SUMO: Glue or Solvent for Phase-Separated Ribonucleoprotein Complexes and Molecular Condensates?

Area of Science:

• Cell Biology
• Biochemistry
• Molecular Biology

Background:

• Cellular processes are spatially organized within membranous or membrane-less organelles (MLOs), also known as molecular condensates.
• MLOs, such as the nucleolus and stress granules, are vital for compartmentalizing biochemical pathways and are often enriched in intrinsically disordered proteins and RNA.
• The formation, disassembly, and composition of MLOs are sensitive to proteotoxic stress, and alterations in MLO dynamics are linked to cell dysfunction and disease.

Purpose of the Study:

• To review the current understanding of the SUMO system's role in regulating the dynamics of MLOs.
• To explore how SUMOylation influences MLO assembly and disassembly under normal and pathological conditions.

Main Methods:

• Literature review of studies on MLOs, proteostasis, and the SUMO system.
• Analysis of evidence linking post-translational modifications, particularly SUMOylation, to MLO dynamics.

Main Results:

• MLOs are key structures for cellular organization and proteostasis.
• The ubiquitin-like SUMO system plays a critical role in regulating the assembly and disassembly of MLOs.
• SUMOylation is increasingly recognized as a key post-translational modification controlling MLO dynamics.

Conclusions:

• The SUMO system is a critical regulator of MLO dynamics.
• Understanding SUMO's function in MLOs is essential for comprehending cell function and disease pathogenesis.
• Targeting SUMOylation pathways may offer therapeutic strategies for diseases associated with MLO dysfunction.