Center for Integrative Genomics, Université de Lausanne, Lausanne, Switzerland.
Simons Centre for the Study of Living Machines, National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India.
Sci Rep. 2022 Jul 2;12(1):11213. doi: 10.1038/s41598-022-15419-9.
Vesicle budding and fusion in eukaryotes depend on a suite of protein types, such as Arfs, Rabs, coats and SNAREs. Distinct paralogs of these proteins act at distinct intracellular locations, suggesting a link between gene duplication and the expansion of vesicle traffic pathways. Genome doubling, a common source of paralogous genes in fungi, provides an ideal setting in which to explore this link. Here we trace the fates of paralog doublets derived from the 100-Ma-old hybridization event that gave rise to the whole genome duplication clade of budding yeast. We find that paralog doublets involved in specific vesicle traffic functions and pathways are convergently retained across the entire clade. Vesicle coats and adaptors involved in secretory and early-endocytic pathways are retained as doublets, at rates several-fold higher than expected by chance. Proteins involved in later endocytic steps and intra-Golgi traffic, including the entire set of multi-subunit and coiled-coil tethers, have reverted to singletons. These patterns demonstrate that selection has acted to expand and diversify the yeast vesicle traffic apparatus, across species and time.
真核生物的囊泡出芽和融合依赖于一系列蛋白质类型，如 Arfs、Rabs、衣被蛋白和 SNAREs。这些蛋白质的不同的同源蛋白在不同的细胞内位置发挥作用，这表明基因复制与囊泡运输途径的扩展之间存在联系。真菌中的基因组加倍是同源基因的常见来源，为探索这种联系提供了一个理想的环境。在这里，我们追踪了源自于 1 亿年前杂交事件的同源蛋白二聚体的命运，该事件产生了出芽酵母全基因组复制进化枝。我们发现，参与特定囊泡运输功能和途径的同源蛋白二聚体在整个进化枝中被趋同保留。涉及分泌和早期内吞途径的囊泡衣被蛋白和衔接蛋白作为二聚体被保留，其频率比预期的随机频率高出数倍。涉及后期内吞步骤和高尔基体内运输的蛋白质，包括整套多亚基和卷曲螺旋系绳蛋白，已经恢复为单体。这些模式表明，选择已经作用于扩大和多样化酵母囊泡运输装置，跨越物种和时间。
