Molecular Evolution of Lycopene Cyclases Involved in the Formation of Carotenoids in Eukaryotic Algae
Molecular Evolution of Lycopene Cyclases Involved in the Formation of Carotenoids in Eukaryotic Algae
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DOI：
10.1007/s11105-011-0297-2
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发表时间：
2011-12-01
影响因子：
2.1
通讯作者：
Qin, Song
中科院分区：
文献类型：
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作者：
Cui, Hongli;Wang, Yinchu;Qin, Song
类胡萝卜素在细菌、藻类和高等植物光合机构的结构和功能中起着至关重要的作用。番茄红素形成类胡萝卜素是由番茄红素环化酶（LCY）催化的，该酶在所有生物体中结构和功能上都是保守的。关于LCY的比较基因组分析显示，高等植物（拟南芥）和绿色藻类（Ostreococcus sp.RCC809、Ostreococcus tauri、Ostreococcus lucimarinus、Micromonas sp.RCC299、Micromonas pusiua、Chlorella vulgaris、Volvox carteri和Coccomyxa sp.C-169）具有两种不同的LCY（β型和ε型）。这表明，一个古老的基因复制事件必须发生，这产生了两个类的LCY在藻类。然而，其他一些绿色藻类仅保留一类LCY，如雨生红球藻（β）、杜氏盐藻（β）、莱茵衣藻（β）和小球藻（NC 64 A），而其他基因拷贝在这些物种中丢失。此外，类似的LCY损失发生在红藻（Cyanidioschyzon merolae）和异鞭毛藻（Phaeodactylum tricornutum和Thalassiosira damana）中，它们只具有LCYB。此外，LCYB的蛋白质序列与辣椒红素-辣椒红素合酶（CCS）高度相似，CCS是另一种植物类胡萝卜素生成酶。因此，有人建议，CCS演变从一个重复的LCYB。在一些藻类中发现两类LCY家族表明类胡萝卜素生物合成响应于这些藻类中的发育和环境胁迫而差异调节，就像LCY家族的成员在一些高等植物中的发育或胁迫期间差异调节一样。
Carotenoids play crucial roles in structure and function of the photosynthetic apparatus of bacteria, algae, and higher plants. The formation of carotenoids from lycopene is catalyzed by the enzyme lycopene cyclase (LCY), which is structurally and functionally conserved in all organisms. A comparative genomic analysis regarding the LCY revealed that the higher plant (Arabidopsis thaliana) and the green alga (Ostreococcus sp. RCC809, Ostreococcus tauri, Ostreococcus lucimarinus, Micromonas sp. RCC299, Micromonas pusiua, Chlorella vulgaris, Volvox carteri, and Coccomyxa sp. C-169) possess two different LCY (beta- and epsilon-type). This indicated that an ancient gene duplication event must have occurred, which produced two classes of LCY in algae. However, some other green alga retained only one class of LCY, such as Haematococcus pluvialis (beta), Dunaliella salina (beta), Chlamydomonas reinhardtii (epsilon), and Chlorella sp. NC64A (epsilon), and the other gene copy was lost in these species. Furthermore, the similar LCY lost occurred in red alga (Cyanidioschyzon merolae) and Heterokontophyta (Phaeodactylum tricornutum and Thalassiosira pseudonana), which possess only the LCYB. In addition, the protein sequence of LCYB is highly similar to capsanthin-capsorubin synthase (CCS), which is another carotenogenic enzyme of plants. As a result, it is proposed that the CCS evolved from a duplicated LCYB. The discovery of two classes of LCY families in some algae suggests that carotenoid biosynthesis is differentially regulated in response to development and environmental stress in these algae, like members of LCY families are differentially regulated during development or stress in some higher plants.