Figure 4

PI3K-AKT signaling stabilizes a set of KSRP-interacting mRNAs and increases their expression. (A) Either mock-αT3-1 or αT3-1-myrAKT1 cells were lysed and total extracts were immunoprecipitated (Ip) with either anti-AKT antibody or control IgG (cIgG). Pellets were incubated (20 min at 30°C) with histone 2B (H2B) in kinase buffer in the presence of γ[³²P]ATP under gentle shaking. Labeled proteins were separated by SDS-PAGE and detected by autoradiography. (B) Expression of KSRP-interacting mRNAs and β2-MG (control transcript), monitored by RT-PCR, in either mock-αT3-1 or αT3-1-myrAKT1 cells. (C) Semi quantitative RT-PCR analysis of both KSRP-interacting mRNAs and β2-MG (control transcript) in either mock-αT3-1 (red lines) or αT3-1-myrAKT1 (blue lines). Total RNA was isolated at the indicated times after addition of Actinomycin D. The amount of each transcript was quantitated by densitometry and plotted using a linear regression program. The values shown are averages (± SEM) of three independent experiments performed in duplicates. A quantitation of the transcripts' t(1/2) is presented in Additional file 7.