国際バイオ特論ⅠDr. Hiroshi Maeda 【230009】 International Forefront in Bioscience Ⅰ【230009】

講義科目基本情報

科目区分 専門 単位数 1
選択・必修 選択 授業形態 講義
開講時期 2017年11月27,28日 講義室 11/27 L13会議室    11/28 L13会議室 大セミナー室

科目の概要

担当教員筆頭者名 Dr. Hiroshi Maeda, Department of Botany, University of Wisconsin-Madison
担当教員 Dr. Hiroshi Maeda, Department of Botany, University of Wisconsin-Madison
教育目的/授業目標 海外から招聘した講師による英語による集中講義を通じて、特定の専門分野の基礎的な知識および最先端の研究内容について学ぶ。積極的に質問を行い議論に参加することを通して科学の現場での英語でのコミュニケーション能力や国際感覚の育成を図る。
To acquire knowledge in current topics in biological sciences, To acquire skills in scientific discussion in English
指導方針 講義に内容に関連する英語論文を事前に読解。学習し。キーワードやキーコンセプトを理解したうえで講義に臨ませる。少人数クラスのゼミ形式の講義と議論に対して主体的で積極的な取り組みを奨励する。これらを通じて、英語でのコミュニケーション能力の向上と国際性の涵養を図る。
Two-day intensive course comprosing three lectures and one research seminar by lecturers from universities abroad

授業計画

備考 回数 テーマ 内容
1回 Lecture 1:  Photosynthetic CO2 fixation and central carbon metabolism Through the process of photosynthesis, plants capture sunlight energy and convert atmospheric carbon dioxide (CO2) into triose-phosphate molecules, which serve as starting materials to synthesize a diverse class of plant metabolites. Through central carbon metabolism, the generated triose-phosphates are metabolized to various carbohydrates and also used to drive cellular respiration for energy generation. This first lecture will discuss how the fundamental carbon metabolism functions in plants to provide carbon skeletons and cellular energy, which are essential for maintaining plant growth and development and producing a variety of metabolites in plants.
2回 Lecture 2:  Nitrogen and amino acid metabolism Nitrogen is one of the most important elements, next to carbon, for synthesis of organic molecules. Unlike the carbon metabolism, however, plants are unable to directly capture abundant atmospheric dinitrogen (N2). Thus, plants have to either uptake soil nitrogen or form a symbiotic relationship with soil bacteria that can fix N2. This lecture will discuss how plants obtain nitrogen from different sources, assimilate nitrogen, and produce a variety of nitrogen containing molecules, such as amino acids.
3回 Lecture 3: Specialized metabolism and plant synthetic biology Plants usually have to live where they initially germinated. To circumvent this physical constrain, complex metabolic machineries have evolved during the plant evolution, which allow plants to synthesize a tremendous array of chemical compounds, known as plant natural products or specialized metabolites. This lecture will first provide overview of different classes of plant specialized metabolites and their functions in both plant and human physiology. Then, we will focus on one particular plant natural product, morphine alkaloid, to discuss how this complex chemical is synthesized from an aromatic amino acid tyrosine. We will also study how the knowledge obtained in plant systems was utilized to synthesize this complex chemical in heterologous hosts (e.g. yeast) through synthetic biology.  The seminar will end with class discussion to identify current limitations and potential future targets of plant synthetic biology, by utilizing metabolic maps each student drew from CO2 to morphine during the three lectures.
4回 Research Seminar: De-regulation of tyrosine biosynthesis facilitated evolutionary expansion of diverse plant natural products
 
Plants synthesize numerous natural products, which play crucial roles in plant adaptation and human health. In contrast to well-documented diversification of specialized metabolic enzymes, little is known about the evolution of primary metabolic enzymes that provide precursors to the production of various specialized metabolites.
The plant order Caryophyllales (e.g. beet, quinoa, cactus) uniquely produces red/yellow betalains pigments that are derived from the aromatic amino acid L-tyrosine (Tyr) and replaced the otherwise ubiquitous phenylalanine (Phe)-derived anthocyanins. In most plants, Tyr production is strongly feedback regulated by Tyr at arogenate dehydrogenase (TyrA); however, we found that TyrA enzymes in Caryophyllales recently duplicated into two isoforms, one of which (TyrAα) exhibits relaxed sensitivity to Tyr inhibition. Interestingly, the de-regulated TyrAα emerged before the evolution of the betalain biosynthetic pathway. Metabolite profiling further revealed that other Tyr-derived compounds, such as dopamine and epinephrine, also accumulate in TyrAα-containing Caryophyllales species. Phylogeny-guided structure function analysis of TyrA enzymes from over hundreds of Caryophyllales transcriptome data identified key mutations responsible for the Tyr insensitivity of TyrAα enzymes. Finally, heterologous expression of beet TyrAα in Nicotiana benthamiana and Arabidopsis thaliana resulted in hyper-accumulation of Tyr and decreased synthesis of Phe.
These results together demonstrate that de-regulation of Tyr biosynthesis redirected carbon flux from Phe to Tyr biosynthesis, which likely pre-conditioned for the evolutionary expansion of diverse specialized metabolites derived from Tyr. Our finding also highlights the significance of upstream primary metabolic regulation for the diversification of specialized metabolism in plants, and also provides novel engineering tools to improve the production of Tyr and Tyr-derived natural products, such as morphine alkaloid and vitamin E.

テキスト・参考書

テキスト 講師よりあらかじめ指定される学術論文4-5報
4 to 5 scienfic papers disgnated by the lecturer
参考書

その他

履修条件 講師が指定する論文等を講義前に読解・学習しておくこと。
Students must read disignated papers before the course starts.
オフィスアワー
成績評価の方法と基準 講義への取り組み(70%)および受講後のレポート(30%)により評価する。
Evaluation will be made based on attendance and active participation in the classes (70%) and the report to be submitted afterwards (30%).
関連科目
注意事項 各講義科目のテーマ及び開講日時は別にE-メールで通知する。履修手続きはそのメールに返信することで完了。
Registration is completed upon responding to the email announcing the opening of the course.