FIG. 5.

The CB-RB fusion inhibits MyoD transcriptional activation of 4R-β-gal (A) and MCK (B) reporters. NIH 3T3 cells were transiently cotransfected with the indicated quantities (in micrograms) of MyoD, plasmids expressing either CB-myc6-RBf1, CB-myc6-RBf2, CB-myc6-RBf1ΔC, or CB-myc6 (as a control), and either the 4R-β-gal or MCK-β-gal reporter. Induction is normalized in each experiment by parallel cotransfection with the reporter (5 μg) and the empty vector (5 μg) to which the β-galactosidase activity is arbitrarily assigned a value of 1 (column 1). The reported β-galactosidase activity is thus expressed as a ratio of the activity for the conditions in lane 1. Error bars represent standard deviation of triplicate experiments.