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Figure 4 | Molecular Cancer

Figure 4

From: The E3 ubiquitin ligases β-TrCP and FBXW7 cooperatively mediates GSK3-dependent Mcl-1 degradation induced by the Akt inhibitor API-1, resulting in apoptosis

Figure 4

API-1 induces proteasome-mediated Mcl-1 degradation (B) and decreases Mcl-1 stability (C) without altering Mcl-1 mRNA levels (A). A, H1299 cells were exposed to the indicated concentrations of API-1 for 8 h. Total cellular RNA was then isolated from the cells for detection of Mcl-1 and GAPDH (internal control) mRNAs with RT-PCR. B, The indicated cell lines were pre-treated with 20 μM MG132 for 30 minutes prior to the addition of 5 μM API-1. After co-treatment for an additional 4 h, the cells were harvested for preparation of whole-cell protein lysates and subsequent Western blot analysis. C, H1299 cells were treated with 5 μM API-1 for 8 h. The cells were then washed with PBS 3 times and refed with fresh medium containing 10 μg/ml CHX. At the indicated times, the cells were harvested for preparation of whole-cell protein lysates and subsequent Western blot analysis. Protein levels were quantified with NIH Image J software (Bethesda, MA) and were normalized to actin. The results were plotted as the relative Mcl-1 levels compared to those at the time 0 of CHX treatment (right panel).

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Molecular Cancer

ISSN: 1476-4598