Figure 1.

Regulation of α7 receptor tyrosine phosphorylation by genistein and pervanadate. SH-α7 cells were treated for 10 min with genistein, followed by addition of 50 μm pervanadate for 20 min in the presence of genistein. In controls, these compounds were omitted or the vehicle alone (0.25% DMSO, +v) was added. Cells were lysed and α7 receptors were precipitated using biotinylated α-BT and streptavidin-agarose (Tox-P). As a control, an excess of free α-BT was added before precipitation (+T). Immunoblotting using phosphotyrosine-specific antibodies, followed by α7 reprobing, reveals that pervanadate causes strong α7 receptor phosphorylation, which is greatly reduced by genistein. Shorter exposure times and side-by-side alignment of blots confirmed precise overlap between phosphotyrosine and α7 signals (data not shown).