ATPase-Modulated Stress Granules Contain a Diverse Proteome and Substructure

Area of Science:

• Cellular Biology
• Neuroscience
• Biochemistry

Background:

• Stress granules are dynamic mRNA-protein complexes formed under cellular stress conditions.
• These granules are implicated in various neurodegenerative diseases, highlighting their pathological relevance.
• Understanding stress granule composition and regulation is crucial for disease research.

Purpose of the Study:

• To investigate the substructure and molecular composition of stress granules.
• To identify key protein components and their roles in stress granule assembly and dynamics.
• To elucidate the function of ATP-dependent machines in modulating stress granule behavior.

Main Methods:

• Utilized super-resolution microscopy to visualize stress granule substructures.
• Purified stress granule cores for subsequent proteomic analysis.
• Performed proteomic analysis to identify protein-protein interactions and components.

Main Results:

• Identified stable core substructures within stress granules.
• Revealed a dense network of protein-protein interactions within stress granule cores.
• Discovered ATP-dependent helicases and protein remodelers as conserved components.
• Demonstrated that ATP is essential for stress granule assembly and dynamics.
• Showed differential regulation by ATP-driven machines: CCT inhibits assembly, while MCM and RVB promote persistence.

Conclusions:

• Stress granules feature a stable core surrounded by a dynamic shell.
• Assembly, disassembly, and core-shell transitions are modulated by protein and RNA remodeling complexes.
• ATP-dependent machines play critical roles in regulating stress granule lifecycle.
• Findings provide insights into the molecular mechanisms underlying stress granule formation and its link to disease.