M45 interacts with the IKK complex.

<p>(A) 293A cells were transfected with plasmids expressing HA-tagged M45 or an unrelated MCMV control protein (m143) and Flag-tagged IKK subunits. Lysates were subjected to immunoprecipitation (IP) using an anti-HA antibody. Immunoprecipitates were analyzed by immunoblotting (IB) using anti-Flag antibody. Whole cell lysates (WCL) were immunoblotted using Flag-, HA-, and actin-specific antibodies, respectively. (B) <i>Nemo</i>^−/− MEFs were transfected with Flag-tagged IKK subunits and HA-tagged M45 or an unrelated MCMV control protein (m142), respectively. IP and IB were performed using anti-HA and anti-Flag antibodies, respectively. WCL were immunoblotted with anti-NEMO antibody and as described for panel A. (C) <i>rip1</i>^−/− MEFs were transfected with HA-tagged M45 or an unrelated MCMV control protein (m142) and Flag-tagged NEMO. IP was done with an anti-HA antibody. Immunoprecipitates and WCL were analyzed by immunoblotting using the indicated antibodies. (D) 293A cells were transfected with plasmids expressing HA-tagged M45 or m143 (as a control). Lysates were subjected to anti-HA immunoprecipitation. Immunoblotting of precipitates and the WCL was done with antibodies as indicated. (E) NIH-3T3 cells were infected for 4 hours with RM45 (MCMV expressing HA-tagged M45), ΔM45, or Rm142 (MCMV expressing HA-tagged m142) at an MOI of 5. Cell lysates were subjected to IP and IB with antibodies as indicated.