Messenger RNA

Stress granule

Physics

Nuclear pore

Translation (biology)

Enzyme

Nucleolus

Nucleus

Biology

Gene

Cajal body

Biophysics

Compartmentalization (fire protection)

Cytoplasm

Chemical physics

Cell nucleus

Phase (matter)

RNA splicing

Quantum mechanics

Cell biology

Biochemistry

Journal of Cell Science

ABSTRACT Cells organize membrane-less internal compartments through a process called liquid–liquid phase separation (LLPS) to create chemically distinct compartments, referred to as condensates, which emerge from interactions among biological macromolecules. These condensates include various cytoplasmic structures such as P-granules and stress granules. However, an even wider array of condensates subcompartmentalize the cell nucleus, forming liquid-like structures that range from nucleoli and Cajal bodies to nuclear speckles and gems. Phase separation provides a biophysical assembly mechanism underlying this non-covalent form of fluid compartmentalization and functionalization. In this Cell Science at a Glance article and the accompanying poster, we term these phase-separated liquids that organize the nucleus the liquid nucleome; we discuss examples of biological phase transitions in the nucleus, how the cell utilizes biophysical aspects of phase separation to form and regulate condensates, and suggest interpretations for the role of phase separation in nuclear organization and function.

The liquid nucleome – phase transitions in the nucleus at a glance