Faculty Profiles - MURATA Yoshiyuki

Papers - MURATA Yoshiyuki

Division display 81 - 100 of about 242 ／ All the affair displays >>

Nonredundant functions of Arabidopsis LecRK-V.2 and LecRK-VII.1 in controlling stomatal immunity and jasmonate-mediated stomatal closure. International journal

Shweta Yekondi, Fu-Chun Liang, Eiji Okuma, Amandine Radziejwoski, Hsien-Wei Mai, Swadhin Swain, Prashant Singh, Mathieu Gauthier, Hsiao-Chiao Chien, Yoshiyuki Murata, Laurent Zimmerli

The New phytologist 218 ( 1 ) 253 - 268 2018.4

Language：English Publishing type：Research paper (scientific journal)

Stomatal immunity restricts bacterial entry to leaves through the recognition of microbe-associated molecular patterns (MAMPs) by pattern-recognition receptors (PRRs) and downstream abscisic acid and salicylic acid signaling. Through a reverse genetics approach, we characterized the function of the L-type lectin receptor kinase-V.2 (LecRK-V.2) and -VII.1 (LecRK-VII.1). Analyses of interactions with the PRR FLAGELLIN SENSING2 (FLS2) were performed by co-immunoprecipitation and bimolecular fluorescence complementation and whole-cell patch-clamp analyses were used to evaluate guard cell Ca2+ -permeable cation channels. The Arabidopsis thaliana LecRK-V.2 and LecRK-VII.1 and notably their kinase activities were required for full activation of stomatal immunity. Knockout lecrk-V.2 and lecrk-VII.1 mutants were hyper-susceptible to Pseudomonas syringae infection and showed defective stomatal closure in response to bacteria or to the MAMPs flagellin and EF-Tu. By contrast, Arabidopsis over-expressing LecRK-V.2 or LecRK-VII.1 demonstrated a potentiated stomatal immunity. LecRK-V.2 and LecRK-VII.1 are shown to be part of the FLS2 PRR complex. In addition, LecRK-V.2 and LecRK-VII.1 were critical for methyl jasmonate (MeJA)-mediated stomatal closure, notably for MeJA-induced activation of guard cell Ca2+ -permeable cation channels. This study highlights the role of LecRK-V.2 and LecRK-VII.1 in stomatal immunity at the FLS2 PRR complex and in MeJA-mediated stomatal closure.

DOI： 10.1111/nph.14953

Effects of calcium and EGTA on thiol homeostasis and defense-related enzymes in Cd-exposed chickpea roots Reviewed International coauthorship International journal

Lamia Sakouhi, Sondès Rahoui, Charfeddine Gharsallah, Shintaro Munemasa, Ezzeddine El Ferjani, Yoshiyuki Murata, Abdelilah Chaoui

Acta Physiologiae Plantarum 40 ( 1 ) 20 2018.1

Mechanism of Stomatal Closure in Plants Exposed to Drought and Cold Stress. International journal

Srinivas Agurla, Shashibhushan Gahir, Shintaro Munemasa, Yoshiyuki Murata, Agepati S Raghavendra

Advances in experimental medicine and biology 1081 215 - 232 2018

Language：English Publishing type：Research paper (scientific journal)

