Figure 4. Truncation of the C-terminal 80 residues of NonO accelerates its cytoplasmic localization and senescence.

(A) Subcellular localization of full-length (GFP-NonO; upper panels) and C-terminal truncated NonO(1-394) clones (middle and lower panels) imaged 12 days following overexpression (OE) in Cos7 cells by fluorescence microscopy (left), DAPI staining (middle), and phase contrast (right). (B) Overexpression (OE) of GFP-NonO(1-394) accelerates senescence of BJ diploid fibroblasts. SA-β-gal staining of plates 12 days post transfection at 1X (upper panels) and 10X (lower panels) magnification. Equivalent transfection efficiencies indicated at bottom by %GFP+ were confirmed by flow cytometry analysis (not shown).