Researcher Profile and Settings

Master

Affiliation (Master)

• Faculty of Fisheries Sciences　Marine Life Science　Marine Bioresources Chemistry

Affiliation (Master)

• Faculty of Fisheries Sciences　Marine Life Science　Marine Bioresources Chemistry

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Profile and Settings

Profile and Settings

• Name (Japanese)

  Fujita

• Name (Kana)

  Masaki J

• Name

  201201058455003794

Alternate Names

http://kaken.nii.ac.jp/d/r/30505251.ja.html

Achievement

Research Interests

• 環境細菌   クオラムセンシング   アオコ   赤潮   魚醤   シデロフォア   海洋生物資源   海洋天然物   生物有機化学   異宿主生産   生合成遺伝子   メタゲノム   生理活性物質   

Research Areas

• Life sciences / Marine/Aquatic life sciences
• Nanotechnology/Materials / Molecular biochemistry
• Life sciences / Pharmaceuticals - chemistry and drug development

Research Experience

• 2012 - Today Hokkaido University
• 2008/01 - 2011/11 Kumamoto University School of Pharmacy

Education

• 1998/04 - 2003/03  東京大学大学院

Published Papers

• Dopamine-Derived Guanidine Alkaloids from a Didemnidae Tunicate: Isolation, Synthesis, and Biological Activities.

  Ryuichi Sakai, Ken Matsumura, Hajime Uchimasu, Kei Miyako, Tohru Taniguchi, V Raghavendra Rao Kovvuri, Anjana Delpe Acharige, Kenneth G Hull, Daniel Romo, Lakkana Thaveepornkul, Sarin Chimnaronk, Hiroko Miyamoto, Ayato Takada, Hiromi Watari, Masaki J Fujita, Jiro Sakaue

  The Journal of organic chemistry 2024/04/01 

  Mellpaladines A-C (1-3) and dopargimine (4) are dopamine-derived guanidine alkaloids isolated from a specimen of Palauan Didemnidae tunicate as possible modulators of neuronal receptors. In this study, we isolated the dopargimine derivative 1-carboxydopargimine (5), three additional mellpaladines D-F (6-8), and serotodopalgimine (9), along with a dimer of serotonin, 5,5'-dihydroxy-4,4'-bistryptamine (10). The structures of these compounds were determined based on spectrometric and spectroscopic analyses. Compound 4 and its congeners dopargine (11), nordopargimine (15), and 2-(6,7-dimethoxy-3,4-dihydroisoquinolin-1-yl)ethan-1-amine (16) were synthetically prepared for biological evaluations. The biological activities of all isolated compounds were evaluated in comparison with those of 1-4 using a mouse behavioral assay upon intracerebroventricular injection, revealing key functional groups in the dopargimines and mellpaladines for in vivo behavioral toxicity. Interestingly, these alkaloids also emerged during a screen of our marine natural product library aimed at identifying antiviral activities against dengue virus, SARS-CoV-2, and vesicular stomatitis Indiana virus (VSV) pseudotyped with Ebola virus glycoprotein (VSV-ZGP).
• Function of the algicidal bacterium Pseudomonas sp. Go58 isolated from the biofilm on a water plant, and its active compounds, pyoluteorins

  Shuhe Chen, Miyu Haga, Ichiro Imai, Ryuichi Sakai, Masaki J. Fujita

  Science of The Total Environment 872 162088 - 162088 0048-9697 2023/05
• Interaction of Polyamine-modified Marine Peptide Aculeine A with Cell Membranes: Disruption or Entry

  Hiromi Watari, Reimi Kishi, Satoko Matsunaga, Takayuki Nishikawa, Yuji Sawada, Akito Honda, Masaki J Fujita, Ryuichi Sakai

  Chemistry Letters 52 (3) 185 - 189 0366-7022 2023/03/05
• Diverse Aromatic Metabolites in the Solitary Tunicate Cnemidocarpa irene

  Kei Miyako, Yoko Yasuno, Tetsuro Shinada, Masaki J. Fujita, Ryuichi Sakai

  Journal of Natural Products 83 (10) 3156 - 3165 0163-3864 2020/10/23 

  Fourteen aromatic metabolites (6-19) were isolated from an aqueous extract of the solitary tunicate Cnemidocarpa irene collected in Hokkaido, Japan. The structures of the metabolites were determined based on the spectroscopic interpretations, including one- and two-dimensional NMR, mass spectra, UV, and circular dichroism data. The biopterin analogue 10 modulated the behavior of mice after intracerebroventricular injection and showed a weak affinity to ionotropic glutamate receptor subtypes. Analyses of fluorescent coelomic fluid of the tunicate revealed that pterin 12 was responsible for the fluorescence of the blood cells, while β-carbolines 1 and 3 were fluorescent compounds in the serum. The metabolic profiles in adults, juveniles, larvae, and eggs of the animal differed substantially, suggesting that the metabolism of the animal, especially biosynthesis of aromatic secondary metabolites, changes over different life stages.
• Questiomycins, Algicidal Compounds Produced by the Marine Bacterium Alteromonas sp. D and Their Production Cue.

  Saki Umetsu, Mamoru Kanda, Ichiro Imai, Ryuichi Sakai, Masaki J Fujita

  Molecules (Basel, Switzerland) 24 (24) 2019/12/10 [Refereed][Not invited]
   

  Questiomycin A (1) along with three new compounds, questiomycins C-E (2-4), were isolated from culture of Alteromonas sp. D, an algicidal marine bacterium, guided by algal lethality assay using the raphidophyte, Chattonella antiqua, one of the causative organisms of harmful algal bloom. The structures of 1-4 were assigned on the basis of their spectrometric and spectroscopic data. Compounds 1 to 4 exhibited algicidal activity against C. antiqua with LC50 values ranging from 0.18 to 6.37 M. Co-cultivation experiment revealed that 1 was produced only when the microalgae and the bacterium are in close contact, suggesting that some interactions between them trigger the biosynthesis of questiomycins. These results suggested that the algicidal bacteria such as Alteromonas sp. D can control microalgae chemically in marine ecosystem.
• Structure and reactivity of a siderophore-interacting protein from the marine bacterium Shewanella reveals unanticipated functional versatility

