Physiological function of paraspeckles: molecular mechanism of assembly and their nuclear distribution

旁斑（Paraspeckle，PS）是一种大的RNA-蛋白质复合物，由数十种RNA结合蛋白和NEAT 1组成，NEAT 1是核体组装所必需的非编码RNA。本研究旨在从PS的分子机制和核内分布两个方面阐明旁斑的生理功能，建立了组成型表达人NEAT 1 RNA的小鼠细胞系，使其在内源性“小鼠PS”的基础上形成外源性“人PS”。在这个异源系统中，“人PS”，一个人RNA和小鼠蛋白质的嵌合体，独立于“小鼠PS”组装。在施用蛋白酶体抑制剂后，人PS和小鼠PS都独立地增大。此外，我们观察到，Neat 1基因座（内源性）和NEAT 1基因座（外源性），编码单独的染色体重新定位附近，这表明PS可能是一个驱动力，以招募连接的基因座接近。

Paraspeckle (PS) is a large RNA-protein complex, consists of several ten RNA binding proteins and NEAT1, a noncoding RNA indispensable for the nuclear body assembly. The current study focuses on the molecular mechanism and nuclear distribution of PS to ellucidate paraspeckles' physiological function.We established a mouse cell constitutively expressing human NEAT1 RNA so that exogenous 'human PS' can be formed in addition to endogenous 'mouse PS'. In this heterologous system, 'human PS', a chimeric sturacutre of human RNA and mouse proteins was assembled independent of 'mouse PS'. Upon administration of a proteasome inhibitor, both humanPS and mouse PS enlarged independently. Furthermore, we observed that Neat1 loci (endogenous) and NEAT1 loci (exogenous), encoded separate chromosomes relocated vicinity, suggesting PS could be a driving force to recruit attached loci to close proximity.