FIG. 3.

Analysis of amino-terminal Zta mutants by transient transfectin analysis. HeLa cells were transfected with the indicated pMARK-Zta expression vector (5 μg), pGFP-SP (1 μg), and the carrier plasmid, pGL3 Basic (24 μg). Twenty-four hours after transfection, cells were harvested, expression of Zta derivatives p53, p21, and p27 was assessed by Western blot analysis (A), and the cell cycle distribution of GFP-positive cells was assessed by FACS analysis (following propidium iodide staining) (B). Western blot analyses were performed with the anti-Zta (M47), anti-p21 (C19G; Santa Cruz), anti-Kip1/p27 (Transduction Laboratories), and anti-p53 (DO-1; Santa Cruz) antisera. (C) Five micrograms of each of the indicated pMARK-Zta expression plasmids was cotransfected into HeLa cells with 2 μg of the Zta-responsive reporter, 2×(ZIIIB)BG-CAT (23 μg of pGL3 Basic was also used as a carrier). Cells were harvested 24 h later, and CAT analysis was performed. The level of acetylated chloramphenicol was quantitated with a Molecular Dynamics PhosphorImager. Control, pMARK (empty vector)-transfected cells. wt, wild type.