Figure 7.

Endogenous L11 regulates c-Myc activity and levels. (A) Reduction of L11 by siRNA enhances c-Myc-induced luciferase reporter expression driven by WT, but not mutant, E box-containing E2F2 promoters in U2OS cells. (B) Knockdown of endogenous L11 enhances c-Myc-dependent transcription of the c-Myc target genes. U2OS cells were transfected with siRNAs as indicated and real-time RT–PCR assays were performed to determine the expression of E2F2, nucleolin, and rRNA genes. (C, D) Knockdown of endogenous L11 induces the percentage of cells in S phase. BrdU incorporation assay were performed in serum-starved U2OS cells transfected with siRNAs as indicated. Percentage of BrdU-positive cells is shown in (D). (E) The representative expression of endogenous c-Myc and L11 in above experiments (B), (C), and (D) as determined by IB with antibodies as indicated. (F) Knockdown of endogenous L11 by L11 siRNAs against two different sequences increases the protein levels of endogenous c-Myc in U2OS cells. *Indicates a nonspecific band. (G) Overexpression of L11 stabilizes ectopically expressed c-Myc. H1299 cells were transfected with plasmids as indicated. Whole-cell lysates were subjected to IB using antibodies as indicated. (H) Adenoviral-mediated overexpression of L11 stabilizes adenoviral encoded c-Myc. U2OS cells were infected with adenoviruses as indicated. Whole-cell lysates were subjected to IB using antibodies as indicated.