Fig. 10.

Filamin A regulates β1 integrin expression and activation via its association with vimentin and PKC. A: schematic diagram illustrating association between filamin A and vimentin. Filamin-vimentin binding is constitutive and only moderately adhesion dependent. B: filamin is a potential scaffold for signaling and adhesion molecules such as PKC and β1 integrin. C: schematic diagram of proposed model for filamin-vimentin-PKC interactions. 1) Filamin binds PKC and vimentin, leading to vimentin phosphorylation at serines-6, -38, and -50. 2) Phosphorylation and subsequent reorganization of vimentin allows recycling of β1 integrins to the cell surface. 3) Cell surface β1 integrin activation is upstream of actin polymerization, the formation of cell extensions and cell spreading (step 4).