Each cell cycle, a human cell must specifically initiate DNA replication at multiple sites and accurately duplicate the entire 4x10-9 base pair human genome. Perturbations of chromosomal DNA replication lead to abnormal growth and are associated with various disease states. The goal of this research is to elucidate molecular mechanisms and regulatory processes of chromosomal DNA replication. Because the process of chromosomal replication is complex, we will use the virus, simian virus 40 (SV40) as a model system for examining the mechanism of eukaryotic DNA replication. With the exception of the virally encoded initiator large T antigen, SV40 relies completely on the host replication apparatus, so it provides an excellent system for the biochemical analysis of cellular replication proteins and processes. This proposal focuses on the human multi-subunit, single-stranded DNA- binding protein, Replication Protein A (hRPA). This protein is essential for DNA replication. In addition, hRPA is involved in DNA repair and recombination, and may be a target for regulation in these processes. hRPA binds tightly to single-strand DNA, affects the activity of other replication proteins and interacts specifically with large T antigen, DNA polymerase alpha, the tumor suppressor p53, several transcriptional initiators (e.g. GAL4 and VP16). The physiological importance of the activities attributed to hRPA and the function of hRPA in the cell are currently not understood. The objective of this research is to determine the specific role of hRPA in DNA replication. A combination of biochemical assays and mutational analysis will be used to elucidate the function of hRPA. The specific functions of each of the three subunits of hRPA and the structure of hRPA will be determined. The interactions of hRPA with both DNA and other proteins will be studied and quantitated to determine their importance for hRPA function. hRPA becomes phosphorylated at the beginning of S-phase. The role of post-translational modifications on hRPA function in DNA replication will be determined.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM044721-09
Application #
2734668
Study Section
Molecular Cytology Study Section (CTY)
Project Start
1990-07-01
Project End
1999-06-30
Budget Start
1998-07-01
Budget End
1999-06-30
Support Year
9
Fiscal Year
1998
Total Cost
Indirect Cost
Name
University of Iowa
Department
Biochemistry
Type
Schools of Medicine
DUNS #
041294109
City
Iowa City
State
IA
Country
United States
Zip Code
52242
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Nguyen, Binh; Sokoloski, Joshua; Galletto, Roberto et al. (2014) Diffusion of human replication protein A along single-stranded DNA. J Mol Biol 426:3246-3261
Sparks, Justin L; Kumar, Rakesh; Singh, Mayank et al. (2012) Human exonuclease 5 is a novel sliding exonuclease required for genome stability. J Biol Chem 287:42773-83
Lindsey-Boltz, Laura A; Reardon, Joyce T; Wold, Marc S et al. (2012) In vitro analysis of the role of replication protein A (RPA) and RPA phosphorylation in ATR-mediated checkpoint signaling. J Biol Chem 287:36123-31
Hass, Cathy S; Lam, Koonyee; Wold, Marc S (2012) Repair-specific functions of replication protein A. J Biol Chem 287:3908-18
Hass, Cathy S; Chen, Ran; Wold, Marc S (2012) Detection of posttranslational modifications of replication protein A. Methods Mol Biol 922:193-204
Choi, Jun-Hyuk; Lindsey-Boltz, Laura A; Kemp, Michael et al. (2010) Reconstitution of RPA-covered single-stranded DNA-activated ATR-Chk1 signaling. Proc Natl Acad Sci U S A 107:13660-5
Hass, Cathy S; Gakhar, Lokesh; Wold, Marc S (2010) Functional characterization of a cancer causing mutation in human replication protein A. Mol Cancer Res 8:1017-26
Mason, Aaron C; Roy, Rupa; Simmons, Daniel T et al. (2010) Functions of alternative replication protein A in initiation and elongation. Biochemistry 49:5919-28
Kemp, Michael G; Mason, Aaron C; Carreira, Aura et al. (2010) An alternative form of replication protein a expressed in normal human tissues supports DNA repair. J Biol Chem 285:4788-97

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