A bioinformatic analysis of the RAB genes of Trypanosoma brucei
A bioinformatic analysis of the RAB genes of Trypanosoma brucei
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DOI：
10.1016/j.molbiopara.2005.01.017
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发表时间：
2005-05-01
影响因子：
1.5
通讯作者：
Field, MC
中科院分区：
文献类型：
--
作者：
Ackers, JP;Dhir, V;Field, MC
RAB蛋白是在真核细胞内转运中具有重要作用的小GTP酶; orthopediaRAB似乎在不同生物体中实现类似的功能。布氏锥虫，人和家畜的旧世界锥虫病的病原生物体具有极有效的内吞和外吞机制，其可能参与感染的维持，使得对这些系统的研究具有重要意义。利用布氏锥虫基因组的基本完成，我们重新检查了布氏锥虫RAB（TbRAB）迄今为止描述和确定了总共16个。BLAST搜索和系统发育分析表明，九个TbRAB可以确信地被分配为直系同源物或同源物的已知RAB蛋白从高等真核生物，和四个合理的概率。核心内吞途径的复杂性可能与酵母相似，而早期的外吞途径似乎比酵母更复杂。两个TbRAB家族（RAB 23和28）与明确的哺乳动物直系同源物似乎是不寻常的，并可能参与核过程，并在随附的文件中进行了更详细的描述。然而，三个TbRAB似乎没有密切的同源物，并可能在这种生物体中履行专门的功能。一套完整的TbRAB的可用性-其中包括负责控制内膜系统的核心的RAB的直系同源物（即RAB 1，2，4-7和11）-提供了存在于动质体寄生虫内的运输复杂性的第一个概述。基于这些同源性，我们建议一个系统的命名TbRAB，以反映其功能的同源性。这一信息是重要的，无论是从了解真核生物贩运的进化和多样性的角度来看，但也提供了一个框架，通过它来了解蛋白质加工，贩运，内吞作用和其他相关过程中，这些寄生虫。(c)2005 Elsevier B. V.保留所有权利。
RAB proteins are small GTPases with vital roles in eukaryotic intracellular transport; orthologous RABs appear to fulfil similar functions in diverse organisms. Trypanosoma brucei spp., the causative organisms of Old World trypanosomiasis of humans and domestic animals, have extremely effective endocytic and exocytic mechanisms that are likely to be involved in maintenance of infection, making study of these systems of importance. Taking advantage of the essential completion of the T brucei genome, we have re-examined the T brucei RABs (TbRABs) so far described and identified a total of 16. BLAST searches and phylogenetic analysis show that nine of the TbRABs can confidently be assigned as orthologues or homologues of known RAB proteins from higher eukaryotes, and four more with reasonable probability. The core endocytic pathway is probably similar in complexity to yeast, whilst the early exocytic pathway appears to be more complex than in yeast. Two of the TbRAB family (RAB23 and 28) with clear mammalian orthologues appear to be unusual, and may be involved in nuclear processes and are described in more detail in an accompanying paper. Three TbRABs appear, however, to have no close homologues and may fulfil specialised functions in this organism. The availability of a complete set of TbRABs - which includes orthologues of the RABs responsible for control of the core of the endomembrane system (i.e. RAB 1, 2, 4-7 and 11) - provides a first overview of the trafficking complexity that is present within a kinetoplastid parasite. Based on these homologies we suggest a systematic nomenclature for the TbRABs to reflect their functional homologies. This information is of importance both from the perspective of understanding the evolution and diversity of eukaryotic trafficking, but also in providing a framework by which to understand protein processing, trafficking, endocytosis and other related processes in these parasites. (c) 2005 Elsevier B.V. All rights reserved.