This application will seek to better understand the mechanism by which the TRIM5alpha protein from rhesus macaques (rhTRIM5alpha) inhibits HIV-1 infection by defining the molecular and cellular biology of rhTRIM5alpha during restriction. We have identified a number of cellular proteins that associate with TRIM5alpha in cells. We have also developed powerful new methods to quantitatively characterize the association of TRIM5alpha with these cellular proteins. In the first aim, we will examine the connection between the ability of rhTRIM5alpha to self-associate and restrict retroviral infection. Specifically, we will characterize the effects of specific rhTRIM5alpha variants that have lost the ability to localize to cytoplasmic bodies due to specific mutations we have introduced into the linker2 region of the protein. We will identify the determinants in this region that mediate ability of rhTRIM5alpha to self-associate, measuring this ability with a novel, imaging based self-association assay we have recently developed. We will utilize the knowledge generated in these studies to develop rhTRIM5alpha variants with increased ability to restrict HIV-1 infection. In the second aim, we will define the role of the protein p62/sequestosome1 in regulating the degradation of TRIM5alpha. The known biological function of this protein, a scaffolding protein that mediates the shuttling of ubiquitylated cargo proteins to the proteasome, makes it an interesting candidate to play a role in the biology of TRIM5alpha mediated retroviral restriction. We will test the hypothesis that p62 conditionally regulates the ability of different cellular degradative pathways to degrade TRIM5alpha. In the third aim, we will use quantitative imaging methods to define the events that occur in cells when restriction sensitive virions enter the cytoplasm of target cells. By monitoring the presence of biologically relevant cellular proteins in TRIM5alpha cytoplasmic bodies during restriction, we will be able g restriction, we will be able to dissect and develop an understanding of this critical biological process.

Public Health Relevance

Primates, including humans, possess proteins, such as TRIM5alpha that have evolved for millions of years to effectively combat viral infection. Understanding the mechanisms by which TRIM5alpha mediates its antiviral effects could allow this knowledge to be harnessed in the form of antiviral therapy for people infected with HIV-1

National Institute of Health (NIH)
National Institute of Allergy and Infectious Diseases (NIAID)
Research Project (R01)
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AIDS Molecular and Cellular Biology Study Section (AMCB)
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Lawrence, Diane M
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Loyola University Chicago
Schools of Medicine
United States
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Lamichhane, Rajan; Mukherjee, Santanu; Smolin, Nikolai et al. (2017) Dynamic conformational changes in the rhesus TRIM5? dimer dictate the potency of HIV-1 restriction. Virology 500:161-168
Imam, Sabrina; Talley, Sarah; Nelson, Rachel S et al. (2016) TRIM5? Degradation via Autophagy Is Not Required for Retroviral Restriction. J Virol 90:3400-10
Campbell, Edward M; Weingart, Jared; Sette, Paola et al. (2016) TRIM5?-Mediated Ubiquitin Chain Conjugation Is Required for Inhibition of HIV-1 Reverse Transcription and Capsid Destabilization. J Virol 90:1849-57
Campbell, Edward M; Hope, Thomas J (2015) HIV-1 capsid: the multifaceted key player in HIV-1 infection. Nat Rev Microbiol 13:471-83
Sastri, Jaya; Johnsen, Laura; Smolin, Nikolai et al. (2014) Restriction of HIV-1 by rhesus TRIM5? is governed by alpha helices in the Linker2 region. J Virol 88:8911-23
Campbell, Edward (2014) Are we done monkeying around with TRIM5?? Mol Ther 22:1072-1073
Lukic, Zana; Dharan, Adarsh; Fricke, Thomas et al. (2014) HIV-1 uncoating is facilitated by dynein and kinesin 1. J Virol 88:13613-25
Fricke, Thomas; White, Tommy E; Schulte, Bianca et al. (2014) MxB binds to the HIV-1 core and prevents the uncoating process of HIV-1. Retrovirology 11:68
Lukic, Zana; Goff, Stephen P; Campbell, Edward M et al. (2013) Role of SUMO-1 and SUMO interacting motifs in rhesus TRIM5?-mediated restriction. Retrovirology 10:10
Lukic, Zana; Campbell, Edward M (2012) The cell biology of TRIM5?. Curr HIV/AIDS Rep 9:73-80

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