Compositional adaptability in NPM1-SURF6 scaffolding networks enabled by dynamic switching of phase separation mechanisms

• DOI: 10.1038/s41467-018-07530-1
• Publication Date: 2018-11-23T14:43:04Z
• Authors: Mylene C. Ferrolino; Diana M. Mitrea; J. Robert Michael; Richard W. Kriwacki
• Keywords: Nucleophosmin; ribosome biogenesis; NPM1; Ribosomal protein

The nucleolus, the site for ribosome biogenesis contains hundreds of proteins and several types RNA. functions many non-ribosomal nucleolar are poorly understood, including Surfeit locus protein 6 (SURF6), an essential disordered with roles in cell proliferation. SURF6 co-localizes Nucleophosmin (NPM1), a highly abundant that mediates liquid-like features granular component region nucleolus through phase separation. Here, we show electrostatically-driven interactions between regions NPM1 drive liquid-liquid We demonstrate co-existing heterotypic (NPM1-SURF6) homotypic (NPM1-NPM1) scaffolding within NPM1-SURF6 liquid-phase droplets dynamically seamlessly interconvert response to variations molecular crowding concentrations. propose mechanism wherein NPM1-dependent scaffolds modulated by active rearrangements interaction networks can possibly contribute directionality ribosomal nucleolus.