FIGURE 5.

Effect of PI 3-kinase signaling and protein-tyrosine phosphatases on NoLS-mediated nucleolar accumulation of reporter proteins. A, treatment with LY294002 reduces the nucleolar accumulation of GFP-hsc70(225–297) in heat-stressed cells. Transiently transfected cells synthesizing GFP-hsc70(225–297) were incubated with DMSO or the PI 3-kinase inhibitor LY284002 (“Experimental Procedures”). B, PAO does not inhibit the nucleolar accumulation of GFP-hsc70(225–297) and GFP-hsc70(225–297aa). Transiently transfected HeLa cells were incubated with DMSO or PAO as described under “Experimental Procedures.” In A and B reporter proteins were detected in unstressed cells, after heat shock and upon 1 h recovery. Size bar is 20 μm. Quantification of nucleolar/nuclear pixel intensities was carried out as described for Fig. 3. DAPI, 4′,6-diamidino-2-phenylindole.