  Inês B. Trindade, José M. Silva, Bruno M. Fonseca, Teresa Catarino, Masaki Fujita, Pedro M. Matias, Elin Moe, Ricardo O. Louro

  Journal of Biological Chemistry 294 (1) 157 - 167 0021-9258 2019/01
• Elemental composition and ultrafine structure of the skeleton in shell-bearing protists—A case study of phaeodarians and radiolarians

  Yasuhide Nakamura, Izumi Iwata, Rie S. Hori, Naomi Uchiyama, Akihiro Tuji, Masaki J. Fujita, Daiske Honda, Hiroaki Ohfuji

  Journal of Structural Biology 204 (1) 45 - 51 1047-8477 2018/10 

  Cross-sections were prepared by ultramicrotome (UM) and focused ion beam (FIB) system in order to examine the skeletal structure of ecologically and geologically important shell-bearing protists: phaeodarians and radiolarians. The elemental composition of the skeleton was clarified by the energy dispersive X-ray spectroscopy, suggesting that the skeletons of both groups are mainly made of amorphous silica (SiO2 center dot nH(2)O) with other minor elements (Na, Mg, Al, Cl, K, Ca and Fe) and that these two groups have similar elemental composition, compared with other siliceous organisms (diatoms and sponges). However, the structural difference among the two groups was confirmed: phaeodarian skeletons are porous, unlike radiolarians with solid skeletons. It was also revealed that the phaeodarian skeleton contains concentric layered structure with spaces, presumably related to the ontogenetic skeleton formation. The distinction in the skeletal ultrafine structure (porous/solid and non-dense/dense) would reflect the ecological difference among the two groups and could be an effective criterion to determine whether microfossils belong to Radiolaria or Phaeodaria. The UM and FIB combined method presented in this study could be a useful approach to examine the chemical and structural characteristics of unculturable and/or rare microorganisms.
• Cloning of the Bisucaberin B Biosynthetic Gene Cluster from the Marine Bacterium Tenacibaculum mesophilum, and Heterologous Production of Bisucaberin B

  Masaki Fujita, Yusuke Goto, Ryuichi Sakai

  Marine Drugs 16 (9) 342 - 342 2018/09/19 

  The biosynthetic gene cluster for bisucaberin B (1, bsb gene cluster), an N-hydroxy-N-succinyl diamine (HSD)-based siderophore, was cloned from the marine bacterium Tenacibaculum mesophilum, originated from a marine sponge. The bsb gene cluster consists of six open reading frames (ORFs), in contrast to the four ORFs typically seen in biosynthetic gene clusters of the related molecules. Heterologous expression of the key enzyme, BsbD2, which is responsible for the final biosynthetic step of 1 resulted in production of bisucaberin B (1), but not bisucaberin (2) a macrocyclic counterpart of 1. To date, numbers of related enzymes producing macrocyclic analogues have been reported, but this work represents the first example of the HSD-based siderophore biosynthetic enzyme which exclusively produces a linear molecule rather than macrocyclic counterparts.
• KB343; a Cyclic Tris-guanidine Alkaloid from Palauan Zoantharian Epizoanthus illoricatus

  Ken Matsumura, Tohru Taniguchi, James D. Reimer, Shuntaro Noguchi, Masaki J. Fujita, Ryuichi Sakai

  Org. Lett. 20 3039 - 3043 2018/05 [Refereed][Not invited]
  
• Two New Mycosporine-like Amino Acids LC-343 and Mycosporine-ethanolamine from the Micronesian Marine Sponge Lendenfeldia chondrodes

  Yuta Oda, Quang Zhang, Satoko Matsunaga, Masaki J. Fujita, Ryuichi Sakai

  CHEMISTRY LETTERS 46 (8) 1272 - 1274 0366-7022 2017/08 [Refereed][Not invited]
   

  New mycosporine-like amino acids (MAA) LC-343 (1) and mycosporine-ethanolamine (2) along with known MAAs asterina-330 (3) and shinorine (4) were isolated from the Micronesian marine sponge Lendenfeldia chondrodes. The structures of 1 and 2 were determined on the basis of their spectroscopic and spectrometric data as well as chemical degradation. LC-343 (1) is the first MAA possessing Nmethylated iminium substructure. Absorption maximum (lambda(max)) for each 2, 3, 4, and 1 was 310, 330, 332, and 343, respectively.
• A novel small compound HPH-15 antagonizes TGF-beta/Smad signaling and ameliorates experimental skin fibrosis

  V. H. Luong, T. Chino, A. Tokuriki, N. Oyama, Y. Sasaki, D. Ogura, S. Niwa, M. Fujita, Y. Okamoto, M. Otsuka, H. Ihn, M. Hasegawa

  JOURNAL OF INVESTIGATIVE DERMATOLOGY 137 (5) S46 - S46 0022-202X 2017/05 [Not refereed][Not invited]
  
• N-Methyl-β-carbolinium Salts and an N-Methylated 8-Oxoisoguanine as Acetylcholinesterase Inhibitors from a Solitary Ascidian, Cnemidocarpa irene.