Drought is one of the abiotic stresses which impairs the plant growth/development and restricts the yield of many crops throughout the world. Stomatal closure is a common adaptation response of plants to the onset of drought condition. Stomata are microscopic pores on the leaf epidermis, which regulate the transpiration/CO2 uptake by leaves. Stomatal guard cells can sense various abiotic and biotic stress stimuli from the internal and external environment and respond quickly to initiate closure under unfavorable conditions. Stomata also limit the entry of pathogens into leaves, restricting their invasion. Drought is accompanied by the production and/or mobilization of the phytohormone, abscisic acid (ABA), which is well-known for its ability to induce stomatal closure. Apart from the ABA, various other factors that accumulate during drought and affect the stomatal function are plant hormones (auxins, MJ, ethylene, brassinosteroids, and cytokinins), microbial elicitors (salicylic acid, harpin, Flg 22, and chitosan), and polyamines . The role of various signaling components/secondary messengers during stomatal opening or closure has been a matter of intense investigation. Reactive oxygen species (ROS) , nitric oxide (NO) , cytosolic pH, and calcium are some of the well-documented signaling components during stomatal closure. The interrelationship and interactions of these signaling components such as ROS, NO, cytosolic pH, and free Ca2+ are quite complex and need further detailed examination.Low temperatures can have deleterious effects on plants. However, plants evolved protection mechanisms to overcome the impact of this stress. Cold temperature inhibits stomatal opening and causes stomatal closure. Cold-acclimated plants often exhibit marked changes in their lipid composition, particularly of the membranes. Cold stress often leads to the accumulation of ABA, besides osmolytes such as glycine betaine and proline. The role of signaling components such as ROS, NO, and Ca2+ during cold acclimation is yet to be established, though the effects of cold stress on plant growth and development are studied extensively. The information on the mitigation processes is quite limited. We have attempted to describe consequences of drought and cold stress in plants, emphasizing stomatal closure. Several of these factors trigger signaling components in roots, shoots, and atmosphere, all leading to stomatal closure. A scheme is presented to show the possible signaling events and their convergence and divergence of action during stomatal closure. The possible directions for future research are discussed.

DOI： 10.1007/978-981-13-1244-1_12

Blue light and CO2 signals converge to regulate light-induced stomatal opening International journal

Asami Hiyama, Atsushi Takemiya, Shintaro Munemasa, Eiji Okuma, Naoyuki Sugiyama, Yasuomi Tada, Yoshiyuki Murata, Ken-ichiro Shimazaki

Nature Communications 8 ( 1 ) 1284 - 1284 2017.12

Language：English Publishing type：Research paper (scientific journal) Publisher：Springer Science and Business Media LLC

Stomata regulate gas exchange between plants and atmosphere by integrating opening and closing signals. Stomata open in response to low CO2 concentrations to maximize photosynthesis in the light; however, the mechanisms that coordinate photosynthesis and stomatal conductance have yet to be identified. Here we identify and characterize CBC1/2 (CONVERGENCE OF BLUE LIGHT (BL) AND CO2 1/2), two kinases that link BL, a major component of photosynthetically active radiation (PAR), and the signals from low concentrations of CO2 in guard cells. CBC1/CBC2 redundantly stimulate stomatal opening by inhibition of S-type anion channels in response to both BL and low concentrations of CO2. CBC1/CBC2 function in the signaling pathways of phototropins and HT1 (HIGH LEAF TEMPERATURE 1). CBC1/CBC2 interact with and are phosphorylated by HT1. We propose that CBCs regulate stomatal aperture by integrating signals from BL and CO2 and act as the convergence site for signals from BL and low CO2.

DOI： 10.1038/s41467-017-01237-5

Other Link： http://www.nature.com/articles/s41467-017-01237-5

Inhibition of phosphatidylinositide 3-kinase impairs the benzyl isothiocyanate-induced accumulation of autophagic molecules and Nrf2 in human colon cancer cells. International journal

Xiaoyang Liu, Naomi Abe-Kanoh, Yujia Liu, Beiwei Zhu, Shintaro Munemasa, Toshiyuki Nakamura, Yoshiyuki Murata, Yoshimasa Nakamura

Bioscience, biotechnology, and biochemistry 81 ( 11 ) 2212 - 2215 2017.11

Language：English Publishing type：Research paper (scientific journal)

The regulating role of phosphatidylinositide 3-kinase (PI3K) in benzyl isothiocyanate (BITC)-induced Nrf2 activation, contributing to the inducible expression of cytoprotective genes, was investigated. BITC significantly enhanced the accumulation of Nrf2 as well as autophagic molecules in human colorectal cancer HCT-116 cells. Experiments using a PI3K-specific inhibitor suggested that PI3K plays the key role in the non-canonical Nrf2 activation by BITC.

