Westphal S, Heins L, Soll J, Vothknecht U C
Botanisches Institut, Christian-Albrecht-Universität Kiel, Am Botanischen Garten 1-9, 24118 Kiel, Germany.
Proc Natl Acad Sci U S A. 2001 Mar 27;98(7):4243-8. doi: 10.1073/pnas.061501198.
Plant chloroplasts originated from an endosymbiotic event by which an ancestor of contemporary cyanobacteria was engulfed by an early eukaryotic cell and then transformed into an organelle. Oxygenic photosynthesis is the specific feature of cyanobacteria and chloroplasts, and the photosynthetic machinery resides in an internal membrane system, the thylakoids. The origin and genesis of thylakoid membranes, which are essential for oxygenic photosynthesis, are still an enigma. Vipp1 (vesicle-inducing protein in plastids 1) is a protein located in both the inner envelope and the thylakoids of Pisum sativum and Arabidopsis thaliana. In Arabidopsis disruption of the VIPP1 gene severely affects the plant's ability to form properly structured thylakoids and as a consequence to carry out photosynthesis. In contrast, Vipp1 in Synechocystis appears to be located exclusively in the plasma membrane. Yet, as in higher plants, disruption of the VIPP1 gene locus leads to the complete loss of thylakoid formation. So far VIPP1 genes are found only in organisms carrying out oxygenic photosynthesis. They share sequence homology with a subunit encoded by the bacterial phage shock operon (PspA) but differ from PspA by a C-terminal extension of about 30 amino acids. In two cyanobacteria, Synechocystis and Anabaena, both a VIPP1 and a pspA gene are present, and phylogenetic analysis indicates that VIPP1 originated from a gene duplication of the latter and thereafter acquired its new function. It also appears that the C-terminal extension that discriminates VIPP1 proteins from PspA is important for its function in thylakoid formation.
植物叶绿体起源于一次内共生事件，即现代蓝细菌的一个祖先被一个早期真核细胞吞噬，随后转变为一种细胞器。产氧光合作用是蓝细菌和叶绿体的独特特征，光合机制存在于内膜系统——类囊体中。对产氧光合作用至关重要的类囊体膜的起源和发生仍然是一个谜。Vipp1（质体中囊泡诱导蛋白1）是一种存在于豌豆和拟南芥的内膜和类囊体中的蛋白质。在拟南芥中，Vipp1基因的破坏严重影响植物形成结构正常的类囊体的能力，从而影响其进行光合作用的能力。相比之下，集胞藻中的Vipp1似乎仅位于质膜中。然而，与高等植物一样，Vipp1基因座的破坏会导致类囊体形成完全丧失。到目前为止，仅在进行产氧光合作用的生物体中发现了Vipp1基因。它们与细菌噬菌体休克操纵子（PspA）编码的一个亚基具有序列同源性，但与PspA的不同之处在于其C端有大约30个氨基酸的延伸。在两种蓝细菌——集胞藻和鱼腥藻中，同时存在Vipp1和pspA基因，系统发育分析表明Vipp1起源于后者的基因复制，此后获得了新功能。似乎将Vipp1蛋白与PspA区分开来的C端延伸对于其在类囊体形成中的功能很重要。
