FIGURE 4.

TKB domain and proline-rich region of CBL-Y371H mutant are essential for the enhanced cytokine-independent and cytokine-dependent proliferation of TF-1 cell lines. A, stable retroviral expression of the indicated CBL constructs was verified using Western blotting with anti-HA antibody, with IgG heavy chain serving as a loading control as in Fig. 3A. B and C, TF-1 cell lines expressing the indicated ectopic CBL constructs were analyzed for SCF-stimulated (B) or cytokine-independent (C) proliferation as in Fig. 3. Shown are pooled data from three independent repeats (mean ± S.E.). *, p < 0.05.