  Yohei Tadokoro, Teruaki Nishikawa, Taichi Ichimori, Satoko Matsunaga, Masaki J. Fujita, Ryuichi Sakai

  ACS Omega 2 (3) 1074 - 1080 2017/02 [Refereed][Not invited]
  
• Mellpaladines and dopargimine, novel neuroactive guanidine alkaloids from a Palauan Didemnidae tunicate

  Hajime Uchimasu, Ken Matsumura, Masashi Tsuda, Keiko Kumagai, Mai Akakabe, Masaki J. Fujita, Ryuichi Sakai

  TETRAHEDRON 72 (45) 7185 - 7193 0040-4020 2016/11 [Not refereed][Not invited]
   

  Novel guanidine alkaloids dopargimine (1) and mellpaladines A-C (2-4) were isolated from a Palauan Didemnidae tunicate. The structures of 1-4 were elucidated on the basis of spectral data along with chemical reactions. A putative biosynthetic building block of 1-4, 4-guanidinobutyric acid (5), and dimeric polysulfur dopamine, as well as lissoclibadins 11 (6a) and 12 (6b) were also isolated. Compounds 1-3 bound to synaptic receptors, and modulated behavioral profiles of mice after intracerebroventricular injection. (C) 2016 Elsevier Ltd. All rights reserved.
• Production of Avaroferrin and Putrebactin by Heterologous Expression of a Deep-Sea Metagenomic DNA

  Masaki Fujita, Ryuichi Sakai

  Marine Drugs 12 (9) 4799 - 4809 2014/09/12
• Protoaculeine B, a Putative N-Terminal Residue for the Novel Peptide Toxin Aculeines

  Satoko Matsunaga, Reimi Kishi, Kazunori Otsuka, Masaki J Fujita, Masato Oikawa, Ryuichi Sakai

  Organic Letters 16 (11) 3090 - 3093 1523-7060 2014/06/06
• Bisucaberin B, a Linear Hydroxamate Class Siderophore from the Marine Bacterium Tenacibaculum mesophilum

  Masaki Fujita, Koji Nakano, Ryuichi Sakai

  Molecules MDPI 18 (4) 3917 - 3926 1420-3049 2013/04/02 

  A siderophore, named bisucaberin B, was isolated from Tenacibaculum mesophilum bacteria separated from a marine sponge collected in the Republic of Palau. Using spectroscopic and chemical methods, the structure of bisucaberin B (1) was clearly determined to be a linear dimeric hydroxamate class siderophore. Although compound 1 is an open form of the known macrocyclic dimer bisucaberin (2), and was previously described as a bacterial degradation product of desferrioxamine B (4), the present report is the first description of the de novo biosynthesis of 1. To the best of our knowledge, compound 1 is the first chemically characterized siderophore isolated from a bacterium belonging to the phylum Bacteroidetes.
• Heterologous production of desferrioxamines with a fusion biosynthetic gene cluster

  Masaki J. Fujita, Ryuichi Sakai

  Bioscience, Biotechnology and Biochemistry 77 (12) 2467 - 2472 0916-8451 2013 [Refereed][Not invited]
   

  Desferrioxamines E (1), D2 (2), X1 (3), and X2 (4), four macrocyclic N-hydroxy-N-succinyl diamine-based siderophores, were produced efficiently by heterologous expression of a fusion biosynthetic gene cluster. This expression system consisted of three genes (mbsA-C) from marine metagenomic DNA and one gene (dfoCC) from the terrestrial bacterium Erwinia amylovora. The first three genes are functional in the production of the common monomers N-hydroxy-N-succinyl cadaverine (5, HSC) and N-hydroxy-N-succinyl putrescine (6, HSP), whereas dfoCC catalyzes the oligomerization and the macrocyclization reactions of compounds 5 and 6 to form compounds 1-4. This fusion gene cluster system provides a convenient expression platform for various biosynthetic genes of HSC-HSP based siderophores by simply switching the fourth gene by the cassette process.
• Phylogenetically Novel LuxI/LuxR-Type Quorum Sensing Systems Isolated Using a Metagenomic Approach

  Eri Nasuno, Nobutada Kimura, Masaki J. Fujita, Cindy H. Nakatsu, Yoichi Kamagata, Satoshi Hanada

  Applied and Environmental Microbiology 78 (22) 8067 - 8074 0099-2240 2012/11/15 

  A great deal of research has been done to understand bacterial cell-to-cell signaling systems, but there is still a large gap in our current knowledge because the majority of microorganisms in natural environments do not have cultivated representatives. Metagenomics is one approach to identify novel quorum sensing (QS) systems from uncultured bacteria in environmental samples. In this study, fosmid metagenomic libraries were constructed from a forest soil and an activated sludge from a coke plant, and the target genes were detected using a green fluorescent protein (GFP)-basedEscherichia colibiosensor strain whose fluorescence was screened by spectrophotometry. DNA sequence analysis revealed two pairs of new LuxI familyN-acyl-l-homoserine lactone (AHL) synthases and LuxR family transcriptional regulators (clones N16 and N52, designated AubI/AubR and AusI/AusR, respectively). AubI and AusI each produced an identical AHL,N-dodecanoyl-l-homoserine lactone (C₁₂-HSL), as determined by nuclear magnetic resonance (NMR) and mass spectrometry. Phylogenetic analysis based on amino acid sequences suggested that AusI/AusR was from an uncultured member of theBetaproteobacteriaand AubI/AubR was very deeply branched from previously described LuxI/LuxR homologues in isolates of theProteobacteria. The phylogenetic position of AubI/AubR indicates that they represent a QS system not acquired recently from theProteobacteriaby horizontal gene transfer but share a more ancient ancestry. We demonstrated that metagenomic screening is useful to provide further insight into the phylogenetic diversity of bacterial QS systems by describing two new LuxI/LuxR-type QS systems from uncultured bacteria.
• The Bioassay-Guided Isolation of Growth Inhibitors of Adult T-Cell Leukemia (ATL), from the Jamaican Plant Hyptis verticillata, and NMR Characterization of Hyptoside

  Toshiyuki Hamada, Yohann White, Mitsuyoshi Nakashima, Yusuke Oiso, Masaki J. Fujita, Hiroaki Okamura, Tetsuo Iwagawa, Naomichi Arima

  Molecules 17 (8) 9931 - 9938 2012/08/17
• Heterologous production of bisucaberin using a biosynthetic gene cluster cloned from a deep sea metagenome

  Masaki J. Fujita, Nobutada Kimura, Hisayoshi Yokose, Masami Otsuka

  Mol. BioSyst. 8 (2) 482 - 485 1742-206X 2012
• Cloning and Heterologous Expression of the Vibrioferrin Biosynthetic Gene Cluster from a Marine Metagenomic Library

