FIG. 6.

Msx1(R31P) lacks transcriptional repressor activity and does not influence the transcriptional repressor activity of Msx1. Transient-transfection assays were performed with C2C12 cells by using expression plasmids encoding the indicated proteins and a luciferase reporter plasmid containing an Msx1-responsive element (the WIP element [15]). In panel A, the amounts of each expression plasmid were 62.5, 125, or 250 ng (indicated by triangles). In panel B, each sample contained 125 ng of the Msx1 expression plasmid (indicated by the bar) alone or in combination with 125 or 250 ng of the Msx1, Msx1(R31P), and Msx1(R31A) expression plasmids (indicated by triangles). Data are represented as fold luciferase activity; a representative assay is shown with error bars indicating the difference between duplicates. Assays were performed a minimum of three times; representative data are shown.