Abstract
Aberrantly active NF-B complexes can contribute to tumorigenesis by regulating genes that promote the growth and survival of cancer cells. We have investigated NF-B during the cell cycle and find that its ability to regulate the G1-phase expression of key proto-oncogenes is subject to regulation by the integrated activity of IB kinase (IKK), IKK, Akt and Chk1. The coordinated binding of NF-B subunits to the Cyclin D1, c-Myc and Skp2 promoters is dynamic with distinct changes in promoter occupancy and RelA(p65) phosphorylation occurring through G1, S and G2 phases, concomitant with a switch from coactivator to corepressor recruitment. Akt activity is required for IKK-dependent phosphorylation of NF-B subunits in G1 and G2 phases, where Chk1 is inactive. However, in S-phase, Akt is inactivated, while Chk1 phosphorylates RelA and associates with IKK, inhibiting the processing of the p100 (NF-B2) subunit, which also plays a critical role in the regulation of these genes. These data reveal a complex regulatory network integrating NF-B with the DNA-replication checkpoint and the expression of critical regulators of cell proliferation.
Original language | English |
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Pages (from-to) | 4841-4855 |
Number of pages | 15 |
Journal | The EMBO Journal |
Volume | 26 |
Issue number | 23 |
DOIs | |
Publication status | Published - 2007 |
Keywords
- Cell cycle
- Transcription