DOI： 10.1080/09168451.2017.1374830

3,4-Dihydroxyphenylacetic acid is a potential aldehyde dehydrogenase inducer in murine hepatoma Hepa1c1c7 cells. International journal

Yujia Liu, Ayuki Kurita, Sayaka Nakashima, Beiwei Zhu, Shintaro Munemasa, Toshiyuki Nakamura, Yoshiyuki Murata, Yoshimasa Nakamura

Bioscience, biotechnology, and biochemistry 81 ( 10 ) 1978 - 1983 2017.10

Language：English Publishing type：Research paper (scientific journal)

3,4-Dihydroxyphenylacetic acid (DOPAC) is one of the major colonic microflora-produced catabolites of quercetin glycosides, such as quercetin 4'-glucoside derived from onion. Here, we investigated whether DOPAC modulates the aldehyde dehydrogenase (ALDH) activity and protects the cells from the acetaldehyde-induced cytotoxicity in vitro. DOPAC was shown to enhance not only the total ALDH activity, but also the gene expression of ALDH1A1, ALDH2 and ALDH3A1 in a concentration-dependent manner. DOPAC simultaneously stimulated the nuclear translocation of NFE2-related factor 2 and aryl hydrocarbon receptor. The pretreatment of DOPAC completely protected the cells from the acetaldehyde-induced cytotoxicity. The present study suggested that DOPAC acts as a potential ALDH inducer to prevent the alcohol-induced abnormal reaction.

DOI： 10.1080/09168451.2017.1361809

Benzyl isothiocyanate ameliorates acetaldehyde-induced cytotoxicity by enhancing aldehyde dehydrogenase activity in murine hepatoma Hepa1c1c7 cells. International journal

Yujia Liu, Momoko Yamanaka, Naomi Abe-Kanoh, Xiaoyang Liu, Beiwei Zhu, Shintaro Munemasa, Toshiyuki Nakamura, Yoshiyuki Murata, Yoshimasa Nakamura

Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association 108 ( Pt A ) 305 - 313 2017.10

Language：English Publishing type：Research paper (scientific journal)

In the present study, we assessed benzyl isothiocyanate (BITC), an organosulfur compound from cruciferous vegetables, as a potential inducer of aldehyde dehydrogenase (ALDH) activity using murine hepatoma Hepa1c1c7 cells. BITC was shown to enhance not only the total ALDH activity, but also the ALDH activity of the cytosolic/microsomal and mitochondrial fraction. BITC also significantly increased the gene and protein expression of ALDH1A1, ALDH2 and ALDH3A1 in a concentration-dependent manner. Simultaneously, the gene expression of phase 2 drug-metabolizing enzymes, such as NAD(P)H: quinone oxidoreductase 1 and heme oxygenase-1, was increased by the BITC treatment. Western blot experiments revealed that BITC not only up-regulated the Nrf2 protein expression, but also stimulated the nuclear translocation of Nrf2. Furthermore, silencing Nrf2 reduced the basal and BITC-enhanced levels of the total activity and gene expression of ALDHs. The pretreatment of BITC completely mitigated the acetaldehyde-induced cytotoxicity, which was impaired by silencing Nrf2. The present study demonstrated that BITC has been identified as a potential inducer of the total ALDH activity to prevent the acetaldehyde-induced cytotoxicity.

DOI： 10.1016/j.fct.2017.08.016

Inhibition of phosphatidylinositide 3-kinase ameliorates antiproliferation by benzyl isothiocyanate in human colon cancer cells. International journal

Xiaoyang Liu, Chiaki Takano, Tomomi Shimizu, Shintaro Yokobe, Naomi Abe-Kanoh, Beiwei Zhu, Toshiyuki Nakamura, Shintaro Munemasa, Yoshiyuki Murata, Yoshimasa Nakamura

Biochemical and biophysical research communications 491 ( 1 ) 209 - 216 2017.9

Language：English Publishing type：Research paper (scientific journal)

In the present study, we clarified the role of phosphatidylinositide 3-kinase (PI3K) in antiproliferation induced by benzyl isothiocyanate (BITC) in human colorectal cancer cells. BITC simultaneously activated the PI3K/Akt/forkhead box O (FoxO) pathway, whereas it significantly inhibited the proliferation in human colorectal cancer cells. Inhibitory experiments using a PI3K selective inhibitor, LY294002 or NVP-BEZ235, significantly enhanced the BITC-induced antiproliferation and apoptotic cell population with the attenuation of the BITC-induced activation of the PI3K/Akt/FoxO survival pathway. Furthermore, BITC enhanced the insulin-activated PI3K/Akt/FoxO pathway, possibly through its inhibition of the protein tyrosine phosphatase 1B enzymatic activity. Taken together, these results suggested that the PI3K/Akt/FoxO pathway negatively regulates the BITC-induced antiproliferation in human colorectal cancer cells.