  Masaki J. FUJITA, Nobutada KIMURA, Atsushi SAKAI, Yoichi ICHIKAWA, Tomohiro HANYU, Masami OTSUKA

  Bioscience, Biotechnology, and Biochemistry Japan Society for Bioscience, Biotechnology, and Agrochemistry 75 (12) 2283 - 2287 0916-8451 2011/12/23 

  A biosynthetic gene cluster of siderophore consisting of five open reading frames (ORFs) was cloned by functional screening of a metagenomic library constructed from tidal-flat sediment. Expression of the cloned biosynthetic genes in Escherichia coli led to the production of vibrioferrin, a siderophore originally reported for the marine bacterium Vibrio parahaemolyticus. To the best of our knowledge, this is the first example of heterologous production of a siderophore by biosynthetic genes cloned from a metagenomic library. The cloned cluster was one of the largest of the clusters obtained by functional screening. In this study, we demonstrated and extended the possibility of function-based metagenomic research.
• Actin-Aggregating Cucurbitacins from Physocarpus capitatus

  Katherine N. Maloney, Masaki Fujita, Ulrike S. Eggert, Frank C. Schroeder, Christine M. Field, Timothy J. Mitchison, Jon Clardy

  Journal of Natural Products 71 (11) 1927 - 1929 0163-3864 2008/12/01
• Small-molecule pheromones that control dauer development in Caenorhabditis elegans

  Rebecca A Butcher, Masaki Fujita, Frank C Schroeder, Jon Clardy

  Nature Chemical Biology 3 (7) 420 - 422 1552-4450 2007/07
• Tyrosol is a quorum-sensing molecule in Candida albicans

  H. Chen, M. Fujita, Q. Feng, J. Clardy, G. R. Fink

  Proceedings of the National Academy of Sciences 101 (14) 5048 - 5052 0027-8424 2004/04/06
• Ageladine A: An Antiangiogenic Matrixmetalloproteinase Inhibitor from the Marine Sponge Agelas nakamurai

  Masaki Fujita, Yoichi Nakao, Shigeki Matsunaga, Motoharu Seiki, Yoshifumi Itoh, Jun Yamashita, Rob W. M. van Soest, Nobuhiro Fusetani

  Journal of the American Chemical Society 125 (51) 15700 - 15701 0002-7863 2003/12/01
• Callysponginol Sulfate A, an MT1-MMP Inhibitor Isolated from the Marine Sponge Callyspongia truncata

  Masaki Fujita, Yoichi Nakao, Shigeki Matsunaga, Rob W. M. van Soest, Yoshifumi Itoh, Motoharu Seiki, Nobuhiro Fusetani

  Journal of Natural Products 66 (4) 569 - 571 0163-3864 2003/04/01
• Sodium 1-(12-Hydroxy)octadecanyl Sulfate, an MMP2 Inhibitor, Isolated from a Tunicate of the Family Polyclinidae

  Masaki Fujita, Yoichi Nakao, Shigeki Matsunaga, Teruaki Nishikawa, Nobuhiro Fusetani

  Journal of Natural Products 65 (12) 1936 - 1938 0163-3864 2002/12/01
• Isolation and structure elucidation of two phosphorylated sterol sulfates, MT1-MMP inhibitors from a marine sponge Cribrochalina sp.: revision of the structures of haplosamates A and B

  Masaki Fujita, Yoichi Nakao, Shigeki Matsunaga, Motoharu Seiki, Yoshifumi Itoh, Rob W.M van Soest, Markus Heubes, D.John Faulkner, Nobuhiro Fusetani

  Tetrahedron 57 (18) 3885 - 3890 0040-4020 2001/04
• Ancorinosides B–D, inhibitors of membrane type 1 matrix metalloproteinase (MT1-MMP), from the marine sponge Penares sollasi Thiele

  Masaki Fujita, Yoichi Nakao, Shigeki Matsunaga, Motoharu Seiki, Yoshifumi Itoh, Rob W.M van Soest, Nobuhiro Fusetani

  Tetrahedron 57 (7) 1229 - 1234 0040-4020 2001/02
• Isolation and Structure Elucidation of Vicenistatin M, and Importance of the Vicenisamine Aminosugar for Exerting Cytotoxicity of Vicenistatin.

  YOSHITAKA MATSUSHIMA, TAKUYA NAKAYAMA, MASAKI FUJITA, RENUKA BHANDARI, TADASHI EGUCHI, KAZUTOSHI SHINDO, KATSUMI KAKINUMA

  The Journal of Antibiotics JAPAN ANTIBIOTICS RESEARCH ASSOCIATION 54 (3) 211 - 219 0021-8820 2001 

  A new analogue of Vicenistatin was isolated from the producing strain Streptomyces sp. HC-34. A characteristic of the elucidated structure involved the existence of a neutral sugar mycarose instead of an aminosugar vicenisamine of Vicenistatin. The absolute stereochemistry of the new analogue (named as Vicenistatin M) was determined by the synthesis of D-mycarose and of vicenistatin M itself. Biological testing of Vicenistatin M suggested the importance of vicenisamine for exerting the cytotoxicity of vicenistatin.
• Biosynthetic Pathway of Macrolactam Polyketide Glycoside Antitumor Antibiotic Vicenistatins

  Miyuki Otsuka, Masaki Fujita, Yoshitaka Matsushima, Tadashi Eguchi, Kazutoshi Shindo, Katsumi Kakinuma

  Tetrahedron 56 (42) 8281 - 8286 0040-4020 2000/10
• Miraziridine A, a Novel Cysteine Protease Inhibitor from the Marine Sponge Theonella aff. mirabilis1

  Yoichi Nakao, Masaki Fujita, Kaoru Warabi, Shigeki Matsunaga, Nobuhiro Fusetani

  Journal of the American Chemical Society 122 (42) 10462 - 10463 0002-7863 2000/10/01
• Tokaramide A,a new cathepsin B inhibitor from the marine sponge Theonella aff. mirabilis

  Nobuhiro Fusetani, Masaki Fujita, Yoichi Nakao, Shigeki Matsunaga, Rob W.M. van Soest

