Umami taste receptor functions as an amino acid sensor via Gαs subunit in N1E-115 neuroblastoma cells

2011 ◽  
pp. n/a-n/a ◽  
Author(s):  
Yoshikage Muroi ◽  
Toshiaki Ishii
Keyword(s):  
Amino Acid ◽  
Taste Receptor ◽  
Neuroblastoma Cells ◽  
Umami Taste ◽  
Amino Acid Sensor

Branched chain amino acids stimulate gut satiety hormone cholecystokinin secretion through activation of the umami taste receptor T1R1/T1R3 using an in vitro porcine jejunum model

2019 ◽  
Vol 10 (6) ◽  
pp. 3356-3367 ◽  
Author(s):  
Min Tian ◽  
Jinghui Heng ◽  
Hanqing Song ◽  
Yufeng Zhang ◽  
Fang Chen ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Taste Receptor ◽  
Branched Chain Amino Acids ◽  
Acid Receptor ◽  
Umami Taste ◽  
Satiety Hormone ◽  
Branched Chain

Branched chain amino acids (BCAAs) modulate the intestinal CCK secretion through the T1R1/ T1R3 amino acid receptor.

scholarly journals Amino acids differ in their capacity to stimulate GLP-1 release from the perfused rat small intestine and stimulate secretion by different sensing mechanisms

2021 ◽  
Author(s):  
Ida Marie Modvig ◽  
Rune Ehrenreich Kuhre ◽  
Sara L. Jepsen ◽  
Stella Xu ◽  
Maja S. Engelstoft ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Expression Analysis ◽  
Hormone Secretion ◽  
Taste Receptor ◽  
Aromatic Amino Acids ◽  
Fold Increase ◽  
Intestinal Lumen ◽  
Umami Taste ◽  
L Cells

The aim of this study was to explore individual amino acid-stimulated GLP-1 responses and the underlying stimulatory mechanisms, as well as to identify the amino acid-sensing-receptors involved in amino acid-stimulated GLP-1 release. Experiments were primarily based on isolated perfused rat small intestines, which have intact epithelial polarization allowing discrimination between luminal and basolateral mechanisms as well as quantitative studies of intestinal absorption and hormone secretion. Expression analysis of amino acid sensors on isolated murine GLP-1 secreting L-cells was assessed by qPCR. We found that L-valine powerfully stimulated GLP-1 secretion but only from the luminal side (2.9-fold increase). When administered from the vascular side, L-arginine and the aromatic amino acids stimulated GLP-1 secretion equally (2.6-2.9 fold increases). Expression analysis revealed that Casr expression was enriched in murine GLP-1 secreting L-cells, whereas Gpr35, Gprc6a, Gpr142, Gpr93 (Lpar5) and the umami taste receptor subunits Tas1r3 and Tas1r1 were not. Consistently, activation of GPR35, GPR93, GPR142 and the umami taste receptor with specific agonists or allosteric modulators did not increase GLP-1 secretion (P>0.05 for all experiments), whereas vascular inhibition of CaSR reduced GLP-1 secretion in response to luminal infusion of mixed amino acids. In conclusion, amino acids differ in their capacity to stimulate GLP-1 secretion. Some amino acids stimulated secretion only from the intestinal lumen, while other amino acids exclusively stimulated secretion from the vascular side, indicating that amino acid-stimulated GLP-1 secretion involves both apical and basolateral (post-absorptive) sensing mechanisms. Sensing of absorbed amino acids involves CaSR activation as vascular inhibition of CaSR markedly diminished amino acid stimulated GLP-1 release.

scholarly journals Activation of the SPS Amino Acid-Sensing Pathway in Saccharomyces cerevisiae Correlates with the Phosphorylation State of a Sensor Component, Ptr3