DOI： 10.1016/j.bbrc.2017.07.078

Exogenous proline enhances the sensitivity of Tobacco BY-2 cells to arsenate International journal

Mst Nur-E-Nazmun Nahar, Mohammad Muzahidul Islam, Md Anamul Hoque, Anna Yonezawa, Md Yeasin Prodhan, Toshiyuki Nakamura, Yoshimasa Nakamura, Shintaro Munemasa, Yoshiyuki Murata

Bioscience, Biotechnology, and Biochemistry 81 ( 9 ) 1726 - 1731 2017.9

Language：English Publishing type：Research paper (scientific journal) Publisher：Oxford University Press (OUP)

<title>Abstract</title>
Arsenic causes physiological and structural disorders in plants. Proline is accumulated as a compatible solute in plants under various stress conditions and mitigates stresses. Here, we investigated the effects of exogenous proline on tobacco Bright Yellow-2 (BY-2) cultured cells under stress. Arsenate did not inhibit BY-2 cell growth at 40 and 50 μM but did it at 60 μM. Proline at 0.5 to 10 mM did not affect the cell growth but delayed it at 20 mM. At 40 μM , neither 0.5 mM nor 1 mM proline affected the cell growth but 10 mM proline inhibited it. In the presence of , 10 mM proline increased the number of Evans Blue-stained (dead) cells and decreased the number of total cells. Together, our results suggest that exogenous proline does not alleviate arsenate toxicity but enhances the sensitivity of BY-2 cells to arsenate.

DOI： 10.1080/09168451.2017.1340088

(-)-Epigallocatechin-3-gallate inhibits human angiotensin-converting enzyme activity through an autoxidation-dependent mechanism. International journal

Zhe Liu, Sayaka Nakashima, Toshiyuki Nakamura, Shintaro Munemasa, Yoshiyuki Murata, Yoshimasa Nakamura

Journal of biochemical and molecular toxicology 31 ( 9 ) 2017.9

Language：English Publishing type：Research paper (scientific journal)

We investigated the molecular mechanisms involved in the angiotensin-converting enzyme (ACE) inhibition by (-)-epigallocatechin-3-gallate (EGCg), a major tea catechin. EGCg inhibited both the ACE activity in the lysate of human colorectal cancer cells and human recombinant ACE (rh-ACE) in a dose-dependent manner. Co-incubation with zinc sulfate showed no influence on the rh-ACE inhibition by EGCg, whereas it completely counteracted the inhibitory effect of ethylenediaminetetraacetic acid, a chelating-type ACE inhibitor. Although hydrogen peroxide was produced by the autoxidation of EGCg, hydrogen peroxide itself had little effect on the ACE activity. Conversely, the co-incubation of EGCg with borate or ascorbic acid significantly diminished the EGCg inhibition. A redox-cycling staining experiment revealed that rh-ACE was covalently modified by EGCg. A Lineweaver-Burk plot analysis indicated that EGCg inhibited the ACE activity in a non-competitive manner. These results suggested that EGCg might allosterically inhibit the ACE activity through oxidative conversion into an electrophilic quinone.

DOI： 10.1002/jbt.21932

Chitosan signaling in guard cells requires endogenous salicylic acid International journal

Md Yeasin Prodhan, Mohammad Issak, Toshiyuki Nakamura, Shintaro Munemasa, Yoshimasa Nakamura, Yoshiyuki Murata

Bioscience, Biotechnology, and Biochemistry 81 ( 8 ) 1536 - 1541 2017.8

Language：English Publishing type：Research paper (scientific journal) Publisher：Oxford University Press (OUP)

<title>Abstract</title>
An elicitor chitosan (CHT) induces stomatal closure but the mechanism remains to be clarified. A phytohormone salicylic acid (SA) is crucial for elicitor-induced defense signaling in plants. Here we investigated whether endogenous SA is required for CHT signaling in guard cells. In the SA-deficient nahG mutant, treatment of CHT did not induce either apoplastic reactive oxygen species (ROS) production or stomatal closure but co-treatment of CHT and SA induced both apoplastic ROS production and stomatal closure, indicating the involvement of endogenous SA in CHT-induced apoplastic ROS production and CHT-induced stomatal closure. Furthermore, CHT induced transient cytosolic free calcium concentration increments in the nahG mutant in the presence of exogenous SA but not in the absence of exogenous SA. These results provide evidence that endogenous SA is a crucial element in CHT-induced stomatal closure.

