FIG. 5.

The H-3/4 domain mediates the inhibition of proliferation by HES-1. To determine if the growth inhibition phenotype resulting from WT HES-1 overexpression was a function of the H-3/4 domain, we performed CFE assays in PC12 cells using expression vectors encoding WT, ΔR, ΔS, Δ3/4, and B∗ HES-1 proteins. The empty expression vector (pCDNA3) was used as the control. The cells were grown in the presence of 200 μg of G418 per ml to select cells containing the expression construct, which has a neomycin resistance gene. The number of colonies present after 1 month of growth was determined and normalized to the control value (1.0). Six separate transfections with the same amount of vector were performed for all except Δ3/4 HES-1, which was transfected twice.