東北大学研究者紹介

経歴 3

2022年4月～継続中

東北大学　大学院工学研究科バイオ工学専攻
2019年10月～ 2022年3月

東北大学　大学院工学研究科バイオ工学専攻
2011年9月～ 2014年3月

Pelita Harapan University　Department of Biology (Biotechnology)　Exploration of probiotic potential from organic local chicken and pig

学歴 2

東北大学

2016年10月～ 2019年9月
東北大学

2014年10月～ 2016年9月

所属学協会 3

日本生化学会

2025年5月～継続中
日本農芸化学会

2022年1月～継続中
日本生物工学会

2015年9月～継続中

研究キーワード 4

Escherichia coli
Yeast
Palmitoylation
Potassium Transporter

研究分野 1

ライフサイエンス / 分子生物学 /

受賞 3

JSPS fellowship. DC2 Special Researcher.

2019年4月　Japan Society for Promotion of Science　Elucidation of novel functions of Escherichia coli Trk/Ktr/HKT transporter
第5回日本生物工学会飛翔賞

2016年9月
文部省外国人国費留学生

2014年4月

論文 12

Two Trk/Ktr/HKT-type potassium transporters, TrkG and TrkH perform distinct functions in Escherichia coli K-12 査読有り

Ellen Tanudjaja, Naomi Hoshi, Kaneyoshi Yamamoto, Kunio Ihara, Tadaomi Furuta, Masaru Tsujii, Yasuhiro Ishimaru, Nobuyuki Uozumi

Journal of Biological Chemistry　102846-102846　2022年12月
出版者・発行元： Elsevier BV
DOI： 10.1016/j.jbc.2022.102846 　

ISSN：0021-9258
Kup-mediated Cs+ uptake and Kdp-driven K+ uptake coordinate to promote cell growth during excess Cs+ conditions in Escherichia coli 査読有り

Ellen Tanudjaja, Naomi Hoshi, Yi-Hsin Su, Shin Hamamoto, Nobuyuki Uozumi

Scientific Reports　7　(1)　2017年12月
出版者・発行元： Springer Science and Business Media LLC
DOI： 10.1038/s41598-017-02164-7 　

eISSN：2045-2322
An ancestral glutamate receptor mediates cell volume regulation during high K+ stress in cyanobacteria. 国際誌査読有り

Haoyu Zhang, Masaru Tsujii, Ellen Tanudjaja, Haruto Shimizukawa, Yuki Muraoka, Yuki Sato, Kota Kera, Tadaomi Furuta, Shingo Kaneko, Satoshi Amaya, Hirotaka Sugiura, Fumihito Arai, Yasuhiro Ishimaru, Nobuyuki Uozumi

Journal of Biological Chemistry　111396-111396　2026年3月21日

DOI： 10.1016/j.jbc.2026.111396 　

詳細を見る詳細を閉じる

Cyanobacteria, able to survive photoautotrophically in harsh environments, possess various ancestral homologs of ion transport systems found in eukaryotic cells. The model cyanobacterium, Synechocystis sp. PCC 6803 contains five K+ channels, however, their function and role have not been fully explained. This study determined the structure, function and physiological role of an ancestral glutamate receptor, GluR0, in Synechocystis. Growth of a gluR0 mutant (ΔgluR0) increased under high KCl conditions. Subcellular fractionation showed that GluR0 was localized in the plasma membrane of Synechocystis, and expression of GluR0 enabled a K+ uptake-deficient E. coli mutant to grow under low K+ conditions. The membrane topology of GluR0 was opposite to that of the canonical K+ channel, but similar to that of the animal glutamate receptor. Microfluidic device-aided single-cell analysis that enabled instantaneous extracellular solution exchange revealed that between 50 and 100 milliseconds after KCl upshock, the cell volume of ΔgluR0 decreased more rapidly than the wild type. These data provide the first direct evidence that a prokaryotic glutamate receptor homolog with K+ channel activity plays a role in responding to rapid changes in the ionic environment. This function likely reflects a property of glutamate receptors that was acquired early on during evolution.
Structure reveals a regulation mechanism of plant outward-rectifying K ⁺ channel GORK by structural rearrangements in the CNBD–Ankyrin bridge