DOI： 10.1080/09168451.2017.1332979

MPK9 and MPK12 function in SA-induced stomatal closure in Arabidopsis thaliana. International journal

Md Atiqur Rahman Khokon, Mohammad Abdus Salam, Fabien Jammes, Wenxiu Ye, Mohammad Anowar Hossain, Eiji Okuma, Yoshimasa Nakamura, Izumi C Mori, June M Kwak, Yoshiyuki Murata

Bioscience, biotechnology, and biochemistry 81 ( 7 ) 1394 - 1400 2017.7

Language：English Publishing type：Research paper (scientific journal)

Salicylic acid (SA) induces stomatal closure sharing several components with abscisic acid (ABA) and methyl jasmonate (MeJA) signaling. We have previously shown that two guard cell-preferential mitogen-activated protein kinases (MAPKs), MPK9 and MPK12, positively regulate ABA signaling and MeJA signaling in Arabidopsis thaliana. In this study, we examined whether these two MAPKs are involved in SA-induced stomatal closure using genetic mutants and a pharmacological, MAPKK inhibitor. Salicylic acid induced stomatal closure in mpk9 and mpk12 single mutants but not in mpk9 mpk12 double mutants. The MAPKK inhibitor PD98059 inhibited SA-induced stomatal closure in wild-type plants. Salicylic acid induced extracellular reactive oxygen species (ROS) production, intracellular ROS accumulation, and cytosolic alkalization in the mpk9, mpk12, and mpk9 mpk12 mutants. Moreover, SA-activated S-type anion channels in guard cells of wild-type plants but not in guard cells of mpk9 mpk12 double mutants. These results imply that MPK9 and MPK12 are positive regulators of SA signaling in Arabidopsis guard cells.

DOI： 10.1080/09168451.2017.1308244

Methylglyoxal induces inhibition of growth, accumulation of anthocyanin, and activation of glyoxalase I and II in Arabidopsis thaliana. International journal

Tahsina Sharmin Hoque, Misugi Uraji, Md Anamul Hoque, Yoshimasa Nakamura, Yoshiyuki Murata

Journal of biochemical and molecular toxicology 31 ( 7 ) 2017.7

Language：English Publishing type：Research paper (scientific journal)

Methylglyoxal (MG) is a highly reactive stress-related α-ketoaldehyde and a physiological metabolite of glycolysis, which is accumulated in ample amount under stressful conditions. In the present study, the effect of different doses of MG on growth, anthocyanin production, MG contents, and activities of two types of glyoxalases (glyoxalase I and glyoxalase II) were examined in Arabidopsis seedlings. MG at 0.1 mM dose did not affect seedling growth, anthocyanin accumulation, MG contents, or activities of glyoxalases, whereas MG at 0.5 mM and 1 mM inhibited seedling growth and induced anthocyanin accumulation, MG accumulation, and glyoxalase (both I and II) activation. Therefore, MG can reduce plant growth as a toxic molecule and can stimulate stress responses as a signal molecule under stress conditions.

DOI： 10.1002/jbt.21901

Brassinosteroid Involvement in Arabidopsis thaliana Stomatal Opening

Shin-ichiro Inoue, Nozomi Iwashita, Yohei Takahashi, Eiji Gotoh, Eiji Okuma, Maki Hayashi, Ryohei Tabata, Atsushi Takemiya, Yoshiyuki Murata, Michio Doi, Toshinori Kinoshita, Ken-ichiro Shimazaki

PLANT AND CELL PHYSIOLOGY 58 ( 6 ) 1048 - 1058 2017.6

Language：English Publishing type：Research paper (scientific journal) Publisher：OXFORD UNIV PRESS

