Detection of TpoR dimers by split-luciferase assay. (A) Luciferase assay of HEK293 cell lysates expressing hGluc-tagged TpoR and its mutants (W515K, W515KQ516W, S505N). The average luminescence of triplicate values ± SD is shown for one representative experiment out of at least three. (B) Immunoblotting of transfected HEK293 cell lysates by anti-HA antibodies. (C) STAT5 transcriptional assays in γ-2A cells transfected with cDNAs coding for hGluc-tagged TpoR, JAK2, and its mutants. *P < 0.01; **P < 0.001, one-way ANOVA.