Zhang Qingfeng, Scherf Artur
a Research Center for Translational Medicine; Key Laboratory of Arrhythmias of the Ministry of Education; Shanghai East Hospital; Tongji University School of Medicine ; Shanghai , China.
RNA Biol. 2015;12(6):586-9. doi: 10.1080/15476286.2015.1038013.
Malaria is caused by a unicellular protozoan pathogen of the genus Plasmodium. Although genes represent monocistronic units that are expressed in a life cycle stage-specific manner, post-transcriptional regulation via translational repression of mRNA has been observed in parasite stages that transition from the vertebrate host to the Anopheles vector. An interesting new type of post-transcriptional control was recently discovered in Plasmodium falciparum stages that infect human erythrocytes. A subgroup of genes that were thought to be transcriptionally silent are actually transcribed but degraded immediately by an RNase II that is recruited to these gene loci. This cryptic RNA is not detectable in steady-state RNA but has been detected using nuclear run-on techniques and in mutant RNase II parasites. Nascent RNA degradation controls virulence genes expressed in a monoallelic fashion and noncoding RNAs (ncRNAs), but also a number of housekeeping-like of genes. More studies on other life cycle stages may reveal the full extent of this type of gene regulation in malaria parasites. It is tempting to speculate that RNase II-mediated gene control may exist in other eukaryotic organisms.
疟疾由疟原虫属的单细胞原生动物病原体引起。尽管基因代表以生命周期阶段特异性方式表达的单顺反子单元，但在从脊椎动物宿主过渡到按蚊载体的寄生虫阶段，已观察到通过mRNA翻译抑制进行的转录后调控。最近在感染人类红细胞的恶性疟原虫阶段发现了一种有趣的新型转录后控制。一组被认为转录沉默的基因实际上被转录，但会立即被招募到这些基因位点的核糖核酸酶II降解。这种隐蔽RNA在稳态RNA中无法检测到，但已通过核延伸技术在突变核糖核酸酶II寄生虫中检测到。新生RNA降解控制以单等位基因方式表达的毒力基因和非编码RNA（ncRNA），以及一些类似管家基因的基因。对其他生命周期阶段的更多研究可能会揭示疟原虫中这种基因调控的全貌。很容易推测核糖核酸酶II介导的基因控制可能存在于其他真核生物中。
