The ubiquity of the coexistence of two FBPases in chloroplasts of photosynthetic eukaryotes and its evolutionary and functional implications
The ubiquity of the coexistence of two FBPases in chloroplasts of photosynthetic eukaryotes and its evolutionary and functional implications
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光合真核生物叶绿体中两种 FBPase 共存的普遍性及其进化和功能意义
DOI：
10.1016/j.pld.2019.09.002
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发表时间：
2019
期刊：
影响因子：
4.8
通讯作者：
Jianfan Wen
中科院分区：
文献类型：
--
作者：
Yujin Li;Qingqing Ye;De He;Huixian Bai;Jianfan Wen
在光合作用的真核生物中，存在两种充分表征的果糖-1，6-二磷酸酶（FBPases）：参与细胞异生的氧化还原不敏感的胞质FBPases（cyFBPases）和氧化还原敏感的叶绿体FBPases 1（cpFBPase 1），其是卡尔文循环中的关键酶。最近的研究已经确定了一个新的叶绿体FBPase 2，然而，它的系统发育分布，进化起源和生理功能仍然不清楚。在这项研究中，我们确定和特点这三个FBPase异构体在不同的，有代表性的光合谱系，并分析其同源性。与以前的假设相反，我们发现cpFBPase 2在光合真核生物中是普遍存在的。此外，来自不同谱系的所有cpFBPase 2形成单系，这表明cpFBPase 2不是最近进化的酶，仅限于陆地植物，而是在光合生物进化的早期进化的，最有可能的是，在光合真核生物的共同祖先。cyFBPase可能首先复制产生cpFBPase 2，然后后者复制产生cpFBPase 1。这两种cpFBPases在叶绿体中的普遍存在最有可能是适应光合作用的不同氧化还原条件的结果，特别是那些由光条件的经常性变化引起的结果。
In photosynthetic eukaryotes, there are two well-characterized fructose-1,6-bisphosphatases (FBPases): the redox-insensitive cytosolic FBPase (cyFBPase), which participates in gluconeogenesis, and the redox-sensitive chloroplastic FBPase (cpFBPase1), which is a critical enzyme in the Calvin cycle. Recent studies have identified a new chloroplastic FBPase, cpFBPase2; however, its phylogenetic distribution, evolutionary origin, and physiological function remain unclear. In this study, we identified and characterized these three FBPase isoforms in diverse, representative photosynthetic lineages and analyzed their phylogeny. In contrast to previous hypotheses, we found that cpFBPase2 is ubiquitous in photosynthetic eukaryotes. Additionally, all cpFBPase2s from diverse lineages form a monophyly, suggesting cpFBPase2 is not a recently evolved enzyme restricted to land plants but rather evolved early in the evolution of photosynthetic organisms, and most likely, in the common ancestor of photosynthetic eukaryotes. cyFBPase was probably first duplicated to produce cpFBPase2, and then the latter duplicated to produce cpFBPase1. The ubiquitous coexistence of these two cpFBPases in chloroplasts is most likely the consequence of adaptation to different redox conditions of photosynthesis, especially those caused by recurrent changes in light conditions.