Aptamer-Mediated Proximity Labeling (ApMPL) for Spatially Resolved Deciphering of Cell Membrane Protein Interactomes.

Area of Science:

• Biochemistry
• Molecular Biology
• Cell Biology

Background:

• Cell membrane protein-protein interactions (PPIs) are vital for cellular homeostasis.
• Understanding membrane PPIs is key for disease mechanism insights and therapeutic target identification.
• Existing proximity labeling methods have limitations in complexity, safety, labeling radius control, and membrane protein accessibility.

Purpose of the Study:

• To develop an innovative aptamer-mediated proximity labeling (ApMPL) system.
• To enable radius-tunable labeling and capture of membrane protein interactomes.
• To overcome limitations of current proximity labeling technologies for membrane proteins.

Main Methods:

• Development of an ApMPL probe combining aptamer targeting, DNA spacers for adjustable radii, and bioorthogonal capture.
• Utilizing DNA nanotechnology for precise spatial control in mapping PPIs.
• Testing the ApMPL system on tumor-associated membrane proteins nucleolin, PTK7, and FGFR2.

Main Results:

• The ApMPL system demonstrated radius-tunable labeling and capture of membrane protein interactomes.
• Accurate spatial control was achieved in mapping membrane PPIs using nucleolin as a model.
• The system successfully captured differential nucleolin interactors between normal and apoptotic states.
• Versatility confirmed on PTK7 and FGFR2 proteins.

Conclusions:

• The ApMPL platform offers a novel, programmable approach for studying membrane PPIs.
• This technology enables precise spatial control and capture of interactomes.
• ApMPL is valuable for discovering membrane protein interactions, elucidating signaling networks, and identifying therapeutic targets.