Department of Emergency and Organ Transplantation (D.E.T.O.), Hematology and Stem Cell Transplantation Unit, University of Bari "Aldo Moro", 70124 Bari, Italy.
Department of Biology, Università degli Studi di Bari "Aldo Moro", 70125 Bari, Italy.
Genes (Basel). 2022 Feb 5;13(2):305. doi: 10.3390/genes13020305.
Mobility of eukaryotic transposable elements (TEs) are finely regulated to avoid an excessive mutational load caused by their movement. The transposition of retrotransposons is usually regulated through the interaction of host- and TE-encoded proteins, with non-coding regions (LTR and 5'-UTR) of the transposon. Examples of new potent cis-acting sequences, identified and characterized in the non-coding regions of retrotransposons, include the insulator of and Idefix, and the enhancer of of . Recently we have shown that in the 5'-UTR of the LTR-retrotransposon there is a sequence structured in tandem-repeat capable of operating as an insulator both in (S2R) and human cells (HEK293). Here, we test the hypothesis that tandem repeated 5'-UTR of a different LTR-retrotransposon could accommodate similar regulatory elements. The comparison of the 5'-UTR of some LTR-transposons allowed us to identify a shared motif of 13 bp, called Transposable Element Redundant Motif (TERM). Surprisingly, we demonstrated, by Yeast One-Hybrid assay, that TERM interacts with the . ribosomal protein RpL22. The RpL22 has additional Ala-, Lys- and Pro-rich sequences at the amino terminus, which resembles the carboxy-terminal portion of histone H1 and histone H5. For this reason, it has been hypothesized that RpL22 might have two functions, namely the role in organizing the ribosome, and a potential regulatory role involving DNA-binding similar to histone H1, which represses transcription in . In this paper, we show, by two independent sets of experiments, that DmRpL22 is able to directly and specifically bind DNA of .
真核转座元件 (TEs) 的移动受到精细调控，以避免其移动造成的过度突变负荷。逆转座子的转座通常通过宿主和 TE 编码蛋白与转座子的非编码区（LTR 和 5'-UTR）的相互作用来调节。在逆转座子的非编码区中，已经鉴定和表征了一些新的有效的顺式作用序列，包括绝缘子 和 Idefix，以及 的增强子 。最近，我们已经证明，在 LTR-逆转座子 的 5'-UTR 中，存在一个串联重复结构的序列，该序列能够作为绝缘子在 （S2R）和人类细胞（HEK293）中发挥作用。在这里，我们检验了假设，即不同 LTR-逆转座子的串联重复 5'-UTR 可以容纳类似的调节元件。比较一些 LTR-转座子的 5'-UTR，我们能够识别出一个 13 个碱基的共享基序，称为转座元件冗余基序 (TERM)。令人惊讶的是，我们通过酵母单杂交实验证明，TERM 与 相互作用。 核糖体蛋白 RpL22。RpL22 在氨基末端还有额外的 Ala、Lys 和 Pro 丰富序列，类似于组蛋白 H1 和组蛋白 H5 的羧基末端部分。因此，有人假设 RpL22 可能具有两种功能，即参与核糖体组织的功能，以及类似于组蛋白 H1 的潜在调节功能，组蛋白 H1 抑制 在 中的转录。在本文中，我们通过两组独立的实验表明，DmRpL22 能够直接和特异性地结合 的 DNA。
