School of Biological and Biomedical Sciences, Durham University Durham, UK.
College of Life and Environmental Sciences, University of Exeter Exeter, UK.
Front Plant Sci. 2014 Jun 5;5:254. doi: 10.3389/fpls.2014.00254. eCollection 2014.
The Arabidopsis Networked (NET) superfamily are plant-specific actin binding proteins which specifically label different membrane compartments and identify specialized sites of interaction between actin and membranes unique to plants. There are 13 members of the superfamily in Arabidopsis, which group into four distinct clades or families. NET homologs are absent from the genomes of metazoa and fungi; furthermore, in plantae, NET sequences are also absent from the genome of mosses and more ancient extant plant clades. A single family of the NET proteins is found encoded in the club moss genome, an extant species of the earliest vascular plants. Gymnosperms have examples from families 4 and 3, with a hybrid form of NET1 and 2 which shows characteristics of both NET1 and NET2. In addition to NET3 and 4 families, the NET1 and pollen-expressed NET2 families are found only as independent sequences in Angiosperms. This is consistent with the divergence of reproductive actin. The four families are conserved across Monocots and Eudicots, with the numbers of members of each clade expanding at this point, due, in part, to regions of genome duplication. Since the emergence of the NET superfamily at the dawn of vascular plants, they have continued to develop and diversify in a manner which has mirrored the divergence and increasing complexity of land-plant species.
拟南芥网络（NET）超家族是植物特有的肌动蛋白结合蛋白，它们特异性地标记不同的膜区室，并识别植物特有的肌动蛋白与膜之间的特殊相互作用位点。在拟南芥中有 13 个该超家族的成员，它们分为四个不同的分支或家族。NET 同源物不存在于后生动物和真菌的基因组中；此外，在植物中，苔藓和更古老的现存植物类群的基因组中也不存在 NET 序列。NET 蛋白的一个家族存在于石松基因组中，石松是最早的维管植物的一个现存物种。裸子植物有来自第 4 家族和第 3 家族的例子，NET1 和 2 的杂交形式表现出 NET1 和 NET2 的特征。除了 NET3 和 4 家族外，NET1 和花粉表达的 NET2 家族仅在被子植物中作为独立序列存在。这与生殖肌动蛋白的分化一致。这四个家族在单子叶植物和双子叶植物中是保守的，每个分支的成员数量在此处增加，部分原因是基因组重复区域。自从 NET 超家族在维管植物出现以来，它们以一种与陆生植物物种的分化和日益复杂化相呼应的方式继续发展和多样化。
