On the shape of migrating cells--a 'front-to-back' model

Area of Science:

• Cell Biology
• Biophysics

Background:

• Cell shape in stationary cells involves microfilaments and microtubules.
• Migrating cells also rely on these structures, but cell-substrate attachments are key.

Purpose of the Study:

• To propose a model where cell surface molecule distribution, specifically integrins, influences cell shape during migration.
• To explain the role of the endocytic cycle in supplying new attachments at the cell front.

Main Methods:

• Conceptual modeling based on existing knowledge of cell biology and molecular dynamics.
• Analysis of the proposed relationship between integrin cycling rate and cell morphology.

Main Results:

• Integrin cycling rate dictates distribution on the ventral cell surface, influencing cell shape.
• Slow cycling correlates with a flattened fibroblast-like shape; rapid cycling leads to a snail-like shape.
• The model explains membrane ruffling and the rearward movement of non-circulating molecules.

Conclusions:

• Cell surface integrin dynamics, regulated by the endocytic cycle, are a critical determinant of cell shape.
• This model provides a framework for understanding cell migration, morphology, and detachment mechanisms.