Structure-function analysis of the interaction of secretory peptides with their target proteins

分泌肽与其靶蛋白相互作用的结构功能分析

• 批准号: 222210976
• 负责人: Professor Dr. Dirk Becker
• 金额: --
• 依托单位: Lehrstuhl für Botanik I: Molekulare Pflanzenphysiologie und Biophysik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/222210976?language=en
• 关键词: Structure; function; analysis; interaction; secretory

In higher plants sperm cells are immobile. For a successful fertilization they need to be transported to the female gametophyte via growth of the pollen tube. Upon arrival at the micropyle the pollen tube stops to grow and bursts, thereby delivering the sperm cells to the egg apparatus. In this context, we have recently shown that the defensin-like (DEFL) protein ZmES4 (Zea mays embryo sac 4) mediates pollen tube burst in maize via opening of the potassium channel KZM1. Since the exact molecular mechanism of this interaction and its relation to pollen tube burst is not known a main goal of the proposal relies on understanding the structure-function relationship of the interaction of ZmES4 with the potassium ion channel KZM1. As this interaction is very specific, we plan to identify domains or residues within the ion channel which are essential for ZmES4 binding. Furthermore we aim on elucidating how ZmES4-mediated channel modulation finally leads to pollen tube burst. We postulate that in addition to K+ flux, sucrose uptake and ensuing water influx represents an essential step for pollen tube rupture. Therefore we will investigate whether the corresponding sucrose transporters are also affected by ZmES4 application. Finally, if time permits we will elucidate whether the interaction of DEFL proteins with ion channels represents a general principle in higher plants to induce pollen tube rupture and sperm release. Therefore, we will test DEFL proteins and ion channels of other plant species regarding their ability to fulfill this function. In case of positively tested DEFL proteins and their respective targets we will model and compare their structures to clarify if the DEFL/target binding site possesses a species-specific structure.

高等植物的精细胞是不动的。为了成功受精，它们需要通过花粉管的生长被运送到雌配子体。到达珠孔后，花粉管停止生长并破裂，从而将精细胞运送到卵器。在这种情况下，我们最近已经表明，防御素样（DEFL）蛋白ZmES 4（玉米胚囊4）介导的玉米花粉管爆裂通过开放的钾通道KZM 1。由于这种相互作用的确切分子机制及其与花粉管爆裂的关系尚不清楚，因此该提案的主要目标依赖于理解ZmES 4与钾离子通道KZM 1相互作用的结构-功能关系。由于这种相互作用是非常具体的，我们计划确定结构域或残基的离子通道内的ZmES 4结合是必不可少的。此外，我们的目的是阐明如何ZmES 4介导的通道调制最终导致花粉管爆裂。我们推测，除了K+流量，蔗糖的吸收和随后的水流入是一个重要的步骤，花粉管破裂。因此，我们将研究相应的蔗糖转运蛋白是否也受到ZmES 4应用的影响。最后，如果时间允许，我们将阐明DEFL蛋白与离子通道的相互作用是否代表了高等植物诱导花粉管破裂和精子释放的一般原则。因此，我们将测试其他植物物种的DEFL蛋白和离子通道是否有能力实现这一功能。如果检测的DEFL蛋白及其各自的靶标呈阳性，我们将对其结构进行建模和比较，以澄清DEFL/靶标结合位点是否具有种属特异性结构。

项目成果

Female gametophyte expressed Arabidopsis thaliana lipid transfer proteins AtLtpI.4 and AtLtpI.8 provide a link between callose homeostasis, pollen tube guidance, and fertilization success

• DOI: 10.1101/2021.01.13.426551
• 发表时间: 2021-01
• 期刊: bioRxiv
• 作者: K. Kumari;Meng Zhao;Sebastian Britz;Christine Weiste;W. Dröge-Laser;C. Stigloher;R. Deeken