Plasmodium falciparum Guanylyl Cyclase-Alpha and the Activity of Its Appended P4-ATPase Domain Are Essential for cGMP Synthesis and Blood-Stage Egress.
Plasmodium falciparum Guanylyl Cyclase-Alpha and the Activity of Its Appended P4-ATPase Domain Are Essential for cGMP Synthesis and Blood-Stage Egress.
复制标题
恶性疟原虫瓜尼氏菌环酶-Alpha及其附加的P4-ATPase结构域对于CGMP合成和血液阶段出口至关重要。
DOI：
10.1128/mbio.02694-20
复制
发表时间：
2021-01-26
期刊：
影响因子：
6.4
通讯作者：
Baker DA
中科院分区：
文献类型：
--
作者：
Nofal SD;Patel A;Blackman MJ;Flueck C;Baker DA
疟疾的临床表现是由于疟原虫寄生虫在红细胞内连续几轮复制而引起的。一旦成熟，子裂殖子从受感染的红细胞中释放出来，在一个被称为出口的严格调控的过程中侵入新细胞。鸟苷酸环化酶（GC）合成环GMP（cGMP），并且与环核苷酸磷酸二酯酶一起负责调节这种细胞内信使的水平，所述细胞内信使介导跨真核生物的无数功能。在疟疾寄生虫（疟原虫属），以及他们的apicomplexan和纤毛虫亲属，GC与一个独特的双功能配置的P4-ATP酶样结构域。P4-ATP酶通过将磷脂从外叶移位到内叶来产生膜双层脂质不对称性。在这里，我们研究恶性疟原虫鸟苷酸环化酶α（GCα）及其相关的P4-ATP酶模块的作用，表明缺乏环化酶和P4-ATP酶结构域的无性血液阶段的寄生虫无法从宿主红细胞中排出。GCα无效寄生虫不能合成cGMP或动员钙，这是cGMP依赖性蛋白激酶（PKG）驱动的外出要求。使用化学互补与cGMP类似物和点突变的一个关键的保守残基内的P4-ATP酶结构域，我们表明，P4-ATP酶活性的上游，并连接到cGMP合成。总的来说，我们的研究结果表明，GCα是PKG的一个关键调节因子，其相关的P4-ATP酶结构域在产生cGMP用于裂殖子排出中起主要作用。
The clinical manifestations of malaria arise due to successive rounds of replication of Plasmodium parasites within red blood cells. Once mature, daughter merozoites are released from infected erythrocytes to invade new cells in a tightly regulated process termed egress. Guanylyl cyclases (GCs) synthesize cyclic GMP (cGMP) and, together with cyclic nucleotide phosphodiesterases, are responsible for regulating levels of this intracellular messenger which mediates myriad functions across eukaryotes. In malaria parasites (Plasmodium spp), as well as their apicomplexan and ciliate relatives, GCs are associated with a P4-ATPase-like domain in a unique bifunctional configuration. P4-ATPases generate membrane bilayer lipid asymmetry by translocating phospholipids from the outer to the inner leaflet. Here, we investigate the role of Plasmodium falciparum guanylyl cyclase alpha (GCα) and its associated P4-ATPase module, showing that asexual blood-stage parasites lacking both the cyclase and P4-ATPase domains are unable to egress from host erythrocytes. GCα-null parasites cannot synthesize cGMP or mobilize calcium, a cGMP-dependent protein kinase (PKG)-driven requirement for egress. Using chemical complementation with a cGMP analogue and point mutagenesis of a crucial conserved residue within the P4-ATPase domain, we show that P4-ATPase activity is upstream of and linked to cGMP synthesis. Collectively, our results demonstrate that GCα is a critical regulator of PKG and that its associated P4-ATPase domain plays a primary role in generating cGMP for merozoite egress.