Figure 3.

NG2 co-localization with α-1 integin. (a and b) NG2-transfected U251 glioma cells were treated for three hours with PMA, fixed with 4% paraformaldehyde, and double stained with antibodies against NG2 (a) and β-1 integrin (b). NG2 and the integrin are co-localized to broad lamellipodia on the leading edges of cells. (c and d) Quiescent NG2-transfected U251 cells were fixed with 4% paraformaldehyde and double-stained with antibodies against NG2 and β-1 integrin (d). NG2 and the integrin are co-localized to arrays of microprotrusions on the apical cell surface. (e) Quiescent NG2-transfected U251 cells were stained live at 4°C with NG2 antibody to confirm the cell surface (as opposed to cytoplasmic) location of apical microprotrusions. (f) Immunogold electron microscopy of NG2 labeling reveals that NG2 (black puncta) is heavily localized to microprotrusions from the apical cell surface.