Related Experiment Video
Updated: Oct 22, 2025
08:01
Detection of Human Immunodeficiency Virus Type 1 HIV-1 Antisense Protein ASP RNA Transcripts in Patients by Strand-Specific RT-PCR
Published on: November 27, 2019
7.7K
HTLV-2 Encoded Antisense Protein APH-2 Suppresses HIV-1 Replication
Rajkumar Londhe1,2, Smita Kulkarni1,2
1Division of Virology, ICMR-National AIDS Research Institute, Pune 411026, Maharashtra, India.
Viruses
|August 28, 2021
Summary
The Human T-cell Leukemia Virus Type 2 (HTLV-2) antisense protein (APH-2) inhibits HIV-1 replication by blocking viral release and Tat-mediated transactivation. This study clarifies APH-2
Area of Science:
- Virology
- Molecular Biology
- Immunology
Background:
- Human T-cell Leukemia Virus Type 2 (HTLV-2) antisense protein (APH-2) regulates HTLV-2 latency.
- HTLV-2 and Human Immunodeficiency Virus Type 1 (HIV-1) co-infections are common, but APH-2's role in HIV-1 replication is unclear.
- Understanding APH-2's function in co-infection is crucial for developing therapeutic strategies.
Purpose of the Study:
- To investigate the role of HTLV-2 APH-2 in regulating HIV-1 replication kinetics.
- To elucidate the molecular mechanisms by which APH-2 influences HIV-1 replication.
- To determine if APH-2 affects HIV-1 Tat transactivation and viral release.
Main Methods:
- Overexpression of APH-2 in 293T cells and HIV-1 gag expression vectors.
- Analysis of HIV-1 pNL4.3 release and cellular gag expression.
- Luciferase reporter assays to assess HIV-1 Tat transactivation of the HIV-1 LTR.
- Site-directed mutagenesis of the APH-2 IXXLL motif.
Main Results:
- APH-2 overexpression dose-dependently inhibited HIV-1 pNL4.3 release and affected cellular gag expression.
- APH-2 inhibited HIV-1 Tat-mediated transactivation of the HIV-1 LTR-driven luciferase expression.
- Mutations in the APH-2 N-terminal IXXLL motif abolished the inhibitory effect on Tat transactivation.
Conclusions:
- HTLV-2 APH-2 negatively regulates HIV-1 replication through multiple mechanisms.
- APH-2 inhibits HIV-1 replication by suppressing Tat-mediated transactivation and hindering viral release via effects on gag expression.
- The IXXLL motif in APH-2 is critical for its ability to downregulate Tat-mediated transactivation.
Related Concept Videos
01:29Viruses with RNA Genomes
255
RNA viruses are categorized into positive-strand, negative-strand, or double-stranded groups based on their genomic structure and replication mechanisms. This classification dictates how they exploit host cellular machinery for protein synthesis and replication. Some RNA viruses also utilize reverse transcription as part of their life cycle, further diversifying their replication strategies.Positive-Strand RNA VirusesPositive-strand RNA viruses have genomes that function directly as messenger...
255
02:28Leaky Scanning
5.3K
During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA. Marilyn Kozak discovered that the sequence RCCAUGG (where R...
5.3K
01:10Retrovirus Life Cycles
47.7K
Retroviruses have a single-stranded RNA genome that undergoes a special form of replication. Once the retrovirus has entered the host cell, an enzyme called reverse transcriptase synthesizes double-stranded DNA from the retroviral RNA genome. This DNA copy of the genome is then integrated into the host’s genome inside the nucleus via an enzyme called integrase. Consequently, the retroviral genome is transcribed into RNA whenever the host’s genome is transcribed, allowing the...
47.7K
01:26Size and Structure of Viral Genomes
273
Viral genomes exhibit remarkable diversity in size, structure, and composition, influencing their replication strategies and interactions with host cells. These genomes consist of either DNA or RNA and may be linear or circular. Additionally, they can be single-stranded or double-stranded, with each configuration affecting how the virus propagates within a host. RNA viruses, for instance, generally have smaller genomes than DNA viruses, a factor that contributes to their high mutation rates and...
273