A potential role for the novel human helicase, G4‐Resolvase 1 in HIV‐1 RNA packaging

HIV‐1 is a retrovirus that infects human immune cells and is responsible for causing aquired immune deficiency syndrome (AIDS). An estimated 34 million people have died from AIDS‐related causes so far, including 1.2 million in 2014(Worldwide). After the viral HIV particle enters the host cell cytoplasm, its RNA is then reverse transcribed into double‐stranded DNA and integrated into the host genome. The provirus is transcribed to produce viral RNA, which is then, exported from nucleus to cytoplasm. The full length and un‐spliced RNA is used for packaging or translated for viral proteins. Previous work has demonstrated that an array of human proteins bind to HIV‐1 RNA. One such protein is G4‐Resolvase1 (G4R1) (aliases: DHX36, RHAU), a multifunctional helicase required for eliciting an interferon immune response to viral nucleic acid. Additionally, G4R1 was discovered as the primary protein in human cells responsible for unwinding G‐quadruplex DNA and RNA structures. G‐quadruplexes are stable nucleic acid secondary structures that form within G‐rich strands of DNA or RNA. These structures are enriched in gene promoters of the HIV and have been known to be involved in transcriptional regulation by antagonizing transcription and also potentially affecting translational expression. We hypothesize that G4R1 affects HIV transcription and subsequent packaging of RNA into viral particles. To test our hypothesis, we utilized HeLa cells containing a tetracycline‐inducible siRNA targeted to knockdown G4R1 protein expression. Thus far, I have confirmed G4R1 knockdown in HeLa cells using western blot analysis and ongoing work includes testing the effect of G4R1 knockdown on HIV RNA packaging and interferon immune response to HIV expression.