FIG. 4.

Analysis of Rb phosphorylation in Shh-treated granule cell cultures. Protein lysates (10 μg) were prepared from cells treated with vehicle alone, Shh (3 μg/ml), or Shh plus forskolin (10 μM) for the indicated periods of time and used for immunoblotting. Autoradiographs were analyzed by densitometry and signal intensities of P-pRb and pRb proteins were quantitated and expressed as a P-pRb/pRb ratio. The data shown are the average ratios ± the SEM from nine separate experiments. Significant differences (P ≤ 0.01) between Shh- and vehicle-treated samples are indicated by an asterisk.