UCL Discovery
UCL home » Library Services » Electronic resources » UCL Discovery

Exploring the roles and mechanisms of Cdc18 in the cell cycle of fission yeast.

Harris, O.J.R.; (2005) Exploring the roles and mechanisms of Cdc18 in the cell cycle of fission yeast. Doctoral thesis , University of London. Green open access

[thumbnail of U592040.pdf] PDF

Download (10MB)


The replication factor Cdc18 (Cdc6 in other organisms) is required to initiate DNA replication and the S phase checkpoint, which restrains mitosis until replication is faithfully completed. In this thesis I have investigated these roles within the cell cycle of the single-celled eukaryote Schizosaccharomyces pombe (fission yeast), and in addition I have identified putative new roles for this replication factor. The Cdc18 ATPase loads the MCM complex, a putative DNA helicase, onto chromatin in late mitosis and early G1 phases in preparation for DNA replication. I have shown that the association of Cdc18 with chromatin does not require ATP binding, whilst ATP binding is necessary to initiate an S phase checkpoint signal. ATP binding and hydrolysis are required for MCM loading activity and hence DNA replication. I also present evidence indicating that Cdc18 can restrain mitosis from G1 in the absence of DNA replication, perhaps as part of a complex with the replication factors Cdtl and the ORC complex. From my work it appears that Cdc18 is required during S phase for at least two further roles. Firstly, Cdc18 is needed to maintain the S phase checkpoint when DNA replication is affected by perturbations that are likely to involve stalled forks or DNA damage. Secondly, Cdc18 may be required in an unperturbed S phase to prepare cells for entry into or progression through mitosis. This latter role is unlikely to involve DNA metabolism, and may instead be related to chromosome preparation or dynamics.

Type: Thesis (Doctoral)
Title: Exploring the roles and mechanisms of Cdc18 in the cell cycle of fission yeast.
Identifier: PQ ETD:592040
Open access status: An open access version is available from UCL Discovery
Language: English
Additional information: Thesis digitised by ProQuest
UCL classification: UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences
URI: https://discovery.ucl.ac.uk/id/eprint/1444731
Downloads since deposit
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item