HIV-1 integrase (IN) is essential for viral replication and thus is an important therapeutic target. During the early stages of viral replication, a tetramer of HIV-1 IN catalyzes integration of reverse transcribed viral DNA into the host genome. The ordered multimerization of IN in the presence of viral DNA is critical for IN catalytic activity. Cellular cofactor LEDGF/p75 binds to the pre-assembled IN- viral DNA complex and tethers the nucleoprotein complex to active genes, thus ensuring effective integration. Allosteric integrase inhibitors (ALLINIs) are a novel class of integrase inhibitors that bind at the LEDGF/p75 binding site at the IN dimer interface and are capable of triggering aberrant IN multimerization. In addition, HIV-1 virions produced in the presence of ALLINIs display abnormal morphology of the virion cores and are defective for subsequent reverse transcription and integration in target cells. Interestingly, these phenotypes are similar to certain IN mutants, which have been termed class II mutants. Collectively, the studies with ALLINIs and select IN class II mutants suggest that HIV-1 IN plays a key role during late stage HIV-1 replication. However, the underlying mechanism is not clear. The present application will test the following hypothesis: ordered IN multimerization is important for its interaction with viral RNA during the late stage viral replication. Therefore, we propose the following two specific aims.
Aim 1 will explore the significance of HIV-1 IN interactions with RNA for formation of the functional ribonuleoprotein complexes during the late stage viral replication.
Aim 2 will characterize IN mutants that affect IN multimerization and/or IN- LEDGF/p75 binding. Mechanistic and structural details that will emerge from these studies will inform drug discovery efforts to develop improved ALLINIs for their clinical application.

Public Health Relevance

HIV-1 integrase catalytic activity is essential during the early steps of HIV-1 infection and has been exploited as an antiviral target in the treatment of HIV-1 infected patients. In addition, recent studies with developmental compounds, termed allosteric IN inhibitors, have highlighted an essential role of integrase for correctly formed cores during late stage viral replication. The present proposal will investigate the significance of interaction between ordered multimeric forms of IN and RNA for the formation of infectious virions.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Exploratory/Developmental Grants (R21)
Project #
1R21AI110270-01A1
Application #
8732362
Study Section
AIDS Molecular and Cellular Biology Study Section (AMCB)
Program Officer
Sharma, Opendra K
Project Start
2014-02-01
Project End
2016-01-31
Budget Start
2014-02-01
Budget End
2015-01-31
Support Year
1
Fiscal Year
2014
Total Cost
$173,016
Indirect Cost
$60,516
Name
Ohio State University
Department
Other Health Professions
Type
Schools of Pharmacy
DUNS #
832127323
City
Columbus
State
OH
Country
United States
Zip Code
43210
Slaughter, Alison; Jurado, Kellie A; Deng, Nanjie et al. (2014) The mechanism of H171T resistance reveals the importance of N?-protonated His171 for the binding of allosteric inhibitor BI-D to HIV-1 integrase. Retrovirology 11:100
Shkriabai, Nikoloz; Dharmarajan, Venkatasubramanian; Slaughter, Alison et al. (2014) A critical role of the C-terminal segment for allosteric inhibitor-induced aberrant multimerization of HIV-1 integrase. J Biol Chem 289:26430-40