Fig. 2. PTP1B DA puncta co-localize with proteins associated with cell-matrix adhesion sites and the cytoskeleton. PTP1B null cells stably expressing PTP1B DA (A,B) or PTP1B null cells transiently transfected with GFP-PTP1B DA (C,D), or GFP-PTP1B DA/QA (E) were plated on fibronectin-coated coverslips and examined 24 hours later. (A) Cells double-stained with a polyclonal anti-PTP1B and a monoclonal (hVIN-1) anti-vinculin followed by secondary antibodies conjugated with Alexa Fluor 488 and Alexa Fluor 568, respectively. Shown is one confocal section (0.5 µm) at the cell-matrix interface. (B) Cells stained with anti-PTP1B and anti-paxillin followed by secondary antibodies conjugated with Alexa Fluor 568 and Alexa Fluor 488, respectively. (C) Cells stained with rhodamine-phalloidin. Dotted line indicates the boundary of the cell. (D) Cells stained with anti-tubulin (DM1 A), followed by a secondary antibody conjugated with Alexa Fluor 568. (E) Cells stained with anti-PTP1B followed by a secondary antibody conjugated with Alexa Fluor 568. In all cases, arrows indicate punctate structures. Note that punctate structures localize at the distal tips of vinculin and paxillin (A,B,E), as well as at the tips of actin (C) and microtubules (D). Bars, (A,B,E) 20 µm; (C,D) 10 µm.