Making order from disorder in the nucleolus

The nucleolus and Cajal bodies in the eukaryotic nucleus serve as dynamic hubs for an intricate network of protein-protein and protein-RNA interactions that drive the macromolecular assembly of large and small ribonucleoproteins. However, the mechanisms by which these membrane-less organelles organize their components to fulfill these functions remain largely unknown. In this issue of Genes & Development, Meznad and colleagues (doi:10.1101/gad.353180.125) reveal that the nucleolar and Cajal body protein Nopp140 engages its protein partners through interactions mediated by intrinsically disordered regions. Together, they serve to build the web of interactions required for the tripartite organization of the nucleolus.