Molecular mechanism for the recognition of sequence-divergent CIF peptides by the plant receptor kinases GSO1/SGN3 and GSO2
Molecular mechanism for the recognition of sequence-divergent CIF peptides by the plant receptor kinases GSO1/SGN3 and GSO2
复制标题
DOI：
10.1073/pnas.1911553117
复制
发表时间：
2020-02-04
影响因子：
11.1
通讯作者：
Hothorn, Michael
中科院分区：
文献类型：
--
作者：
Okuda, Satohiro;Fujita, Satoshi;Hothorn, Michael
植物利用富含亮氨酸的重复序列受体激酶（LRR-RKs）在细胞表面感知序列多样的肽激素。调节内皮层中凯氏带形成的LRR-RK GSO 1/SGN 3的3.0埃晶体结构揭示了大的螺旋形胞外域。该结构域为21个氨基酸的CIF肽配体提供结合平台，所述配体被酪氨酰蛋白磺基转移酶TPST/SGN 2酪氨酸硫酸化。GSO 1/SGN 3具有磺基酪氨酸的结合口袋，并与CIF 2形成扩展的骨架相互作用。定量生化比较表明，GSO 1/SGN 3-CIF 2代表了植物中已知的最强的受体-配体对之一。需要多个错义突变来阻断体外CIF 2结合和体内GSO 1/SGN 3功能。使用结构指导的序列分析，我们发现以前未知的CIF肽保守的高等植物。与已知和新的CIF 5的定量结合试验表明，同源LRR-RKs GSO 1/SGN 3和GSO 2已经进化出独特的肽结合特性，以控制不同的发育过程。一个定量的生化相互作用的屏幕，CIF肽拮抗剂和遗传分析一起牵连SERK蛋白作为GSO 1/SGN 3和GSO 2受体激活所需的必要辅助受体激酶。我们的工作提供了一个机制框架，在植物中的序列不同的肽激素的识别。
Plants use leucine-rich repeat receptor kinases (LRR-RKs) to sense sequence diverse peptide hormones at the cell surface. A 3.0-angstrom crystal structure of the LRR-RK GSO1/SGN3 regulating Casparian strip formation in the endodermis reveals a large spiral-shaped ectodomain. The domain provides a binding platform for 21 amino acid CIF peptide ligands, which are tyrosine sulfated by the tyrosylprotein sulfotransferase TPST/SGN2. GSO1/SGN3 harbors a binding pocket for sulfotyrosine and makes extended backbone interactions with CIF2. Quantitative biochemical comparisons reveal that GSO1/SGN3-CIF2 represents one of the strongest receptor-ligand pairs known in plants. Multiple missense mutations are required to block CIF2 binding in vitro and GSO1/SGN3 function in vivo. Using structure-guided sequence analysis we uncover previously uncharacterized CIF peptides conserved among higher plants. Quantitative binding assays with known and novel CIF5 suggest that the homologous LRR-RKs GSO1/SGN3 and GSO2 have evolved unique peptide binding properties to control different developmental processes. A quantitative biochemical interaction screen, a CIF peptide antagonist and genetic analyses together implicate SERK proteins as essential coreceptor kinases required for GSO1/SGN3 and GSO2 receptor activation. Our work provides a mechanistic framework for the recognition of sequence-divergent peptide hormones in plants.