HIV-1 Circular RNA Enhances Viral Transcription via Tat Binding
Publication Title: HIV-1-encoded circular RNA enhances viral transcription through Tat binding
Summary
- Question
- This study examined whether the human immunodeficiency virus type 1 (HIV-1), a retrovirus known for its complex RNA processing, produces circular RNA (circRNA). The researchers aimed to identify and characterize any circRNA encoded by HIV-1 and determine its functional role in viral replication.
- Why it Matters
- HIV-1 is a major global health challenge, and understanding its replication mechanisms is essential for developing new treatments. CircRNAs are stable RNA molecules that can regulate cellular and viral processes, but their role in HIV-1 infection has been largely unexplored. Identifying and understanding HIV-1-encoded circRNA could reveal new pathways for viral regulation and offer potential targets for antiviral therapies.
- Methods
- The researchers used high-throughput RNA sequencing and biochemical methods to identify circRNAs in HIV-1-infected cells. They confirmed the presence of circHIV, a specific HIV-1-encoded circRNA, through reverse transcription quantitative PCR (RT-qPCR) and Northern blot analyses. Functional studies involved manipulating circHIV levels using RNA knockdown and overexpression techniques in cell culture models.
- Key Findings
- The researchers discovered that HIV-1 produces a circRNA called circHIV during infection. CircHIV is packaged into viral particles and binds to the HIV-1 Tat protein, a key regulator of viral transcription. Functional experiments showed that circHIV enhances transcription from the HIV-1 genome, thereby promoting viral replication. Unlike its linear counterpart, circHIV uniquely interacts with Tat, suggesting its circular structure is critical for function.
- Implications
- These findings highlight circHIV as a novel regulator of HIV-1 transcription and replication. CircHIV's ability to amplify viral gene expression through Tat binding suggests it plays a significant role in HIV-1 pathogenesis. Targeting circHIV or its interaction with Tat could represent a new therapeutic strategy to inhibit viral replication and reduce disease progression.
- Next Steps
Future research should investigate the mechanisms of how circHIV functions during infection and explore its interactions with other cellular molecules. Studies are needed to evaluate the potential of circHIV as a therapeutic target and to assess whether similar circRNAs exist in other retroviruses.
- Funding Information
- This research was supported by the National Institutes of Health (awards T32AI07019 and R35GM142687). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. Funding was also provided by the Rita Allen Foundation, the Paul G. Allen Frontiers Group, and the Francis Trudeau Fellowship. Yale University also provided funding and support for this research.
Full Citation
Obi P, Yan L, Dujsikova A, Yeh Y, Li I, Mueller N, Back H, Yi B, Liu N, Mbadugha F, Yu H, Brown C, St. Denis K, Landry M, Sumigray K, Emu B, Ho Y, Chen Y. HIV-1-encoded circular RNA enhances viral transcription through Tat binding. Nature Microbiology 2026, 11: 1008-1021. PMID: 41826685, PMCID: PMC13056509, DOI: 10.1038/s41564-026-02271-0.
This AI-assisted summary has been reviewed and approved by at least one of the study's authors to ensure it accurately reflects the research.
Authors
Prisca Obi
First AuthorGrace Chen, PhD
Last AuthorAssistant Professor