Fig. 5. Residues 45-59 of the cytoplasmic tail of NgCAM contain a necessary and sufficient axonal targeting signal. (A) The location of the cytoplasmic axonal targeting signal of NgCAM was mapped by sequential truncations and deletions. The constructs depicted diagrammatically were expressed in neurons and the axon/dendrite polarity index of the surface pool determined. ^***P<0.0001, ^*P<0.01; significantly different from LCT. (B,C) Examples of one axonally enriched construct LexNct45-59 (B) and one uniform construct LexNct66-114 (C) are shown. Surface distribution of the chimeras was detected with an anti-Lex antibody without permeabilization (green). DsRed was co-expressed (red) to delineate all neuronal processes. The soma region containing the dendrites (arrows) are shown in the top row, whereas the distal regions of the long axons (arrowheads) are shown in the bottom row for both B and C.