Taro Yamanashi, Yuki Muraoka, Tadaomi Furuta, Tsukasa Kume, Natsuko Sekido, Shunya Saito, Shota Terashima, Takeshi Yokoyama, Yoshikazu Tanaka, Atsushi Miyamoto, Kanane Sato, Tomoyuki Ito, Hikaru Nakazawa, Mitsuo Umetsu, Ellen Tanudjaja, Masaru Tsujii, Ingo Dreyer, Julian I. Schroeder, Yasuhiro Ishimaru, Nobuyuki Uozumi

Proceedings of the National Academy of Sciences　122　(30)　2025年7月23日
出版者・発行元： Proceedings of the National Academy of Sciences
DOI： 10.1073/pnas.2500070122 　

ISSN：0027-8424

eISSN：1091-6490

詳細を見る詳細を閉じる

Guard cells, which regulate stomatal apertures in plants, possess a sophisticated mechanism for regulating turgor pressure. The outward-rectifying “K ⁺ _out ” channel GORK, expressed in guard cells of the plant Arabidopsis thaliana , is a central component that promotes stomatal closure by releasing K ⁺ to the extracellular space, thereby lowering turgor pressure. To date, the structural basis underlying the regulation of the K ⁺ transport activity of GORK is unclear. Using cryo-EM, we determined the structures of the GORK outward-rectifying K ⁺ channel with a resolution of 3.16 to 3.27 Å in five distinct conformations that differ significantly in their C-terminal cyclic nucleotide binding domain (CNBD) and ankyrin repeat (ANK) domain. The C-linker connects the transmembrane domains to the C-terminal domains, i.e., CNBD, CNBD–Ankyrin bridge, and ANK. The structural changes and interactions in the C-linker determine whether the closed state of GORK is closer to the preopen state or in a more removed state from the open state of the channel. In particular, interconversion in the short sequence within the CNBD–Ankyrin bridge plays a decisive role in this determination. This region forms an α-helix in the preopened state, while it adopts a nonhelical structure in further distant closed states. The dynamics of the cytosolic region strongly suggest that the K ⁺ channel activity of GORK is regulated by cytosolic signaling factors during stomatal closure.
Functional characterization of an additional transmembrane domain unique to TrkG and TrkH in Escherichia coli 査読有り

Ellen Tanudjaja, Haoyu Zhang, Tadaomi Furuta, Masaru Tsujii, Yasuhiro Ishimaru, Nobuyuki Uozumi

Bioscience, Biotechnology, and Biochemistry　2025年7月15日
出版者・発行元： Oxford University Press (OUP)
DOI： 10.1093/bbb/zbaf101 　

eISSN：1347-6947

詳細を見る詳細を閉じる

Abstract Escherichia coli TrkG and TrkH transporters contain a unique N-terminal Domain-0 (D0). Our findings reveal that D0 supports both the function and stability of TrkG, enabling K+ and Na+ uptake, whereas it is not essential for TrkH-mediated K+ uptake. This difference can be attributed to D0 role in stabilizing polar residues within TrkG core transmembrane domains.
Dissecting structure and function of the monovalent cation/H ⁺ antiporters Mdm38 and Ylh47 in Saccharomyces cerevisiae 査読有り

Masaru Tsujii, Ellen Tanudjaja, Haoyu Zhang, Haruto Shimizukawa, Ayumi Konishi, Tadaomi Furuta, Yasuhiro Ishimaru, Nobuyuki Uozumi

Journal of Bacteriology　2024年7月31日
出版者・発行元： American Society for Microbiology
DOI： 10.1128/jb.00182-24 　

