Letter abstract
Nature Cell Biology 8, 84 - 90 (2005)
Published online: 18 December 2005 | doi:10.1038/ncb1346
PCNA functions as a molecular platform to trigger Cdt1 destruction and prevent re-replication
Emily E. Arias1 & Johannes C. Walter1
Ubiquitin-mediated proteolysis of the replication licensing factor Cdt1 (Cdc10-dependent transcript 1) in S phase is a key mechanism that limits DNA replication to a single round per cell cycle in metazoans1, 2, 3, 4, 5, 6. In Xenopus egg extracts, Cdt1 is destroyed on chromatin during DNA replication1. Here, we report that replication-dependent proteolysis of Cdt1 requires its interaction with proliferating cell nuclear antigen (PCNA), a homotrimeric processivity factor for DNA polymerases7. Cdt1 binds to PCNA through a consensus PCNA-interaction motif that is conserved in Cdt1 of all metazoans, and removal of PCNA from egg extracts inhibits replication-dependent Cdt1 destruction. Mutation of the PCNA-interaction motif yields a stabilized Cdt1 protein that induces re-replication. DDB1, a component of the Cul4 E3 ubiquitin ligase that mediates human Cdt1 proteolysis in response to DNA damage8, is also required for replication-dependent Cdt1 destruction. Cdt1 and DDB1 interact in extracts, and DDB1 chromatin loading is dependent on the binding of Cdt1 to PCNA, which indicates that PCNA docking activates the pre-formed Cdt1–Cul4DDB1 ligase complex. Thus, PCNA functions as a platform for Cdt1 destruction, ensuring efficient and temporally restricted inactivation of a key cell-cycle regulator.
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.
Correspondence to: Johannes C. Walter1 e-mail: johannes_walter@hms.harvard.edu
MORE ARTICLES LIKE THIS
These links to content published by NPG are automatically generated.
RESEARCH
Recruitment of Xenopus Scc2 and cohesin to chromatin requires the pre-replication complexNature Cell Biology Letter (01 Oct 2004)
Two E3 ubiquitin ligases, SCF-Skp2 and DDB1-Cul4, target human Cdt1 for proteolysisThe EMBO Journal Article (08 Mar 2006)
Triggering ubiquitination of a CDK inhibitor at origins of DNA replicationNature Cell Biology Article (01 Aug 2001)
See all 16 matches for Research
