BPLF1 promotes the selective stabilization of nuclear CRL substrates.

<p>The expression levels of nuclear and cytoplasmic CRL substrates were monitored over time in induced Akata-Bx1 cells. <b>A</b>. Representative western blots illustrating the expression levels of CRL1 substrates: p21, p27 and IκBα, CRL2 substrates: VAV and HIF1α, and CRL4A substrates: CDT1 and Cdc25A. The expression level of β-actin is shown as loading control. As control, CRL2 was inactivated by exposing Akata-Bx1 to hypoxia, which resulted in stabilization of HIF1α (indicated by an asterisk). One representative experiment out of three is shown. <b>B</b>. Changes in the expression of nuclear and cytoplasmic CRL substrates in induced Akata-Bx1. The intensity of the specific bands detected at time 0 and after induction for 48 h was quantified. The mean ± SE of the fold change in three independent experiments is shown. <b>C</b>. The selective degradation of nuclear cullins and stabilization of nuclear CRL substrates is dependent on BPLF1. The productive cycle was induced in Akata-Bx1 transfected with a control or BPLF1 specific shRNA and cell lysates collected after 48 h were probed as indicated. One representative experiment out of three where each cullin and CRL substrate was tested is shown.