Elucidation of molecular mechanism of intestinal iron absorption in mammals by mugineic acid precursor

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K01927
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Biomolecular chemistry
• Research Institution: Suntory Foundation for Life Sciences
• Principal Investigator: Murata Yoshiko 公益財団法人サントリー生命科学財団, 生物有機科学研究所・統合生体分子機能研究部, 特任研究員 (60256047)
• Co-Investigator(Kenkyū-buntansha): 難波 康祐 徳島大学, 大学院医歯薬学研究部(薬学域), 教授 (50414123)
• Research Collaborator: Takahashi toshio ; Watanabe takehiro
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 鉄 / ムギネ酸 / ニコチアナミン / 植物性食物 / 小腸 / 錯体 / トランスポーター

Outline of Final Research Achievements

Nicotianamine (NA), a precursor of mugineic acid important for soil iron absorption in grasses, is responsible for iron transport as a chelator of iron in all plant bodies and is abundantly contained in vegetable foods. In this study, the amino acid transporter PAT1 present in the epithelial cells of small intestine is transporter of NA-Fe(II) complex by genetic analysis and cell transport activity experiment. When mice were orally administered with NA-59Fe(II), the highest iron content was found at the proximal jejunum of the intestine, the location where PAT1 was primarily expressed. In contrast, iron content was not prominent in the duodenum, the location where the divalent metal transporter SLC11A2 (DMT1) is expressed and absorbs free Fe(II). From these findings, we aim to further elucidate the molecular mechanism of a new iron transport in mammals.

Free Research Field

生化学

Academic Significance and Societal Importance of the Research Achievements

植物性キレート化合物の鉄錯体トランスポーターが同定できれば、これまでの鉄輸送遺伝子１種類の鉄吸収機構だけでは説明できない疑問の解明により、学術的な突破口を開くことになる。我々がこれまで成果を挙げてきたイネ科植物のムギネ酸類鉄錯体トランスポーター研究やヒトでの微量元素研究を足がかりに、哺乳動物の腸からの鉄錯体吸収とその後の体内輸送の分子機構をトランスポーターの分子レベルの基質認識に基づいて理解し、応用研究に発展できる。