Previous Article | Next Article ![]()
Molecular and Cellular Biology, May 2001, p. 3289-3301, Vol. 21, No. 10
Department of Pathology, Stanford University
School of Medicine, Stanford, California
94305-5324,1 and Department of
Biochemistry and Molecular Biology, The University of Tokyo
Graduate School of Medicine, Bunkyo-ku, Tokyo 113-0033, Japan2
Received 13 October 2000/Returned for modification 5 December
2000/Accepted 26 February 2001
Fission yeast checkpoint protein Rad17 is required for the DNA
integrity checkpoint responses. A fraction of Rad17 is chromatin bound
independent of the other checkpoint proteins throughout the cell cycle.
Here we show that in response to DNA damage induced by either methyl
methanesulfonate treatment or ionizing radiation, increased levels of
Rad17 bind to chromatin. Following S-phase stall induced by hydroxyurea
or a cdc22 mutation, the chromatin-bound Rad17
progressively dissociates from the chromatin. After S-phase arrest by
hydroxyurea in cds1
0270-7306/01/$04.00+0 DOI: 10.1128/MCB.21.10.3289-3301.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.
Fission Yeast Rad17 Associates with Chromatin in
Response to Aberrant Genomic Structures
or rad3
cells or by
replication mutants, Rad17 remains chromatin bound. Rad17 is able to
complex in vivo with an Rfc small subunit, Rfc2, but not with Rfc1.
Furthermore, cells with rfc1
are checkpoint proficient,
suggesting that Rfc1 does not have a role in checkpoint function. A
checkpoint-defective mutant protein, Rad17(K118E), which has similar
nuclear localization to that of the wild type, is unable to bind ATP
and has reduced ability in chromatin binding. Mutant Rad17(K118E)
protein also has reduced ability to complex with Rfc2, suggesting that
Lys118 of Rad17 plays a role in Rad17-Rfc small-subunit
complex formation and chromatin association. However, in the
rad17.K118E mutant cells, Cds1 can be activated by
hydroxyurea. Together, these results suggest that Rad17 binds to
chromatin in response to an aberrant genomic structure generated from
DNA damage, replication mutant arrest, or hydroxyurea arrest in the
absence of Cds1. Rad17 is not required to bind chromatin when genomic
structures are protected by hydroxyurea-activated Cds1. The possible
checkpoint events induced by chromatin-bound Rad17 are discussed.
*
Corresponding author. Mailing address: Department of
Pathology, Stanford University School of Medicine, 300 Pasteur Dr.,
Stanford, CA 94305-5324. Phone: (650) 725-4907. Fax: (650) 725-6902. E-mail: twang{at}cmgm.stanford.edu.
This article has been cited by other articles:
| J. Bacteriol. | J. Virol. | Eukaryot. Cell |
|---|
| Microbiol. Mol. Biol. Rev. | Clin. Vaccine Immunol. | All ASM Journals |
|---|