EBNA3C stabilizes Cyclin D1 through inhibiting its poly-ubiquitination.

<p>A) 50 million EBV negative BJAB cells, BJAB cells stably expressing EBNA3C (BJAB_E3C#7) and an EBV transformed cell, LCL2 were harvested after 6h incubation with proteasome inhibitor MG132 (20 µM). Cells were lysed and Cyclin D1 was immunoprecipitated (IP). Samples were resolved by 10% SDS-PAGE. Western blotting (WB) was done by stripping and reprobing the same membrane. B-E) 15 million HEK 293T cells were transiently transfected with different combinations of expression plasmids as indicated. Cells were harvested at 36h, and total protein was immunoprecipitated (IP) with indicated antibody and samples were resolved by 10% SDS-PAGE. Western blotting was done by stripping and reprobing the same membrane. Asterisks (*) indicate the immunoglobulin bands and poly-(ub) indicates poly-ubiquitination.