The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Elizabeth Henny Herningtyas - One of the best experts on this subject based on the ideXlab platform.
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branched chain amino acids and arginine suppress mafbx atrogin 1 mrna expression via mtor pathway in c2c12 cell line
Biochimica et Biophysica Acta, 2008Co-Authors: Elizabeth Henny Herningtyas, Yasuhiko Okimura, Anastasia Evi Handayaningsih, Daisuke Yamamoto, Taiki Maki, Keiji Iida, Yutaka Takahashi, Hidesuke Kaji, Kazuo ChiharaAbstract:Abstract The effect of amino acid on muscle protein degradation remains unclear. Recent studies have elucidated that proteolysis in catabolic conditions occurs through ubiquitin–proteasome proteolysis pathway and that muscle-specific ubiquitin ligases (atrogin-1 and MuRF1) play an important role in protein degradation. In the present study, we examined the direct effect of 5 mM amino acids (leucine, Isoleucine, valine, glutamine and arginine) on atrogin-1 and MuRF1 levels in C2C12 muscle cells and the involved intracellular signal transduction pathway. Leucine, Isoleucine and valine suppressed atrogin-1 and MuRF1 mRNA levels (≈ 50%) at 6 and 24 h stimulations. Arginine showed a similar effect except at 24 h-treatment for atrogin-1 mRNA. However, glutamine failed to reduce atrogin-1 and MuRF1 mRNA levels. The inhibitory effect of leucine, Isoleucine or arginine on atrogin-1 mRNA level was reversed by rapamycin, although wortmannin did not reverse the effect. PD98059 and HA89 reduced basal atrogin-1 level without influencing the inhibitory effects of those amino acids. The inhibitory effect of leucine, Isoleucine or arginine on MuRF1 mRNA levels was not reversed by rapamycin. Taken together, these findings indicated that leucine, Isoleucine and arginine decreased atrogin-1 mRNA levels via mTOR and that different pathways were involved in the effect of those amino acids on MuRF1 mRNA levels.
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branched chain amino acids and arginine suppress mafbx atrogin 1 mrna expression via mtor pathway in c2c12 cell line
Biochimica et Biophysica Acta, 2008Co-Authors: Elizabeth Henny Herningtyas, Yasuhiko Okimura, Anastasia Evi Handayaningsih, Daisuke Yamamoto, Taiki Maki, Keiji Iida, Yutaka Takahashi, Hidesuke Kaji, Kazuo ChiharaAbstract:The effect of amino acid on muscle protein degradation remains unclear. Recent studies have elucidated that proteolysis in catabolic conditions occurs through ubiquitin-proteasome proteolysis pathway and that muscle-specific ubiquitin ligases (atrogin-1 and MuRF1) play an important role in protein degradation. In the present study, we examined the direct effect of 5 mM amino acids (leucine, Isoleucine, valine, glutamine and arginine) on atrogin-1 and MuRF1 levels in C2C12 muscle cells and the involved intracellular signal transduction pathway. Leucine, Isoleucine and valine suppressed atrogin-1 and MuRF1 mRNA levels (approximately equal to 50%) at 6 and 24 h stimulations. Arginine showed a similar effect except at 24 h-treatment for atrogin-1 mRNA. However, glutamine failed to reduce atrogin-1 and MuRF1 mRNA levels. The inhibitory effect of leucine, Isoleucine or arginine on atrogin-1 mRNA level was reversed by rapamycin, although wortmannin did not reverse the effect. PD98059 and HA89 reduced basal atrogin-1 level without influencing the inhibitory effects of those amino acids. The inhibitory effect of leucine, Isoleucine or arginine on MuRF1 mRNA levels was not reversed by rapamycin. Taken together, these findings indicated that leucine, Isoleucine and arginine decreased atrogin-1 mRNA levels via mTOR and that different pathways were involved in the effect of those amino acids on MuRF1 mRNA levels.
Kazuo Chihara - One of the best experts on this subject based on the ideXlab platform.
