The paper 'Interaction of N-acetyl-l-glutamate kinase with the PII signal transducer in the non-photosynthetic alga Polytomella parva: Co-evolution towards a hetero-oligomeric enzyme' by Selim et al. highlights how the study of a true taxonomic oddity, the heterotrophic unicellular alga P. parva, has been instrumental in uncovering the large potential for adaptive variation in the signaling complex of PII with the enzyme N-acetylglutamate kinase (NAGK). This complex modifies the regulatory properties of NAGK, allowing nitrogen stockpiling as arginine. In P. parva, a stable PII-NAGK complex is formed which lacks regulation by canonical PII effectors but which exhibits novel adaptive responses to nitrogen abundance mediated by glutamine, a neo-effector of PII proteins of photosynthetic eukaryotes.

中文翻译：

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PII蛋白对氮存储的调控：从分类异常值中吸取的教训。

Selim等人的论文“ N-乙酰基-1-谷氨酸激酶与PII信号传感器在非光合作用藻中的相互作用：共同进化为异寡聚酶”。强调了对真正的分类学奇异性（即异养单细胞藻类P. parva）的研究如何有助于发现PII信号复合物与N-乙酰谷氨酸激酶（NAGK）的适应性变异的巨大潜力。该复合物改变了NAGK的调节特性，允许氮作为精氨酸储存。在P. parva中，形成了稳定的PII-NAGK复合物，该复合物缺乏规范的PII效应子的调控，但对谷氨酰胺（光合作用的真核生物的PII蛋白的新效应子）介导的氮丰度表现出新的适应性反应。