Tatosyan K A, Koval A P, Kramerov D A
Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, 119991 Russia.
Mol Biol (Mosk). 2018 Nov-Dec;52(6):1038-1044. doi: 10.1134/S0026898418060162.
The functions of small noncoding RNAs 4.5SH and 4.5SI found in murine-like rodents are unclear. These RNAs synthesized by RNA polymerase III are widely expressed in rodent organs and tissues. Using crosslinking assays, it was shown that approximately half of all 4.5SI and 4.5SH RNA molecules were bound to proteins provisionally called X and Y, respectively. An immunoprecipitation experiment showed that both these RNAs were associated with the La protein, which did not crosslink to them. The termini of 4.5SI RNA form a long duplex stem, which makes the molecule more stable than 4.5SH RNA. Modification of the 5'-end sequence destructing the stem of 4.5SI RNA altered its protein-binding properties; after the 3'-end sequence was changed to the complementary, both the stem structure and the RNA binding to protein X were restored. Presumably, this protein plays a role in increasing the half-life of 4.5SI RNA.
在鼠类啮齿动物中发现的小非编码RNA 4.5SH和4.5SI的功能尚不清楚。这些由RNA聚合酶III合成的RNA在啮齿动物的器官和组织中广泛表达。通过交联试验表明，所有4.5SI和4.5SH RNA分子中约有一半分别与暂时称为X和Y的蛋白质结合。免疫沉淀实验表明，这两种RNA都与La蛋白相关，而La蛋白并未与它们交联。4.5SI RNA的末端形成一个长的双链茎，这使得该分子比4.5SH RNA更稳定。破坏4.5SI RNA茎的5'端序列的修饰改变了其蛋白质结合特性；将3'端序列改为互补序列后，茎结构和RNA与蛋白质X的结合均得以恢复。据推测，这种蛋白质在延长4.5SI RNA的半衰期方面发挥作用。
