A working model for condensate RNA-binding proteins as matchmakers for protein complex assembly.

Area of Science:

• Cell Biology
• Molecular Biology
• Biochemistry

Background:

• Cellular processes rely on protein complexes, but the assembly of low-abundance complexes remains poorly understood.
• The crowded cellular environment poses challenges for protein subunits to find each other.

Purpose of the Study:

• To propose a model explaining how subunits of lowly expressed protein complexes assemble.
• To elucidate the role of RNA-binding proteins and cytoplasmic condensates in protein complex formation.

Main Methods:

• The study describes a working model based on existing biological principles.
• It focuses on the proposed interactions between RNA-binding proteins, RNA, and protein targets within cytoplasmic condensates.

Main Results:

• RNA-binding proteins in cytoplasmic condensates act as scaffolds and matchmakers.
• They recruit both bound proteins and newly translated proteins to promote complex assembly.
• Multivalent RNA-binding proteins transiently entrap subunits, increasing assembly efficiency.

Conclusions:

• Lowly expressed protein complex subunits colocalize in the cytoplasm by integrating mRNA and protein information.
• Cytoplasmic condensates, mediated by multivalent RNA-binding proteins, enhance protein complex assembly through transient entrapment.