Multi-omics analysis using antibody-based in situ biotinylation technique suggests the mechanism of Cajal body formation

Membrane-less subcellular compartments play important roles in various cellular functions. Although techniques exist to identify components of cellular bodies, a comprehensive method for analyzing both static and dynamic states has not been established. Here, we apply an antibody-based in situ biotinylation proximity-labeling technique to identify components of static and dynamic nuclear bodies. Using this approach, we comprehensively identify DNA, RNA, and protein components of Cajal bodies (CBs) and then clarify their interactome. By inhibiting transcription, we capture dynamic changes in CBs. Our analysis reveals that nascent small nuclear RNAs (snRNAs) transcribed in CBs contribute to CB formation by assembling RNA-binding proteins, including frontotemporal dementia-related proteins, RNA-binding motif proteins, and heterogeneous nuclear ribonucleoproteins. [Display omitted] •In situ biotinylation technique is applied to identify the components of nuclear bodies•The analysis clarifies the interactome of DNA, RNA, and protein in Cajal bodies (CBs)•Nascent snRNAs in CBs contribute to CB formation by assembling RNA-binding proteins Noguchi et al. apply an antibody-based in situ biotinylation proximity-labeling technique and succeed in identifying the components of nuclear bodies, including nucleolus, γH2AX foci, and Cajal bodies (CBs). The analysis reveals that nascent snRNAs transcribed in CBs play a role in CB formation through assembling RNA-binding proteins.