Functional analyses of <i>RUNX2</i> mutations on protein subcellular localization and transactivation of down-stream target gene.

<p>(A) Subcellular localization of wild-type and mutant RUNX2-GFP fusion proteins in MC3T3-E1 cells. Confocal micrographs showed the intracellular distribution of control GFP, wild-type RUNX2-GFP, Q67X, L113R, and R186T mutant proteins. (B) Transactivation activity of mutant RUNX2 proteins on <i>osteocalcin</i> promoter. MC3T3-E1 cells were co-transfected with a control pCMV5 vector or a vector that expressed wild-type or mutant RUNX2 protein, together with <i>osteocalcin</i> reporter plasmid. <i>Renilla</i> luciferase reporter was used as the internal control. Bars represent firefly/Renilla luciferase ratios for different constructs. *<i>p</i> < 0.05 (compared with wild-type control).