FIGURE 6.

Mcl-1 is not rapidly degraded during vaccinia virus infection. A, HeLa cells were mock-infected or infected at an m.o.i. of 10 with VV, VVΔF1L, or VVFLAG-F1L. Cellular lysates were collected over 24 h and Western-blotted (WB) with anti-Mcl-1 (20% of sample), anti-I5L (5% of sample), and anti-β-tubulin (20% of sample). B, HeLa cells were treated with UV light in the absence or presence of 10 μm MG132 to inhibit the proteasome. Cellular lysates were harvested at 2, 4, or 6 h post-UV treatment, and 20% of whole cell lysates were Western-blotted with anti-Mcl-1 and anti-Bak. C, mock-infected HeLa cells or HeLa cells infected with VV, VVFLAG-F1L, or VVΔF1L at an m.o.i. of 10 for 6 h were mock-treated or treated with 100 μm etoposide or 200 mJ/cm² UV-C. Whole cell lysates were harvested at 0, 2, 4, or 6 h post-etoposide or UV-C treatment, and 20% of these samples were subject to Western blotting with an antibody specific for phosphorylated histone H2AX to determine the induction of a DNA damage response.