Fig. 4. Effects of calpain inhibition on focal adhesion targeting of microtubules in cells plated on fibronectin. CAR fibroblasts were stained for paxillin and tubulin. Cells were pretreated with nocodozole and plated on 50 µg/ml fibronectin for 2 hours before nocodozole wash-out. Cells were then allowed to recover in the presence (B) or absence (A) of ALLN and stained for actin (left panel) or paxillin and tubulin (middle and right panel). Top images were fixed 10 minutes after nocodozole wash-out and bottom images were fixed 1.5 hours after washout. Microtubule targeting occurs in the presence (B) or absence (A) of ALLN. Bars, 10 µm.