| First Author | Kawauchi K | Year | 2009 |
| Journal | Proc Natl Acad Sci U S A | Volume | 106 |
| Issue | 9 | Pages | 3431-6 |
| PubMed ID | 19202066 | Mgi Jnum | J:146455 |
| Mgi Id | MGI:3837596 | Doi | 10.1073/pnas.0813210106 |
| Citation | Kawauchi K, et al. (2009) Loss of p53 enhances catalytic activity of IKKbeta through O-linked beta-N-acetyl glucosamine modification. Proc Natl Acad Sci U S A 106(9):3431-6 |
| abstractText | The IkappaB kinase (IKK)-NF-kappaB pathway plays a critical role in oncogenesis. Recently, we have shown that p53 regulates glucose metabolism through the IKK-NF-kappaB pathway and that, in the absence of p53, the positive feedback loop between IKK-NF-kappaB and glycolysis has an integral role in oncogene-induced cell transformation. Here, we demonstrate that IKKbeta, a component of the IKK complex, was constitutively modified with O-linked beta-N-acetyl glucosamine (O-GlcNAc) in both p53-deficient mouse embryonic fibroblasts (MEFs) and transformed human fibroblasts. In p53-deficient cells, the O-GlcNAcylated IKKbeta and the activating phosphorylation of IKK were decreased by p65/NF-kappaB knockdown or glucose depletion. We also found that high glucose induced the O-GlcNAcylation of IKKbeta and sustained the TNFalpha-dependent IKKbeta activity. Moreover, the O-GlcNAcase inhibitor streptozotocin intensified O-GlcNAcylation and concomitant activating phosphorylation of IKKbeta. Mutational analysis revealed that O-GlcNAcylation of IKKbeta occurred at Ser 733 in the C-terminal domain, which was identified as an inactivating phosphorylation site, suggesting that IKKbeta O-GlcNAcylation regulates its catalytic activity. Taken together, we propose a novel mechanism for the enhancement of NF-kappaB activity by loss of p53, which evokes positive feedback regulation from enhanced glucose metabolism to IKK in oncogenesis. |
