Oxidative Stress Posttranslationally Regulates the Expression of Ha-Ras and Ki-Ras in Cultured Astrocytes
Figure 1
Oxidative stress induces a transient increase in the expression of Ha-Ras and Ki-Ras in cultured astrocytes. The kinetics of total Ras expression in control cultures and in cultures exposed to 1 mM hydrogen peroxide is shown in (a). The growing medium was switched into fresh medium and added of hydrogen peroxide. In control cultures, Ras expression was very low at 5 min and did not change at 30 or 60 min after the medium switch. Only control values at 5 min are show (Ctrl). Values shown in the graph are means ± SEM of 3 determinations. * (one-way ANOVA + Fisher’s PLSD) versus Ctrl. Immunoblot analysis with Ha-Ras ad Ki-Ras antibodies carried out in HEK-293 cells expressing Val-12 Ha-Ras or Val-12 Ki-Ras is shown in (b). Note that the antibodies used preferentially, but not exclusively, labelled the respective Ras isoform. Expression of Ha-Ras and Ki-Ras in cultures exposed to hydrogen peroxide for 5, 30, or 60 min is shown in (b). Note that immunoblots were carried out on pan-Ras immunoprecipitates. Values were calculated as per cent of Ctrl and are means ± SEM of 4 determinations. (one-way ANOVA + Fisher’s PLSD) versus the respective values at 5 (*) or 30 (#) min.
