FIG. 4.

Sumoylated MafG behaves as a transcriptional repressor. (A) The effect of PIASy on the function of MafG and its mutants in MARE-dependent transcription. An increasing amount of His-MafG (left panel), His-MafG K14R (middle panel), or MafG E16A (right panel) expression vector was transiently introduced into 293T cells with pRBGP2 and p45 expression vectors in the absence or presence of PIASy. (B and C) Protein accumulation of His-MafG, His-MafG K14R, and His-MafG E16A transiently expressed in 293T cells. Whole-cell extracts were examined by immunoblot analysis using an anti-His antibody. The expression vector for p45 was cotransfected and used as a control for monitoring the transfection efficiency.