Fig. 5: Inhibition or overexpression of P-TEFb modulates efficiency of Myc-driven transcription.
From: Reactivation of Myc transcription in the mouse heart unlocks its proliferative capacity
a Immunoblot analysis of the C-terminal domain (CTD) of RNA Polymerase II—total (Rpb1) and phosphorylated (p-Rpb1(S5) and p-Rpb1(S2)), CDK9, Cyclin T1 and Larp7 expression in the heart, liver, lung and kidney isolated from wild-type (R26+/+) mice. The composite figure is generated from the same samples loaded across multiple blots and a representative image for GAPDH is shown. b Immunoblot analysis of the CTD of RNA Polymerase II, phosphorylated (p-Rpb1(S2)), and MycERT2 protein expression in wild type (R26+/+) or R26CMER/+ livers, isolated 4 h post administration of 4-OHT either alone (4-OHT) or in combination with 60 mg/kg AZ5576 (4-OHT + AZ5576). c Quantitative RT-PCR analysis of Smpdl3b, Cad, Gnl3 and Polr3g in wild type (R26+/+) and R26CMER/+ livers, isolated 4 h post administration of 4-OHT (n = 6 R26+/+, n = 3 R26CMER/+) either alone or in combination with 60 mg/kg AZ5576 (4-OHT + AZ5576, n = 4). Expression is relative to the respective wild type (R26+/+). Mean and s.d shown. Two-way ANOVA with Tukey’s multiple comparisons test; R26+/+ vs 4-OHT: ***P = 0.001 (Smpdl3b, Cad, Gnl3 and Polr3g), R26CMER/+ 4-OHT vs 4-OHT + AZ5576: ***P = 0.001 (Smpdl3b, Cad and Gnl3), **P ≤ 0.01 (Polr3g). d Immunoblot analysis of Cyclin T1 and phosphorylated CTD of RNA polymerase II (p-Rpb1(S2)) in R26CMER/+ primary cardiomyocytes infected with an adenovirus encoding either GFP (Ad-GFP) or Ccnt1 (Ad-Ccnt1). Replicate samples are derived from independent primary cardiomyocyte isolations. e Quantitative RT-PCR analysis of Cad, Bzw2, Pinx1, Polr3d, St6 and Cdc25a in wild type (R26+/+, n = 5 except Pinx1 where n = 4 for Ad-GFP control) and R26CMER/+ (n = 5 except St6 where n = 4 for Ad-GFP control) primary cardiomyocytes infected with an adenovirus encoding either GFP (Ad-GFP) or Ccnt1 (Ad-Ccnt1), 4 h post addition of 100 nM 4-OHT. Expression is relative to an individual wild type (R26+/+) Ad-GFP control. Mean and s.d shown. One-way ANOVA with Tukey’s multiple comparisons test; Ad-GFP R26+/+ vs R26CMER/+: *P = 0.05 (Cad), Ad-Ccnt1 R26+/+ vs R26CMER/+: *P = 0.05 (Cad, Pinx1, Polr3d and St6) **P = 0.01 (Bzw2 and Cdc25a). Replicate samples are derived from independent primary cardiomyocyte isolations and independent mice. Source data are provided as a Source Data file.
