The involvement of survival signaling pathways in rubella-virus induced apoptosis

Cooray, Samantha; Jin, Li; Best, Jennifer M

The effect of RV infection on PI3K-Akt and Ras-Raf-MEK-ERK pathways was investigated by examining the expression and phosphorylation profiles of Akt, ERK1/2 and their downstream targets. Cell lysates from RV and mock infected RK13 cells were collected 12-96 hours post-infection (p.i.), separated by SDS-PAGE, and analyzed for total and phosphorylated Akt and ERK1/2 by Western blotting. Phosphorylated Akt and ERK1/2 could be detected in RVinfected cells from 48 hours p.i., and band intensity increased from 48-96 hours p.i. compared to total levels (Fig. 1A) . Phosphorylated Akt and ERK2 (but not ERK1) were detected in the mock-infected cells at 96 hours p.i. but not before, whereas total levels of Akt and ERK 1/2 were detectable at all time points (Fig. 1A) . Treatment of RV-infected cells with PI3K inhibitor LY294002 and MEK1/2 inhibitor U0126 completely inhibited activation of Akt and ERK1/2 respectively (data not shown).