Figure 7.

Minimal targeting motifs for association with the NE. HeLa cells transiently transfected with NLS-MT-GFP-N-Ras (A and B) or NLS-MT-GFP (C) chimeras were fixed 24 h after transfection and examined by fluorescence confocal laser scan microscopy. For sequences, see Table 1. GFP that contains a NLS at its NH₂ terminus and the CaaX motif and the palmitoylation site of N-Ras at its COOH terminus is targeted to the NE (A and B), whereas NLS-GFP without the COOH-terminal membrane-targeting motifs is accumulated within the nucleoplasm (C). Note that cells expressing NLS-GFP–N-Ras show deep invaginations of the NE that are decorated by the chimeric GFP. Cells in B and C are shown at the same magnification. Bars in A and C, 25 μ m.