Microtubules in bacteria: Ancient tubulins build a five-protofilament homolog of the eukaryotic cytoskeleton.
Microtubules in bacteria: Ancient tubulins build a five-protofilament homolog of the eukaryotic cytoskeleton.
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DOI：
10.1371/journal.pbio.1001213
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发表时间：
2011-12
期刊：
影响因子：
9.8
通讯作者：
Jensen GJ
中科院分区：
文献类型：
--
作者：
Pilhofer M;Ladinsky MS;McDowall AW;Petroni G;Jensen GJ
细菌中微管的明确鉴定为现代真核生物微管从原始结构的进化提供了线索。微管在细胞分裂、运输和运动中起着至关重要的作用，因此是抗癌药物的极好靶点。所有的微管蛋白都是从一个共同的祖先进化而来的，它们与远亲细菌细胞分裂蛋白FtsZ共享，但是当真核小管蛋白进化成高度保守的微管形成异二聚体时，细菌的FtsZ可能像今天一样继续作为单一的均聚原丝发挥作用。微管以前没有在细菌中发现过，我们对它们从微管蛋白/FtsZ祖先进化而来的情况缺乏了解。利用电子冷冻显微镜，我们发现微管蛋白同源物BtubA和BtubB在细菌中形成微管，并建议将这些微管称为“细菌微管”（bMTs）。bmt与真核生物具有相同的重要特征，如直原丝和类似的原丝相互作用。然而，bmt仅由5根原丝组成，而不是真核生物中典型的13根。这些和其他结果表明，BtubA和BtubB不是来源于现代真核微管蛋白，而是起源于形成小微管的早期微管蛋白中间体。由于我们表明细菌微管可以在没有伴侣的情况下在体外大量产生，它们应该是微管蛋白研究和药物筛选的有用工具。细菌与真菌、植物和动物的细胞（真核生物）的区别不仅在于它们的体积小得多，而且在于它们没有某些亚细胞结构，如细胞核、内部细胞器和微管。使用最先进的显微镜，我们在这里证明微管确实存在于一些细菌中。这些细菌微管是由与真核生物中的微管蛋白密切相关的蛋白质构成的。细菌微管的直径比真核细胞中的微管小，但具有相同的基本结构。我们认为细菌微管在进化上代表了先于真核生物微管的原始结构。由于细菌微管比真核生物更容易在实验室中生产和处理，它们可能成为微管研究和抗癌药物筛选的有用工具。
The unequivocal identification of microtubules in bacteria throws light on the evolution of modern eukaryotic microtubules from a primordial structure. Microtubules play crucial roles in cytokinesis, transport, and motility, and are therefore superb targets for anti-cancer drugs. All tubulins evolved from a common ancestor they share with the distantly related bacterial cell division protein FtsZ, but while eukaryotic tubulins evolved into highly conserved microtubule-forming heterodimers, bacterial FtsZ presumably continued to function as single homopolymeric protofilaments as it does today. Microtubules have not previously been found in bacteria, and we lack insight into their evolution from the tubulin/FtsZ ancestor. Using electron cryomicroscopy, here we show that the tubulin homologs BtubA and BtubB form microtubules in bacteria and suggest these be referred to as “bacterial microtubules” (bMTs). bMTs share important features with their eukaryotic counterparts, such as straight protofilaments and similar protofilament interactions. bMTs are composed of only five protofilaments, however, instead of the 13 typical in eukaryotes. These and other results suggest that rather than being derived from modern eukaryotic tubulin, BtubA and BtubB arose from early tubulin intermediates that formed small microtubules. Since we show that bacterial microtubules can be produced in abundance in vitro without chaperones, they should be useful tools for tubulin research and drug screening. Bacteria are generally distinguished from the cells of fungi, plants, and animals (eukaryotes) not only by their much smaller size but also by the absence of certain subcellular structures such as nuclei, internal organelles, and microtubules. Using state-of-the-art microscopy, we demonstrate here that microtubules do exist in some bacteria. These bacterial microtubules are built from proteins that are closely related to the microtubule proteins in eukaryotes. Bacterial microtubules are smaller in diameter than their counterparts in eukaryotic cells but have the same basic architecture. We propose that bacterial microtubules represent primordial structures that preceded eukaryotic microtubules evolutionarily. Because bacterial microtubules can be produced and handled in the lab more easily than their eukaryotic counterparts, they may become useful tools for microtubule research and anti-cancer drug screening.
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影响因子：
14.9
作者：
Ludwig, W;Strunk, O;Schleifer, KH
通讯作者：
Schleifer, KH
DOI：
10.1073/pnas.012516899
发表时间：
2002-12-24
影响因子：
11.1
作者：
Jenkins, C;Samudrala, R;Staley, JT
通讯作者：
Staley, JT
影响因子：
3
作者：
Amat, Fernando;Moussavi, Farshid;Horowitz, Mark
通讯作者：
Horowitz, Mark
影响因子：
4.2
作者：
Lee KC;Webb RI;Janssen PH;Sangwan P;Romeo T;Staley JT;Fuerst JA
通讯作者：
Fuerst JA
影响因子：
2
作者：
Mastronarde, D. N.
通讯作者：
Mastronarde, D. N.