Regulation of Plant Phototropic Growth by NPH3/RPT2-like Substrate Phosphorylation and 14-3-3 Binding
Regulation of Plant Phototropic Growth by NPH3/RPT2-like Substrate Phosphorylation and 14-3-3 Binding
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NPH3/RPT2 样底物磷酸化和 14-3-3 结合对植物向光性生长的调节
DOI：
10.1101/2021.04.09.439135
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Sullivan S
中科院分区：
文献类型：
--
作者：
Sullivan S
极性是植物所有定向生长反应的基础，包括对光的生长(向光性)。质膜相关蛋白--非光性下胚轴3(NPH3)是光亲和性生长的关键决定因素，它受促光激素(Phot)AGC激酶的调节。在这里，我们证明了NPH3在一个保守的C-末端一致序列(Rxs)中被Pho1直接磷酸化，Rxs是促进拟南芥向光性和叶柄定位所必需的。结合NPH3的磷酸化和定位状态的改变，RXS的磷酸化也触发了14-3-3结合。不能结合或结构性结合14-3-3 S的NPH3突变体显示出折衷的功能，这与一个模型一致，该模型认为光致曲率是通过传递NPH3 Rxs在茎上的磷酸化梯度产生的输出来建立的。因此，我们的发现证明NPH3/RPT2样蛋白(NRL)是植物AGC激酶的磷酸化靶标。此外，Rxs的磷酸化在NRL家族的其他成员中是保守的，这表明了一种共同的机制，即调节植物生长以适应普遍的光环境。
Polarity underlies all directional growth responses in plants including growth towards the light (phototropism). The plasma-membrane associated protein, NON-PHOTOTROPIC HYPOCOTYL 3 (NPH3) is a key determinant of phototropic growth which is regulated by phototropin (phot) AGC kinases. Here we demonstrate that NPH3 is directly phosphorylated by phot1 within a conserved C-terminal consensus sequence (RxS) that is necessary to promote phototropism and petiole positioning inArabidopsis. RxS phosphorylation also triggers 14-3-3 binding combined with changes in NPH3 phosphorylation and localisation status. Mutants of NPH3 that are unable to bind or constitutively bind 14-3-3 s show compromised functionality consistent with a model where phototropic curvature is established by signalling outputs arising from a gradient of NPH3 RxS phosphorylation across the stem. Our findings therefore establish that NPH3/RPT2-Like (NRL) proteins are phosphorylation targets for plant AGC kinases. Moreover, RxS phosphorylation is conserved in other members of the NRL family, suggesting a common mechanism of regulating plant growth to the prevailing light environment.