2007 ◽  
Vol 28 (2) ◽  
pp. 551-563 ◽  
Author(s):  
Zhengchang Liu ◽  
Janet Thornton ◽  
Mário Spírek ◽  
Ronald A. Butow
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Amino Acids ◽  
Amino Acid ◽  
Nuclear Translocation ◽  
Proteolytic Processing ◽  
Casein Kinase I ◽  
Positive Regulators ◽  
Amino Acid Permeases ◽  
Amino Acid Sensing ◽  
Amino Acid Sensor

ABSTRACT Cells of the budding yeast Saccharomyces cerevisiae sense extracellular amino acids and activate expression of amino acid permeases through the SPS-sensing pathway, which consists of Ssy1, an amino acid sensor on the plasma membrane, and two downstream factors, Ptr3 and Ssy5. Upon activation of SPS signaling, two transcription factors, Stp1 and Stp2, undergo Ssy5-dependent proteolytic processing that enables their nuclear translocation. Here we show that Ptr3 is a phosphoprotein whose hyperphosphorylation is increased by external amino acids and is dependent on Ssy1 but not on Ssy5. A deletion mutation in GRR1, encoding a component of the SCFGrr1 E3 ubiquitin ligase, blocks amino acid-induced hyperphosphorylation of Ptr3. We found that two casein kinase I (CKI) proteins, Yck1 and Yck2, previously identified as positive regulators of SPS signaling, are required for hyperphosphorylation of Ptr3. Loss- and gain-of-function mutations in PTR3 result in decreased and increased Ptr3 hyperphosporylation, respectively. We found that a defect in PP2A phosphatase activity leads to the hyperphosphorylation of Ptr3 and constitutive activation of SPS signaling. Two-hybrid analysis revealed interactions between the N-terminal signal transduction domain of Ssy1 with Ptr3 and Yck1. Our findings reveal that CKI and PP2A phosphatase play antagonistic roles in SPS sensing by regulating Ptr3 phosphorylation.

Regulatory pathways and uptake ofl-DOPA by capillary cerebral endothelial cells, astrocytes, and neuronal cells

2001 ◽  
Vol 280 (2) ◽  
pp. C333-C342 ◽  
Author(s):  
B. Sampaio-Maia ◽  
M. P. Serrão ◽  
P. Soares-da-Silva
Keyword(s):  
Amino Acid ◽  
Neuroblastoma Cells ◽  
Cell Types ◽  
Amino Acid Transporter ◽  
Nitric Oxide Donor ◽  
Intracellular Camp ◽  
Regulatory Pathways ◽  
Dopa Accumulation ◽  
Acid Transporter ◽  
Dopa Uptake

We examined the nature and regulation of the inwardl-3,4-dihydroxyphenylalanine (l-DOPA) transporter in rat capillary cerebral endothelial (RBE4) cells, type 1 astrocytes (DI TNC1), and Neuro-2a neuroblastoma cells. In all three cell types, the inward transfer of l-DOPA was largely promoted through the 2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid-sensitive and sodium-independent L-type amino acid transporter. Only in DI TNC1 cells was the effect of maneuvers that increase intracellular cAMP levels accompanied by increases inl-DOPA uptake. Also, only in DI TNC1 cells was the effect of the guanylyl cyclase inhibitor LY-83583 accompanied by a 65% increase in l-DOPA accumulation, whereas the nitric oxide donor sodium nitroprusside produced a 25% decrease inl-DOPA accumulation. In all three cell types, the Ca2+/calmodulin inhibitors calmidazolium and trifluoperazine inhibited l-DOPA uptake in a noncompetitive manner. Thapsigargin (1 and 3 μM) and A-23187 (1 and 3 μM) failed to alter l-DOPA accumulation in RBE4 and Neuro-2a cells but markedly increased l-DOPA uptake in DI TNC1cells. We concluded that l-DOPA in RBE4, DI TNC1, and Neuro-2a cells is transported through the L-type amino acid transporter and appears to be under the control of Ca2+/calmodulin-mediated pathways. Astrocytes, however, are endowed with other processes that appear to regulate the accumulation of l-DOPA, responding positively to increases in intracellular Ca2+ and cAMP and to decreases in cGMP.