Stomata within the plant epidermis regulate CO2 uptake for photosynthesis and water loss through transpiration. Stomatal opening in Arabidopsis thaliana is determined by various factors, including blue light as a signal and multiple phytohormones. Plasma membrane transporters, including H+-ATPase, K+ channels and anion channels in guard cells, mediate these processes, and the activities and expression levels of these components determine stomatal aperture. However, the regulatory mechanisms involved in these processes are not fully understood. In this study, we used infrared thermography to isolate a mutant defective in stomatal opening in response to light. The causative mutation was identified as an allele of the brassinosteroid (BR) biosynthetic mutant dwarf5. Guard cells from this mutant exhibited normal H+-ATPase activity in response to blue light, but showed reduced K+ accumulation and inward-rectifying K+ (K-in(+)) channel activity as a consequence of decreased expression of major K-in(+) channel genes. Consistent with these results, another BR bio-synthetic mutant, det2-1, and a BR receptor mutant, bri1-6, exhibited reduced blue light-dependent stomatal opening. Furthermore, application of BR to the hydroponic culture medium completely restored stomatal opening in dwarf5 and det2-1 but not in bri1-6. However, application of BR to the epidermis of dwarf5 did not restore stomatal response. From these results, we conclude that endogenous BR acts in a long-term manner and is required in guard cells with the ability to open stomata in response to light, probably through regulation of K-in(+) channel activity.

DOI： 10.1093/pcp/pcx049

Editorial: Signal Transduction in Stomatal Guard Cells. International journal

Agepati S Raghavendra, Yoshiyuki Murata

Frontiers in plant science 8 114 - 114 2017

Reactive Carbonyl Species Mediate ABA Signaling in Guard Cells

Md. Moshiul Islam, Wenxiu Ye, Daiki Matsushima, Shintaro Munemasa, Eiji Okuma, Yoshimasa Nakamura, Sanaullah Biswas, Jun’ichi Mano, Yoshiyuki Murata

Plant and Cell Physiology 57 ( 12 ) 2552 - 2563 2016.12

Language：English Publishing type：Research paper (scientific journal) Publisher：Oxford University Press (OUP)

Drought is responsible for a massive reduction in crop yields. In response to drought, plants synthesize the hormone ABA, which induces stomatal closure, thus reducing water loss. In guard cells, ABA triggers production of reactive oxygen species (ROS), which is mediated by NAD(P)H oxidases. The production of ROS is a key factor for ABA-induced stomatal closure, but it remains to be clarified how the production of ROS is transduced into downstream signaling components in guard cells. We investigated roles of reactive carbonyl species (RCS) in ABA-induced stomatal closure using transgenic tobacco (Nicotiana tabacum) overexpressing Arabidopsis 2-alkenal reductase (AER-OE), which scavenges RCS. ABA and hydrogen peroxide (H2O2) induced accumulation of RCS including acrolein and 4-hydroxy-(E)-2-nonenal in wild-type tobacco but not in AER-OE. Stomatal closure and RCS accumulation in response to ABA and H2O2 were inhibited in AER-OE unlike in the wild type, while ABA-induced H2O2 production in guard cells was observed in AER-OE as well as in the wild type. Moreover, ABA inhibited inward-rectifying K+ channels in wild-type guard cells but not in AER-OE guard cells. These results suggest that RCS is involved in ABA-induced stomatal closure and functions downstream of H2O2 production in the ABA signaling pathway in guard cells.

DOI： 10.1093/pcp/pcw166

L-Met Activates Arabidopsis GLR Ca2+ Channels Upstream of ROS Production and Regulates Stomatal Movement International journal

Dongdong Kong, Heng-Cheng Hu, Eiji Okuma, Yuree Lee, Hui Sun Lee, Shintaro Munemasa, Daeshik Cho, Chuanli Ju, Leah Pedoeim, Barbara Rodriguez, Juan Wang, Wonpil Im, Yoshiyuki Murata, Zhen-Ming Pei, June M. Kwak

Cell Reports 17 ( 10 ) 2553 - 2561 2016.12

Language：English Publishing type：Research paper (scientific journal) Publisher：Elsevier BV