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branched chain amino acids and arginine suppress mafbx atrogin 1 mrna expression via mtor pathway in c2c12 cell line
Biochimica et Biophysica Acta, 2008Co-Authors: Elizabeth Henny Herningtyas, Yasuhiko Okimura, Anastasia Evi Handayaningsih, Daisuke Yamamoto, Taiki Maki, Keiji Iida, Yutaka Takahashi, Hidesuke Kaji, Kazuo ChiharaAbstract:Abstract The effect of amino acid on muscle protein degradation remains unclear. Recent studies have elucidated that proteolysis in catabolic conditions occurs through ubiquitin–proteasome proteolysis pathway and that muscle-specific ubiquitin ligases (atrogin-1 and MuRF1) play an important role in protein degradation. In the present study, we examined the direct effect of 5 mM amino acids (leucine, Isoleucine, valine, glutamine and arginine) on atrogin-1 and MuRF1 levels in C2C12 muscle cells and the involved intracellular signal transduction pathway. Leucine, Isoleucine and valine suppressed atrogin-1 and MuRF1 mRNA levels (≈ 50%) at 6 and 24 h stimulations. Arginine showed a similar effect except at 24 h-treatment for atrogin-1 mRNA. However, glutamine failed to reduce atrogin-1 and MuRF1 mRNA levels. The inhibitory effect of leucine, Isoleucine or arginine on atrogin-1 mRNA level was reversed by rapamycin, although wortmannin did not reverse the effect. PD98059 and HA89 reduced basal atrogin-1 level without influencing the inhibitory effects of those amino acids. The inhibitory effect of leucine, Isoleucine or arginine on MuRF1 mRNA levels was not reversed by rapamycin. Taken together, these findings indicated that leucine, Isoleucine and arginine decreased atrogin-1 mRNA levels via mTOR and that different pathways were involved in the effect of those amino acids on MuRF1 mRNA levels.
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branched chain amino acids and arginine suppress mafbx atrogin 1 mrna expression via mtor pathway in c2c12 cell line
Biochimica et Biophysica Acta, 2008Co-Authors: Elizabeth Henny Herningtyas, Yasuhiko Okimura, Anastasia Evi Handayaningsih, Daisuke Yamamoto, Taiki Maki, Keiji Iida, Yutaka Takahashi, Hidesuke Kaji, Kazuo ChiharaAbstract:The effect of amino acid on muscle protein degradation remains unclear. Recent studies have elucidated that proteolysis in catabolic conditions occurs through ubiquitin-proteasome proteolysis pathway and that muscle-specific ubiquitin ligases (atrogin-1 and MuRF1) play an important role in protein degradation. In the present study, we examined the direct effect of 5 mM amino acids (leucine, Isoleucine, valine, glutamine and arginine) on atrogin-1 and MuRF1 levels in C2C12 muscle cells and the involved intracellular signal transduction pathway. Leucine, Isoleucine and valine suppressed atrogin-1 and MuRF1 mRNA levels (approximately equal to 50%) at 6 and 24 h stimulations. Arginine showed a similar effect except at 24 h-treatment for atrogin-1 mRNA. However, glutamine failed to reduce atrogin-1 and MuRF1 mRNA levels. The inhibitory effect of leucine, Isoleucine or arginine on atrogin-1 mRNA level was reversed by rapamycin, although wortmannin did not reverse the effect. PD98059 and HA89 reduced basal atrogin-1 level without influencing the inhibitory effects of those amino acids. The inhibitory effect of leucine, Isoleucine or arginine on MuRF1 mRNA levels was not reversed by rapamycin. Taken together, these findings indicated that leucine, Isoleucine and arginine decreased atrogin-1 mRNA levels via mTOR and that different pathways were involved in the effect of those amino acids on MuRF1 mRNA levels.
Yuta Mutaguchi - One of the best experts on this subject based on the ideXlab platform.
