Life and Environmental Sciences, 5200 North Lake Rd, University of California Merced, Merced, CA 95343, USA.
Sierra Nevada Research Institute, School of Natural Sciences, 5200 North Lake Rd, University of California Merced, Merced, CA 95343, USA.
FEMS Microbiol Lett. 2019 Feb 1;366(4). doi: 10.1093/femsle/fnz038.
It is common among intracellular bacterial pathogens to use eukaryotic-like proteins that mimic and manipulate host cellular processes to promote colonization and intracellular survival. Eukaryotic-like proteins are bacterial proteins with domains that are rare in bacteria, and known to function in the context of a eukaryotic cell. Such proteins can originate through horizontal gene transfer from eukaryotes or, in the case of simple repeat proteins, through convergent evolution. Recent studies of microbiomes associated with several eukaryotic hosts suggest that similar molecular strategies are deployed by cooperative bacteria that interact closely with eukaryotic cells. Some mimics, like ankyrin repeats, leucine rich repeats and tetratricopeptide repeats are shared across diverse symbiotic systems ranging from amoebae to plants, and may have originated early, or evolved independently in multiple systems. Others, like plant-mimicking domains in members of the plant microbiome are likely to be more recent innovations resulting from horizontal gene transfer from the host, or from microbial eukaryotes occupying the same host. Host protein mimics have only been described in a limited set of symbiotic systems, but are likely to be more widespread. Systematic searches for eukaryote-like proteins in symbiont genomes could lead to the discovery of novel mechanisms underlying host-symbiont interactions.
在胞内细菌病原体中，使用类似真核生物的蛋白质来模拟和操纵宿主细胞过程以促进定植和细胞内生存是很常见的。类似真核生物的蛋白质是细菌蛋白质，其结构域在细菌中很少见，并且已知在真核细胞的背景下发挥作用。这些蛋白质可以通过从真核生物的水平基因转移产生，或者在简单重复蛋白的情况下通过趋同进化产生。对几种真核宿主相关微生物组的最近研究表明，与真核细胞密切相互作用的合作细菌也会部署类似的分子策略。一些模拟物，如锚蛋白重复序列、富含亮氨酸重复序列和四肽重复序列，在从变形虫到植物的各种共生系统中广泛共享，可能起源较早，或者在多个系统中独立进化。其他的，如植物微生物组中成员的植物模拟结构域，可能是宿主横向基因转移或同一宿主中微生物真核生物的结果，是最近的创新。宿主蛋白模拟物仅在有限的共生系统中被描述，但可能更为普遍。在共生体基因组中对真核生物样蛋白进行系统搜索可能会发现宿主-共生体相互作用的新机制。
