ingestion is known to increase the exercise-induced stimulation of muscle protein synthesis following resistance exercise. Less is known about the effect of nutrients on muscle protein synthesis following sprint exercise. At two occasions separated by 1 mo, 12 healthy subjects performed three 30-s sprints with 20-min rest between bouts. In randomized order, they consumed a drink with essential amino acids and maltodextrin (nutrient) or flavored water (placebo). Muscle biopsies were obtained 80 and 200 min after the last sprint, and blood samples were taken repeatedly during the experiment. Fractional synthetic rate (FSR) was measured by continuous infusion of l-[2H5]phenylalanine up to 200 min postexercise. The mRNA expression and protein expression of SNAT2 were both 1.4-fold higher ( P < 0.05) after nutrient intake compared with placebo at 200 min postexercise. Phosphorylated Akt, mammalian target of rapamycin (mTOR), and p70S6k were 1.7- to 3.6-fold higher ( P < 0.01) 80 min after the last sprint with nutrient ingestion as compared with placebo. In addition, FSR was higher ( P < 0.05) with nutrients when plasma phenylalanine (FSRplasma) was used as a precursor but not when intracellular phenylalanine (FSRmuscle) was used. Significant correlations were also found between FSRplasma on the one hand and plasma leucine and serum insulin on the other hand in the nutrient condition. The results show that nutrient ingestion induces the expression of the amino acid transporter SNAT2 stimulates Akt/mTOR signaling and most likely the rate of muscle protein synthesis following sprint exercise. NEW & NOTEWORTHY There is limited knowledge regarding the effect of nutrients on muscle protein synthesis following sprint as compared with resistance exercise. The results demonstrate that nutrient ingestion during repeated 30-s bouts of sprint exercise induces expression of the amino acid transporter SNAT2 and stimulates Akt/mTOR signaling and most likely the rate of muscle protein synthesis. Future studies to explore the chronic effects of nutritional ingestion during sprint exercise sessions on muscle mass accretion are warranted.

scholarly journals Wnt regulates amino acid transporter Slc7a5 and so constrains the integrated stress response in mouse embryos

EMBO Reports ◽  
2019 ◽  
Vol 21 (1) ◽  
Author(s):  
Nadège Poncet ◽  
Pamela A Halley ◽  
Christopher Lipina ◽  
Marek Gierliński ◽  
Alwyn Dady ◽  
...  
Keyword(s):  
Amino Acid ◽  
Stress Response ◽  
Amino Acid Transporter ◽  
Mouse Embryos ◽  
Integrated Stress Response ◽  
Acid Transporter

Leucine supplementation after mechanical stimulation activates protein synthesis via L‐type amino acid transporter 1 in vitro

2017 ◽  
Vol 119 (2) ◽  
pp. 2094-2101 ◽  
Author(s):  
Naoya Nakai ◽  
Fuminori Kawano ◽  
Taro Murakami ◽  
Ken Nakata ◽  
Kazuhiko Higashida
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Mechanical Stimulation ◽  
Amino Acid Transporter ◽  
Leucine Supplementation ◽  
Acid Transporter

scholarly journals The effects of L-type amino acid transporter 1 on milk protein synthesis in mammary glands of dairy cows

2018 ◽  
Vol 101 (2) ◽  
pp. 1687-1696 ◽  
Author(s):  
Ye Lin ◽  
Xiaoyu Duan ◽  
He Lv ◽  
Yang Yang ◽  
Ying Liu ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Dairy Cows ◽  
Milk Protein ◽  
Mammary Glands ◽  
Amino Acid Transporter ◽  
Acid Transporter

Sodium-coupled neutral amino acid transporter 4 functions as a regulator of protein synthesis during liver development

2013 ◽  
Vol 43 (11) ◽  
pp. 1211-1223 ◽  
Author(s):  
Hiroki Kondou ◽  
Masanobu Kawai ◽  
Kanako Tachikawa ◽  
Akihito Kimoto ◽  
Masayo Yamagata ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Amino Acid Transporter ◽  
Neutral Amino Acid ◽  
Liver Development ◽  
Neutral Amino Acid Transporter ◽  
Acid Transporter

scholarly journals Increased Expression of UMAMIT Amino Acid Transporters Results in Activation of Salicylic Acid Dependent Stress Response

