Simian virus 40 (SV40) infects cells by binding to plasma membrane MHC class I molecules and then entering via a unique mechanism mediated by caveolae, rather than clathrin-coated pits. A notable feature of the unusual SV40 entry pathway is that it transports the virus to the endoplasmic reticulum (ER), rather than to endosomes. Importantly, the ER is the site in which the SV40 internal capsid proteins VP2 and VP3 separate from virions. VP2/3 then enter the cytosol, whereas virions and the major capsid protein VP1 remain in the ER. The goal of this project is to investigate the molecular features of SV40 that underlie cell recognition, entry and intracellular trafficking, and to clarify the process of release of the SV40 genome (the minichromosome) and its transport to the nucleus. Specific objectives are as follows. First, to determine the roles of the SV40 capsid proteins in the binding and intracellular trafficking of SV40, and to identify the molecular features of those proteins that underlie the unusual entry and trafficking of this virus. Second, to identify the.cellular compartment.into which wild type SV40 virions release their minichromosomes and the route of the minichromosomes to the nucleus. Third, to characterize the function of VP2 and VP3 in the processes of uncoating the minichromosome and transporting it out of the ER. A particular aim here is to determine whether myristylated VP2 has a role in these events. Fourth, to determine whether the cellular cytoskeleton has a role in transporting the minichromosome to the nucleus. If it does, then experiments will be carried out to identify the relevant motor proteins and to evaluate the possible role of VP2/3 in the cytoskeleton-mediated transport process. Experimental procedures will make use of confocal microscopy, in which virions, virus proteins, and cellular organelles will be visualized by immunofluorescent staining. In some experiments, fluorescent in situ hybrization (FISH) will be combined with immunocytochemistry, to visualize minichromosomes with respect to cellular organelles, the cytoskeleton, and virus proteins. Experimental samples will include wild type virus, constructed virus mutants, and in vitro assembled virus particles that contain specific combinations of virus proteins. Recent studies report evidence that SV40 infection may lead to neoplastic disease in humans, including mesotheliornas, osteosarcomas, childhood brain tumors, and non-Hodgkin's Iymphoma.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA100479-05
Application #
7415258
Study Section
Virology Study Section (VR)
Program Officer
Blair, Donald G
Project Start
2004-09-01
Project End
2010-10-31
Budget Start
2008-05-01
Budget End
2010-10-31
Support Year
5
Fiscal Year
2008
Total Cost
$196,767
Indirect Cost
Name
University of Massachusetts Amherst
Department
Microbiology/Immun/Virology
Type
Schools of Arts and Sciences
DUNS #
153926712
City
Amherst
State
MA
Country
United States
Zip Code
01003
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Kuksin, Dmitry; Norkin, Leonard C (2012) Disassociation of the SV40 genome from capsid proteins prior to nuclear entry. Virol J 9:158
Butin-Israeli, Veronika; Drayman, Nir; Oppenheim, Ariella (2010) Simian virus 40 infection triggers a balanced network that includes apoptotic, survival, and stress pathways. J Virol 84:3431-42
Ben-nun-Shaul, Orly; Bronfeld, Hagit; Reshef, Dan et al. (2009) The SV40 capsid is stabilized by a conserved pentapeptide hinge of the major capsid protein VP1. J Mol Biol 386:1382-91
Butin-Israeli, Veronika; Uzi, Dotan; Abd-El-Latif, Mahmoud et al. (2008) DNA-free recombinant SV40 capsids protect mice from acute renal failure by inducing stress response, survival pathway and apoptotic arrest. PLoS One 3:e2998
Daniels, Robert; Rusan, Nasser M; Wilbuer, Anne-Kathrin et al. (2006) Simian virus 40 late proteins possess lytic properties that render them capable of permeabilizing cellular membranes. J Virol 80:6575-87
Norkin, Leonard C; Kuksin, Dmitry (2005) The caveolae-mediated sv40 entry pathway bypasses the golgi complex en route to the endoplasmic reticulum. Virol J 2:38