From the archives: Nuclear import of pathogenic noncoding RNAs, ubiquitination and the control of heading date in rice, and the use of ribozymes to modulate gene expression

Abstract

RNAs are commonly considered to either remain inside the nucleus or be transported out of it after synthesis. However, functional RNAs often move from the cytoplasm to the nucleus. For example, viroids are single-stranded circular noncoding RNAs that can cause diseases by traveling into the nucleus. Although RNA export from the nucleus has been well studied, the RNA nuclear import machinery and the underlying molecular mechanism are not well understood. Ma et al. (2022) elucidated how potato spindle tuber viroid (PSTVd) RNA is recognized for nuclear import and which cellular proteins mediate this process. They identified a conserved RNA structure known as the C-loop in PSTVd, which serves as a signal for nuclear import.