Fig. 7. Paxillin overexpression attenuates paxillin phosphorylation at Y118 during respreading on fibronectin in the CHO.K1 cell line. (A) CHO.K1 cells were transiently transfected with either full-length paxillin KM (FL pax KM; lane 1) or paxillin (pax ; lane 2). Total cell lysates were probed with paxillin 165 monoclonal antibody to paxillin to demonstrate equal expression levels. (B) CHO.K1 cells transfected with full-length paxillin KM (a,b) or paxillin (c,d) were respread on fibronectin-coated coverslips (10 µg/ml) for 120 minutes and processed for immunofluorescence microscopy. Phosphorylation of paxillin Y118 was visualized with a phospho-specific antibody (b,d). Transfected cells were visualized by cotransfection with pEGFPc1 vector (a,c). Overexpression of paxillin attenuates paxillin Y118 phosphorylation in focal adhesions during cell spreading on fibronectin. (C) Quantification of the suppression of paxillin phosphorylation at Y118. Results are expressed as the percentage of transfected cells showing a reduction in paxillin pY118 focal adhesion staining visualized by a phospho-specific antibody after respreading on fibronectin for 60, 120 and 240 minutes. Results are from three independent experiments with error bars representing the calculated s.d. Bar, 5 µm.