Studies on the self assembly of viral capsid proteins have served as a model system for intermolecular interactions. The major capsid protein of simian virus 40 (SV40) is synthesized in the cytoplasm of infected cells and is transported to the nucleus shortly after synthesis for viral assembly. The protein forms the pentameric capsomeres of the SV40 capsid. Vp1 pentamers are detectable both in the cytoplasm of infected cells and in vitro. The nature of the interactions involved in Vp1 capsomere formation, as well as the residues involved, are not known. Cytoplasmic Vp1 pentamer formation is not only the initial stage of SV40 assembly, but may also have a role in the efficient nuclear transport of Vp1. Here, we propose to examine the chemical nature and the amino acid residues involved in Vp1 multimer formation in vitro. Results from the proposed experiments will later be used to study the role of pentamer formation in the transport of Vp1 to the nucleus. %%% Due to the relative simplicity of its gene structure, simian virus 40 has been used as a model system for studies of virus assembly, structure, and function. The virus assembles in the nucleus of the host cell, and thus it is also an ideal model system for study of nuclear localization and nuclear localization signals. This project will take advantage of these features of SV40 to increase our understanding of viral assembly and nucleocytoplasmic trafficking. In addition, the project will provide an opportunity and a vehicle for undergraduate student involvement in biological research.
