Fig. 3.
Effect of Hcy on the protein expression and kinase activity of G1/S cyclins and CDK2.
HUVECs were exposed to 50 μg dl-Hcy or l-Cys for the indicated times. Proteins (50 μg) were analyzed by Western blotting with antibodies against cyclins A, D1, E, or CDK2 respectively (A), and by immunoprecipitation with the same antibody for associated kinase or kinase activity (B). Histone H1 (200 μg/mL) was used as phosphorylation substrate for cyclin A, E, or CDK2. GST-RB (40 μg/mL) was used as phosphorylation substrate for cyclin D1.