Plant glutamate receptor homologs (GLRs) have long been proposed to function as ligand-gated Ca2+ channels, but no in planta evidence has been provided. Here, we present genetic evidence that Arabidopsis GLR3.1 and GLR3.5 form Ca2+ channels activated by L-methionine (L-Met) at physiological concentrations and regulate stomatal apertures and plant growth. The glr3.1/3.5 mutations resulted in a lower cytosolic Ca2+ level, defective Ca2+-induced stomatal closure, and Ca2+-deficient growth disorder, all of which involved L-Met. Patch-clamp analyses of guard cells showed that GLR3.1/3.5 Ca2+ channels are activated specifically by L-Met, with the activation abolished in glr3.1/3.5. Moreover, GLR3.1/3.5 Ca2+ channels are distinct from previously characterized ROS-activated Ca2+ channels and act upstream of ROS, providing Ca2+ transients necessary for the activation of NADPH oxidases. Our data indicate that GLR3.1/3.5 constitute L-Met-activated Ca2+ channels responsible for maintaining basal [Ca2+]cyt, play a pivotal role in plant growth, and act upstream of ROS, thereby regulating stomatal aperture.

DOI： 10.1016/j.celrep.2016.11.015

Calcium and EGTA Alleviate Cadmium Toxicity in Germinating Chickpea Seeds Reviewed International coauthorship International journal

Lamia Sakouhi, Sondès Rahoui, Marouane Ben Massoud, Shintaro Munemasa, Ezzeddine EL Ferjani, Yoshiyuki Murata, Abdelilah Chaoui

Journal of Plant Growth Regulation 35 ( 4 ) 1064 - 1073 2016.12

3,4-Dihydroxyphenylacetic acid is a predominant biologically-active catabolite of quercetin glycosides. International journal

Yue Tang, Sayaka Nakashima, Shunya Saiki, Yui Myoi, Naomi Abe, Shoko Kuwazuru, Beiwei Zhu, Hitoshi Ashida, Yoshiyuki Murata, Yoshimasa Nakamura

Food research international (Ottawa, Ont.) 89 ( Pt 1 ) 716 - 723 2016.11

Language：English Publishing type：Research paper (scientific journal)

Since dietary flavonoid glycosides, including quercetin 4'-glucoside from onion, are poorly absorbed from the gastrointestinal tract, they are converted into smaller phenolic acids, which can be absorbed into the circulation. The purpose of this study was to compare the effects of the major phenolic acid catabolites of quercetin 4'-glucoside, including 3,4-dihydroxyphenylacetic acid (DOPAC), 3-hydroxyphenylacetic acid, 3,4-dihydroxybenzoic acid (protocatechuic acid) and hippuric acid, on the antioxidant activity and phase II cytoprotective enzyme induction in vitro. Both DOPAC and protocatechuic acid, having a catechol moiety, exhibited both DPPH radical scavenging and superoxide dismutase-like activities, whereas 3-hydroxyphenyl acetic acid and hippuric acid did not. DOPAC also more potently enhanced the gene expression of several phase II drug-metabolizing enzymes than the other phenolic acid catabolites. DOPAC significantly inhibited the hydrogen peroxide-induced cytotoxicity in hepatocytes with the enhancement of the total glutathione S-transferase activity. In conclusion, DOPAC may play a key role in the antioxidative potential of the colonic lumen after the ingestion of the quercetin glycoside-rich onion.

DOI： 10.1016/j.foodres.2016.09.034

A novel tag-free probe for targeting molecules interacting with a flavonoid catabolite. International journal

Sayaka Nakashima, Zhe Liu, Yuya Yamaguchi, Shunya Saiki, Shintaro Munemasa, Toshiyuki Nakamura, Yoshiyuki Murata, Yoshimasa Nakamura

Biochemistry and biophysics reports 7 240 - 245 2016.9

Language：English Publishing type：Research paper (scientific journal)

3,4-Dihydroxyphenylacetic acid (DOPAC) is one of the colonic microflora-produced catabolites of quercetin 4'-glucoside (Q4'G). Although the interaction of DOPAC with cellular proteins might be involved in its biological activity, the actual proteins have not yet been identified. In this study, we developed a novel tag-free DOPAC probe to label the targeted proteins by the copper(I)-catalyzed azide alkyne cycloaddition (CuAAC) and verified its efficacy. Various labeled proteins were detected by the DOPAC probe with the azide labeled biotin and a horseradish peroxidase (HRP)-streptavidin complex. Furthermore, a pulldown assay identified Keap1 and aryl hydrocarbon receptor (AhR) as the target proteins for the phase 2 enzyme up-regulation.

DOI： 10.1016/j.bbrep.2016.06.020

　 PREV - NEXT 　

1
2
3
4
5
6
7
8
9
10
11
12
13