Proximity Labeling Expansion Microscopy (PL-ExM) resolves structure of the interactome

Area of Science:

• Cellular Biology
• Molecular Imaging
• Biochemistry

Background:

• Understanding protein-protein interactions is crucial for cell function.
• Current methods struggle with precise 3D interactome mapping and super-resolution imaging.

Approach:

• Introduced Proximity Labeling Expansion Microscopy (PL-ExM), combining proximity labeling (PL) and expansion microscopy (ExM).
• PL-ExM spatially biotinylates interacting proteins and physically enlarges cells for enhanced resolution.
• Utilizes standard microscopy (confocal, Airyscan) and multiplexing with immunofluorescence staining.

Key Points:

• PL-ExM visualizes the 3D spatial layout of the protein interactome in cells.
• Enables multicolor imaging to show protein positioning within interaction networks.
• Serves as an assessment tool for proximity labeling technique efficiency and radius.

Conclusions:

• PL-ExM provides an accessible solution for 3D interactome structure mapping.
• Offers an accurate method to evaluate proximity labeling quality.
• Validates accuracy through proteomic results from PL mass spectrometry.