Seifert Georg J, Roberts Keith
Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Colney, Norwich, United Kingdom.
Annu Rev Plant Biol. 2007;58:137-61. doi: 10.1146/annurev.arplant.58.032806.103801.
Arabinogalactan proteins is an umbrella term applied to a highly diverse class of cell surface glycoproteins, many of which contain glycosylphosphatidylinositol lipid anchors. The structures of protein and glycan moieties of arabinogalactan proteins are overwhelmingly diverse while the "hydroxproline contiguity hypothesis" predicts arabinogalactan modification of members of many families of extracellular proteins. Descriptive studies using monoclonal antibodies reacting with carbohydrate epitopes on arabinogalactan proteins and experimental work using beta-Yariv reagent implicate arabinogalactan proteins in many biological processes of cell proliferation and survival, pattern formation and growth, and in plant microbe interaction. Advanced structural understanding of arabinogalactan proteins and an emerging molecular genetic definition of biological roles of individual arabinogalactan protein species, in conjunction with potentially analogous extracellular matrix components of animals, stimulate hypotheses about their mode of action. Arabinogalactan proteins might be soluble signals, or might act as modulators and coreceptors of apoplastic morphogens; their amphiphilic molecular nature makes them prime candidates of mediators between the cell wall, the plasma membrane, and the cytoplasm.
阿拉伯半乳聚糖蛋白是一个适用于高度多样化的一类细胞表面糖蛋白的统称，其中许多含有糖基磷脂酰肌醇脂质锚定。阿拉伯半乳聚糖蛋白的蛋白质和聚糖部分的结构极其多样，而“羟脯氨酸邻接假说”预测许多细胞外蛋白家族成员会被阿拉伯半乳聚糖修饰。使用与阿拉伯半乳聚糖蛋白上碳水化合物表位反应的单克隆抗体的描述性研究以及使用β-里夫试剂的实验工作表明，阿拉伯半乳聚糖蛋白参与细胞增殖与存活、模式形成与生长以及植物与微生物相互作用等许多生物学过程。对阿拉伯半乳聚糖蛋白的高级结构理解以及对单个阿拉伯半乳聚糖蛋白种类生物学作用的新出现的分子遗传学定义，连同动物中潜在类似的细胞外基质成分，激发了关于它们作用方式的假说。阿拉伯半乳聚糖蛋白可能是可溶性信号，或者可能充当质外体形态发生素的调节剂和共受体；它们的两亲分子性质使它们成为细胞壁、质膜和细胞质之间介质的主要候选者。