  Bioorganic & Medicinal Chemistry Letters 9 (24) 3397 - 3402 0960-894X 1999/12

MISC

• メタゲノム由来新規オートインデューサー様物質の生理活性

  新村樹, 三輪俊太, 酒井隆一, 藤田雅紀, 木村信忠  日本水産学会大会講演要旨集(CD-ROM)  2021-  2021
• メタゲノム由来新規オートインデューサー様物質の生産と同定

  伊藤秀輝, 酒井隆一, 藤田雅紀, 木村信忠  日本水産学会大会講演要旨集(CD-ROM)  2021-  2021
• Pseudomonas属アオコ殺藻細菌および活性物質の野生藻類に対する影響

  陳樹河, 酒井隆一, 藤田雅紀, 今井一郎  日本水産学会大会講演要旨集(CD-ROM)  2021-  2021
• メタボロミクスを用いた藻類と殺藻細菌の共培養系における活性物質の探索

  羽賀美優, 今井一朗, 酒井隆一, 藤田雅紀  日本水産学会大会講演要旨集(CD-ROM)  2021-  2021
• 海綿-シアノバクテリア共生系由来新規糖代謝物の単離・構造解析

  野口祐輔, 小田悠太, 張権, 藤田雅紀, 酒井隆一  日本水産学会北海道支部大会講演要旨集  2020 (CD-ROM)-  2020
• Alteromonas属殺藻細菌由来シデロフォアの同定と機能解析

  神手大輝, 酒井隆一, 藤田雅紀, 今井一郎  日本水産学会大会講演要旨集  2019-  2019
• カイメン（海綿）に共生する製薬工場

  生物工学  96-  (10)  593  -593  2018/10  [Not refereed][Invited]
  
• Alteromonas属由来の殺藻物質の生産と殺藻様式に関する研究

  梅津早希, 今井一郎, 酒井隆一, 藤田雅紀  日本水産学会大会講演要旨集  2017-  102  2017/03/26  [Not refereed][Not invited]
  
• アオコ原因種Microcystis aeruginosaに対する殺藻細菌の殺藻機構におけるクオラムセンシング関与の可能性

  大洞裕貴, 宮下洋平, 小林淳希, 小峯佳奈子, 藤田雅紀, 酒井隆一, 織田さやか, 田中邦明, 今井一郎  日本陸水学会大会講演要旨集  82nd (Web)-  2017
• カリブ海産ホヤTrididemnum solidumに含まれる抗腫瘍性化合物didemnin類の産生について

  市森大地, 藤田雅紀, 今田千秋, 酒井隆一  日本水産学会大会講演要旨集  2016-  116  2016/03/26  [Not refereed][Not invited]
  
• Alteromonas属海洋細菌由来の赤潮殺藻物質

  梅津早希, 今井一郎, 酒井隆一, 藤田雅紀  日本水産学会大会講演要旨集  2016-  113  2016/03/26  [Not refereed][Not invited]
  
• 西表島産Spongosorites属海綿に含まれるタンパク質毒素の分離

  酒井隆一, 中野宏治, 上田拓也, 北野雅也, 小野巧, 棚野豪太, 神保充, 藤田雅紀  日本水産学会大会講演要旨集  2016-  2016
• Algicidal Compounds from Alteromonas sp.

  Umetsu Saki, Imai Ichiro, Sakai Ryuichi, Fujita Masaki  Symposium on the Chemistry of Natural Products, symposium papers  58-  (0)  Poster32  2016  [Not refereed][Not invited]
   

  Utilization of algicidal bacteria is expected as a new method to prevent red-tide, a harmful algal blooming, which causes serious damage on fisheries industry and also marine animals. However, algicidal molecules produced by marine bacteria are hardly known. In this study, we present isolation, structure elucidation and biological activity of algicidal phenoxazinon derivatives including three novel compounds.

  Four deep-yellow pigments (1-4) were purified as main algicidal molecules from a culture broth of Alteromonassp. strain D which isolated from red-tide blooming sea water around Hiroshima-bay. Structures were determined based on spectroscopic analysis along with comparison with literature data as 2-aminophenoxazin-3-on (APO, 1) and its derivatives.

  Compound 1 and 2 showed algicidal activity against Chattnella antiquawhich is one of the red-tide forming phytoplankton with LD₅₀ values of 0.29 and 0.23 mg/mL, respectively. However, compound 1was less toxic against other marine organisms including macro-alga, Bangia fuscopurpurea, and crustacean, Artemia salina, with LD₅₀ values of 4.0 and 7 mg/mL.

• 海綿・ホヤに共生する藍藻のケミカルバイオロジー

  SAKAI RYUICHI, ICHIMORI DAICHI, ODA YUTA, FUJITA MASAKI, IMADA CHIAKI  マリンバイオテクノロジー学会大会講演要旨集  17th-  51  2015/05/30  [Not refereed][Not invited]
  
• Mellpaladines, novel neuroactive compounds from a Palauan Didemnidae tunicate

  Uchimasu Hajime, Matsumura Ken, Tsuda Masashi, Kumagai Keiko, Akakabe Mai, Fujita M.J., Sakai Ryuichi  Symposium on the Chemistry of Natural Products, symposium papers  57-  (0)  PosterP31  2015  [Not refereed][Not invited]
   

  Various ionotropic receptors, metabotropic receptors and ion channels in the central nervous system play key roles in neurotransmission and homeostasis. We have been searching for neuroactive compounds interacting with these receptors or ion channels from aqueous extracts of marine benthic organisms including sponges and tunicates. Recently, we found that the extract of a Palauan Didemnidae tunicate suppressed voluntary behaviors in mice after intracerebroventricular administration. A bioassay-guided separation resulted in isolation of novel 3,4-dihydroisoquinoline alkaloids, dopargimine（1）and mellpaladines A-F（2-7）. Moreover, 4-guanidino butyric acid （8） and polysulfur alkaloid lissoclibadins（9）were also identified from this specimen. The structures of 1-7 and a known 8, 9 were assigned on the basis of spectroscopic data and chemical reactions.

