Details of the Researcher

PHOTO

Ellen
Section
Graduate School of Engineering
Job title
Specially Appointed Assistant Professor(Research)

Research History 3

  • 2022/04 - Present
    Tohoku University　Graduate School of Engineering Department of Biomolecular Engineering　Protein Palmitoylation

  • 2019/10 - 2022/03
    Tohoku University　Graduate School of Engineering Department of Biomolecular Engineering　Elucidation of K+ transporters in Eschericia coli

  • 2011/09 - 2014/03
    Pelita Harapan University　Department of Biology (Biotechnology)　Exploration of probiotic potential from organic local chicken and pig

Education 2

  • Tohoku University　Biomolecular Engineering Department

    2016/10 - 2019/09

  • Tohoku University　Biomolecular Engineering Department

    2014/10 - 2016/09

Professional Memberships 3

  • The Japanese Biochemical Society

    2025/05 - Present

  • Japan Society for Bioscience, Biotechnology, and Agrochemistry

    2022/01 - Present

  • TheSociety for Biotechnology, Japan

    2015/09 - Present

Research Interests 4

  • Escherichia coli

  • Yeast

  • Palmitoylation

  • Potassium Transporter

Research Areas 1

  • Life sciences / Molecular biology /

Awards 3

  1. JSPS fellowship. DC2 Special Researcher.

    2019/04　Japan Society for Promotion of Science　Elucidation of novel functions of Escherichia coli Trk/Ktr/HKT transporter

  2. Hisho award

    2016/09　The Society of Biotechnology, Japan (SBJ)　Analysis of K+- uptake transporters in Escherichia coli

  3. MEXT scholarship

    2014/04

Papers 12

  1. Two Trk/Ktr/HKT-type potassium transporters, TrkG and TrkH perform distinct functions in Escherichia coli K-12 Peer-reviewed

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

    Journal of Biological Chemistry　102846-102846　2022/12

    Publisher: Elsevier BV

    DOI： 10.1016/j.jbc.2022.102846 　

    ISSN： 0021-9258

  2. Kup-mediated Cs+ uptake and Kdp-driven K+ uptake coordinate to promote cell growth during excess Cs+ conditions in Escherichia coli Peer-reviewed

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

    Scientific Reports　7　(1)　2017/12

    Publisher: Springer Science and Business Media LLC

    DOI： 10.1038/s41598-017-02164-7 　

    eISSN： 2045-2322

  3. An ancestral glutamate receptor mediates cell volume regulation during high K+ stress in cyanobacteria. International-journal Peer-reviewed

    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　2026/03/21

    DOI： 10.1016/j.jbc.2026.111396 　

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    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.

  4. 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)　2025/07/23

    Publisher: Proceedings of the National Academy of Sciences

    DOI： 10.1073/pnas.2500070122 　

    ISSN： 0027-8424

    eISSN： 1091-6490

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    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.

  5. Functional characterization of an additional transmembrane domain unique to TrkG and TrkH in Escherichia coli Peer-reviewed

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

    Bioscience, Biotechnology, and Biochemistry　2025/07/15

    Publisher: Oxford University Press (OUP)

    DOI： 10.1093/bbb/zbaf101 　

    eISSN： 1347-6947

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    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.

  6. Dissecting structure and function of the monovalent cation/H + antiporters Mdm38 and Ylh47 in Saccharomyces cerevisiae Peer-reviewed

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

    Journal of Bacteriology　2024/07/31

    Publisher: American Society for Microbiology

    DOI： 10.1128/jb.00182-24 　

    ISSN： 0021-9193

    eISSN： 1098-5530

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    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.

  7. Two cyanobacterial response regulators with diguanylate cyclase activity, Rre2 and Rre8, participate in biofilm formation Peer-reviewed

    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　2023/03/16

    Publisher: Wiley

    DOI： 10.1111/mmi.15057 　

    ISSN： 0950-382X

    eISSN： 1365-2958

  8. Draft genome sequence of a malachite green-decolorizing Bacillus velezensis N1 isolated from Indonesian chicken crop Peer-reviewed

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

    Korean Journal of Microbiology　58　(1)　47-48　2022/03

    DOI： 10.7845/kjm.2022.1101 　

  9. Diverse Physiological Functions of Cation Proton Antiporters across Bacteria and Plant Cells Invited Peer-reviewed

    Masaru Tsujii, Ellen Tanudjaja, Nobuyuki Uozumi

    International Journal of Molecular Sciences　21　(12)　4566-4566　2020/06/26

    Publisher: MDPI AG

    DOI： 10.3390/ijms21124566 　

    eISSN： 1422-0067

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    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.

  10. Analysis of Arabidopsis TPK2 and KCO3 reveals structural properties required for K+ channel function Peer-reviewed

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

    Channels　14　(1)　336-346　2020/01/01

    Publisher: Informa UK Limited

    DOI： 10.1080/19336950.2020.1825894 　

    ISSN： 1933-6950

    eISSN： 1933-6969

  11. Characterization of Alpha-Amylase from Aspergillus niger Aggregate F Isolated from a Fermented Cassava Gatot Grown in Potato Peel Waste Medium Peer-reviewed

    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　2019/09/28

    Publisher: Korean Society for Microbiology and Biotechnology

    DOI： 10.4014/mbl.1811.11011 　

    ISSN： 1598-642X

    eISSN： 2234-7305

  12. A Second Generation Biofuel from Cellulosic Agricultural By-product Fermentation Using Clostridium Species for Electricity Generation Peer-reviewed

    Yalun Arifin, Ellen Tanudjaja, Arbi Dimyati, Reinhard Pinontoan

    Energy Procedia　47　310-315　2014/02

    Publisher: Elsevier BV

    DOI： 10.1016/j.egypro.2014.01.230 　

    ISSN： 1876-6102

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Misc. 2

  1. Elucidation of the Mechanisms of Potassium Utilization Mediated by High-Affinity Potassium Transporters in Arabidopsis thaliana

    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

  2. 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

    Publisher: 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

Presentations 9

  1. Specialized Functions of Escherichia coli K+ Transport Systems

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

    The 159th Annual Meeting of the Tohoku Branch of the Society for Bioscience, Biotechnology, and Agricultural Chemistry of Japan　2024/09/28

  2. Evolutionary Dynamics of Dual Trk-type K+ Uptake in Escherichia coli K-12.

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

    Japan Society of Bioscience, Biotechnology, and Agrochemistry　2024/03

  3. Identification of the Na activation site of K transporter in Escherichia coli

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

    The 75th Annual Meeting of the Society for Biotechnology, Japan　2023/09/05

  4. Distinct property of two types of Trk K+ transport system in Escherichia coli

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

    JSBBA 2022 Annual Meeting　2022/03

  5. 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　2019/06

  6. 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　2016/09

  7. 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　2015/10

  8. 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　2013/05

  9. Identification and Characterization of Lactobacillus fermentum from Local Chicken Crop

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

    The 5th Indonesia Biotechnology Conference　2012/07

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Research Projects 2

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

    ELLEN

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 若手研究

    Institution: 東北大学

    2023/04/01 - 2025/03/31

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    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.

  2. Study on the molecular mechanism of Ca signaling mediated by plant K channels

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Fund for the Promotion of Joint International Research (Fostering Joint International Research (B))

    Institution: Tohoku University

    2020/10/27 - 2024/03/31