Glycosylphosphatidylinositol-anchored proteins as chaperones and co-receptors for FERONIA receptor kinase signaling in Arabidopsis.
Glycosylphosphatidylinositol-anchored proteins as chaperones and co-receptors for FERONIA receptor kinase signaling in Arabidopsis.
复制标题
作者：
Li C;Yeh FL;Cheung AY;Duan Q;Kita D;Liu MC;Maman J;Luu EJ;Wu BW;Gates L;Jalal M;Kwong A;Carpenter H;Wu HM
拟南芥受体激酶FERONIA（FER）是植物生长和繁殖的多功能调节因子。在这里，我们报告说，雌配子体表达的糖基磷脂酰肌醇锚定蛋白（GPI-AP）LORELEI和幼苗表达的LRE样GPI-AP 1（LLG 1）结合到细胞外质膜区域的FER，并表明这种相互作用是关键的FER功能。LLG1在内质网和细胞表面与FER相互作用，LLG1功能的丧失诱导FER的细胞质滞留，这与FER从内质网转运到质膜与LLG1形成复合物一致。我们进一步证明，LLG1是一个组成部分的FER调节的RHO GT3信号复合物和FER和llg1突变体显示难以区分的生长，发育和信号表型，类似于如何lre和fer共享类似的生殖缺陷。总之，我们的研究结果支持LLG1/LRE作为FER的伴侣和共受体，并阐明GPI-AP使细胞表面受体的信号传导能力的机制。DOI：www.example.com植物通过改变它们的生长方式和繁殖时间来应对环境的变化。一种名为FERONIA的蛋白质存在于大多数类型的细胞中，并调节许多驱动这些反应的过程，例如细胞生长和雄性和雌性细胞之间的通信。FERONIA位于包围细胞的膜中，在那里它可以检测细胞壁和细胞外的分子，并将信号发送到细胞内的位置。然而，目前尚不清楚FERONIA如何能够特异性地调节不同的过程，以在特定时间在特定细胞中产生正确的反应。糖基磷脂酰肌醇锚定蛋白（GPI-AP）家族在植物、动物等真核生物中发挥着重要作用。Li等人研究了FERONIA和两种密切相关的GPI-AP，即LLG 1（在幼苗中产生）和LORELEI（仅在雌性性细胞中发现）。实验表明，缺失LLG1或FERONIA的植物在生长和对植物激素的反应方面都有类似的缺陷。缺失LORELEI的植物在繁殖能力上与缺失FERONIA的植物有相似的缺陷。这表明FERONIA与LLG1或LORELEI一起在不同情况下调节类似的过程。Li等人发现，FERONIA在细胞内称为内质网的隔室中与LLG 1结合，在这两种蛋白质一起移动到细胞膜之前，蛋白质在内质网中被折叠。在缺乏LLG1的情况下，FERONIA不能到达细胞膜，大量FERONIA仍然被困在内质网中。因此，LLG 1作为一种“伴侣”，将FERONIA传递到细胞膜上，调节植物生长。Li等人发现LORELEI也与FERONIA相互作用。LLG 1和LORELEI都与FERONIA的相同区域结合，该区域位于细胞膜的外表面上。这些发现表明，FERONIA能够通过与GPI-AP蛋白家族的不同成员合作，在细胞中发挥不同的作用。接下来的挑战将是找出LLG1和LORELEI是否以及如何影响FERONIA对来自细胞壁和细胞外信号的反应能力。DOI：www.example.com网站
The Arabidopsis receptor kinase FERONIA (FER) is a multifunctional regulator for plant growth and reproduction. Here we report that the female gametophyte-expressed glycosylphosphatidylinositol-anchored protein (GPI-AP) LORELEI and the seedling-expressed LRE-like GPI-AP1 (LLG1) bind to the extracellular juxtamembrane region of FER and show that this interaction is pivotal for FER function. LLG1 interacts with FER in the endoplasmic reticulum and on the cell surface, and loss of LLG1 function induces cytoplasmic retention of FER, consistent with transport of FER from the endoplasmic reticulum to the plasma membrane in a complex with LLG1. We further demonstrate that LLG1 is a component of the FER-regulated RHO GTPase signaling complex and that fer and llg1 mutants display indistinguishable growth, developmental and signaling phenotypes, analogous to how lre and fer share similar reproductive defects. Together our results support LLG1/LRE acting as a chaperone and co-receptor for FER and elucidate a mechanism by which GPI-APs enable the signaling capacity of a cell surface receptor. DOI: http://dx.doi.org/10.7554/eLife.06587.001 Plants respond to changes in their environment by altering how they grow and when they reproduce. A protein called FERONIA is found in most types of cells and regulates many of the processes that drive these responses, such as cell growth and communication between male and female cells. FERONIA sits in the membrane that surrounds the cell, where it can detect molecules in the cell wall and from outside the cell, and send signals to locations within the cell. However, it is not clear how FERONIA is able to specifically regulate different processes to produce the right response in a particular cell at a particular time. A family of proteins called glycosylphosphatidylinositol-anchored proteins (GPI-APs for short) play important roles in plants, animals, and other eukaryotic organisms. Li et al. studied FERONIA and two closely related GPI-APs called LLG1—which is produced in seedlings, and LORELEI, which is only found in female sex cells. The experiments show that plants missing either LLG1 or FERONIA had similar defects in growth and in how they respond to plant hormones. Plants missing LORELEI had similar defects in their ability to reproduce as the plants missing FERONIA. This suggests that FERONIA works with either LLG1 or LORELEI to regulate similar processes in different situations. Li et al. found that FERONIA binds to LLG1 in a compartment within the cell called the endoplasmic reticulum—where proteins are assembled—before both proteins are moved together to the cell membrane. In the absence of LLG1, FERONIA fails to reach the cell membrane, and a large amount of FERONIA remains trapped in the endoplasmic reticulum. Therefore, LLG1 acts as a ‘chaperone’ that delivers FERONIA to the membrane where it is required to regulate plant growth. Li et al. found that LORELEI also interacts with FERONIA. Both LLG1 and LORELEI bind to the same region of FERONIA, which is on the outer surface of the cell membrane. These findings show that FERONIA is able to perform different roles in cells by teaming up with different members of the GPI-AP family of proteins. The next challenges will be to find out if, and how, LLG1 and LORELEI affect the ability of FERONIA to respond to signals from the cell wall and outside the cell. DOI: http://dx.doi.org/10.7554/eLife.06587.002