The Mre11 Cellular Protein Is Modified by Conjugation of Both SUMO-1 and SUMO-2/3 during Adenovirus Infection
Figure 4
The addition of SUMO to Mre11 is influenced by E1B 55 kDa, E4 Orf6, and E4 Orf3, but none of these viral early proteins is absolutely required. (a) H1299 cells were transfected with pcDNA3-empty, pcDNA3-E1B 55 kDa wt, pcDNA3-E4 Orf6 wt, pcDNA3-E4 Orf3 wt, and/or pcDNA3-HA-Ubc9. Cells were harvested and total cell extracts were prepared at 28 h posttransfection, as described in Section 2. Protein samples (20 μg) were separated on 10% SDS-PAGE followed by immunoblotting with anti-Mre11, anti-E1B 55 kDa, anti-E4 Orf6, anti-E4 Orf3, anti-HA, and anti-actin mAbs. (b) H1299 cells were either mock-infected or infected with Ad5, RF6, or the E1B 55 kDa null mutant. Cells were harvested at 16 and 28 h p.i. for analysis by Western blot with anti-Mre11 rabbit pAb (NB100-142. Novus Biologicals), anti-E4 Orf6, anti-DBP, anti-E1B 55 kDa, and anti-actin mouse mAb (AC-15. Sigma-Aldrich, Inc.). Bands with molecular masses corresponding to Mre11-SUMO-1 and Mre11-SUMO-2/3 are indicated by (*).
