Despite great advances in AIDS diagnosis and treatment, the continuing devastation of the AIDS epidemic demands continuing efforts to understand all aspects of HIV replication, and to develop new methods for its inhibition. In pursuit of these goals, we have sought to define the activities of the HIV-1 structural (Gag) proteins so as to design antivirals that interfere with these functions. The Gag proteins are attractive targets since they perform multiple roles during the life cycle. The proteins initially are synthesized as N-terminally myristylated precursor (PrGag) proteins that employ their N-terminal matrix (MA) domains to target delivery to plasma membrane (PM) virus assembly sites. Evidence indicates that MA preferentially binds to the signaling phospholipid phosphatidylinositol 4,5 bisphosphate (PI[4,5]P2), and that HIV-1 virus membranes are enriched for lipid raft constituents such as cholesterol, sphingomyelin, and ceramide. MA also has been shown to mediate the incorporation of the HIV-1 envelope (Env) glycoprotein complex into virus particles, and interacts with the cytoplasmic tail (CT) of the transmembrane (TM, gp41) portion of Env. Retrovirus matrix proteins also have been known to bind nucleic acids, and we recently discovered that the RNA and PI(4,5)P2 binding sites on MA overlap, supporting a new model in which RNA binding protects MA from association with inappropriate cellular membranes prior to PrGag delivery to the PM. Using our previous studies and preliminary results as a foundation, we propose novel approaches to dissect the mechanisms of matrix protein membrane, nucleic acid, and envelope protein binding, and to characterize methods for their inhibition. Our results will help elucidate how the HIV assembly machinery operates;and will lead to the development of Gag-targeted antivirals, and an understanding of how they work. To achieve these ends, our specific aims are as follows: 1. Characterization of the nucleic acid binding activity of the HIV-1 matrix protein. 2. Determination of membrane binding properties of HIV-1 MA. 3. Elucidation of HIV-1 matrix-envelope protein interactions.

Public Health Relevance

Our investigations focus on an analysis of the activities of the HIV-1 precursor Gag (PrGag) protein, the structural protein of HIV. We propose to characterize the functions of the matrix (MA) Gag protein and how they may be inhibited. These studies are of direct public health relevance in that they will lead to the development of new Gag- targeted anti-HIV therapeutics and an understanding of how they work.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM060170-14
Application #
8456996
Study Section
AIDS Discovery and Development of Therapeutics Study Section (ADDT)
Program Officer
Sakalian, Michael
Project Start
1999-09-01
Project End
2016-04-30
Budget Start
2013-05-01
Budget End
2014-04-30
Support Year
14
Fiscal Year
2013
Total Cost
$308,781
Indirect Cost
$108,274
Name
Oregon Health and Science University
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
096997515
City
Portland
State
OR
Country
United States
Zip Code
97239
Barklis, Eric; Staubus, August O; Mack, Andrew et al. (2018) Lipid biosensor interactions with wild type and matrix deletion HIV-1 Gag proteins. Virology 518:264-271
Alfadhli, Ayna; Mack, Andrew; Harper, Logan et al. (2016) Analysis of quinolinequinone reactivity, cytotoxicity, and anti-HIV-1 properties. Bioorg Med Chem 24:5618-5625
Alfadhli, Ayna; Mack, Andrew; Ritchie, Christopher et al. (2016) Trimer Enhancement Mutation Effects on HIV-1 Matrix Protein Binding Activities. J Virol 90:5657-5664
Ritchie, Christopher; Cylinder, Isabel; Platt, Emily J et al. (2015) Analysis of HIV-1 Gag protein interactions via biotin ligase tagging. J Virol 89:3988-4001
López, Claudia S; Sloan, Rachel; Cylinder, Isabel et al. (2014) RRE-dependent HIV-1 Env RNA effects on Gag protein expression, assembly and release. Virology 462-463:126-34
Alfadhli, Ayna; Barklis, Eric (2014) The roles of lipids and nucleic acids in HIV-1 assembly. Front Microbiol 5:253
López, Claudia S; Tsagli, Seyram M; Sloan, Rachel et al. (2013) Second site reversion of a mutation near the amino terminus of the HIV-1 capsid protein. Virology 447:95-103
Alfadhli, Ayna; McNett, Henry; Eccles, Jacob et al. (2013) Analysis of small molecule ligands targeting the HIV-1 matrix protein-RNA binding site. J Biol Chem 288:666-76
Noviello, Colleen M; Lopez, Claudia S; Kukull, Ben et al. (2011) Second-site compensatory mutations of HIV-1 capsid mutations. J Virol 85:4730-8
Alfadhli, Ayna; McNett, Henry; Tsagli, Seyram et al. (2011) HIV-1 matrix protein binding to RNA. J Mol Biol 410:653-66

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