PDF(Pubmed)
Abstract：
Malaria parasites must be able to respond quickly to changes in their environment, including during their transmission between mammalian hosts and mosquito vectors. Therefore, before transmission, female gametocytes proactively produce and translationally repress mRNAs that encode essential proteins that the zygote requires to establish a new infection. This essential regulatory control requires the orthologues of DDX6 (DOZI), LSM14a (CITH), and ALBA proteins to form a translationally repressive complex in female gametocytes that associates with many of the affected mRNAs. However, while the release of translational repression of individual mRNAs has been documented, the details of the global release of translational repression have not. Moreover, the changes in spatial arrangement and composition of the DOZI/CITH/ALBA complex that contribute to translational control are also not known. Therefore, we have conducted the first quantitative, comparative transcriptomics and DIA-MS proteomics of Plasmodium parasites across the host-to-vector transmission event to document the global release of translational repression. Using female gametocytes and zygotes of P. yoelii, we found that nearly 200 transcripts are released for translation soon after fertilization, including those with essential functions for the zygote. However, we also observed that some transcripts remain repressed beyond this point. In addition, we have used TurboID-based proximity proteomics to interrogate the spatial and compositional changes in the DOZI/CITH/ALBA complex across this transmission event. Consistent with recent models of translational control, proteins that associate with either the 5\' or 3\' end of mRNAs are in close proximity to one another during translational repression in female gametocytes and then dissociate upon release of repression in zygotes. This observation is cross-validated for several protein colocalizations in female gametocytes via ultrastructure expansion microscopy and structured illumination microscopy. Moreover, DOZI exchanges its interaction from NOT1-G in female gametocytes to the canonical NOT1 in zygotes, providing a model for a trigger for the release of mRNAs from DOZI. Finally, unenriched phosphoproteomics revealed the modification of key translational control proteins in the zygote. Together, these data provide a model for the essential translational control mechanisms used by malaria parasites to promote their efficient transmission from their mammalian host to their mosquito vector.
摘要：
疟疾寄生虫必须能够对环境的变化做出快速反应，包括它们在哺乳动物宿主和蚊子媒介之间传播的过程。因此,在传输之前，雌配子体细胞主动产生并翻译抑制编码合子建立新感染所需的必需蛋白的mRNA。这种基本的调节控制需要DDX6的直系同源物（DOZI），LSM14a(CITH),和ALBA蛋白在雌配子体细胞中形成翻译抑制复合物，与许多受影响的mRNA相关。然而,虽然已经记录了单个mRNA的翻译抑制的释放，翻译压抑的全球释放的细节还没有。此外，也不知道有助于翻译控制的DOZI/CITH/ALBA复合物的空间排列和组成的变化。因此,我们进行了第一次定量，疟原虫寄生虫在整个宿主到载体传播事件中的比较转录组学和DIA-MS蛋白质组学，以记录翻译抑制的全球释放。使用雌性配子细胞和约氏疟原虫的受精卵，我们发现受精后不久就发布了近200份成绩单供翻译，包括那些具有受精卵基本功能的。然而,我们还观察到，在这一点之外，一些成绩单仍然被压抑。此外,我们使用基于TurboID的邻近蛋白质组学研究了DOZI/CITH/ALBA复合体在该传播事件中的空间和组成变化.与最近的平移控制模型一致，与mRNAs的5'或3'末端相关的蛋白质在雌配子体细胞的翻译抑制期间彼此紧密接近，然后在受精卵中释放抑制时解离。通过超微结构扩展显微镜和结构化照明显微镜，对雌配子体细胞中的几种蛋白质共定位进行了交叉验证。此外，DOZI将其相互作用从雌性配子细胞中的NOT1-G交换到受精卵中的经典NOT1，为从DOZI释放mRNA的触发因素提供模型。最后,未富集的磷酸蛋白质组学揭示了合子中关键翻译控制蛋白的修饰。一起,这些数据为疟疾寄生虫使用的基本翻译控制机制提供了一个模型，以促进它们从哺乳动物宿主到蚊子媒介的有效传播。
