Division of Molecular Microbiology and Immunology, CSIR-Central Drug Research Institute, Lucknow 226031, India.
Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India.
ACS Infect Dis. 2024 Jun 14;10(6):1904-1913. doi: 10.1021/acsinfecdis.4c00240. Epub 2024 May 16.
Malaria parasites have a complex life cycle and undergo replication and population expansion within vertebrate hosts and mosquito vectors. These developmental transitions rely on changes in gene expression and chromatin reorganization that result in the activation and silencing of stage-specific genes. The ApiAp2 family of DNA-binding proteins plays an important role in regulating gene expression in malaria parasites. Here, we characterized the ApiAp2 protein in , which we termed Ap2-D. In silico analysis revealed that Ap2-D has three beta-sheets followed by a helix at the C-terminus for DNA binding. Using gene tagging with 3XHA-mCherry, we found that Ap2-D is expressed in blood stages and is present in the parasite cytoplasm and nucleus. Surprisingly, our gene deletion study revealed a completely dispensable role for Ap2-D in the entirety of the life cycle. KO parasites were found to grow in the blood successfully and progress through the mosquito midgut and salivary glands. Sporozoites isolated from mosquito salivary glands were infective for hepatocytes and achieved similar patency as WT in mice. We emphasize the importance of genetic validation of antimalarial drug targets before progressing them to drug discovery.
疟原虫具有复杂的生命周期，在脊椎动物宿主和蚊子媒介中经历复制和种群扩张。这些发育转变依赖于基因表达和染色质重排的变化，导致阶段特异性基因的激活和沉默。DNA 结合蛋白的 ApiAp2 家族在调节疟原虫基因表达中发挥重要作用。在这里，我们对 中的 ApiAp2 蛋白进行了表征，我们称之为 Ap2-D。计算机分析显示，Ap2-D 在 C 末端具有三个β-折叠，随后是一个螺旋，用于 DNA 结合。使用 3XHA-mCherry 基因标记，我们发现 Ap2-D 在 血阶段表达，并存在于寄生虫细胞质和核内。令人惊讶的是，我们的基因缺失研究表明 Ap2-D 在整个 生命周期中完全可有可无。Ap2-D KO 寄生虫在血液中成功生长，并通过蚊子中肠和唾液腺发育。从蚊子唾液腺中分离出的子孢子对肝细胞具有感染力，在小鼠中的通透性与 WT 相似。我们强调在将抗疟药物靶点推进药物发现之前，对其进行遗传验证的重要性。
