HIV-1 and Human PEG10 Frameshift Elements Are Functionally Distinct and Distinguished by Novel Small Molecule...

Area of Science:

• Molecular Biology
• Virology
• Drug Discovery

Background:

• Frameshifting in mRNA translation produces proteins from overlapping reading frames.
• In HIV-1, frameshifting is essential for synthesizing viral enzymes like protease, reverse transcriptase, and integrase, maintaining a critical structural protein to enzyme ratio for replication.
• Human genes like PEG10 also utilize -1 frameshifting, raising concerns about off-target effects of potential antiviral drugs.

Purpose of the Study:

• To compare the functional characteristics of HIV-1 and PEG10 frameshift elements.
• To evaluate the specificity of frameshift modulators on HIV-1 versus human frameshift elements.
• To explore the potential for developing targeted antiviral therapies against HIV-1 without impacting human gene expression.

Main Methods:

• Comparative analysis of HIV-1 and PEG10 frameshift elements.
• High-throughput screening of a compound library to identify frameshift modulators.
• Reporter assay systems to quantify frameshifting efficiency.
• Specific assays in virally-infected cells to assess protease:gag protein ratios and viral infectivity.

Main Results:

• HIV-1 and PEG10 frameshift elements exhibit distinct functional characteristics and frameshifting occurs at multiple sites within each.
• Identified compounds enhanced HIV-1 frameshifting by up to 2.5-fold, altering the protease:gag protein ratio in infected cells.
• The most effective compounds for HIV-1 did not affect PEG10 frameshifting, and one compound even inhibited it, indicating differential responses.
• Modulation of frameshifting did not significantly impact viral infectivity in initial trials.

Conclusions:

• HIV-1 and human frameshift elements possess unique properties that can be exploited for targeted drug development.
• Compounds targeting HIV-1 frameshifting show specificity and do not appear to interfere with human gene frameshifting mechanisms like PEG10.
• This distinctiveness offers a promising avenue for developing novel antiviral therapeutics against HIV-1 with reduced risk of off-target effects on host cellular processes.