Interplay between membrane protrusive activities and their adhesion strength regulates cell migration.

Area of Science:

• Cell Biology
• Biophysics
• Biochemistry

Background:

• Cell migration is crucial for development and disease, involving dynamic membrane protrusions like blebs and lamellipodia.
• The mechanisms governing the switching between these protrusion types and their impact on migration speed remain incompletely understood.

Purpose of the Study:

• To investigate the role of nonmuscle myosin II (NM II) in regulating the conversion between blebbing and lamellipodia.
• To determine how this protrusion switching affects cell migration speed across different cell types and substrates.
• To elucidate the relationship between cell adhesion, membrane protrusions, and migratory behavior.

Main Methods:

• Utilized various cell types including cancerous cells, mesenchymal stem cells, and T-lymphocytes.
• Manipulated nonmuscle myosin II (NM II) activity to induce blebbing to lamellipodia conversion (BLC) and lamellipodia to blebbing conversion (LBC).
• Assessed cell migration speed on different substrates (Collagen I, poly-L-lysine, uncoated) and after integrinβ1 knockdown.

Main Results:

• NM II-mediated BLC increased migration speed, while LBC decreased it in diverse cell types.
• Lamellipodia-possessing cells exhibited larger and more numerous focal adhesions than blebbing cells, indicating stronger adhesion.
• Cells on Collagen I showed faster BLC and migration compared to uncoated surfaces; integrinβ1 knockdown delayed protrusion conversion and reduced migration.

Conclusions:

• Cells dynamically regulate migration strategies through NM II-controlled protrusion switching.
• Integrin-dependent adhesion strength plays a significant role in modulating cell migration via membrane protrusion dynamics.