PDF
- Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
742kB |
Item Type: | Article |
---|---|
Title: | PCNA acts as a stationary loading platform for transiently interacting Okazaki fragment maturation proteins |
Creators Name: | Sporbert, A., Domaing, P., Leonhardt, H. and Cardoso, M.C. |
Abstract: | In DNA replication, the leading strand is synthesized continuously, but lagging strand synthesis requires the complex, discontinuous synthesis of Okazaki fragments, and their subsequent joining. We have used a combination of in situ extraction and dual color photobleaching to compare the dynamic properties of three proteins essential for lagging strand synthesis: the polymerase clamp proliferating cell nuclear antigen (PCNA) and two proteins that bind to it, DNA Ligase I and Fen1. All three proteins are localized at replication foci (RF), but in contrast to PCNA, Ligase and Fen1 were readily extracted. Dual photobleaching combined with time overlays revealed a rapid exchange of Ligase and Fen1 at RF, which is consistent with de novo loading at every Okazaki fragment, while the slow recovery of PCNA mostly occurred at adjacent, newly assembled RF. These data indicate that PCNA works as a stationary loading platform that is reused for multiple Okazaki fragments, while PCNA binding proteins only transiently associate and are not stable components of the replication machinery. |
Keywords: | Cell Line, Cell Nucleus Structures, DNA, DNA Ligases, DNA Replication, Flap Endonucleases, Fluorescence Microscopy, Proliferating Cell Nuclear Antigen, Replicon, Animals, Mice |
Source: | Nucleic Acids Research |
ISSN: | 0305-1048 |
Publisher: | Oxford University Press |
Volume: | 33 |
Number: | 11 |
Page Range: | 3521-3528 |
Date: | 21 June 2005 |
Official Publication: | https://doi.org/10.1093/nar/gki665 |
PubMed: | View item in PubMed |
Repository Staff Only: item control page