A,Top, Quantification of NGF-stimulated PC12 cells with neurites after transient transfection with GFP (white columns), GFP-α2-chimaerin (black columns), GFP-α2-chimaerin E49W (dark gray columns), GFP-α2-chimaerin R73L (light gray columns), or GFP-α2-chimaerin N94H (striped columns) and NGF treatment (100 ng/ml) for 24 hr. We counted 250 cells per category. NGF treatment for 48–60 hr gave similar results. Error bars indicate SD. Chimaerin N94H transfectants showed significant differences from wild-type (p < 0.003), E49W (p < 0.01), R73L (p < 0.0001), and GFP transfectants (p < 0.05). Chimaerin E49W and R73L also showed significant differences from GFP transfectants (p < 0.05, p < 0.01; Student's t test). A,Bottom, Cells expressing GFP-α2-chimaerin were more spread and flattened than GFP-expressing cells (p < 0.001). Error bars indicate SEM from three experiments. B, Transient PC12 cell transfectants stimulated with NGF for 60 hr expressing GFP-α2-chimaerin (b) (GFP) and phalloidin-stained (actin) ina shows chimaerin is present throughout neurites. Expression of α2-chimaerin N94H (d, GFP;c, phalloidin-stained) led to altered cell morphology (c) and protein distribution (d).