KAP1 binds to other DNA methyltransferases. A, Myc-tagged DNMT1 was co-expressed with FLAG-tagged KAP1 or KAP1 deletion mutants in COS cells. The monoclonal antibody against the FLAG epitope was used for immunoprecipitation, and the monoclonal antibody against the MYC epitope was used to probe the immunoprecipitate. Lane 1, wild-type KAP1; lane 2, vector only; lane 3, wild-type KAP1; lane 4, KAP1ΔBCC; lane 5, KAP1ΔHP1; lane 6, KAP1ΔPhD-BRM. B, FLAG-tagged DNMT1 was co-expressed with Myc-tagged KAP1 in COS cells. The monoclonal antibody against the FLAG epitope was used for immunoprecipitation, and the monoclonal antibody against the Myc epitope was used to probe the immunoprecipitate. Lane 1, wild-type DNMT1; lane 2, vector only. C, FLAG-tagged DNMT3L was co-expressed with Myc-tagged KAP1 in COS cells. The monoclonal antibody against the FLAG epitope was used for immunoprecipitation, and the monoclonal antibody against the Myc epitope was used to probe the immunoprecipitate. Lane 1, vector only; lane 2, FLAG::DNMT3L. D, FLAG-tagged DNMT3a (lanes 1–3) or HP1a (lanes 4–6) was co-expressed with Myc-tagged KAP1 or KAP1 deletion mutants. The monoclonal antibody against the FLAG epitope was used for immunoprecipitation, and the monoclonal antibody against the Myc epitope was used to probe the immunoprecipitate. Lane 1, KAP1ΔRBCC; lane 2, wild-type KAP1; lane 3, KAP1ΔHP1; lane 4, KAP1ΔHP1; lane 5, wild-type KAP1; lane 6, KAP1ΔRBCC.