Apicomplexan parasites harbor chimeric proteins embodying P4-type ATPase and guanylate cyclase domains. Such proteins – serving as the actuator of cGMP signaling in this group of important pathogens – are indeed unusual in terms of their sheer size, modus operandi, and evolutionary repurposing. Much like the mythological Sphinx, a human-lion chimeric creature that posed challenging riddles, the P4-type ATPase–guanylate cyclase chimeras present both structural and functional conundrums. Here we review the function, topology, mechanism, and intramolecular coordination of the alveolate-specific chimeras in apicomplexan parasites. The steep technological challenge to understand these molecular Sphinxes will surely keep many interdisciplinary researchers busy in the next decades.

蚜虫寄生虫带有嵌合蛋白，其中包含P4型ATPase和鸟苷酸环化酶结构域。这类蛋白质-在这组重要病原体中充当cGMP信号的启动子-就其绝对大小，操作方式和进化目的而言确实不寻常。与神话般的狮身人面像一样，人类狮子的嵌合生物提出了具有挑战性的谜语，P4型ATPase-鸟苷酸环化酶嵌合体同时存在结构和功能难题。在这里，我们审查了apicomplexan寄生虫中的特定的肺泡嵌合体的功能，拓扑结构，机理和分子内协调。理解这些分子狮身人面像所面临的严峻技术挑战必将在未来几十年中使许多跨学科的研究人员忙碌。