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production of d branched chain amino acids by lactic acid bacteria carrying homologs to Isoleucine 2 epimerase of lactobacillus buchneri
Frontiers in Microbiology, 2018Co-Authors: Yuta Mutaguchi, Kano Kasuga, Ikuo KojimaAbstract:Isoleucine 2-epimerase (ILEP) is a novel branched-chain amino acid racemase isolated from Lactobacillus buchneri. In this study, we examined production of free D-branched-chain amino acids such as D-valine, D-leucine, and D-allo-Isoleucine, using lactic acid bacteria carrying homologs to ILEP. Twelve selected strains of lactic acid bacteria were grown at optimal growth temperatures and accumulation of D-branched-chain amino acids in the medium was monitored in exponential, early stationary, and stationary phases. To analyze the D-branched-chain amino acids, enantiomers in the medium were initially converted into diastereomers using pre-column derivatization with o-phthaldialdehyde plus N-isobutyryl-L-cysteine. The resultant fluorescent isoindole derivatives were analyzed on an octadecylsilyl stationary phase using ultra-high performance liquid chromatography. The analyses revealed that the seven following lactic acid bacteria carrying homologs showing 53– 60% amino acid sequence identity to the L. buchneri ILEP accumulate D-branched-chain amino acids: Lactobacillus fermentum and Weissella paramesenteroides produce D-valine, D-leucine, and D-allo-Isoleucine; Lactobacillus reuteri, Leuconostoc mesenteroides subsp. mesenteroides, and Leuconostoc gelidum subsp. gasicomitatum accumulate D-leucine and D-allo-Isoleucine; and Lactobacillus vaginalis and Leuconostoc pseudomesenteroides produce D-allo-Isoleucine. These results suggest that D-branched-chain amino acids are produced by a variety of lactic acid bacteria species, particularly those carrying homologs to the ILEP.
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crystal structure of the novel amino acid racemase Isoleucine 2 epimerase from lactobacillus buchneri
Acta Crystallographica Section D-biological Crystallography, 2017Co-Authors: Junji Hayashi, Yuta Mutaguchi, Yume Minemura, Taketo Ohmori, Toshihisa Ohshima, Kazunari Yoneda, Noriko Nakagawa, Haruhiko SakurabaAbstract:Crystal structures of Lactobacillus buchneri Isoleucine 2-epimerase, a novel branched-chain amino-acid racemase, were determined for the enzyme in the apo form, in complex with pyridoxal 5′-phosphate (PLP), in complex with N-(5′-phosphopyridoxyl)-l-Isoleucine (PLP-l-Ile) and in complex with N-(5′-phosphopyridoxyl)-d-allo-Isoleucine (PLP-d-allo-Ile) at resolutions of 2.77, 1.94, 2.65 and 2.12 A, respectively. The enzyme assembled as a tetramer, with each subunit being composed of N-terminal, C-terminal and large PLP-binding domains. The active-site cavity in the apo structure was much more solvent-accessible than that in the PLP-bound structure. This indicates that a marked structural change occurs around the active site upon binding of PLP that provides a solvent-inaccessible environment for the enzymatic reaction. The main-chain coordinates of the L. buchneri Isoleucine 2-epimerase monomer showed a notable similarity to those of α-amino-∊-caprolactam racemase from Achromobactor obae and γ-aminobutyrate aminotransferase from Escherichia coli. However, the amino-acid residues involved in substrate binding in those two enzymes are only partially conserved in L. buchneri Isoleucine 2-epimerase, which may account for the differences in substrate recognition by the three enzymes. The structures bound with reaction-intermediate analogues (PLP-l-Ile and PLP-d-allo-Ile) and site-directed mutagenesis suggest that l-Isoleucine epimerization proceeds through abstraction of the α-hydrogen of the substrate by Lys280, while Asp222 serves as the catalytic residue adding an α-hydrogen to the quinonoid intermediate to form d-allo-Isoleucine.
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identification purification and characterization of a novel amino acid racemase Isoleucine 2 epimerase from lactobacillus species
Journal of Bacteriology, 2013Co-Authors: Yuta Mutaguchi, Taketo Ohmori, Taisuke Wakamatsu, Katsumi Doi, Toshihisa OhshimaAbstract:Accumulation of d-leucine, d-allo-Isoleucine, and d-valine was observed in the growth medium of a lactic acid bacterium, Lactobacillus otakiensis JCM 15040, and the racemase responsible was purified from the cells and identified. The N-terminal amino acid sequence of the purified enzyme was GKLDKASKLI, which is consistent with that of a putative γ-aminobutyrate aminotransferase from Lactobacillus buchneri. The putative γ-aminobutyrate aminotransferase gene from L. buchneri JCM 1115 was expressed in recombinant Escherichia coli and then purified to homogeneity. The enzyme catalyzed the racemization of a broad spectrum of nonpolar amino acids. In particular, it catalyzed at high rates the epimerization of l-Isoleucine to d-allo-Isoleucine and d-allo-Isoleucine to l-Isoleucine. In contrast, the enzyme showed no γ-aminobutyrate aminotransferase activity. The relative molecular masses of the subunit and native enzyme were estimated to be about 49 kDa and 200 kDa, respectively, indicating that the enzyme was composed of four subunits of equal molecular masses. The Km and Vmax values of the enzyme for l-Isoleucine were 5.00 mM and 153 μmol·min−1·mg−1, respectively, and those for d-allo-Isoleucine were 13.2 mM and 286 μmol·min−1·mg−1, respectively. Hydroxylamine and other inhibitors of pyridoxal 5′-phosphate-dependent enzymes completely blocked the enzyme activity, indicating the enzyme requires pyridoxal 5′-phosphate as a coenzyme. This is the first evidence of an amino acid racemase that specifically catalyzes racemization of nonpolar amino acids at the C-2 position.
