Figure 3.

Hoxa2, Pbx and Prep synergize onto HRE in COS7 cells. Reporter constructs based on the wild-type 1.25-kb regulatory fragment (1.25 kb) or its HRE mutant derivative (m1.25 kb) were transfected alone (control) or in combination with expression vectors for Pbx1a, Prep1, Hoxa2 or Hoxa2(QN-AA) proteins. Values are expressed as fold activation over transfection of the reporter plasmid alone. Bars indicate the standard deviation of at least three independent experiments, except for experiments involving Hoxa2 and Pbx1a alone that were reproduced twice.