2021 ◽  
Vol 11 ◽  
Author(s):  
Julien Besnard ◽  
Unnati Sonawala ◽  
Bal Maharjan ◽  
Eva Collakova ◽  
Scott A. Finlayson ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Amino Acid ◽  
Stress Response ◽  
Stress Responses ◽  
Amino Acid Transporter ◽  
Marker Genes ◽  
Amino Acid Transporters ◽  
Loss Of Function ◽  
Over Expression ◽  
Acid Transporter

In addition to their role in the biosynthesis of important molecules such as proteins and specialized metabolites, amino acids are known to function as signaling molecules through various pathways to report nitrogen status and trigger appropriate metabolic and cellular responses. Moreover, changes in amino acid levels through altered amino acid transporter activities trigger plant immune responses. Specifically, loss of function of major amino acid transporter, over-expression of cationic amino acid transporter, or over-expression of the positive regulators of membrane amino acid export all lead to dwarfed phenotypes and upregulated salicylic acid (SA)-induced stress marker genes. However, whether increasing amino acid exporter protein levels lead to similar stress phenotypes has not been investigated so far. Recently, a family of transporters, namely USUALLY MULTIPLE ACIDS MOVE IN AND OUT TRANSPORTERS (UMAMITs), were identified as amino acid exporters. The goal of this study was to investigate the effects of increased amino acid export on plant development, growth, and reproduction to further examine the link between amino acid transport and stress responses. The results presented here show strong evidence that an increased expression of UMAMIT transporters induces stress phenotypes and pathogen resistance, likely due to the establishment of a constitutive stress response via a SA-dependent pathway.

scholarly journals An increase in essential amino acid availability upregulates amino acid transporter expression in human skeletal muscle

2010 ◽  
Vol 298 (5) ◽  
pp. E1011-E1018 ◽  
Author(s):  
Micah J. Drummond ◽  
Erin L. Glynn ◽  
Christopher S. Fry ◽  
Kyle L. Timmerman ◽  
Elena Volpi ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Protein Expression ◽  
Human Skeletal Muscle ◽  
Amino Acid Transporter ◽  
Dependent Manner ◽  
Mtorc1 Signaling ◽  
Acid Transporter ◽  
Transporter Expression

Essential amino acids (EAA) stimulate skeletal muscle mammalian target of rapamycin complex 1 (mTORC1) signaling and protein synthesis. It has recently been reported that an increase in amino acid (AA) transporter expression during anabolic conditions is rapamycin-sensitive. The purpose of this study was to determine whether an increase in EAA availability increases AA transporter expression in human skeletal muscle. Muscle biopsies were obtained from the vastus lateralis of seven young adult subjects (3 male, 4 female) before and 1–3 h after EAA ingestion (10 g). Blood and muscle samples were analyzed for leucine kinetics using stable isotopic techniques. Quantitative RT-PCR, and immunoblotting were used to determine the mRNA and protein expression, respectively, of AA transporters and members of the general AA control pathway [general control nonrepressed (GCN2), activating transcription factor (ATF4), and eukaryotic initiation factor (eIF2) α-subunit (Ser52)]. EAA ingestion increased blood leucine concentration, delivery of leucine to muscle, transport of leucine from blood into muscle, intracellular muscle leucine concentration, ribosomal protein S6 (Ser240/244) phosphorylation, and muscle protein synthesis. This was followed with increased L-type AA transporter (LAT1), CD98, sodium-coupled neutral AA transporter (SNAT2), and proton-coupled amino acid transporter (PAT1) mRNA expression at 1 h ( P < 0.05) and modest increases in LAT1 protein expression (3 h post-EAA) and SNAT2 protein expression (2 and 3 h post-EAA, P < 0.05). Although there were no changes in GCN2 expression and eIF2α phosphorylation, ATF4 protein expression reached significance by 2 h post-EAA ( P < 0.05). We conclude that an increase in EAA availability upregulates human skeletal muscle AA transporter expression, perhaps in an mTORC1-dependent manner, which may be an adaptive response necessary for improved AA intracellular delivery.

Increased expression of an amino acid transporter LAT1 in healing of acetic acid-induced chronic gastric ulcer in rats

2001 ◽  
Vol 120 (5) ◽  
pp. A153-A153
Author(s):  
S MIYAMOTO ◽  
K KATO ◽  
Y ISHII ◽  
S ASAI ◽  
T NAGAISHI ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Gastric Ulcer ◽  
Amino Acid ◽  
Amino Acid Transporter ◽  
Chronic Gastric Ulcer ◽  
Acid Transporter
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