AID
            recruits the
            RNA
            exosome to degrade
            HIV
            ‐1 nascent transcripts through interaction with the Tat‐P‐
            TEF
            b‐
            TAR RNP
            complex

The Rev protein of human immunodeficiency virus type 1 (HIV-1) facilitates the nuclear export of unspliced and partially spliced viral RNAs. In the absence of Rev, these intron-containing HIV-1 RNAs are retained in the nucleus. The basis for nuclear retention is unclear and is an important aspect of Rev regulation. Here we use in situ hybridization and digital imaging microscopy to examine the intranuclear distributions of intron-containing HIV RNAs and to determine their spatial relationships to intranuclear structures. HeLa cells were transfected with an HIV-1 expression vector, and viral transcripts were localized using oligonucleotide probes specific for the unspliced or spliced forms of a particular viral RNA. In the absence of Rev, the unspliced viral RNAs were predominantly nuclear and had two distinct distributions. First, a population of viral transcripts was distributed as approximately 10-20 intranuclear punctate signals. Actinomycin D chase experiments indicate that these signals represent nascent transcripts. A second, stable population of viral transcripts was dispersed throughout the nucleoplasm excluding nucleoli. Rev promoted the export of this stable population of viral RNAs to the cytoplasm in a time-dependent fashion. Significantly, the distributions of neither the nascent nor the stable populations of viral RNAs coincided with intranuclear speckles in which splicing factors are enriched. Using splice-junction-specific probes, splicing of human beta-globin pre-mRNA occurred cotranscriptionally, whereas splicing of HIV-1 pre-mRNA did not. Taken together, our results indicate that the nucleolus and intranuclear speckles are not involved in Rev regulation, and provide further evidence that efficient splicing signals are critical for cotranscriptional splicing.

Download Full-text

Association of Potent Human Antiviral Cytidine Deaminases with 7SL RNA and Viral RNP in HIV-1 Virions

Journal of Virology ◽

10.1128/jvi.01632-10 ◽

2010 ◽

Vol 84 (24) ◽

pp. 12903-12913 ◽

Cited By ~ 23

Author(s):

Wenyan Zhang ◽

Juan Du ◽

Kevin Yu ◽

Tao Wang ◽

Xiong Yong ◽

...

Keyword(s):

Rna Binding ◽

Signal Recognition Particle ◽

Viral Inhibition ◽

Cytidine Deaminases ◽

Amino Terminal ◽

7Sl Rna ◽

Rnp Complex ◽

Rna Interaction ◽

Anti Hiv ◽

Hiv 1

ABSTRACT 7SL RNA promotes the formation of the signal recognition particle that targets secretory and membrane proteins to the endoplasmic reticulum. 7SL RNA is also selectively packaged by many retroviruses, including HIV-1. Here, we demonstrate that 7SL RNA is an integral component of the viral ribonucleoprotein (RNP) complex containing Gag, viral genomic RNA, and \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathbf{tRNA}_{3}^{Lys}\) \end{document} . Only the potent anti-HIV-1 cytidine deaminases can bind to 7SL RNA and target to HIV-1 RNP. A conserved motif in the amino-terminal region of A3G is important for 7SL RNA interaction. The weak anti-HIV-1 A3C did not interact with 7SL RNA and failed to target to viral RNPs, despite efficient virion packaging. However, a chimeric construct of A3C plus the 7SL-binding amino terminus of A3G did target to viral RNPs and showed enhanced anti-HIV-1 activity. 7SL RNA binding is a conserved feature of human anti-HIV-1 cytidine deaminases. Thus, potent anti-HIV-1 cytidine deaminases have evolved to possess a unique RNA-binding ability for precise HIV-1 targeting and viral inhibition.

Download Full-text

The Role of DNA Repair Complex DNA-PK in HIV-1 Transcription

Proceedings ◽

10.3390/proceedings2020050133 ◽

2020 ◽

Vol 50 (1) ◽

pp. 133

Author(s):

Olga Shadrina ◽

Andrey Anisenko ◽

Marina Gottikh

Keyword(s):

Dna Repair ◽

Transcription Factors ◽

Firefly Luciferase ◽

Coding Region ◽

Dna Breaks ◽

Rnp Complex ◽

The Impact ◽

Hiv 1

The human DNA-dependent protein kinase (DNA-PK), composed of the heterodimeric protein Ku and catalytic subunit DNA-PKcs, is a sensor of double-strand DNA breaks in the non-homologous end-joining DNA repair pathway. The key role of DNA-PK in the post-integrational repair of HIV-1 has been shown. It has also been suggested that DNA-PK can participate in the regulation of HIV transcription, although the mechanism is unclear. To clarify the impact of each DNA-PK subunit on the transcription of HIV-1, HEK 293T cells, in which each of the DNA-PK components was depleted, were transfected with reporter vectors containing firefly luciferase under the control of HIV LTR promoter. We detected a positive influence of both Ku subunits, but not of DNA-PKcs, on the transcription from the HIV promoter. Ku is known to interact with HIV-1 TAR RNA, playing an essential role in viral transcription; nonetheless, the deletion of the TAR-coding region from LTR did not alter the Ku effect. Human small noncoding 7SK RNA participates in HIV-1 transcription. The direct binding of recombinant Ku and in vitro transcribed 7SK RNA was demonstrated using EMSA. In addition, we identified the interactions of endogenous Ku with proteins HEXIM1 and Cdk9 from the 7SK RNP complex. These results suggest that Ku exerts its effects on HIV-1 transcription via interaction with the 7SK RNP complex. However, we cannot rule out an indirect effect of Ku on transcription via the regulation of the levels of some transcription factors participating in HIV-1 transcription. We performed a transcriptome analysis of wild type HEK 293T cells and those with depleted DNA-PK subunits. The genes regulated by each subunit were defined and the genes that were mainly dependent on Ku subunits were selected. Among them, we identified transcription factors enhancing HIV-1 transcription, whose levels were downregulated in Ku-depleted cells. The study was supported by RFBR grant №18-04-00542 and RSF grant №17-14-01107.

Download Full-text

Ultrastructural observations of human monocytes infected with HIV-1

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100084843 ◽

1991 ◽

Vol 49 ◽

pp. 108-109

Author(s):

James K. Koehler ◽

Steven G. Reed ◽

Joao S. Silva

Keyword(s):

Gradient Centrifugation ◽

Virus Production ◽

Human Monocyte ◽

Red Cross ◽

Human Monocytes ◽

Blood Monocytes ◽

Hiv Replication ◽

Electron Microscopic ◽

Ultrastructural Studies ◽

Hiv 1

As part of a larger study involving the co-infection of human monocyte cultures with HIV and protozoan parasites, electron microscopic observations were made on the course of HIV replication and infection in these cells. Although several ultrastructural studies of the cytopathology associated with HIV infection have appeared, few studies have shown the details of virus production in “normal,” human monocytes/macrophages, one of the natural targets of the virus, and suspected of being a locus of quiescent virus during its long latent period. In this report, we detail some of the interactions of developing virons with the membranes and organelles of the monocyte host.Peripheral blood monocytes were prepared from buffy coats (Portland Red Cross) by Percoll gradient centrifugation, followed by adherence to cover slips. 90-95% pure monocytes were cultured in RPMI with 5% non-activated human AB serum for four days and infected with 100 TCID50/ml of HIV-1 for four hours, washed and incubated in fresh medium for 14 days.

Download Full-text