TRIM5? restriction factors bind retroviral capsids after cell entry and restrict retroviral infection by blocking reverse transcription and/or integration of the viral genetic material. The C-terminal SPRY domain of TRIM5? is believed to form most of the capsid-TRIM5? interface as species-specific sequence variations within the SPRY domain account for differences in the viral specificity of the TRIM5?-mediated restriction. Most notably, recent evolution of the human TRIM5? SPRY resulted in the variant that has poor affinity for the HIV capsid, the vulnerability that contributed to the emergence of the AIDS pandemic when the simian immunodeficiency virus (SIV) passed from chimpanzees into a human host. Mutation or deletion of a single amino acid residue (R332) within the SPRY domain restores HIV restriction by the human TRIM5? variant. TRIM5? SPRY domains have proven refractory to structural and biophysical studies limiting our understanding of retroviral capsid recognition by TRIM5?. This research proposal seeks to fill that knowledge gap by solving the structures of several primate TRIM5? SPRY variants with distinct retroviral specificities and characterizing their interactions with the cognate retroviral capsids. The goal of the proposed research is to understand the mechanism of capsid recognition by TRIM5? restriction factors, elucidate why the human TRIM5? variant is not potent against HIV and to explore whether this defect could be alleviated by pharmacological or other means. The following three specific aims will be pursued: (1) The structures of the rhesus, human and possibly other TRIM5? SPRY domains will be solved using a novel experimental approach that combines NMR spectroscopy and X-ray crystallography. (2) Interaction of several SPRY-capsid pairs will be characterized using a variety of biophysical approaches. (3) High-resolution models of the SPRY-capsid complexes will be generated using computational methods and tested using mutagenesis and restriction assays.

Public Health Relevance

Retroviral restriction factors, cellular proteins whose expression protects cells against retroviral infection, are important components of innate immunity defenses that protect higher organisms against retroviral pathogens. Targeting viral evasion from the host's restriction factors is an attractive albeit largely unexplored intervention strategy for treatment and/or prevention of retroviral infections. The goal of the research proposed here is to understand the mechanism of capsid recognition by TRIM5? restriction factors, elucidate why the human TRIM5? variant is not potent against HIV and to explore whether this defect could be alleviated by pharmacological or other means.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI104476-03
Application #
8996114
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Kuo, Lillian S
Project Start
2014-02-01
Project End
2019-01-31
Budget Start
2016-02-01
Budget End
2017-01-31
Support Year
3
Fiscal Year
2016
Total Cost
Indirect Cost
Name
University of Texas Health Science Center
Department
Biochemistry
Type
Schools of Medicine
DUNS #
800772162
City
San Antonio
State
TX
Country
United States
Zip Code
78229
Wang, Zhonghua; Bhattacharya, Akash; White, Tommy et al. (2018) Functionality of Redox-Active Cysteines Is Required for Restriction of Retroviral Replication by SAMHD1. Cell Rep 24:815-823
Opp, Silvana; Fricke, Thomas; Shepard, Caitlin et al. (2017) The small-molecule 3G11 inhibits HIV-1 reverse transcription. Chem Biol Drug Des 89:608-618
Lam, Tonika; Kulp, Dennis V; Wang, Rui et al. (2016) Small Molecule Inhibition of Rab7 Impairs B Cell Class Switching and Plasma Cell Survival To Dampen the Autoantibody Response in Murine Lupus. J Immunol 197:3792-3805
Wang, Zhonghua; Bhattacharya, Akash; Villacorta, Jessica et al. (2016) Allosteric Activation of SAMHD1 Protein by Deoxynucleotide Triphosphate (dNTP)-dependent Tetramerization Requires dNTP Concentrations That Are Similar to dNTP Concentrations Observed in Cycling T Cells. J Biol Chem 291:21407-21413
Fricke, Thomas; Diaz-Griffero, Felipe (2016) HIV-1 Capsid Stabilization Assay. Methods Mol Biol 1354:39-47
Rajamanickam, Subapriya; Panneerdoss, Subbarayalu; Gorthi, Aparna et al. (2016) Inhibition of FoxM1-Mediated DNA Repair by Imipramine Blue Suppresses Breast Cancer Growth and Metastasis. Clin Cancer Res 22:3524-36
Hou, Caixia; Weidenbach, Stevi; Cano, Kristin E et al. (2016) Structures of mithramycin analogues bound to DNA and implications for targeting transcription factor FLI1. Nucleic Acids Res 44:8990-9004
St Gelais, Corine; Kim, Sun Hee; Ding, Lingmei et al. (2016) A Putative Cyclin-binding Motif in Human SAMHD1 Contributes to Protein Phosphorylation, Localization, and Stability. J Biol Chem 291:26332-26342
Bhattacharya, Akash; Wang, Zhonghua; White, Tommy et al. (2016) Effects of T592 phosphomimetic mutations on tetramer stability and dNTPase activity of SAMHD1 can not explain the retroviral restriction defect. Sci Rep 6:31353
Wang, Zhonghua; Bhattacharya, Akash; Ivanov, Dmitri N (2015) Identification of Small-Molecule Inhibitors of the HuR/RNA Interaction Using a Fluorescence Polarization Screening Assay Followed by NMR Validation. PLoS One 10:e0138780

Showing the most recent 10 out of 14 publications