MTBP, the Partner of Treslin, Contains a Novel DNA-Binding Domain, That Is Essential for Proper Initiation of DNA Replication
- Creators
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Kumagai, Akiko
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Dunphy, William G.
Abstract
Treslin, which is essential for incorporation of Cdc45 into the replicative helicase, possesses a partner called MTBP. We have analyzed Xenopus and human MTBP to assess its role in DNA replication. Depletion of MTBP from Xenopus egg extracts, which also removes Treslin, abolishes DNA replication. These extracts be can rescued with recombinant Treslin-MTBP, but not Treslin or MTBP alone. Thus, Treslin-MTBP is collectively necessary for replication. We have identified a C-terminal region of MTBP (the CTM domain) that binds efficiently to both double-stranded DNA and G-quadruplex (G4) DNA. This domain also exhibits homology with budding yeast Sld7. Mutants of MTBP without a functional CTM domain are defective for DNA replication in Xenopus egg extracts. These mutants display an impaired localization to chromatin and the inability to support loading of Cdc45. Human cells harboring such a mutant also display severe S-phase defects. Thus, the CTM domain of MTBP plays a critical role in localizing Treslin-MTBP to the replication apparatus for initiation.
Additional Information
© 2017 by The American Society for Cell Biology. Free via Creative Commons 2 months after publication. Submitted July 10, 2017; Revised August 30, 2017; Accepted August 31, 2017. Published online before print September 6, 2017. We are grateful to Kanomi Sasaki-Capela and Bashar Alhoch for technical assistance. We also thank Rochelle Diamond for assistance with the FACS analyses. Imaging studies were performed in the Caltech Biological Imaging Center, which is supported by the Beckman Institute and the Arnold and Mabel Beckman Foundation. We are also grateful to Lea Goentoro for access to the Zeiss AxioObserver.Z1 microscope. This work was supported by National Institutes of Health grants GM-043974 and GM-070891 to W.G.D. Author contributions: A.K. and W.G.D. conceived the study. A.K. carried out the experiments. A.K. and W.G.D. wrote the paper.Attached Files
Published - Mol._Biol._Cell-2017-Kumagai-2998-3012.pdf
Supplemental Material - CombinedSupMats.pdf
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Additional details
- PMCID
- PMC5662258
- Eprint ID
- 81356
- Resolver ID
- CaltechAUTHORS:20170912-102544473
- Caltech Beckman Institute
- Arnold and Mabel Beckman Foundation
- NIH
- GM043974
- NIH
- GM070891
- Created
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2017-09-12Created from EPrint's datestamp field
- Updated
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2021-11-15Created from EPrint's last_modified field