Structural study of the transcription mechanism by GRAS/IDD family essential for root development

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K07448
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Plant molecular biology/Plant physiology
• Research Institution: The University of Tokyo (2018-2019); Yokohama City University (2017)
• Principal Investigator: Hirano Yoshinori 東京大学, 大学院薬学系研究科(薬学部), 助教 (50452529)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: X線結晶構造解析 / 転写制御 / 分子認識 / GRASファミリー

Outline of Final Research Achievements

We have performed structural and biochemical analyses of the plant proteins, GRAS family and transcription factor IDD family, essential for the plant root development. The crystal structure of the SCL3-IDD protein complex
revealed that SCL3 forms a homodimer and binds two BIRD/IDD transcription factors. The binding mode in SCL3-IDD complex is in sharp contrast to that found in a previous structure of the SHOOT-ROOT (SHR)-SCARECROW (SCR) heterodimer bound to BIRD/IDD transcription factors where N-terminal ZF motifs dock into the ZF-binding groove located at the alpha/beta core subdomain of SHR. We identified a conserved SDB motif in 12 out of 16 Arabidopsis BIRD/IDD-TF members. We also provide evidence that BIRD/IDD binds SHR/SCR and SCL3 simultaneously. These results expand and deepen our knowledge of the molecular mechanisms by which GRAS and BIRD/IDD members mediate cross-talk and networking of signaling pathways.

Free Research Field

構造生物学

Academic Significance and Societal Importance of the Research Achievements

植物の根の形態形成は成長過程と調和して転写制御をオン・オフにするため、複雑に制御されている。本研究では根の形態形成に重要な2つのファミリーGRAS, IDDファミリーについてその立体構造解析と分子相互作用解析の結果から、GRASファミリーとIDDファミリーの相互作用様式には多様性があることを示し、結合する組み合わせによって様々な転写制御複合体を形成し得ることを明らかにした。本成果は植物の複雑な転写制御機構の理解を深めると期待される。