Fig. 5.

L1 wild-type and mutant constructs are expressed at equivalent levels in B35 neuroblastoma cell lines. The following stable cell lines of rat B35 neuroblastoma cells were processed for L1 indirect immunofluorescence and Western blot analysis as described in Materials and Methods: untransfected parental B35 cells (—,E); B35 cells expressing wild-type L1 (WT+RSLE, A, A′, E); or the L1 point mutants L1+S1194L (S1194L, B, B′, E), L1+S1224L (S1224L, C, C′, E), or L1+Y1229H (Y1229H, D, D′, E). A–D′, B35 cells were fixed and processed for indirect immunofluorescence staining and confocal microscopy analysis to determine relative levels of L1 expression at the cell surface. The left columnpresents confocal microscopy images of immunostained L1 (L1, A–D) and the right column presents differential interference contrast images (DIC, A′–D′). Each of thehorizontal panels (A–A′ throughD–D′) presents the same field of cells. Scale bar, 10 μm. E, B35 cells were lysed, and the aliquots were analyzed by SDS-PAGE and Western blotting with monoclonal antibodies that are specific for L1 to determine relative levels of L1 expression. The position of the 175 kDa molecular mass marker is indicated to the left of the panel.