Abstract
Networks of actin filaments, controlled by the Arp2/3 complex, drive membrane protrusion during cell migration. How integrins
signal to the Arp2/3 complex is not well understood. Here, we show that focal adhesion kinase (FAK) and the Arp2/3 complex
associate and colocalize at transient structures formed early after adhesion. Nascent lamellipodia, which originate at these
structures, do not form in FAK-deficient cells, or in cells in which FAK mutants cannot be autophosphorylated after integrin
engagement. The FERM domain of FAK binds directly to Arp3 and can enhance Arp2/3-dependent actin polymerization.
Critically, Arp2/3 is not bound when FAK is phosphorylated on Tyr 397. Interfering peptides and FERM-domain point mutants
show that FAK binding to Arp2/3 controls protrusive lamellipodia formation and cell spreading. This establishes a new function
for the FAK FERM domain in forming a phosphorylation-regulated complex with Arp2/3, linking integrin signalling directly with
the actin polymerization machinery.
Original language | English |
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Pages (from-to) | 1046 - 1056 |
Number of pages | 11 |
Journal | Nature Cell Biology |
Volume | 9 |
Issue number | 9 |
DOIs | |
Publication status | Published - Sept 2007 |