Zhou Ke
Department of Biology, Pennsylvania State University, University Park, PA, United States.
Front Cell Dev Biol. 2022 Aug 12;10:904714. doi: 10.3389/fcell.2022.904714. eCollection 2022.
A polysaccharides-based cell wall covers the plant cell, shaping it and protecting it from the harsh environment. Cellulose microfibrils constitute the cell wall backbone and are embedded in a matrix of pectic and hemicellulosic polysaccharides and glycoproteins. Various environmental and developmental cues can regulate the plant cell wall, and diverse glycosylphosphatidylinositol (GPI)-anchored proteins participate in these regulations. GPI is a common lipid modification on eukaryotic proteins, which covalently tethers the proteins to the membrane lipid bilayer. Catalyzed by a series of enzymic complexes, protein precursors are post-translationally modified at their hydrophobic carboxyl-terminus in the endomembrane system and anchored to the lipid bilayer through an oligosaccharidic GPI modification. Ultimately, mature proteins reach the plasma membrane the secretory pathway facing toward the apoplast and cell wall in plants. In , more than three hundred GPI-anchored proteins (GPI-APs) have been predicted, and many are reported to be involved in diverse regulations of the cell wall. In this review, we summarize GPI-APs involved in cell wall regulation. GPI-APs are proposed to act as structural components of the cell wall, organize cellulose microfibrils at the cell surface, and during cell wall integrity signaling transduction. Besides regulating protein trafficking, the GPI modification is potentially governed by a GPI shedding system that cleaves and releases the GPI-anchored proteins from the plasma membrane into the cell wall.
基于多糖的细胞壁覆盖着植物细胞，塑造细胞形态并保护其免受恶劣环境的影响。纤维素微纤丝构成细胞壁的骨架，并嵌入果胶和半纤维素多糖以及糖蛋白的基质中。各种环境和发育信号可以调节植物细胞壁，多种糖基磷脂酰肌醇（GPI）锚定蛋白参与这些调节过程。GPI是真核生物蛋白质上常见的脂质修饰，它将蛋白质共价连接到膜脂双层上。在一系列酶复合物的催化下，蛋白质前体在内膜系统中其疏水羧基末端进行翻译后修饰，并通过寡糖GPI修饰锚定到脂双层上。最终，成熟的蛋白质到达质膜——植物中面向质外体和细胞壁的分泌途径。在植物中，已经预测出超过三百种GPI锚定蛋白（GPI-APs），并且许多被报道参与细胞壁的多种调节。在本综述中，我们总结了参与细胞壁调节的GPI-APs。GPI-APs被认为是细胞壁的结构成分，在细胞表面组织纤维素微纤丝，并参与细胞壁完整性信号转导。除了调节蛋白质运输外，GPI修饰可能受GPI脱落系统的控制，该系统将GPI锚定蛋白从质膜上切割并释放到细胞壁中。
