Characterization of the Molecular Mechanism Underlying Gibberellin Perception Complex Formation in Rice
Characterization of the Molecular Mechanism Underlying Gibberellin Perception Complex Formation in Rice
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DOI：
10.1105/tpc.110.075549
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发表时间：
2010-08-01
期刊：
影响因子：
11.6
通讯作者：
Matsuoka, Makoto
中科院分区：
文献类型：
--
作者：
Hirano, Ko;Asano, Kenji;Matsuoka, Makoto
Della蛋白SILLINE RICE1(SLR1)是水稻赤霉素(GA)信号的抑制子，大部分与GA相关的反应都是由SLR1降解诱导的。据推测，赤霉素不敏感的DWARF1(GID1)与SLR1的N端della/TVHYNP基序相互作用，触发了F-box蛋白GID2介导的SLR1降解。我们鉴定了一个半显性矮秆突变体SLr1-d4，它在SLR1(SLR1(G576V))的C-末端GRAS结构域编码区域含有突变。在酵母细胞中，SLR1(G576V)与GID1的相互作用减弱，与SLR1相比，SLR1(G576V)与GID1的相互作用减少，与GID2的作用几乎为零。GID1-SLR1和GID1-SLR1(G576V)相互作用的表面等离子体共振表明，SLR1的GRAS结构域通过降低其解离速率来稳定GID1-SLR1相互作用，而SLR1中的G576V替换降低了这种稳定性。这些结果表明，GID1-SLR1通过GRAS结构域的稳定相互作用对于GID2识别SLR1是必不可少的。我们认为，当SLR1的DELA/TVHYNP基序与GID1结合时，它使SLR1的GRAS结构域与GID1相互作用，稳定的GID1-SLR1复合体能被GID2有效识别。
The DELLA protein SLENDER RICE1 (SLR1) is a repressor of gibberellin (GA) signaling in rice (Oryza sativa), and most of the GA-associated responses are induced upon SLR1 degradation. It is assumed that interaction between GIBBERELLIN INSENSITIVE DWARF1 (GID1) and the N-terminal DELLA/TVHYNP motif of SLR1 triggers F-box protein GID2-mediated SLR1 degradation. We identified a semidominant dwarf mutant, Slr1-d4, which contains a mutation in the region encoding the C-terminal GRAS domain of SLR1 (SLR1(G576V)). The GA-dependent degradation of SLR1(G576V) was reduced in Slr1-d4, and compared with SLR1, SLR1(G576V) showed reduced interaction with GID1 and almost none with GID2 when tested in yeast cells. Surface plasmon resonance of GID1-SLR1 and GID1-SLR1(G576V) interactions revealed that the GRAS domain of SLR1 functions to stabilize the GID1-SLR1 interaction by reducing its dissociation rate and that the G576V substitution in SLR1 diminishes this stability. These results suggest that the stable interaction of GID1-SLR1 through the GRAS domain is essential for the recognition of SLR1 by GID2. We propose that when the DELLA/TVHYNP motif of SLR1 binds with GID1, it enables the GRAS domain of SLR1 to interact with GID1 and that the stable GID1-SLR1 complex is efficiently recognized by GID2.