日本产业技术综合研究所日前发布公报说，该所科学家发现过去功能一直不明确的一种细胞核内RNA是形成核内RNA—蛋白复合体的核心，而后者在调节基因表达过程中发挥着重要作用。
公报说，2002年曾有科学家报告说，核内RNA—蛋白复合体内有2个能和RNA结合的控制蛋白，但科学家一直未能确认与这两个控制蛋白结合的RNA。而产业技术综合研究所的科学家在最新研究中发现，在核内RNA—蛋白复合体中分布着一种非编码的细胞核内RNA，名为MENε/b RNA，正是它和两个控制蛋白产生结合。
科学家使这种RNA分解，发现核内RNA—蛋白复合体也随之消失。他们由此得出结论，这种非编码的细胞核内RNA是核内RNA—蛋白复合体形成的核心物质。
公报说，随着基因组研究工作的推进，科学家在人类和小鼠的细胞核内找到了数量众多且功能不明确的RNA。这些RNA引起了人们广泛关注。揭示这些RNA的功能将有助于新药的研发工作。（生物谷Bioon.com）
生物谷推荐原始出处：
PNAS Published online before print February 2, 2009, doi: 10.1073/pnas.0807899106
MENε/β noncoding RNAs are essential for structural integrity of nuclear paraspeckles
Yasnory T. F. Sasakia, Takashi Ideuea,b, Miho Sanoa,b, Toutai Mituyamac and Tetsuro Hirosea,1
aFunctional RNomics Team, Biomedicinal Information Research Center,
cRNA Informatics Team, Computational Biology Research Center, and
bJapan Biological Informatics Consortium, National Institute of Advanced Industrial Science and Technology, 2-42 Aomi, Koutou, Tokyo 135-0064, Japan
Abstract
Recent transcriptome analyses have shown that thousands of noncoding RNAs (ncRNAs) are transcribed from mammalian genomes. Although the number of functionally annotated ncRNAs is still limited, they are known to be frequently retained in the nucleus, where they coordinate regulatory networks of gene expression. Some subnuclear organelles or nuclear bodies include RNA species whose identity and structural roles are largely unknown. We identified 2 abundant overlapping ncRNAs, MENε and MENβ (MENε/β), which are transcribed from the corresponding site in the multiple endocrine neoplasia (MEN) I locus and which localize to nuclear paraspeckles. This finding raises the intriguing possibility that MENε/β are involved in paraspeckle organization, because paraspeckles are, reportedly, RNase-sensitive structures. Successful removal of MENε/β by a refined knockdown method resulted in paraspeckle disintegration. Furthermore, the reassembly of paraspeckles disassembled by transcriptional arrest appeared to be unsuccessful in the absence of MENε/β. RNA interference and immunoprecipitation further revealed that the paraspeckle proteins p54/nrb and PSF selectively associate with and stabilize the longer MENβ, thereby contributing to the organization of the paraspeckle structure. The paraspeckle protein PSP1 is not directly involved in either MENε/β stabilization or paraspeckle organization. We postulate a model for nuclear paraspeckle body organization where specific ncRNAs and RNA-binding proteins cooperate to maintain and, presumably, establish the structure.
