Nudel and FAK as antagonizing strength modulators of nascent adhesions through paxillin

Area of Science:

• Cell biology
• Molecular biology
• Biophysics

Background:

• Cell migration is essential for development and disease, involving coordinated adhesion and detachment at the cell front and rear.
• Nascent adhesions at the leading edge stabilize protrusions, while focal adhesions at the trailing edge must be disrupted for retraction.

Purpose of the Study:

• To investigate the role of Nudel in regulating cell adhesion and migration.
• To elucidate the molecular mechanism by which Nudel interacts with paxillin and focal adhesion kinase (FAK) to control adhesion dynamics.

Main Methods:

• RNA interference (RNAi) to knock down Nudel expression in cells.
• Immunofluorescence microscopy to visualize the localization of Nudel, paxillin, and FAK.
• Biochemical assays to study the interaction between Nudel, paxillin, and FAK.
• Genetic manipulation to alter Nudel and FAK expression and localization.

Main Results:

• Nudel knockdown led to cell edge shrinkage, indicating impaired membrane protrusion adhesions.
• Nudel was found to bind and colocalize with paxillin at nascent adhesions.
• The Nudel-paxillin interaction was negatively regulated by FAK.
• Forced localization of Nudel to focal adhesions strengthened adhesivity, while specific FAK mutants caused cell edge shrinkage.

Conclusions:

• Nudel plays a critical role in reinforcing nascent adhesions, thereby facilitating cell migration.
• A novel mechanism involving the interplay of Nudel, paxillin, and FAK selectively strengthens nascent adhesions.
• This mechanism is essential for coordinating cell front protrusion stabilization and rear retraction during cell migration.