Department of Biology, Berry College, Mt. Berry, Georgia, USA.
Department of Biology, University of North Carolina at Chapel Hill, North Carolina, USA.
Genome Biol Evol. 2022 Feb 4;14(2). doi: 10.1093/gbe/evac002.
GTPases of Immunity-Associated Proteins (GIMAP) are a group of small GTP-binding proteins found in a variety of organisms, including vertebrates, invertebrates, and plants. These proteins are characterized by the highly conserved AIG1 domain, and in vertebrates, have been implicated in regulation of the immune system as well as apoptosis and autophagy, though their exact mechanism of action remains unclear. Recent work on cnidarian GIMAPs suggests a conserved role in immunity, apoptosis, and autophagy-three processes involved in coral bleaching, or the breakdown of cnidarian-dinoflagellate symbiosis. Therefore, to further understand the evolution of GIMAPs in this group of organisms, the purpose of this study was to characterize GIMAP or GIMAP-like sequences utilizing publicly available genomic and transcriptomic data in species across the cnidarian phylogeny. The results revealed a patchy distribution of GIMAPs in cnidarians, with three distinct types referred to as L-GIMAP, S-GIMAP, and GIMAP-like. Additionally, GIMAPs were present in most dinoflagellate species and formed seven well-supported clades. Overall, these results elucidate the distribution of GIMAPs within two distantly related eukaryotic groups and represent the first in-depth investigation on the evolution of these proteins within both protists and basal metazoans.
免疫相关蛋白的 GTPases（GIMAP）是一组在各种生物体中发现的小 GTP 结合蛋白，包括脊椎动物、无脊椎动物和植物。这些蛋白质的特征是高度保守的 AIG1 结构域，在脊椎动物中，它们被认为参与免疫系统的调节以及细胞凋亡和自噬，尽管它们的确切作用机制尚不清楚。最近对刺胞动物 GIMAP 的研究表明，它们在免疫、细胞凋亡和自噬方面具有保守作用——这三个过程都与珊瑚白化或刺胞动物-甲藻共生关系的破裂有关。因此，为了进一步了解这组生物体中 GIMAP 的进化，本研究的目的是利用刺胞动物系统发育中各物种的公开基因组和转录组数据来描述 GIMAP 或 GIMAP 样序列。研究结果表明，GIMAP 在刺胞动物中的分布不均匀，有三种不同的类型，分别称为 L-GIMAP、S-GIMAP 和 GIMAP 样。此外，GIMAP 存在于大多数甲藻物种中，并形成了七个支持良好的分支。总的来说，这些结果阐明了 GIMAP 在两个远缘真核生物群中的分布，代表了对这些蛋白质在原生生物和基础后生动物中的进化的首次深入研究。
