Long noncoding RNAs (lncRNAs) have long been collectively and passively defined as transcripts that do not encode proteins. However, extensive functional studies performed over the last decade have enabled the classification of lncRNAs into multiple categories according to their functions and/or molecular properties. Architectual RNAs (arcRNAs) are a group of lncRNAs that serve as architectural components of submicron-scale cellular bodies or nonmembranous organelles, which are composed of specific sets of proteins and nucleic acids involved in particular molecular processes. In this review, we focus on arcRNAs that function in the nucleus, which provide a structural basis for the formation of nuclear bodies, nonmembranous organelles in the cell nucleus. We will summarize the current list of arcRNAs and proteins associated with classic and more recently discovered nuclear bodies and discuss general rules that govern the formation of nuclear bodies, emphasizing weak multivalent interactions mediated by innately flexible biomolecules.

长期以来，长非编码 RNA (lncRNA) 一直被集体和被动地定义为不编码蛋白质的转录本。然而，在过去十年中进行的广泛的功能研究已经能够根据 lncRNA 的功能和/或分子特性将其分类为多个类别。结构 RNA (arcRNA) 是一组 lncRNA，它们充当亚微米级细胞体或非膜细胞器的结构成分，由参与特定分子过程的特定蛋白质和核酸组组成。在这篇综述中，我们专注于在细胞核中发挥作用的 arcRNA，它们为细胞核中核体、非膜细胞器的形成提供了结构基础。