The Tetrahymena thermophila phagosome proteome
The Tetrahymena thermophila phagosome proteome
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DOI：
10.1128/ec.00195-06
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发表时间：
2006-12-01
期刊：
影响因子：
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通讯作者：
Klobutcher, Lawrence A.
中科院分区：
文献类型：
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作者：
Jacobs, Mary Ellen;DeSouza, Leroi V.;Klobutcher, Lawrence A.
在脊椎动物中，吞噬作用主要发生在免疫系统的特化细胞中，并作为抵抗入侵病原体的主要防御，但它也在发育期间清除凋亡细胞和组织重塑中发挥作用。相比之下，单细胞真核生物，如纤毛虫嗜热四膜虫，利用吞噬作用摄取和降解其他微生物，以满足其营养需求。为了进一步了解吞噬作用多步骤过程中的蛋白质组分，我们对四膜虫吞噬体蛋白质组进行了分析。四膜虫细胞喂食聚苯乙烯珠粒，其允许吞噬体的有效纯化。然后通过多维分离与串联质谱联用分析纯化的吞噬体的蛋白质组成。共鉴定出453种肽，导致鉴定出73种推定的吞噬体蛋白。其中28种蛋白质与其他生物的吞噬作用有关，这表明吞噬作用的关键方面在进化过程中是保守的。其他已鉴定的蛋白质以前没有与吞噬作用相关，包括一些未知的功能。活细胞共聚焦荧光成像的四膜虫菌株表达绿色荧光蛋白标记的版本的四个确定的吞噬体蛋白提供的证据表明，至少有三个蛋白质（包括两个未知功能）与吞噬体，表明在分析中确定的蛋白质的大部分确实是吞噬体相关。
In vertebrates, phagocytosis occurs mainly in specialized cells of the immune system and serves as a primary defense against invading pathogens, but it also plays a role in clearing apoptotic cells and in tissue remodeling during development. In contrast, unicellular eukaryotes, such as the ciliate Tetrahymena thermophila, employ phagocytosis to ingest and degrade other microorganisms to meet their nutritional needs. To learn more about the protein components of the multistep process of phagocytosis, we carried out an analysis of the Tetrahymena phagosome proteome. Tetrahymena cells were fed polystyrene beads, which allowed for the efficient purification of phagosomes. The protein composition of purified phagosomes was then analyzed by multidimensional separation coupled with tandem mass spectrometry. A total of 453 peptides were identified that resulted in the identification of 73 putative phagosome proteins. Twenty-eight of the proteins have been implicated in phagocytosis in other organisms, indicating that key aspects of phagocytosis were conserved during evolution. Other identified proteins have not previously been associated with phagocytosis, including some of unknown function. Live-cell confocal fluorescence imaging of Tetrahymena strains expressing green fluorescent protein-tagged versions of four of the identified phagosome proteins provided evidence that at least three of the proteins (including two with unknown functions) are associated with phagosomes, indicating that the bulk of the proteins identified in the analyses are indeed phagosome associated.