Fig. 7. Focal adhesion components are recruited at late stages in the formation processes. (A) Video frames showing a cell co-transfected with DsRed SM22 and YFP-vinculin. Vinculin is absent from stress fiber-associated podosomes after 6 minutes (long arrows) but accumulates in late podosomes (32 minutes, short arrows). Right panels: Vinculin; left panels: Merged images. (B) Transient accumulation of vinculin in late podosomes in YFP-vinculin transfected cells. Images are a merger of YFP and phase contrast images. Time of PDBu treatment is indicated in minutes. (C) A GFP-zyxin transfected cell microinjected with TAMRA vinculin prior to PDBu treatment (50 minutes). The merged image (upper left panel) shows that vinculin and zyxin co-localize in both adhesions and late podosomes (arrow), which are identified by phase contrast microscopy as dense structures. (D) Late podosomes in DsRed zyxin and GFP--actinin co-transfected cells. At later stages of PDBu stimulation zyxin localizes to phase-dense podosomes together with -actinin (arrow).