Chromatin remodeling complexes in the assembly of long noncoding RNA-dependent nuclear bodies.

Paraspeckles are subnuclear structures that assemble on nuclear paraspeckle assembly transcript 1 (NEAT1) long noncoding (lnc)RNA. Paraspeckle formation requires appropriate NEAT1 biogenesis and subsequent assembly with multiple prion-like domain (PLD) containing RNA-binding proteins. We found that SWI/SNF chromatin remodeling complexes function as paraspeckle components that interact with paraspeckle proteins (PSPs) and NEAT1. SWI/SNF complexes play an essential role in paraspeckle formation that does not require their ATP-dependent chromatin remodeling activity. Instead, SWI/SNF complexes facilitate organization of the PSP interaction network required for intact paraspeckle assembly. SWI/SNF complexes may collectively bind multiple PSPs to recruit them onto NEAT1. SWI/SNF complexes are also required for Sat III (Satellite III) lncRNA-dependent formation of nuclear stress bodies under heat shock conditions. Organization of the lncRNA-dependent omega speckle in Drosophila also depends on the chromatin remodeling complex. These findings raise the possibility that a common mechanism controls the formation of lncRNA-dependent nuclear body architecture.