Fig. 6. N-terminal sequences of SLMAP are required for targeting GFP to centrosomes. (A) Transient expression of GFP-tagged SLMAP mutants showed that green fluorescence was observed at centrosomes in live cells expressing GFP-SLMAP3M1LZ (a) and GFP-SLMAP3M1C (b) but not in mitotic cells expressing GFP-SLMAP3M2C (c). Corresponding phase contrast images are shown for SLMAP3M1LZ (d), GFP-SLAP3M1C (e) and GFP-SLMAP3M2C (f). Bar, 25 µm. (B) N-terminal SLMAP3 constructs encoding amino acids 1-163 (a), 1-183 (b) or 1-206 (c) were expressed in fibroblast cells. GFP fluorescence was detected throughout the cell, including the nucleus in (a) or within detergent-insoluble aggregates (b, c). Bar, 10 µm. (C) Transient expression of the full-length GFP-SLMAP fusion protein, GFP-SLMAP3M1 (a), was detected at perinuclear sites in interphase cells, indicative of membrane localization. Diffuse cytosolic localization was observed for both C-terminal mutants, GFP-SLMAP3M1C (b) and SLMAP3M2C (c). Bar, 50 µm. (D) At 36 hours post-transfection, cells expressing GFP-SLMAP3M1 were rounded (b), whereas those cells expressing either GFP-pcDNA3 (a), GFP-SLMAP3M1C (c) or GFP-SLMAP3M2C appeared normal. Bar, 10 µm.