Department of Health, Life and Environmental Sciences, University of L'Aquila, 67100, L'Aquila, Italy.
Department of Science, University 'Roma Tre', 00146, Rome, Italy.
Sci Rep. 2020 Oct 20;10(1):17858. doi: 10.1038/s41598-020-74708-3.
Polyamine oxidases (PAOs) are characterized by a broad variability in catalytic properties and subcellular localization, and impact key cellular processes in diverse organisms. In the present study, a comprehensive phylogenetic analysis was performed to understand the evolution of PAOs across the three domains of life and particularly within eukaryotes. Phylogenetic trees show that PAO-like sequences of bacteria, archaea, and eukaryotes form three distinct clades, with the exception of a few procaryotes that probably acquired a PAO gene through horizontal transfer from a eukaryotic donor. Results strongly support a common origin for archaeal PAO-like proteins and eukaryotic PAOs, as well as a shared origin between PAOs and monoamine oxidases. Within eukaryotes, four main lineages were identified that likely originated from an ancestral eukaryotic PAO before the split of the main superphyla, followed by specific gene losses in each superphylum. Plant PAOs show the highest diversity within eukaryotes and belong to three distinct clades that underwent to multiple events of gene duplication and gene loss. Peptide deletion along the evolution of plant PAOs of Clade I accounted for further diversification of function and subcellular localization. This study provides a reference for future structure-function studies and emphasizes the importance of extending comparisons among PAO subfamilies across multiple eukaryotic superphyla.
多胺氧化酶（PAOs）的催化特性和亚细胞定位广泛多样，对不同生物的关键细胞过程都有影响。本研究进行了全面的系统发育分析，以了解 PAO 在生命的三个领域（尤其是真核生物中）的进化情况。系统发育树表明，细菌、古菌和真核生物的 PAO 样序列形成了三个不同的分支，除了少数原核生物可能通过从真核供体的水平转移获得了 PAO 基因。结果强烈支持古菌 PAO 样蛋白和真核 PAO 具有共同的起源，以及 PAO 和单胺氧化酶具有共同的起源。在真核生物中，鉴定出了四个主要谱系，它们可能起源于主要超门分裂前的祖先真核 PAO，随后在每个超门中都发生了特定的基因丢失。植物 PAO 在真核生物中表现出最高的多样性，属于三个不同的分支，经历了多次基因复制和基因丢失事件。在 I 类植物 PAO 的进化过程中，肽的缺失导致了功能和亚细胞定位的进一步多样化。本研究为未来的结构-功能研究提供了参考，并强调了在多个真核超门中扩展 PAO 亚家族之间比较的重要性。
