Date of Award

Spring 2011

Author's School

College of Arts & Sciences

Author's Department/Program



HIV is a retrovirus that infects CD4+ human T cells and results in profound immunodeficiency. Viral protein X (Vpx) is an accessory protein encoded by viruses of the HIV-2/SIV sooty mangabey (SIVsm) lineage of primate lentiviruses that are essential for infection of monocyte-derived cells, like macrophages. Viral protein R (Vpr) is an accessory protein that is present in both HIV-1 and HIV-2, which induces cell cycle arrest at the G2 phase of the cell cycle. Recent research has shown that Vpr and Vpx function through interaction with the Cullin 4 E3 ubiquitin ligase, through an association with Vpr-binding protein (VprBP), also known as DDB-1-Cul4-associated factor 1 (DCAF-1). Interaction of Vpx with DCAF-1 is essential for Vpx to overcome cellular restriction to reverse transcription of HIV in macrophages. It has been hypothesized that Vpx increases E3 ubiquitin ligase activity, resulting in the degradation of a cellular protein that blocks reverse transcription. Through yeast 2-hybrid screens of a human T cell cDNA library, we identified proteins that bind DCAF-1, in order to identify the target of Vpx activity.


English (en)

Advisor/Committee Chair

Lee Ratner

Second Advisor

Xiaogang Cheng

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