Mapping molecular diffusion in the plasma membrane by Multiple-Target Tracing (MTT)

Area of Science:

• Cell Biology
• Biophysics
• Molecular Imaging

Background:

• Cellular membranes are crucial for biological functions, but their molecular organization and dynamics are complex.
• Understanding these dynamics at the single-molecule level requires advanced imaging and analytical tools.

Purpose of the Study:

• To develop and validate advanced analytical tools for high-density Single-Particle Tracking (SPT) at the plasma membrane.
• To characterize the complex organization and dynamics of cellular membranes at the single-molecule level using Multiple-Target Tracing (MTT).

Main Methods:

• Developed Multiple-Target Tracing (MTT), an algorithmic and experimental approach for high-density Single-Particle Tracking (SPT).
• Optimized experimental setups and cell labeling for high labeling density to capture dynamic molecular snapshots.
• Implemented advanced image analysis techniques for peak detection, estimation, and trajectory reconnection, including deflation for hidden peaks.

Main Results:

• MTT enables accurate mapping of cell receptor localization, mobility, confinement, and interactions at the plasma membrane.
• Validated MTT performance using Monte-Carlo simulations, addressing limitations of labeling density and noise.
• Achieved nanometric accuracy for single-molecule tracking, suitable for nanoscopy applications.

Conclusions:

• MTT is a powerful and versatile tracking algorithm for analyzing molecular and cellular dynamics.
• The developed methods provide a comprehensive description of molecular processes at cellular membranes.
• MTT offers broad applicability across various scales, from molecules to cells and even animals.