Intracellular evaluation of protein droplet-forming capability using self-assembling peptide tags

Area of Science:

• Biochemistry
• Cell Biology
• Molecular Biology

Background:

• Protein droplet formation is vital for cellular functions and disease.
• Current methods (in vitro) are limited by environmental sensitivity.
• Intracellular evaluation is challenging due to difficulties in inducing droplet formation.

Purpose of the Study:

• To develop a novel intracellular assay for evaluating protein droplet formation.
• To overcome limitations of in vitro studies and intracellular expression challenges.
• To identify proteins with droplet-forming capabilities within living cells.

Main Methods:

• Developed an intracellular droplet-forming assay using genetically fused YK peptide tags.
• YK peptide tags (7-15 residues) induce artificial protein oligomerization.
• Applied the assay to study protein droplet formation in living cells.

Main Results:

• Successfully demonstrated intracellular protein droplet formation using the YK tag system.
• Discovered that the Hsp70/Hsp90 organizing protein exhibits droplet-forming capability.
• Identified the specific region within the protein essential for droplet formation.

Conclusions:

• The YK peptide tag system provides a robust method for intracellular droplet formation assays.
• This assay facilitates the discovery of new protein droplet formers within cellular environments.
• The findings offer new perspectives on protein aggregation and cellular responses.