scholarly journals Amino Acid at Position 166 of NS2A in Japanese Encephalitis Virus (JEV) Is Associated with In Vitro Growth Characteristics of JEV

Viruses ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 709
Author(s):  
Shigeru Tajima ◽  
Satoshi Taniguchi ◽  
Eri Nakayama ◽  
Takahiro Maeki ◽  
Takuya Inagaki ◽  
...  
Keyword(s):  
Amino Acid ◽  
Japanese Encephalitis Virus ◽  
Japanese Encephalitis ◽  
Neuroblastoma Cells ◽  
Encephalitis Virus ◽  
Growth Potential ◽  
Sequencing Analysis ◽  
Murine Neuroblastoma ◽  
Growth Ability

We previously showed that the growth ability of the Japanese encephalitis virus (JEV) genotype V (GV) strain Muar is clearly lower than that of the genotype I (GI) JEV strain Mie/41/2002 in murine neuroblastoma cells. Here, we sought to identify the region in GV JEV that is involved in its low growth potential in cultured cells. An intertypic virus containing the NS1-3 region of Muar in the Mie/41/2002 backbone (NS1-3Muar) exhibited a markedly diminished growth ability in murine neuroblastoma cells. Moreover, the growth rate of a Muar NS2A-bearing intertypic virus (NS2AMuar) was also similar to that of Muar in these cells, indicating that NS2A of Muar is one of the regions responsible for the Muar-specific growth ability in murine neuroblastoma cells. Sequencing analysis of murine neuroblastoma Neuro-2a cell-adapted NS1-3Muar virus clones revealed that His-to-Tyr mutation at position 166 of NS2A (NS2A166) could rescue the low replication ability of NS1-3Muar in Neuro-2a cells. Notably, a virus harboring a Tyr-to-His substitution at NS2A166 (NS2AY166H) showed a decreased growth ability relative to that of the parental virus Mie/41/2002, whereas an NS2AMuar-based mutant virus, NS2AMuar-H166Y, showed a higher growth ability than NS2AMuar in Neuro-2a cells. Thus, these results indicate that the NS2A166 amino acid in JEV is critical for the growth and tissue tropism of JEV in vitro.

scholarly journals Component Profiling of Soy-Sauce-Like Seasoning Produced from Different Raw Materials

Metabolites ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 137 ◽  
Author(s):  
Tomoyuki Yamana ◽  
Moyu Taniguchi ◽  
Takeharu Nakahara ◽  
Yusuke Ito ◽  
Natsuki Okochi ◽  
...  
Keyword(s):  
Amino Acid ◽  
Raw Materials ◽  
Paired Comparison ◽  
Salt Water ◽  
Amino Acid Content ◽  
Principal Component ◽  
Soy Sauce ◽  
Umami Taste ◽  
Metabolomics Study ◽  
Saccharide Content

Soy sauce is a traditional Japanese umami seasoning commonly made from soybeans, wheat, and salt water. Soy-sauce-like seasoning, made from other raw materials, such as rice and peas, has recently been developed. However, differences in the taste of soy-sauce-like seasoning, depending on the raw materials, have not been evaluated. Component profiling based on GC/MS combined with a paired comparison test were used to investigate the effect of raw materials on seasoning components and umami taste in five grain-based and four bean-based soy-sauce-like seasonings. In a principal component (PC) analysis, grain-based samples and bean-based samples were separated along the PC1 axis (explaining 48.1% of the total variance). Grain-based samples had a higher saccharide content, and bean-based samples had a higher amino acid content. Furthermore, differences in the umami intensity were also observed among sample types. This is the first detailed metabolomics study of the characteristic compounds and umami of a variety of soy-sauce-like seasonings made from different raw materials.

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