ジャーナル: Mol Plant / 年: 2025 タイトル: Structural insights into gibberellin-mediated DELLA protein degradation. 著者: Soyaab Islam / Kunwoong Park / Jing Xia / Eunju Kwon / Dong Young Kim / 要旨: Gibberellin promotes plant growth by downregulating DELLA proteins, which act as growth repressors. In the presence of gibberellin, the gibberellin receptor GID1 binds DELLA proteins, triggering ...Gibberellin promotes plant growth by downregulating DELLA proteins, which act as growth repressors. In the presence of gibberellin, the gibberellin receptor GID1 binds DELLA proteins, triggering their degradation through polyubiquitination by the SCF ubiquitin E3 ligase. Despite extensive studies, the molecular mechanisms by which DELLA proteins assemble with SCF to regulate plant growth remain poorly understood. Here, we present two cryo-electron microscopy structures of the Arabidopsis thaliana DELLA protein RGA in complex with GID1A and GID1A-SLY1-ASK2, respectively. Structural analyses revealed that RGA interacts with GID1A and SLY1 through nonoverlapping binding surfaces, stabilizing the proteins. This suggests that the SCF-RGA-GID1A complex assembles through a stepwise stabilization process induced by gibberellin. Furthermore, structural comparison with GRAS proteins indicates that RGA does not interact with IDD-family transcription factors when bound to SLY1, suggesting that DELLA protein binding to GID1/SLY1 and to transcription factors is mutually exclusive. These findings provide new insights into the gibberellin-mediated regulation of transcription factor activity by DELLA proteins.
全体 : Partial model of RGA/GID1A/SLY/ASK2 heterotetramer
全体
名称: Partial model of RGA/GID1A/SLY/ASK2 heterotetramer
要素
複合体: Partial model of RGA/GID1A/SLY/ASK2 heterotetramer
タンパク質・ペプチド: DELLA protein RGA
タンパク質・ペプチド: F-box protein GID2
タンパク質・ペプチド: SKP1-like protein 1B
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超分子 #1: Partial model of RGA/GID1A/SLY/ASK2 heterotetramer
超分子
名称: Partial model of RGA/GID1A/SLY/ASK2 heterotetramer / タイプ: complex / ID: 1 / 親要素: 0 / 含まれる分子: all / 詳細: Partial model of RGA/GID1A/SLY/ASK2 heterotetramer
由来(天然)
生物種: Arabidopsis thaliana (シロイヌナズナ)
分子量
理論値: 140 KDa
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分子 #1: DELLA protein RGA
分子
名称: DELLA protein RGA / タイプ: protein_or_peptide / ID: 1 / コピー数: 1 / 光学異性体: LEVO