TLS (FUS) binds RNA in vivo and engages in nucleo-cytoplasmic shuttling.
TLS (FUS) binds RNA in vivo and engages in nucleo-cytoplasmic shuttling.
复制标题
DOI：
--
复制
发表时间：
1997-08
影响因子：
4
通讯作者：
Helene Zinszner;John Sok;D. Immanuel;Yin Yin-Yin;D. Ron
中科院分区：
文献类型：
--
作者：
Helene Zinszner;John Sok;D. Immanuel;Yin Yin-Yin;D. Ron
TLS是脂肪肉瘤（TLS）中一种常见易位基因的产物，是一类新发现的核蛋白的原型，其包含一个具有独特RNA识别基序（RRM）的c端结构域，由Arg-Gly-Gly （RGG）重复序列包围。其独特的N端是人类肉瘤和白血病中许多融合癌蛋白的重要转化域。在这项研究中，我们使用体内紫外交联程序来探测TLS与RNA的相互作用。在体内发现TLS与RNA结合，用转录抑制剂处理细胞后，TLS与RNA的关联迅速减弱。这表明被TLS结合的物种更替很快。令人惊讶的是，RRM在体内被发现是TLS与RNA结合所不需要的，这表明在任何时候，细胞中TLS与RNA之间的大多数相互作用都不是序列特异性的。对人与小鼠或爪蟾细胞之间形成的特异异核体的分析表明，TLS参与核细胞质的快速穿梭，当注入HeLa细胞的细胞质时，抗TLS抗体能够捕获TLS，这一发现得到了证实。细胞分离实验表明，TLS在细胞核和细胞质中都与RNA结合，支持TLS作为RNA的异质核糖核蛋白（hnRNP）样伴侣的假设。这些发现是在作用的背景下讨论改变形式的TLS在细胞转化中发挥作用。
TLS, the product of a gene commonly translocated in liposarcomas (TLS), is prototypical of a newly identified class of nuclear proteins that contain a C-terminal domain with a distinct RNA recognition motif (RRM) surrounded by Arg-Gly-Gly (RGG) repeats. Its unique N terminus serves as an essential transforming domain for a number of fusion oncoproteins in human sarcomas and leukemias. In this study we use an in vivo UV crosslinking procedure to probe the interactions of TLS with RNA. TLS is found to bind RNA in vivo and the association of TLS with RNA is rapidly diminished by treating cells with transcriptional inhibitors. This suggests that the species bound by TLS turns over rapidly. Surprisingly, the RRM was found to be dispensable for RNA binding by TLS in vivo, suggesting that at any one time most of the interactions between TLS and RNA in the cell are not sequence specific. Analysis of inter specific heterokaryons formed between human and mouse or Xenopus cells revealed that TLS engages in rapid nucleocytoplasmic shuttling, a finding confirmed by the ability of anti-TLS antibodies to trap TLS when injected into the cytoplasm of HeLa cells. Cellular fractionation experiments suggest that TLS binds to RNA in both the nucleus and cytoplasm and support the hypothesis that TLS functions as a heterogeneous ribonuclear protein (hnRNP)-like chaperone of RNA. These findings are discussed in the context of the role altered forms of TLS play in cellular transformation.