Figure 8.
Sam68 promotes MBP expression in an SFK-dependent but not PI3K-dependent manner. A, The scheme describes the cultivation protocol used for knockdown or overexpression of Sam68. OPCs were expanded in the OPC expansion phase (PDGF+FGF-2) and differentiated after transfection by adding T3 + 1%FCS. Pharmacological inhibitors were applied when indicated. B, Immunoblotting shows a prominent decrease in Sam68 and also of MBP levels after transfection with Sam68 siRNA. C, Immunostaining for MBP showing that, in contrast to control cells, many transfected cells (Venus-positive) do not coexpress MBP after Sam68 knockdown. The quantitative numbers are given in the text. D, Immunocytochemical staining for Sam68 and MBP reveals that after transfection of a Sam68 full-length plasmid, most of the Sam68high-expressing cells coexpress MBP (arrowheads). The quantitative numbers are given in the text. E, Immunoblotting showing increased expression levels of MBP upon transfection with a Sam68 full-length plasmid. F, G, Immunoblottings showing that PP2-dependent reduction (F) but not LY294002-dependent reduction (G) of MBP expression is overcome by overexpressing Sam68. Scale bars, 100 μm.