Figure 1

Paxillin expression, phosphorylation and localization in 4-HC-treated cells. A. Representative immunoblot showing decreased levels of both paxillin isoforms in 4-HC-treated cells. As loading control, β-tubulin was detected in the same membrane. Quantification of paxillin expression (graph) was performed by densitometric analysis from 4 independent experiments. On each experiment, the value of the band corresponding to α-paxillin in control lane was arbitrarily set to 1. Paxillin/tubulin ratios (mean ± SE) were reduced in 4-HC-treated cells (open bars in graph) when compared with control cells (closed bars). B. Semiquantitative RT-PCR using primers for pan-paxillin (upper panel), β-paxillin (middle panel) or GAPDH (lower panel). One representative experiment from 3 is shown. C. Representative photomicrographs from immunofluorescences performed with anti-paxillin antibody. In control cells (left), paxillin was located in focal adhesions around the cell periphery; this pattern was modified by the treatment with 4-HC (right). Scale bar = 20 μm. D. The level of phosphotyr¹¹⁸-paxillin (pY118) was also diminished by 4-HC. We were only able to detect phosphorylation in the α isofom of paxillin. One representative experiment from 3 is shown.