Two E3 ubiquitin ligases, SCF-Skp2 and DDB1-Cul4, target human Cdt1 for proteolysis
| Autor: | Keiichi I. Nakayama, Keiko Nakayama, Toshiki Tsurimoto, Masatoshi Fujita, Masafumi Saijo, Hideo Nishitani, Vassilis Roukos, Yohsuke Nakanishi, Nozomi Sugimoto, Chikashi Obuse, Takeharu Nishimoto, Zoi Lygerou |
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| Rok vydání: | 2006 |
| Předmět: |
DNA Replication
Ultraviolet Rays Proteolysis Cell Cycle Proteins Cyclin A Kidney Article General Biochemistry Genetics and Molecular Biology DNA replication factor CDT1 Mice Ubiquitin Proliferating Cell Nuclear Antigen Cyclin E medicine Animals Humans Gene Silencing Cell division control protein 4 Phosphorylation RNA Small Interfering S-Phase Kinase-Associated Proteins Molecular Biology Cells Cultured SKP Cullin F-Box Protein Ligases General Immunology and Microbiology biology medicine.diagnostic_test General Neuroscience Geminin DNA replication Fibroblasts Cullin Proteins DNA-Binding Proteins Licensing factor Biochemistry embryonic structures biology.protein Origin recognition complex DNA Damage HeLa Cells Peptide Hydrolases |
| Zdroj: | The EMBO Journal. 25:1126-1136 |
| ISSN: | 1460-2075 0261-4189 |
| DOI: | 10.1038/sj.emboj.7601002 |
| Popis: | Replication licensing is carefully regulated to restrict replication to once in a cell cycle. In higher eukaryotes, regulation of the licensing factor Cdt1 by proteolysis and Geminin is essential to prevent re-replication. We show here that the N-terminal 100 amino acids of human Cdt1 are recognized for proteolysis by two distinct E3 ubiquitin ligases during S-G2 phases. Six highly conserved amino acids within the 10 first amino acids of Cdt1 are essential for DDB1-Cul4-mediated proteolysis. This region is also involved in proteolysis following DNA damage. The second E3 is SCF-Skp2, which recognizes the Cy-motif-mediated Cyclin E/A-cyclin-dependent kinase-phosphorylated region. Consistently, in HeLa cells cosilenced of Skp2 and Cul4, Cdt1 remained stable in S-G2 phases. The Cul4-containing E3 is active during ongoing replication, while SCF-Skp2 operates both in S and G2 phases. PCNA binds to Cdt1 through the six conserved N-terminal amino acids. PCNA is essential for Cul4- but not Skp2-directed degradation during DNA replication and following ultraviolet-irradiation. Our data unravel multiple distinct pathways regulating Cdt1 to block re-replication. |
| Databáze: | OpenAIRE |
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