Feng Yonghui, Gao Wenyan, Wang Chengqi, Shi Shuangrui, Zhou Dan, Sun Lin, Zhu Liying, Cui Liwang, Cao Yaming, Zhu Xiaotong
Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, China.
Department of Laboratory Medicine, The First Hospital of China Medical University, Shenyang, Liaoning, China.
PLoS Pathog. 2025 Jul 7;21(7):e1013318. doi: 10.1371/journal.ppat.1013318. eCollection 2025 Jul.
Protein phosphorylation plays a critical role during the development of malaria parasites. Here, we performed a functional analysis of the Plasmodium berghei Ser/Thr protein phosphatase 6 (PbPP6), which is associated with the plasma membrane of macrogametes and ookinetes. Compared to wild-type P. berghei, the genetic disruption of pbpp6 (∆pbpp6) resulted in reduced asexual growth of the parasites and prolonged survival of infected mice. The ∆pbpp6 parasites showed impaired gametogenesis, particularly affecting male gametogenesis, which substantially decreased both ookinete formation and mosquito transmission. Transcriptomic analysis revealed an over 11-fold downregulation of nek3, a regulator of MAPK2 within the PKG-Ca2⁺ signaling cascade, foreshadowing pathway dysregulation that was further evidenced by significantly diminished intracellular cGMP levels, decreased cytosolic Ca2⁺ mobilization, and reduced DNA replication in activated Δpbpp6 gametocytes. Phosphoproteomic analysis detected increased phosphorylation at the Ser508 site of guanylyl cyclase alpha (GCα), indicating that PbPP6 regulates cGMP-PKG-Ca2+ signaling through modulation of GCα activity during gametogenesis. Additionally, we observed altered expression of messenger ribonucleoproteins in the Δpbpp6 parasites, which may affect the translational repression of stored mRNAs in female gametocytes and impact post-fertilization development in mosquitoes. Collectively, this study highlights the potential of targeting PP6 to disrupt malaria transmission.
蛋白质磷酸化在疟原虫发育过程中起着关键作用。在此，我们对伯氏疟原虫丝氨酸/苏氨酸蛋白磷酸酶6（PbPP6）进行了功能分析，该酶与大配子和动合子的质膜相关。与野生型伯氏疟原虫相比，pbpp6基因敲除（∆pbpp6）导致寄生虫无性生长减少，感染小鼠的存活时间延长。∆pbpp6寄生虫的配子发生受损，尤其影响雄配子发生，这大幅降低了动合子形成和蚊子传播。转录组分析显示nek3（PKG-Ca2⁺信号级联中MAPK2的调节因子）下调超过11倍，预示着信号通路失调，细胞内cGMP水平显著降低、胞质Ca2⁺动员减少以及活化的∆pbpp6配子细胞中DNA复制减少进一步证明了这一点。磷酸蛋白质组分析检测到鸟苷酸环化酶α（GCα）的Ser508位点磷酸化增加，表明PbPP6在配子发生过程中通过调节GCα活性来调控cGMP-PKG-Ca2⁺信号。此外，我们观察到∆pbpp6寄生虫中信使核糖核蛋白的表达发生改变，这可能影响雌配子细胞中储存mRNA的翻译抑制，并影响蚊子体内受精后的发育。总的来说，这项研究突出了靶向PP6破坏疟疾传播的潜力。
