| Autor: |
Grenon, M., Tillit, J., Piard, K., Baldacci, G., Francesconi, S. |
| Zdroj: |
Molecular & General Genetics MGG; Jan1999, Vol. 260 Issue 6, p522-534, 13p |
| Abstrakt: |
We have isolated a mutant in fission yeast, in which mitosis is uncoupled from completion of DNA replication when DNA synthesis is impaired by a thermosensitive mutation in the gene encoding the catalytic subunit of DNA polymerase δ. By functional complementation, we cloned the wild-type gene and identified it as the recently cloned checkpoint gene crb2 + /rhp9 + . This gene has been implicated in the DNA damage checkpoint and acts in the Chk1 pathway. Unlike the deleted strain dcrb2, cells bearing the crb2-1 allele were not affected in the DNA repair checkpoint after UV or MMS treatment at 30° C, but were defective in this checkpoint function when treated with MMS at 37° C. We analysed the involvement of Crb2 in the S/M checkpoint by blocking DNA replication with hydroxyurea, by using S phase cdc mutants, or by overexpression of the mutant PCNA L68S. Both crb2 mutants were unable to maintain the S/M checkpoint at 37° C. Furthermore, the crb2 + gene was required, together with the cds1 + gene, for the S/M checkpoint at 30° C. Finally, both the crb2 deletion and the crb2-1 allele induced a rapid death phenotype in the polδts3 background at both 30° C and 37° C. The rapid death phenotype was independent of the checkpoint functions. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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