Anastasia Evi Handayaningsih - One of the best experts on this subject based on the ideXlab platform.
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branched chain amino acids and arginine suppress mafbx atrogin 1 mrna expression via mtor pathway in c2c12 cell line
Biochimica et Biophysica Acta, 2008Co-Authors: Elizabeth Henny Herningtyas, Yasuhiko Okimura, Anastasia Evi Handayaningsih, Daisuke Yamamoto, Taiki Maki, Keiji Iida, Yutaka Takahashi, Hidesuke Kaji, Kazuo ChiharaAbstract:Abstract The effect of amino acid on muscle protein degradation remains unclear. Recent studies have elucidated that proteolysis in catabolic conditions occurs through ubiquitin–proteasome proteolysis pathway and that muscle-specific ubiquitin ligases (atrogin-1 and MuRF1) play an important role in protein degradation. In the present study, we examined the direct effect of 5 mM amino acids (leucine, Isoleucine, valine, glutamine and arginine) on atrogin-1 and MuRF1 levels in C2C12 muscle cells and the involved intracellular signal transduction pathway. Leucine, Isoleucine and valine suppressed atrogin-1 and MuRF1 mRNA levels (≈ 50%) at 6 and 24 h stimulations. Arginine showed a similar effect except at 24 h-treatment for atrogin-1 mRNA. However, glutamine failed to reduce atrogin-1 and MuRF1 mRNA levels. The inhibitory effect of leucine, Isoleucine or arginine on atrogin-1 mRNA level was reversed by rapamycin, although wortmannin did not reverse the effect. PD98059 and HA89 reduced basal atrogin-1 level without influencing the inhibitory effects of those amino acids. The inhibitory effect of leucine, Isoleucine or arginine on MuRF1 mRNA levels was not reversed by rapamycin. Taken together, these findings indicated that leucine, Isoleucine and arginine decreased atrogin-1 mRNA levels via mTOR and that different pathways were involved in the effect of those amino acids on MuRF1 mRNA levels.
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branched chain amino acids and arginine suppress mafbx atrogin 1 mrna expression via mtor pathway in c2c12 cell line
Biochimica et Biophysica Acta, 2008Co-Authors: Elizabeth Henny Herningtyas, Yasuhiko Okimura, Anastasia Evi Handayaningsih, Daisuke Yamamoto, Taiki Maki, Keiji Iida, Yutaka Takahashi, Hidesuke Kaji, Kazuo ChiharaAbstract:The effect of amino acid on muscle protein degradation remains unclear. Recent studies have elucidated that proteolysis in catabolic conditions occurs through ubiquitin-proteasome proteolysis pathway and that muscle-specific ubiquitin ligases (atrogin-1 and MuRF1) play an important role in protein degradation. In the present study, we examined the direct effect of 5 mM amino acids (leucine, Isoleucine, valine, glutamine and arginine) on atrogin-1 and MuRF1 levels in C2C12 muscle cells and the involved intracellular signal transduction pathway. Leucine, Isoleucine and valine suppressed atrogin-1 and MuRF1 mRNA levels (approximately equal to 50%) at 6 and 24 h stimulations. Arginine showed a similar effect except at 24 h-treatment for atrogin-1 mRNA. However, glutamine failed to reduce atrogin-1 and MuRF1 mRNA levels. The inhibitory effect of leucine, Isoleucine or arginine on atrogin-1 mRNA level was reversed by rapamycin, although wortmannin did not reverse the effect. PD98059 and HA89 reduced basal atrogin-1 level without influencing the inhibitory effects of those amino acids. The inhibitory effect of leucine, Isoleucine or arginine on MuRF1 mRNA levels was not reversed by rapamycin. Taken together, these findings indicated that leucine, Isoleucine and arginine decreased atrogin-1 mRNA levels via mTOR and that different pathways were involved in the effect of those amino acids on MuRF1 mRNA levels.
