Wang Cheng-Xian, S Rong Yi-Kang, Cui Min
Hengyang Medical College, University of South China, Hengyang 421200, China.
Yi Chuan. 2023 Mar 20;45(3):221-228. doi: 10.16288/j.yczz.22-399.
Linear chromosomes of eukaryotes are protected by a DNA-protein-RNA structure called telomere. Remarkably and unlike those of most organisms studied, telomeric DNA is not composed of a group of short repeats, but three classes of retrotransposons at the chromosome ends. Telomeric transposons in on the other hand serves the function of elongating the host chromosomes yet prevent little harm to the host genome as their insertion sites are strictly limited to the telomere. How the host achieves such precise regulation is still unclear. The currently known genome-wide repression of transposon expression includes piRNA pathway and the heterochromatin pathway involving H3K9me3. Recent studies have found that telomere capping proteins are involved in the specific regulation of telomeric retrotransposons. In this review, we discuss the specific functions of telomere capping proteins in regulating telomeric transposons. By studying how the host interacts and regulates telomeric transposons, we hope to shed lights on universal principles in guiding their co-evolution.
真核生物的线性染色体由一种称为端粒的DNA-蛋白质-RNA结构保护。值得注意的是，与大多数已研究的生物体不同，端粒DNA不是由一组短重复序列组成，而是由染色体末端的三类逆转录转座子组成。另一方面，端粒转座子具有延长宿主染色体的功能，但由于其插入位点严格限于端粒，因此对宿主基因组几乎没有危害。宿主如何实现这种精确调控仍不清楚。目前已知的全基因组转座子表达抑制包括piRNA途径和涉及H3K9me3的异染色质途径。最近的研究发现，端粒封端蛋白参与端粒逆转录转座子的特异性调控。在这篇综述中，我们讨论了端粒封端蛋白在调节端粒转座子中的具体功能。通过研究宿主如何与端粒转座子相互作用并对其进行调控，我们希望揭示指导它们共同进化的普遍原则。
