Abstract
Cdc7, a protein kinase required for the initiation of eukaryotic DNA replication, is activated by a regulatory subunit, Dbf4. A second activator of Cdc7 called Drf1 exists in vertebrates, but its function is unknown. Here, we report that in Xenopus egg extracts, Cdc7-Drf1 is far more abundant than Cdc7-Dbf4, and removal of Drf1 but not Dbf4 severely inhibits phosphorylation of Mcm4 and DNA replication. After gastrulation, when the cell cycle acquires somatic characteristics, Drf1 levels decline sharply and Cdc7-Dbf4 becomes the more abundant kinase. These results identify Drf1 as a developmentally regulated, essential activator of Cdc7 in Xenopus.
Original language | English |
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Pages (from-to) | 2295-2300 |
Number of pages | 6 |
Journal | Genes and Development |
Volume | 19 |
Issue number | 19 |
DOIs | |
Publication status | Published - Oct 1 2005 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- Genetics
- Developmental Biology