  Biological targets for 1-3 were screened by binding assays using 43 neuronal receptors and transporters. Functions of those compounds for high affinity receptors were also evaluated. 1 showed affinity for d-opioid receptor and determined to be an agonist. 2and 3 showed high affinity for three subtypes（5-HT_1B, 5-HT_1D, 5-HT_5A）of serotonin receptors and shown to be a potent antagonists for 5-HT_5A.

• 海洋メタゲノムからの未知シデロフォア生合成遺伝子のクローニングと異宿主生産

  藤田雅紀, 時田学幸, 石川高史, 酒井隆一  日本水産学会大会講演要旨集  2014-  121  2014/03/27  [Not refereed][Not invited]
  
• Cloning and Heterologous Expression of the Agrobactin Biosynthetic Gene Cluster from a Marine Metagenome

  Fujita Masaki, Tokita Takayuki, Ishikawa Takafumi, Sakai Ryuichi  Symposium on the Chemistry of Natural Products, symposium papers  56-  (0)  Poster55  2014  [Not refereed][Not invited]
   

  A biosynthetic gene cluster of unknown siderophore was cloned from a metagenomic library constructed from a marine sponge by function based screening method. Sequencing of the cloned DNA revealed presence of a putative biosynthetic gene cluster consisted of 15 ORFs which showed similarity to vibriobactin biosynthetic gene cluster from Vibrio cholera.

  Culture broth of the siderophore producing clone exhibited characteristic mass peak at m/z 637 which rack in the negative clone. The crude extract of the broth was fractionated by repetitive column chromatography guided by mass signal. The product was finally purified by HPLC as hexamethyl derivative. Structure of the methylated product was determined by combination of spectroscopic analysis as well as speculation from biosynthetic information to be a hexamethyl agrobactin suggested that the original product was agrobaction which has been reported from a terrestrial plant pathogen Agrobacterium tumefaciens.

  It was the first report of agrobaction from marine environmental samples and also the first heterologous production of this class of molecules.

• 海洋細菌からの非環状ヒドロキサム酸型シデロフォアの単離と推定生合成遺伝子のクローニング

  藤田雅紀, 中野宏治, 酒井隆一  日本水産学会大会講演要旨集  2013-  100  2013/03/26  [Not refereed][Not invited]
  
• Cloning and Expression of the Biosynthetic Gene Cluster of Bisucaberin B

  Fujita Masaki, Nakano Koji, Sakai Ryuichi  Symposium on the Chemistry of Natural Products, symposium papers  55-  (0)  PosterP  -56  2013  [Not refereed][Not invited]
   

  A siderophore, bisucaberin B, was isolated from a bacterium Tenacibaculum mesophilum separated from a marine sponge collected in the Republic of Palau. Using spectroscopic and chemical methods, the structure of bisucaberin B was determined asa linear dimer of N-hydroxy-N-succinyl cadaverine (HSC). To the best of our knowledge, it is the first report of bisucaberin B as a biosynthetic product, and also this compound is the first siderophore found from the bacteria belong to the phylum Bacteroidetes.

  The putative bisucaberin B biosynthetic gene cluster bsbA-E was cloned from a genomic library of T. mesophilum using homology sequence conserved in the known HSC based siderophore biosynthetic genes. It consists of 6 ORFs instead of 4 genes found in the other bacteria. The last HSC condensation gene was duplicated in the bsb cluster, and the additional gene which showed homology with major facilitator superfamily also existed.

  To confirm that the cloned genes were actually responsible for bisucaberin B bioproduction, two candidate enzymes for HSC dimerization, BsbD1 and BsbD2, were co-expressed with MbsA-C which were marine metagenome originated enzymes already confirmed to produce HSC in the E. coli. As a result, only BsbD2 containing recombinant clone produced bisucaberin B efficiently (production yield 16.1 mg/L) suggested that the cloned bsb cluster is bisucaberin B biosynthetic genes, and presence of only BsbD2 is enough for dimerization of HSC.

• 線虫C. elegansの耐性幼虫フェロモン フェロモンで寿命が延びる！？モデル生物の化学生態学

  藤田 雅紀  化学と生物  46-  (7)  442  -443  2008/07  [Not refereed][Invited]
  

Books etc

• 海をまるごとサイエンス : 水産科学の世界へようこそ

  海に魅せられた北大の研究者たち (第11章 海の遺伝子で薬を作る？)
  海文堂出版 2018/08 (ISBN: 9784303800017) 127p
• 生体有機化学

  橋本, 祐一, 村田, 道雄 (第1章 核酸)
  東京化学同人 2012/10 (ISBN: 9784807907656) x, 220p

Presentations

• Mycale Sponge Inherits Mycalolide Producers Through Vertical Microbial Transmission  [Invited]

  藤田雅紀, 高田健太郎

  2018 Gordon Research Conference marine Natural Products  2018/03
• 遺伝子から探す・作る海洋天然物  [Invited]

  藤田雅紀

  日本化学会北海道支部会講演会  2016/10
• アカデミックキャリアパス  [Invited]

  藤田雅紀

  第18回マリンバイオテクノロジー学会大会 若手シンポジウム  2016/05
• メタゲノム法を用いた海洋天然物化学研究  [Invited]

  藤田雅紀

  2015年度マリンケミカルバイオロジー研究会  2015/03
• メタゲノム法を用いた海洋天然物の異宿主生産

  藤田雅紀

  日本農芸化学会東北支部会第13回若手の会  2012/10
• 海洋天然物の異宿主生産を指向したメタゲノム研究  [Invited]

  藤田雅紀

  第5回札幌微生物生態学セミナー  2012/08
• 異宿主発現法を用いた新規抗菌物質Pantocin Cの生産と同定

  藤田雅紀

  第3回万有若手シンポジウム  2008/11

Association Memberships

• 日本農芸化学会   アメリカ化学会   日本化学会   日本水産学会   

Research Projects

• メタゲノムおよびメタボローム解析を用いた実環境での殺藻細菌の機能解明

  日本学術振興会：科学研究費助成事業 基盤研究(B)