Hidesuke Kaji - One of the best experts on this subject based on the ideXlab platform.
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branched chain amino acids and arginine suppress mafbx atrogin 1 mrna expression via mtor pathway in c2c12 cell line
Biochimica et Biophysica Acta, 2008Co-Authors: Elizabeth Henny Herningtyas, Yasuhiko Okimura, Anastasia Evi Handayaningsih, Daisuke Yamamoto, Taiki Maki, Keiji Iida, Yutaka Takahashi, Hidesuke Kaji, Kazuo ChiharaAbstract:Abstract The effect of amino acid on muscle protein degradation remains unclear. Recent studies have elucidated that proteolysis in catabolic conditions occurs through ubiquitin–proteasome proteolysis pathway and that muscle-specific ubiquitin ligases (atrogin-1 and MuRF1) play an important role in protein degradation. In the present study, we examined the direct effect of 5 mM amino acids (leucine, Isoleucine, valine, glutamine and arginine) on atrogin-1 and MuRF1 levels in C2C12 muscle cells and the involved intracellular signal transduction pathway. Leucine, Isoleucine and valine suppressed atrogin-1 and MuRF1 mRNA levels (≈ 50%) at 6 and 24 h stimulations. Arginine showed a similar effect except at 24 h-treatment for atrogin-1 mRNA. However, glutamine failed to reduce atrogin-1 and MuRF1 mRNA levels. The inhibitory effect of leucine, Isoleucine or arginine on atrogin-1 mRNA level was reversed by rapamycin, although wortmannin did not reverse the effect. PD98059 and HA89 reduced basal atrogin-1 level without influencing the inhibitory effects of those amino acids. The inhibitory effect of leucine, Isoleucine or arginine on MuRF1 mRNA levels was not reversed by rapamycin. Taken together, these findings indicated that leucine, Isoleucine and arginine decreased atrogin-1 mRNA levels via mTOR and that different pathways were involved in the effect of those amino acids on MuRF1 mRNA levels.
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branched chain amino acids and arginine suppress mafbx atrogin 1 mrna expression via mtor pathway in c2c12 cell line
Biochimica et Biophysica Acta, 2008Co-Authors: Elizabeth Henny Herningtyas, Yasuhiko Okimura, Anastasia Evi Handayaningsih, Daisuke Yamamoto, Taiki Maki, Keiji Iida, Yutaka Takahashi, Hidesuke Kaji, Kazuo ChiharaAbstract:The effect of amino acid on muscle protein degradation remains unclear. Recent studies have elucidated that proteolysis in catabolic conditions occurs through ubiquitin-proteasome proteolysis pathway and that muscle-specific ubiquitin ligases (atrogin-1 and MuRF1) play an important role in protein degradation. In the present study, we examined the direct effect of 5 mM amino acids (leucine, Isoleucine, valine, glutamine and arginine) on atrogin-1 and MuRF1 levels in C2C12 muscle cells and the involved intracellular signal transduction pathway. Leucine, Isoleucine and valine suppressed atrogin-1 and MuRF1 mRNA levels (approximately equal to 50%) at 6 and 24 h stimulations. Arginine showed a similar effect except at 24 h-treatment for atrogin-1 mRNA. However, glutamine failed to reduce atrogin-1 and MuRF1 mRNA levels. The inhibitory effect of leucine, Isoleucine or arginine on atrogin-1 mRNA level was reversed by rapamycin, although wortmannin did not reverse the effect. PD98059 and HA89 reduced basal atrogin-1 level without influencing the inhibitory effects of those amino acids. The inhibitory effect of leucine, Isoleucine or arginine on MuRF1 mRNA levels was not reversed by rapamycin. Taken together, these findings indicated that leucine, Isoleucine and arginine decreased atrogin-1 mRNA levels via mTOR and that different pathways were involved in the effect of those amino acids on MuRF1 mRNA levels.
