Welcome! Click here to login or here to register.
 |
|||||||||||||||||||
|
|||||||||||||||||||
 |
|||||||||||||||||||
"Plk1-mediated phosphorylation of Topors regulates p53 stability." |
Yang X, Li H, Zhou Z, Wang WH, Deng A, Andrisani O, Liu X |
Published July 10, 2009 in J Biol Chem volume 284 .
Pubmed ID: 19473992
Abstract:
| Polo-like kinase 1 (Plk1) overexpression is associated with tumorigenesis by an unknown mechanism. Likewise, Plk1 was suggested to act as a negative regulator of tumor suppressor p53, but the mechanism remains to be determined. Herein, we have identified topoisomerase I-binding protein (Topors), a p53-binding protein, as a Plk1 target. We show that Plk1 phosphorylates Topors on Ser(718) in vivo. Significantly, expression of a Plk1-unphosphorylatable Topors mutant (S718A) leads to a dramatic accumulation of p53 through inhibition of p53 degradation. Topors is an ubiquitin and small ubiquitin-like modifier ubiquitin-protein isopeptide ligase (SUMO E3) ligase. Plk1-mediated phosphorylation of Topors inhibits Topors-mediated sumoylation of p53, whereas p53 ubiquitination is enhanced, leading to p53 degradation. These results demonstrate that Plk1 modulates Topors activity in suppressing p53 function and identify a likely mechanism for the tumorigenic potential of Plk1. |
This publication refers to following REPAIRtoire entries:
| Proteins |
Last modification of this entry: Oct. 6, 2010
Add your own comment!
There is no comment yet.
|
|
|
|