Figure 1
Transactivation activity of p89c-Mybex9b. (a) Schematic diagram of c-Myb proteins; levels of p75c-Myb, p89c-Mybex9b and Δ(358–452)c-Myb in transfected 293T cells (b) and K562 cells (c) used for luciferase assays. Expression of β-actin was detected as loading control; c-Myb and β-actin were detected by anti-c-Myb (clone 1-1, Upstate Biotechnology) and anti-β-actin antibody (sc-47778, Santa Cruz Biotechnology). (d) Densitometric analysis of c-Myb protein levels in transfected K562 normalized by corresponding β-actin expression. (e) Luciferase activity in 293T cells co-transfected with c-Myb plasmids and pGL3-cyclin B1-Luc (upper panel) or pGL3-Slug-Luc (lower panel). Results (from three and two experiments performed in duplicate, respectively) are expressed as fold activation relative to MSCV empty vector-transfected cells, after normalization for Renilla luciferase activity. (f, upper panel) Luciferase activity in K562 cells transfected with pGL3-cyclin B1-Luc and c-Myb plasmids. Results (means of three different experiments) are reported as fold activation relative to the pGL3 empty vector, after normalization for Renilla activity. (f, lower panel) Luciferase activity in K562 cells transfected with pGL3-Slug-Luc and c-Myb plasmids. Results (from two independent experiments, performed in duplicate) show fold activation relative to the MSCV empty vector, after normalization for Renilla activity. Error bars in e and f represent the s.d. of the means. P-values were calculated using unpaired, two-tailed Student's t-test, *denotes statistical significance of differences in transactivation activity of p75c-Myb versus p89c-Mybex9b or Δ(358–452)c-Myb and of p89c-Mybex9b versus Δ(358–452)c-Myb.
