Alpha-tubulin acetylation in Trypanosoma cruzi : a dynamic instability of microtubules is required for replication and cell cycle progression
Alpha-tubulin acetylation in Trypanosoma cruzi : a dynamic instability of microtubules is required for replication and cell cycle progression
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克氏锥虫中的α-微管蛋白乙酰化：复制和细胞周期进展需要微管的动态不稳定性
DOI：
10.1101/2020.12.15.422917
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Alonso V
中科院分区：
文献类型：
--
作者：
Alonso V
锥虫的细胞骨架排列比大多数真核细胞中发现的要简单。然而，它是由稳定的微管精确地组织和构成的。这些微管在有丝分裂期间组成有丝分裂纺锤体、基体、鞭毛轴丝和膜下微管，它们彼此连接并且也与质膜连接，从而形成沿着寄生虫细胞体的中心轴的螺旋排列。克氏锥虫膜下微管、有丝分裂微管和轴丝微管的乙酰化。从低等真核生物到哺乳动物，α-微管蛋白赖氨酸（K）40上的乙酰化是保守的，与微管稳定性有关。已知K40乙酰化在真核生物的鞭毛、中心粒、纤毛、基体和有丝分裂纺锤体上均有发生。一些微管蛋白的翻译后修饰，包括乙酰化K40，已被归类在锥虫，但这些修改微管动力学和寄生虫生物学的功能的重要性仍然在很大程度上不确定。主要的微管蛋白乙酰转移酶最近在几种真核生物中被鉴定为Mec-17/ATAT，一种Gcn 5相关的N-乙酰转移酶。在这里，我们报告说，T。cruziATAT在体内乙酰化α-tubulin并能自动乙酰化，TcATAT位于鞭毛体的细胞骨架和鞭毛中，与乙酰化的α-tubulin共定位于这些结构中。我们使用诱导型载体pTcINDEX-GW在克氏锥虫中表达了带有HA标签的TcATAT。过表达的TcATAT导致增加的α微管蛋白乙酰化的种类的水平，诱导形态和超微结构的缺陷，特别是在的Escapon，并导致停止在细胞周期的进程的epimastigotes，这是有关的动质体分裂的损害。最后，由于TcATAT过表达，我们观察到寄生虫对微管解聚药物的耐药性增强。这些结果支持α-微管蛋白乙酰化水平在T细胞正常进展中受到精细调控的观点。克氏循环
Trypanosomatids have a cytoskeleton arrangement that is simpler than what is found in most eukaryotic cells. However, it is precisely organized and constituted by stable microtubules. Such microtubules compose the mitotic spindle during mitosis, the basal body, the flagellar axoneme and the subpellicular microtubules, which are connected to each other and also to the plasma membrane forming a helical arrangement along the central axis of the parasite cell body. Subpellicular, mitotic and axonemal microtubules are extensively acetylated inTrypanosoma cruzi. Acetylation on lysine (K) 40 of α-tubulin is conserved from lower eukaryotes to mammals and is associated with microtubule stability. It is also known that K40 acetylation occurs significantly on flagella, centrioles, cilia, basal body and the mitotic spindle in eukaryotes. Several tubulin posttranslational modifications, including acetylation of K40, have been cataloged in trypanosomatids, but the functional importance of these modifications for microtubule dynamics and parasite biology remains largely undefined. The primary tubulin acetyltransferase was recently identified in several eukaryotes as Mec-17/ATAT, a Gcn5-related N-acetyltransferase. Here, we report thatT. cruziATAT acetylates α-tubulinin vivoand is capable of auto-acetylation.TcATAT is located in the cytoskeleton and flagella of epimastigotes and colocalizes with acetylated α-tubulin in these structures. We have expressedTcATAT with an HA tag using the inducible vector pTcINDEX-GW inT. cruzi. Over-expression ofTcATAT causes increased levels of the alpha tubulin acetylated species, induces morphological and ultrastructural defects, especially in the mitochondrion, and causes a halt in the cell cycle progression of epimastigotes, which is related to an impairment of the kinetoplast division. Finally, as a result ofTcATAT over-expression we observed that parasites became more resistant to microtubule depolymerizing drugs. These results support the idea that α-tubulin acetylation levels are finely regulated for the normal progression ofT. cruzicell cycle.