Institute of Cell Biology, University of Bern, Bern, Switzerland.
Multidisciplinary Center for Infectious Diseases, University of Bern, Bern, Switzerland.
Mol Microbiol. 2024 Jun;121(6):1095-1111. doi: 10.1111/mmi.15259. Epub 2024 Apr 4.
The protozoan parasite Plasmodium, the causative agent of malaria, undergoes an obligatory stage of intra-hepatic development before initiating a blood-stage infection. Productive invasion of hepatocytes involves the formation of a parasitophorous vacuole (PV) generated by the invagination of the host cell plasma membrane. Surrounded by the PV membrane (PVM), the parasite undergoes extensive replication. During intracellular development in the hepatocyte, the parasites provoke the Plasmodium-associated autophagy-related (PAAR) response. This is characterized by a long-lasting association of the autophagy marker protein, and ATG8 family member, LC3B with the PVM. LC3B localization at the PVM does not follow the canonical autophagy pathway since upstream events specific to canonical autophagy are dispensable. Here, we describe that LC3B localization at the PVM of Plasmodium parasites requires the V-ATPase and its interaction with ATG16L1. The WD40 domain of ATG16L1 is crucial for its recruitment to the PVM. Thus, we provide new mechanistic insight into the previously described PAAR response targeting Plasmodium liver stage parasites.
疟原虫是引起疟疾的原生动物寄生虫,在开始血液阶段感染之前,必须经历一个肝内发育阶段。疟原虫对肝细胞的有效入侵涉及由宿主细胞膜内陷形成的滋养体空泡(PV)。被 PV 膜(PVM)包围,寄生虫经历广泛的复制。在肝细胞内的细胞内发育过程中,寄生虫引发疟原虫相关自噬相关(PAAR)反应。其特征是自噬标记蛋白和 ATG8 家族成员 LC3B 与 PVM 的长时间关联。LC3B 定位于 PVM 并不遵循经典的自噬途径,因为经典自噬特有的上游事件是可有可无的。在这里,我们描述了 LC3B 定位于疟原虫寄生虫的 PVM 需要 V-ATPase 及其与 ATG16L1 的相互作用。ATG16L1 的 WD40 结构域对于其募集到 PVM 是至关重要的。因此,我们为之前描述的针对肝期疟原虫的 PAAR 反应提供了新的机制见解。