Emergent eukaryotic directional sensing via receptor degradation and diffusion

Area of Science:

• Cell biology
• Biophysics

Background:

• Eukaryotic cells detect extracellular ligand gradients for orientation and migration.
• Existing models rely on signaling circuits with distinct diffusion rates.

Purpose of the Study:

• Propose a new mechanism for directional sensing at the receptor level.
• Integrate receptor diffusion, basal activation, and degradation for robust sensing.

Main Methods:

• Developed a computational model integrating three receptor processes.
• Analyzed the interplay of diffusion, basal activity, and degradation.
• Investigated the impact on receptor activity and spatial distribution.

Main Results:

• The model demonstrates how diffusion, basal activity, and degradation synergize for directional sensing.
• Identified an optimal diffusion constant for maximal cell polarization.
• Showed receptors can encode relative ligand concentrations.

Conclusions:

• A diffusion-degradation synergy at the receptor level provides a robust directional sensing mechanism.
• This mechanism is broadly applicable across various receptor families.
• Receptor-level processes offer an alternative to complex signaling circuits for cellular orientation.