Lineage-specific proteins essential for endocytosis in trypanosomes.
Lineage-specific proteins essential for endocytosis in trypanosomes.
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DOI：
10.1242/jcs.191478
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发表时间：
2017-04-15
影响因子：
4
通讯作者：
Field MC
中科院分区：
文献类型：
--
作者：
Manna PT;Obado SO;Boehm C;Gadelha C;Sali A;Chait BT;Rout MP;Field MC
网格蛋白介导的内吞作用（CME）是已知的进化上最古老的内吞机制，在许多谱系中是唯一的内化机制。值得注意的是，在哺乳动物细胞中，CME负责大量的内吞通量，并且可能经历了多次适应以适应个体物种的特定需求。在非洲锥虫中，我们先前证明了CME独立于AP-2接头蛋白复合物，缺乏与许多动物和真菌CME蛋白群同源的蛋白群，并且一种新的锥虫限制性蛋白群与网格蛋白相互作用并驱动CME。在这里，我们使用了一种新的低温研磨亲和分离策略来保存瞬态低亲和相互作用，得到了迄今为止最全面的锥虫网格蛋白相互作用组。我们发现锥虫AP-1复合物、布鲁氏锥虫（Tb）EpsinR、几个内体SNAREs和SMAP的同源物以及AP-2相关激酶AAK1与网格蛋白相互作用。鉴定出新的谱系特异性蛋白，我们将其命名为TbCAP80和TbCAP141。它们的缺失在胞吞作用和膜系统组织中产生了广泛的缺陷，揭示了一种与早期分支和高度分化的CME形式相关的新分子途径，这种途径是保守的，可能在整个着丝质体寄生虫中具有重要的功能。摘要：在大多数细胞中，内吞作用是一个至关重要的过程，在这里，我们确定了锥虫体内这一过程所需的重要蛋白质。值得注意的是，这些都是独一无二的，不存在于动物、真菌或植物中。
Clathrin-mediated endocytosis (CME) is the most evolutionarily ancient endocytic mechanism known, and in many lineages the sole mechanism for internalisation. Significantly, in mammalian cells CME is responsible for the vast bulk of endocytic flux and has likely undergone multiple adaptations to accommodate specific requirements by individual species. In African trypanosomes, we previously demonstrated that CME is independent of the AP-2 adaptor protein complex, that orthologues to many of the animal and fungal CME protein cohort are absent, and that a novel, trypanosome-restricted protein cohort interacts with clathrin and drives CME. Here, we used a novel cryomilling affinity isolation strategy to preserve transient low-affinity interactions, giving the most comprehensive trypanosome clathrin interactome to date. We identified the trypanosome AP-1 complex, Trypanosoma brucei (Tb)EpsinR, several endosomal SNAREs plus orthologues of SMAP and the AP-2 associated kinase AAK1 as interacting with clathrin. Novel lineage-specific proteins were identified, which we designate TbCAP80 and TbCAP141. Their depletion produced extensive defects in endocytosis and endomembrane system organisation, revealing a novel molecular pathway subtending an early-branching and highly divergent form of CME, which is conserved and likely functionally important across the kinetoplastid parasites. Summary: Endocytosis is a vital process in most cells, and here we identify important proteins required for this process in trypanosomes. Significantly, these are unique and not present in animals, fungi or plants.
影响因子：
2.1
作者：
Natesan, Senthil Kumar A.;Black, Alana;Matthews, Keith R.;Mottram, Jeremy C.;Field, Mark C.
通讯作者：
Field, Mark C.