A plant-specific dynamin-related protein forms a ring at the chloroplast division site
A plant-specific dynamin-related protein forms a ring at the chloroplast division site
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DOI：
10.1105/tpc.009373
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发表时间：
2003-03-01
期刊：
影响因子：
11.6
通讯作者：
Kuroiwa, T
中科院分区：
文献类型：
--
作者：
Miyagishima, S;Nishida, K;Kuroiwa, T
叶绿体保留细菌FtsZ进行分裂，而线粒体除了在一些低等真核生物中没有FtsZ外，没有FtsZ。相反，线粒体分裂涉及一种与动力蛋白相关的蛋白质，这表明在进化过程中，叶绿体保留了细菌分裂系统，而基于动力蛋白的系统取代了线粒体中的细菌系统。在这项研究中，我们从原始红藻蓝藻Merolae中鉴定了一组新的植物特异性动力素。叶绿体分裂的同步性和免疫印迹分析表明，该蛋白(CmDnm2)仅在分裂期间与叶绿体结合。免疫细胞化学分析表明，CmDnm2出现在叶绿体分裂前的细胞质斑块中，并在分裂后期被募集到叶绿体分裂部位的胞质侧形成环状。环会收缩，直到分裂完成，之后它就消失了。这些结果表明，动力蛋白相关的蛋白质也参与叶绿体的分裂，其行为不同于FtsZ和叶绿体分裂环，后者是在分裂部位收缩之前形成的。结合最近对蓝藻细胞线粒体分裂的研究结果，我们的发现引导我们提出假设，当线粒体和叶绿体首次在低等真核生物中建立时，线粒体和叶绿体使用非常相似的系统进行分裂，包括FtsZ环、叶绿体分裂/线粒体分裂环和动力蛋白环。
Chloroplasts have retained the bacterial FtsZ for division, whereas mitochondria lack FtsZ except in some lower eukaryotes. Instead, mitochondrial division involves a dynamin-related protein, suggesting that chloroplasts retained the bacterial division system, whereas a dynamin-based system replaced the bacterial system in mitochondria during evolution. In this study, we identified a novel plant-specific group of dynamins from the primitive red alga Cyanidioschyzon merolae. Synchronization of chloroplast division and immunoblot analyses showed that the protein (CmDnm2) associates with the chloroplast only during division. Immunocytochemical analyses showed that CmDnm2 appears in cytoplasmic patches just before chloroplast division and is recruited to the cytosolic side of the chloroplast division site to form a ring in the late stage of division. The ring constricts until division is complete, after which it disappears. These results show that a dynamin-related protein also participates in chloroplast division and that its behavior differs from that of FtsZ and plastid-dividing rings that form before constriction at the site of division. Combined with the results of a recent study of mitochondrial division in Cyanidioschyzon, our findings led us to hypothesize that when first established in lower eukaryotes, mitochondria and chloroplasts divided using a very similar system that included the FtsZ ring, the plastid-dividing/mitochondrion-dividing ring, and the dynamin ring.