ISSN：0021-9193

eISSN：1098-5530

詳細を見る詳細を閉じる

ABSTRACT Saccharomyces cerevisiae Mdm38 and Ylh47 are homologs of the Ca ²⁺ /H ⁺ antiporter Letm1, a candidate gene for seizures associated with Wolf-Hirschhorn syndrome in humans. Mdm38 is important for K ⁺ /H ⁺ exchange across the inner mitochondrial membrane and contributes to membrane potential formation and mitochondrial protein translation. Ylh47 also localizes to the inner mitochondrial membrane. However, knowledge of the structures and detailed transport activities of Mdm38 and Ylh47 is limited. In this study, we conducted characterization of the ion transport activities and related structural properties of Mdm38 and Ylh47. Growth tests using Na ⁺ /H ⁺ antiporter-deficient Escherichia coli strain TO114 showed that Mdm38 and Ylh47 had Na ⁺ efflux activity. Measurement of transport activity across E. coli -inverted membranes showed that Mdm38 and Ylh47 had K ⁺ /H ⁺ , Na ⁺ /H ⁺ , and Li ⁺ /H ⁺ antiport activity, but unlike Letm1, they lacked Ca ²⁺ /H ⁺ antiport activity. Deletion of the ribosome-binding domain resulted in decreased Na ⁺ efflux activity in Mdm38. Structural models of Mdm38 and Ylh47 identified a highly conserved glutamic acid in the pore-forming membrane-spanning region. Replacement of this glutamic acid with alanine, a non-polar amino acid, significantly impaired the ability of Mdm38 and Ylh47 to complement the salt sensitivity of E. coli TO114. These findings not only provide important insights into the structure and function of the Letm1-Mdm38-Ylh47 antiporter family but by revealing their distinctive properties also shed light on the physiological roles of these transporters in yeast and animals. IMPORTANCE The inner membrane of mitochondria contains numerous ion transporters, including those facilitating H ⁺ transport by the electron transport chain and ATP synthase to maintain membrane potential. Letm1 in the inner membrane of mitochondria in animals functions as a Ca ²⁺ /H ⁺ antiporter. However, this study reveals that homologous antiporters in mitochondria of yeast, Mdm38 and Ylh47, do not transport Ca ²⁺ but instead are selective for K ⁺ and Na ⁺ . Additionally, the identification of conserved amino acids crucial for antiporter activity further expanded our understanding of the structure and function of the Letm1-Mdm38-Ylh47 antiporter family.
Two cyanobacterial response regulators with diguanylate cyclase activity, Rre2 and Rre8, participate in biofilm formation 査読有り

Ayumu Kobayashi, Masamune Nakamura, Masaru Tsujii, Kohei Makino, Tatsuya Nagayama, Kensuke Nakamura, Kei Nanatani, Kera Kota, Yuki Furuuchi, Shunsuke Kayamori, Tadaomi Furuta, Iwane Suzuki, Yoshihiro Hayakawa, Tanudjaja Ellen, Yasuhiro Ishimaru, Nobuyuki Uozumi

Molecular Microbiology　119　(5)　599-611　2023年3月16日
出版者・発行元： Wiley
DOI： 10.1111/mmi.15057 　

ISSN：0950-382X

eISSN：1365-2958
Draft genome sequence of a malachite green-decolorizing Bacillus velezensis N1 isolated from Indonesian chicken crop 査読有り

Reinhard Pinontoan, Hans Victor, Dikson, Steven Ryan, Susanto Tan, Ellen Tanudjaja, Melanie Cornelia

Korean Journal of Microbiology　58　(1)　47-48　2022年3月

DOI： 10.7845/kjm.2022.1101 　
Diverse Physiological Functions of Cation Proton Antiporters across Bacteria and Plant Cells 招待有り査読有り

Masaru Tsujii, Ellen Tanudjaja, Nobuyuki Uozumi

International Journal of Molecular Sciences　21　(12)　4566-4566　2020年6月26日
出版者・発行元： MDPI AG
DOI： 10.3390/ijms21124566 　

eISSN：1422-0067

詳細を見る詳細を閉じる

Membrane intrinsic transport systems play an important role in maintaining ion and pH homeostasis and forming the proton motive force in the cytoplasm and cell organelles. In most organisms, cation/proton antiporters (CPAs) mediate the exchange of K+, Na+ and Ca2+ for H+ across the membrane in response to a variety of environmental stimuli. The tertiary structure of the ion selective filter and the regulatory domains of Escherichia coli CPAs have been determined and a molecular mechanism of cation exchange has been proposed. Due to symbiogenesis, CPAs localized in mitochondria and chloroplasts of eukaryotic cells resemble prokaryotic CPAs. CPAs primarily contribute to keeping cytoplasmic Na+ concentrations low and controlling pH, which promotes the detoxification of electrophiles and formation of proton motive force across the membrane. CPAs in cyanobacteria and chloroplasts are regulators of photosynthesis and are essential for adaptation to high light or osmotic stress. CPAs in organellar membranes and in the plasma membrane also participate in various intracellular signal transduction pathways. This review discusses recent advances in our understanding of the role of CPAs in cyanobacteria and plant cells.
Analysis of Arabidopsis TPK2 and KCO3 reveals structural properties required for K⁺ channel function 査読有り

