FIG 1.

PHLPP1 and PHLPP2 interact with UAF1 in a mutually exclusive manner with E1. (A) Coimmunoprecipitation of GFP-tagged PHLPP1 and PHLPP2 with 3F-UAF1. C33A cells were cotransfected with a 3F-UAF1 expression plasmid together with an expression vector for either PHLPP1-GFP or PHLPP2-GFP. UAF1-containing protein complexes were immunoprecipitated with an anti-Flag antibody, and the presence of PHLPP1 and PHLPP12 in the immunoprecipitates (IP) and input cell extracts (IN) was determined by Western blotting with anti-GFP antibodies. (B and C) Inhibitory effect of full-length E1 and of the E1 UBS on the interaction of UAF1 with endogenous PHLPP1. C33A cells were transfected with a 3F-UAF1 expression vector and increasing amounts of E1 expression plasmid encoding either the full-length protein (B) or the UBS alone (C), fused to YFP. UAF1-containing protein complexes were immunoprecipitated with an anti-Flag antibody and the presence of endogenous PHLPP1 in the immunoprecipitates determined by Western blotting with an anti-PHLPP1 antibody.