The Fanconi anemia pathway and HELQ work alongside dormant replication origins to suppress replication-associated genome instability
2014-07
Loading...
View/Download File
Persistent link to this item
Statistics
View StatisticsJournal Title
Journal ISSN
Volume Title
Title
The Fanconi anemia pathway and HELQ work alongside dormant replication origins to suppress replication-associated genome instability
Authors
Published Date
2014-07
Publisher
Type
Thesis or Dissertation
Abstract
DNA replication is continually impeded by endogenous lesions that cause the stalling of replication forks. If left unchecked, this threatens the integrity of the genome and may be a driver of cancer development. Utilizing the <italic>Mcm4<super>chaos3</super></italic> mouse model, we found that dormant replication origins, which act as backup initiation sites, play a critical role in the recovery of stalled replication forks. A reduced number of dormant origins in these mice led to persistently stalled forks, incomplete replication and the mis-segregation of sister chromatids in mitosis, causing elevated genome instability. <italic>Mcm4<super>chaos3/chaos3</super></italic> cells also displayed intrinsic activation of the Fanconi anemia (FA) pathway, suggesting that it too plays a functional role in fork progression. Indeed, disruption of FA pathway activation in the <italic>Mcm4<super>chaos3/chaos3</super></italic> background led to an even higher number of persistently stalled forks. Furthermore, we discovered that a lack of dormant origins also leads to delayed replication, as seen by extremely late DNA synthesis. Accordingly, concomitant loss of both mechanisms led to heightened genomic instability, causing mice to either die shortly after birth or exhibit accelerated tumorigenesis. Finally, we investigated if <italic>HELQ</italic> is perhaps another FA gene by characterizing the first <italic>Helq</italic> mutant mouse model (<italic>Helq<super>gt</super></italic>). <italic>Helq<super>gt/gt</super></italic> cells/mice displayed modest FA-like phenotypes such as interstrand crosslink hypersensitivity and hypogonadism, but not defects in homologous recombination repair. Rather, HELQ was found to work in parallel to the FA protein FANCC to suppress replication-associated genome instability.
Keywords
Description
University of Minnesota Ph.D. dissertation. July 2014. Major:Molecular, Cellular, Developmental Biology and Genetics. Advisor: Naoko Shima, Ph.D. 1 computer file (PDF); xi, 266 pages.
Related to
Replaces
License
Collections
Series/Report Number
Funding information
Isbn identifier
Doi identifier
Previously Published Citation
Suggested citation
Luebben, Spencer William. (2014). The Fanconi anemia pathway and HELQ work alongside dormant replication origins to suppress replication-associated genome instability. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/165753.
Content distributed via the University Digital Conservancy may be subject to additional license and use restrictions applied by the depositor. By using these files, users agree to the Terms of Use. Materials in the UDC may contain content that is disturbing and/or harmful. For more information, please see our statement on harmful content in digital repositories.