Chihiro Uehara, Kota Takeda, Tatsuki Ibuki, Tadaomi Furuta, Naomi Hoshi, Ellen Tanudjaja, Nobuyuki Uozumi

Channels　14　(1)　336-346　2020年1月1日
出版者・発行元： Informa UK Limited
DOI： 10.1080/19336950.2020.1825894 　

ISSN：1933-6950

eISSN：1933-6969
Characterization of Alpha-Amylase from Aspergillus niger Aggregate F Isolated from a Fermented Cassava Gatot Grown in Potato Peel Waste Medium 査読有り

Cindy Angelia, Astia Sanjaya, Aida Aida, Ellen Tanudjaja, Hans Victor, Antari Daru Cahyani, Tjie Jan Tan, Reinhard Pinontoan

Microbiology and Biotechnology Letters　47　(3)　364-371　2019年9月28日
出版者・発行元： Korean Society for Microbiology and Biotechnology
DOI： 10.4014/mbl.1811.11011 　

ISSN：1598-642X

eISSN：2234-7305
A Second Generation Biofuel from Cellulosic Agricultural By-product Fermentation Using Clostridium Species for Electricity Generation 査読有り

Yalun Arifin, Ellen Tanudjaja, Arbi Dimyati, Reinhard Pinontoan

Energy Procedia　47　310-315　2014年2月
出版者・発行元： Elsevier BV
DOI： 10.1016/j.egypro.2014.01.230 　

ISSN：1876-6102

︎全件表示 ︎最初の5件までを表示

MISC 2

シロイヌナズナにおける高親和性K⁺輸送体を介したK⁺利用機構の解明

山梨太郎, 内山剛志, 堀越智也, 高木智子, 吉田哲, 池田隼人, 横北卓也, 菊永英寿, 清水未崎, 斎藤芳郎, 三輪美沙子, 遠山翔, 松山成男, 永田典子, 山上睦, TANUDJAJA Ellen, 石丸泰寛, 魚住信之

日本植物生理学会年会(Web)　66th　2025年
植物のカリウム吸収・移行を調節する膜輸送体の機能解析

山梨太郎, 東大起, 内山剛志, 池田隼人, 菊永英寿, 須田利美, 山上睦, Tanudjaja Ellen, 石丸泰寛, 魚住信之

アイソトープ・放射線研究発表会　2　64　2022年
出版者・発行元：公益社団法人日本アイソトープ協会
DOI： 10.50955/happyokai.2.0_64 　

eISSN： 2436-4487

講演・口頭発表等 9

大腸菌K⁺輸送システムの特化機能

Ellen Tanudjaja, 星直美, 山本兼由, 井原邦夫, 古田忠臣, 辻井雅, 石丸泰寛, 魚住信之

本農芸化学会東北支部第159回大会　2024年9月28日
大腸菌Trk型K取込みトランスポーターの進化的背景

日本農芸化学会　2024年3月
大腸菌KトランスポーターのNa活性化部位の同定

Ellen Tanudjaja, 星直美, 山本兼由, 井原邦夫, 古田忠臣, 辻井雅, 石丸泰寛, 魚住信之

第75回日本生物工学会　2023年9月5日
大腸菌の Trk 系 K トランスポーターの機能解析

2022 年度（令和4 年度）［京都］大会　2022年3月
Kup-driven Cs+ uptake promote Escherichia coli growth under K+ limited condition.

Ellen Tanudjaja, Naomi Hoshi, Yi-Hsin Su, Nanatani Kei, Shin Hamamoto, Nobuyuki Uozumi

American Society of Microbiology (ASM) Microbe 2019　2019年6月
Functional analysis of Kup transport system in Escherichia coli.

Ellen Tanudjaja, Naomi Hoshi, Yi-Hsin Su, Nanatani Kei, Shin Hamamoto, Nobuyuki Uozumi.