  Date (from‐to) : 2020/04 -2025/03 

  Author : 藤田 雅紀, 木村 信忠, 二階堂 雅人

   

  ① 同定した殺藻細菌および殺藻物質の実環境での機能解析 Pseudomonas属殺藻細菌をモデルとし、アオコ原因藻類との共培養により産生誘導される殺藻物質を同定するためのメタボロミクス解析方法を確立した。解析の結果、共培養下で特異的に産生される化合物を見出し、赤潮原因藻類に対する殺藻物質として報告のあるpseudopyronine Aであり、またアオコ原因藻類である藍藻Microcystis aeruginosaに対しても顕著な活性を示した。以上の結果から、確立したメタボロミクス法は共培養で機能する殺藻物質を見出す手法として有望と考えられた。 ② 赤潮・アオコ発生促進に関与する微生物の存在解析 Pseudomonas属殺藻細菌の機能解析の過程において緑藻および浮草などの光合成生物に対して増殖促進活性を示す植物ホルモン様化合物を見いだした。また、Pseudomonas属殺藻細菌の産物であるpyoluteorinを環境試水に作用したところ、緑藻Chlamydomonasが顕著に増加した。 ③ 未分離未培養の殺藻細菌の検出とそれが生産する殺藻物質の同定 メタゲノム解析から水草バイオフィルムがPseudomonas属、Acidovorax属、Stenotrophomonas属、Rhizobium属などの培養可能な殺藻細菌の供給源である事が示された。また、殺藻細菌の割合はいずれも1－3％程度の存在率で十分な活性を示す事、未培養の殺藻細菌候補も存在する事が示唆された。 ④ 分離殺藻細菌からの殺藻物質および生合成遺伝子の同定 環境試料から新たにRhizobium属、Stenotrophomonas属、Hydrogenophaga属を主とする殺藻細菌を得て、その培養液に殺藻活性を検出している。そのうちの一つであるRhizobium属細菌の培養液から、殺藻活性を示す炭化水素の結晶を得た。
• Cultivation of the uncultured symbiotic bacteria based on the metagenomic information

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2018/06 -2021/03 

  Author : Fujita Masaki

   

  In order to develop a methodology for isolation and cultivation of the useful marine natural products producing bacteria, we conducted metagenomic and symbiotic condition analysis of the mycalolide producing bacterium using marine sponge genus Mycale as a model organisms. As a result, complete cyclic genome of mycalolide producer was determined. Although the genome size was shrunk compared to that of the related culturable species, the basic metabolic capacity was conserved. It was also confirmed that the producing bacterium is extracellular symbiont existing from the embryonic stage by vertical transmission from the previous generation. In addition, it was also observed that the bacterium was transferred from the parental generation through a bacteriocyte-like structure. These findings are expected to lead to development of isolation and cultivation techniques of valuable bacteria based on the metabolic control and symbiosis mechanisms.
• Identification of functional compounds and biosynthetic genes by metagenomic methods

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (A)

  Date (from‐to) : 2015/04 -2019/03 

  Author : Fujita Masaki, Imai Ichiro, Kimura Nobutada

   

  In order to clarify the chemical communication among the environmental microorganisms, general scheme consisted of following methods and knowledges; metagenomics, biosynthesis, isolation and structure elucidation, bioinformatics, and variety of bioassays, were established. Species, compounds, and biosynthetic genes clusters were identified from algicidal bacteria obtained from algal-blooming environmental samples. Furthermore, mechanisms of production and action of the active compounds were revealed which are important for practical usage of algicidal bacteria. From the metagenomic clones, novel super-agonist of quorum sensing whose structure was completely different from the known signaling molecule was determined. Biosynthetic gene cluster of anti-tumor substance and its producer were identified from marine sponge symbiotic bacteria by metagenomics analysis. The producer is a quite unique bacterium belongs to the putative novel phylum, and exist in the specific marine sponge.
• レポーターアッセイを用いた海洋メタゲノムからの新規生合成マシナリーの探索

  日本学術振興会：科学研究費助成事業 新学術領域研究(研究領域提案型)

  Date (from‐to) : 2013/04 -2015/03 

  Author : 藤田 雅紀

   

  グラム陰性細菌のクオラムセンシングに関与するLux系を改変したレポーターアッセイシステムを用いて、メタゲノム法による未培養微生物のクオラムセンシングに関して解析を行った。陸上由来のメタゲノムライブラリから、レポーターアッセイの結果を指標に取得した活性物質生産クローンは、予想されたアシルホモセリンラクトンの生合成遺伝子ではなく、モノオキシゲナーゼに相同性を示す遺伝子を保有していた。 また、活性クローンは青色色素であるインジゴを生産したが、インジゴにはクオラムセンシグ活性は無かった事から、他の微量生産物が活性本体であると考えられた。活性クローンを大量培養後、培養上清および菌体を有機溶媒で抽出し、レポーターアッセイ結果を指標に抽出物の分画を行った。逆相および順相クロマトグラフィー、複数の担体によるゲルろ過、4種のカラムを用いたHPLC分画により、40 Lの培養液から0.1 mg以下の活性物質を単一ピークとして取得した。 ESI-LC-MSによる分析から本物質は分子量293であり、また高分解質量分析結果からその分子式をC16H11N3O3と推測した。これは関連が推測されたインジゴと比較しNOH大きいものであった。また、重水素交換実験から、交換性プロトンを3個含むと推測された。 また、海洋メタゲノムライブラリ中に複数見出されたインジゴ生産クローンについても解析したところ、いずれもクオラムセンシング活性物質を生産していた。一方、それらクローンが保有する酸化酵素は陸上メタゲノム由来のものと比較して相同性が10％程度であり、配列的にはほぼ関連が無かった。以上のことから、未知のクオラムセンシング物質の生産には酵素の配列では無く、インジゴの産生能が大きく関与していることが推測された。また、陸上海洋問わず、広く分布する酵素により産生されることが示唆された。
• メタゲノム法による難培養海洋環境微生物からの新規生合成マシナリーの探索と物質生産

