Key message

Glycosylphosphatidylinositol (GPI)-anchored proteins (GAPs) are a unique type of membrane-associated proteins in eukaryotes. GPI and GAP biogenesis and function have been well studied in non-plant models and play an important role in the fertility of mouse sperm and egg. Although GPI and GAP biogenesis and function in plants are less known, they are critical for flowering plant reproduction because of their essential roles in the fertility of the male and female gametophytes.

Abstract

In Eukaryotes, GPI, a glycolipid molecule, can be post-translationally attached to proteins to serve as an anchor in the plasma membrane. GPI-anchoring, compared to other modes of membrane attachment and lipidation processes, localizes proteins to the extracellular portion of the plasma membrane and confers several unique attributes including specialized sorting during secretion, molecular painting onto membranes, and enzyme-mediated release of protein through anchor cleavage. While the biosynthesis, structure, and role of GPI are mostly studied in mammals, yeast and protists, the function of GPI and GAPs in plants is being discovered, particularly in gametophyte development and function. Here, we review GPI biosynthesis, protein attachment, and remodeling in plants with insights about this process in mammals. Additionally, we summarize the reproductive phenotypes of all loss of function mutations in Arabidopsis GPI biosynthesis and GAP genes and compare these to the reproductive phenotypes seen in mice to serve as a framework to identify gaps in our understanding of plant GPI and GAPs. In addition, we present an analysis on the gametophyte expression of all Arabidopsis GAPs to assist in further research on the role of GPI and GAPs in all aspects of the gametophyte generation in the life cycle of a plant.

中文翻译：

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弥合植物繁殖中的差距：植物和动物 GPI 锚定蛋白的比较。

关键信息

糖基磷脂酰肌醇 (GPI) 锚定蛋白 (GAP) 是真核生物中一种独特的膜相关蛋白。GPI 和 GAP 的生物发生和功能已在非植物模型中得到很好的研究，并在小鼠精子和卵子的生育能力中发挥重要作用。尽管 GPI 和 GAP 在植物中的生物发生和功能鲜为人知，但它们对开花植物的繁殖至关重要，因为它们在雄性和雌性配子体的生育力中发挥着重要作用。

抽象的

在真核生物中，糖脂分子 GPI 可以翻译后附着在蛋白质上，作为质膜中的锚。与膜附着和脂化过程的其他模式相比，GPI 锚定将蛋白质定位于质膜的细胞外部分，并赋予几个独特的属性，包括分泌过程中的专门分类、分子涂在膜上以及通过锚定酶介导的蛋白质释放乳沟。虽然 GPI 的生物合成、结构和作用主要在哺乳动物、酵母和原生生物中进行研究，但 GPI 和 GAP 在植物中的功能正在被发现，特别是在配子体发育和功能方面。在这里，我们回顾了植物中的 GPI 生物合成、蛋白质附着和重塑，并深入了解了哺乳动物中的这一过程。此外，我们总结了拟南芥 GPI 生物合成和 GAP 基因中所有功能缺失突变的生殖表型，并将这些与在小鼠中观察到的生殖表型进行比较，以作为确定我们对植物 GPI 和 GAP 理解差距的框架。此外，我们对所有拟南芥 GAP 的配子体表达进行了分析，以帮助进一步研究 GPI 和 GAP 在植物生命周期中配子体生成的各个方面的作用。