The 68th annual meeting of the Society for Biotechnology Japan　2016年9月
Characterization of Kup potassium transport system in Escherichia coli

Ellen Tanudjaja, Naomi Hoshi, Yi-Hsin Su, Nanatani Kei, Shin Hamamoto, Nobuyuki Uozumi

The 67th annual meeting of the Society for Biotechnology Japan　2015年10月
Isolation of Probiotic Potential Bacillus amyloliquefaciens from Chicken Crop

Ellen Tanudjaja, Febiola Natasha, Ariella Samantha, Astia Sanjaya, Michael Gotama, Tan Tije Jan, Reinhard Pinontoan

Probiotics and Their Applications International Conference　2013年5月
Identification and Characterization of Lactobacillus fermentum from Local Chicken Crop

Ellen Tanudjaja, Febiola Natasha, Tan Tjie Jan, Reinhard Pinontoan

The 5th Indonesia Biotechnology Conference　2012年7月

︎全件表示 ︎最初の5件までを表示

共同研究・競争的資金等の研究課題 2

Acquisition of TrkG added new functionalities to the K+ uptake system of Escherichia coli

ELLEN

2023年4月1日～ 2025年3月31日

詳細を見る詳細を閉じる

K+ is an essential cation that has many important functions for living cells. Cells tend to accumulate high intracellular concentrations of K+ via protein transporters located in the cell membrane. The Trk/Ktr/HKT K+ transporter family is one of the main K+ transporters found in non-animal cells, including bacteria, yeast,and plants. In the model organism, Escherichia coli K-12, Trk transporter is further divided into two types: TrkG and TrkH. Although they are homologous protein, previously, we had found the differences in their uptake activities. But the information about their gene regulation is very limited. In this study, we investigate the expression of trkG and trkH in relation to various factors, such as salt stress, extracellular K+ concentration and xenogenic silencing proteins.
植物Kチャネルが制御する新規Caシグナリングの分子機構の解析

魚住信之, 石丸泰寛, 辻井雅, 齋藤俊也, ELLEN

提供機関：Japan Society for the Promotion of Science

制度名：Grants-in-Aid for Scientific Research

研究種目：Fund for the Promotion of Joint International Research (Fostering Joint International Research (B))

研究機関：Tohoku University

2020年10月27日～ 2024年3月31日

詳細を見る詳細を閉じる

植物シロイヌナズナに緑茶を噴霧すると植物の生育状態に変化が観察された．さらに乾燥環境においた場合は，緑茶の噴霧により乾燥への感受性が上昇することが明らかになった．緑茶成分が乾燥の感受性を高める化合物として作用したことに加えて，緑茶成分の水溶性分子が気孔の外部から影響を与えた．申請者は，緑茶の主成分がカテキン類であること，耐乾燥性に関わり外界と接点の孔辺細胞の原形質膜で機能することから，カテキン類がKチャネルに影響を与えると推定して電気生理学的測定法によりカテキンの効果を検討した．主要なカテキンとして8種類を用いてKAT1の阻害度合いを評価した結果，ガレート基を有するカテキンで阻害活性が認められた．また，KAT1とヘテロ四量体を構成するKAT2も阻害することが明らかとなった．また，孔辺細胞でK排出系として機能するGORKも影響を受けることが明らかとなった．膜電位センターを有するKチャネルのみが影響を受けるか否かを動物のKチャネルを用いて検討したところ，膜電位センサーを有するShakerBで阻害活性が検出された．CBL-CIPK複合体の組み合わせの中から，イオン輸送体の調節を行う分子を見いだすために，酵母の共発現系の構築を行った．3種類のプラスミドを用いて，遺伝子を共発現させた酵母を用いて，複数のイオン輸送体の輸送活性調節に関わる組み合わせを酵母の生育テストを行った．中には，CBL-CIPKの2つの組み合わせだけでも優位にK輸送活性変異を相補してしまう場合が見いだされ，それらはアッセイから除外した．昨年度から進めている阻害剤の官能基を置換した類縁体を用いて，イオン輸送体活性の影響を電気生理学的手法により検討を行った．6つの有機合成化合物を調べているが，もとの化合物よりも強力に阻害する化合物は現在までのところ検出されていない．今後，さらに類縁体の評価をすすめる．