  日本学術振興会：科学研究費助成事業 新学術領域研究(研究領域提案型)

  Date (from‐to) : 2011/04 -2013/03 

  Author : 藤田 雅紀

   

  海洋メタゲノムからの新規生合成マシナリーの探索を目的に研究を行った。その結果、研究期間において多様な海洋サンプルから70万以上のメタゲノムクローンを構築した。また複数のスクリーニング系において合計200を超える活性クローンを見出し、そのうち13クローンについてはDNA配列の決定も行った。その中には既知遺伝子に相同性を示すものも存在した一方、配列相同性からは全く活性機構が不明なものも存在し、未知のマシナリーを取得できた可能性が期待された。 シデロフォア生産クローンのうち二つについてはその生産物を同定し、また生合成遺伝子クラスターに変異を加えることで、最終産物の構造変換を行うなどの応用研究も展開し、生物生産の多様化の例を示した。さらにメタゲノムから取得したbisucaberin 生合成酵素は未解明な点が多い、酵素による大環状化反応機構の解明に有用であると考え構造生物学的な検討を行っている。また、別のシデロフォア生産クローンの一つを解析したところ、生合成遺伝子クラスター全長が25 kbp程度と非常に大きく、これまでにメタゲノムから機能ベーススクリーニング法で取得した生合成遺伝子クラスターとしては最大級のものであった。未だ生産物の同定には至っていないが、配列上の特徴から新規化合物を生産していると考えられた。この結果はメタゲノム法で非常に大きな生合成遺伝子クラスターを取得可能であること、またそれを異宿主で発現し活性物質を生産できることを示すものであり、本方法論の実用性を示す例であると考える。 一方、抗菌活性クローンの一つが保有するDNA配列を決定したが、配列情報からは全く活性機構を予測することはできなかった。現在生産物の同定を進めているが、このように配列情報からは見出すことが困難な遺伝子を取得できたことは機能ベースメタゲノム法の有用な点であると考える。
• Cloning and Expression of Siderophore Biosynthetic Gene Clusters from Marine Metagenome

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B)

  Date (from‐to) : 2011 -2012 

  Author : FUJITA Masaki

   

  More than 50 siderophore producing clones were found from the marine metagenomic library. Among them, DNA sequences of the four clones were determined. By chemical and spectroscopic methods, vibrioferrin and bisucaberin were identified as active products from the obtained clones. Especially, isolation yield of vibrioferrin was 40 times higher than that of the original producer. The other clone had a biosynthetic gene cluster whose total size was about 25 kbp which is one of the largest one found by functional metagenomic screening. These results suggested the promising potential of the functional metagenomic technique for cloning of biosynthetic genes and heterologous production of active molecules.
• Research for useful marineorganisms in Asia and Pacific regions

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

  Date (from‐to) : 2009 -2011 

  Author : NAKAO Yoichi, HORI Kanji, SAKAI Ryuichi, FUSETANI Nobuhiro, MATSUOKA Shunji, FUKUZAWA Seketsu, WAKIMOTO Toshiyuki, FUJITA Masaki, TAKADA Kentarou

   

  In this project, a total 515 marine organisms were collected from 3 countries and preserved as the extract-, microbe-, and genome-libraries. Currently, evaluation for bioactivities of these extracts are being carried out. At the same time, thight collaborative relationship among the researchers of these countries and our group was founded, through this project.
• Cloning and Expression of Marine Natural Product Biosynthetic by Function Based Screening

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (Start-up)

  Date (from‐to) : 2008 -2009 

  Author : FUJITA Masaki

   

  Metagenomics is a promising method to obtain useful genes from environmental samples. In order to prove that metagenomics is applicable to produce marine natural products, high quality marine metagenomic library consist of about 100 thousands clones was constructed. More than 300 pigment producing clones were screened from the library and their biosynthetic genes and products were characterized.
• 抗転移剤の開発を指向した海洋無脊椎動物からのプロテアーゼ阻害物質の探索

  日本学術振興会：科学研究費助成事業 特別研究員奨励費

  Date (from‐to) : 2001 -2002 

  Author : 藤田 雅紀

   

  1.日本沿岸各地で採集された海洋無脊椎動物の抽出物、計2608検体について、ガン転移に深く関与していると考えられるカテプシンB、MT1-MMPおよびMMP2に対する阻害アッセイを行った。その結果それぞれの酵素に対して約8%のサンプルが阻害活性を示した。その中から、特に活性が強く、酵素間の選択性に優れたサンプルについてその活性本体の解明を試みた。 2.MT1-MMP阻害活性が認められた、高知県二並島産海綿Chribrochalina sp.の抽出物を、各種クロマトグラフィーで順次精製したところ、2つの阻害物質を単離した。阻害物質のスペクトルデータは、既知物質haplosamate Aと完全に一致したが、報告されたデータにいくつかの疑問点を認めたので、詳細な構造解析を行った。その結果、本物質の構造をリン酸化ステロールと改定した。なお、本物質はMT1-MMPをIC_<50>値150-180μg/mLで阻害した。 3.和歌山県五ヶ所湾産のPolyclinidae科ホヤの脂溶性抽出物に顕著なMMP2阻害活性が認められた。凍結資料を抽出後、各種クロマトグラフィーにより精製し、活性成分として1-(12-hydroxy)octadecanyl sulfateを単離した。その構造は各種スペクトルデータから、C_<18>の硫酸化アルコールと決定した。本物質はMMP2をIC_<50>値9.0μg/mLで阻害した。 4.高知県箱島産海綿、Callyspongia truncataからは、MT1-MMP阻害物質として、既知物質であるhalistanol sulfateとともに、新規化合物であるcallysponginol sulfate Aを得た。本物質の構造は、分光学および化学的な解析からC_<24>の硫酸化された不飽和脂肪酸であることが明らかになった。本阻害剤はMI1-分光学MMPをIC_<50>値15.0μg/mLで阻害した。