The nucleolus is a plurifunctional organelle with dynamic protein exchange involved in diverse aspects of cell biology. Additionally, the nucleolus has been shown to have a role in the replication of numerous viruses, which includes HIV-1. Several groups have reported HIV-1 vRNA localization within the nucleolus. Moreover, it has been demonstrated the HIV-1 Rev protein localizes to the nucleolus and interacts with nucleolar proteins, including NPM1. Despite evidence for a nucleolar involvement during replication, a functional link has not been demonstrated. I investigated whether introncontaining vRNAs have a Rev-mediated nucleolar localization step prior to export. Furthermore, I examined whether NPM1 mediates Rev nucleolar localization, participates in Rev function, and/or post-transcriptional events during viral replication. I used coupled RNA fluorescence in situhybridization and indirect immunofluorescence to visualize intron-containing vRNA relative to the nucleolus in the absence or presence of Rev expression. An RNAi-based approach was used to examine the role of NPM1 in Rev function and viral replication in cell lines and primary human macrophages. My research findings support a model for a Rev-independent nucleolar localization step of introncontaining vRNA prior to export. Intriguingly, my results also suggest NPM1 does not participate in Rev nucleolar localization or Rev-mediated vRNA export, as previously proposed. Rather, my findings support a novel role for NPM1, the cytoplasmic localization and utilization of a select class of Rev-dependent vRNAs. Collectively, my findings provide novel insight for a functional role of the nucleolus and NPM1 in HIV-1 replication, which enhances our current understanding of HIV-1 biology.
| Identifer | oai:union.ndltd.org:umassmed.edu/oai:escholarship.umassmed.edu:gsbs_diss-1692 |
| Date | 21 August 2013 |
| Creators | Schmidt, Tracy E. |
| Publisher | eScholarship@UMassChan |
| Source Sets | University of Massachusetts Medical School |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Morningside Graduate School of Biomedical Sciences Dissertations and Theses |
| Rights | Copyright is held by the author, with all rights reserved. |
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