scholarly journals Chemically Modified Oligonucleotides Modulate an Epigenetically Varied and Transient Form of Transcription Silencing of HIV-1 in Human Cells

2012 ◽  
Vol 1 ◽  
pp. e16 ◽  
Author(s):  
Stuart Knowling ◽  
Kenneth Stapleton ◽  
Anne-Marie W Turner ◽  
Eugen Uhlmann ◽  
Thomas Lehmann ◽  
...  
Biomedicines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 628
Author(s):  
Dagmara Baraniak ◽  
Jerzy Boryski

This review covers studies which exploit triazole-modified nucleic acids in the range of chemistry and biology to medicine. The 1,2,3-triazole unit, which is obtained via click chemistry approach, shows valuable and unique properties. For example, it does not occur in nature, constitutes an additional pharmacophore with attractive properties being resistant to hydrolysis and other reactions at physiological pH, exhibits biological activity (i.e., antibacterial, antitumor, and antiviral), and can be considered as a rigid mimetic of amide linkage. Herein, it is presented a whole area of useful artificial compounds, from the clickable monomers and dimers to modified oligonucleotides, in the field of nucleic acids sciences. Such modifications of internucleotide linkages are designed to increase the hybridization binding affinity toward native DNA or RNA, to enhance resistance to nucleases, and to improve ability to penetrate cell membranes. The insertion of an artificial backbone is used for understanding effects of chemically modified oligonucleotides, and their potential usefulness in therapeutic applications. We describe the state-of-the-art knowledge on their implications for synthetic genes and other large modified DNA and RNA constructs including non-coding RNAs.


2007 ◽  
Vol 81 (22) ◽  
pp. 12218-12226 ◽  
Author(s):  
Jennifer Lin ◽  
Bryan R. Cullen

ABSTRACT The question of whether retroviruses, including human immunodeficiency virus type 1 (HIV-1), interact with the cellular RNA interference machinery has been controversial. Here, we present data showing that neither HIV-1 nor human T-cell leukemia virus type 1 (HTLV-1) expresses significant levels of either small interfering RNAs or microRNAs in persistently infected T cells. We also demonstrate that the retroviral nuclear transcription factors HIV-1 Tat and HTLV-1 Tax, as well as the Tas transactivator encoded by primate foamy virus, fail to inhibit RNA interference in human cells. Moreover, the stable expression of physiological levels of HIV-1 Tat did not globally inhibit microRNA production or expression in infected human cells. Together, these data argue that HIV-1 and HTLV-1 neither induce the production of viral small interfering RNAs or microRNAs nor repress the cellular RNA interference machinery in infected cells.


2017 ◽  
Vol 12 (6) ◽  
pp. 1674-1682 ◽  
Author(s):  
Thomas A. Hilimire ◽  
Jeffrey M. Chamberlain ◽  
Viktoriya Anokhina ◽  
Ryan P. Bennett ◽  
Oliver Swart ◽  
...  
Keyword(s):  

2004 ◽  
Vol 279 (15) ◽  
pp. 14509-14519 ◽  
Author(s):  
David J. Segal ◽  
João Gonçalves ◽  
Scott Eberhardy ◽  
Christina H. Swan ◽  
Bruce E. Torbett ◽  
...  

2020 ◽  
Vol 48 (19) ◽  
pp. 10890-10908
Author(s):  
Smitha Srinivasachar Badarinarayan ◽  
Irina Shcherbakova ◽  
Simon Langer ◽  
Lennart Koepke ◽  
Andrea Preising ◽  
...  

Abstract Although endogenous retroviruses (ERVs) are known to harbor cis-regulatory elements, their role in modulating cellular immune responses remains poorly understood. Using an RNA-seq approach, we show that several members of the ERV9 lineage, particularly LTR12C elements, are activated upon HIV-1 infection of primary CD4+ T cells. Intriguingly, HIV-1-induced ERVs harboring transcription start sites are primarily found in the vicinity of immunity genes. For example, HIV-1 infection activates LTR12C elements upstream of the interferon-inducible genes GBP2 and GBP5 that encode for broad-spectrum antiviral factors. Reporter assays demonstrated that these LTR12C elements drive gene expression in primary CD4+ T cells. In line with this, HIV-1 infection triggered the expression of a unique GBP2 transcript variant by activating a cryptic transcription start site within LTR12C. Furthermore, stimulation with HIV-1-induced cytokines increased GBP2 and GBP5 expression in human cells, but not in macaque cells that naturally lack the GBP5 gene and the LTR12C element upstream of GBP2. Finally, our findings suggest that GBP2 and GBP5 have already been active against ancient viral pathogens as they suppress the maturation of the extinct retrovirus HERV-K (HML-2). In summary, our findings uncover how human cells can exploit remnants of once-infectious retroviruses to regulate antiviral gene expression.


1999 ◽  
Vol 19 (7) ◽  
pp. 4592-4599 ◽  
Author(s):  
Paul D. Bieniasz ◽  
Therese A. Grdina ◽  
Hal P. Bogerd ◽  
Bryan R. Cullen

ABSTRACT The human immunodeficiency virus type 1 (HIV-1) Tat protein (hTat) activates transcription initiated at the viral long terminal repeat (LTR) promoter by a unique mechanism requiring recruitment of the human cyclin T1 (hCycT1) cofactor to the viral TAR RNA target element. While activation of equine infectious anemia virus (EIAV) gene expression by the EIAV Tat (eTat) protein appears similar in that the target element is a promoter proximal RNA, eTat shows little sequence homology to hTat, does not activate the HIV-1 LTR, and is not active in human cells that effectively support hTat function. To address whether eTat and hTat utilize similar or distinct mechanisms of action, we have cloned the equine homolog of hCycT1 (eCycT1) and examined whether it is required to mediate eTat function. Here, we report that expression of eCycT1 in human cells fully rescues eTat function and that eCycT1 and eTat form a protein complex that specifically binds to the EIAV, but not the HIV-1, TAR element. While hCycT1 is also shown to interact with eTat, the lack of eTat function in human cells is explained by the failure of the resultant protein complex to bind to EIAV TAR. Critical sequences in eCycT1 required to support eTat function are located very close to the amino terminus, i.e., distal to the HIV-1 Tat-TAR interaction motif previously identified in the hCycT1 protein. Together, these data provide a molecular explanation for the species tropism displayed by eTat and demonstrate that highly divergent lentiviral Tat proteins activate transcription from their cognate LTR promoters by essentially identical mechanisms.


2001 ◽  
Vol 268 (4) ◽  
pp. 980-986 ◽  
Author(s):  
Jan Snášel ◽  
Dominik Rejman ◽  
Radek Liboska ◽  
Zdenčk Točík ◽  
Tomáš Ruml ◽  
...  

2010 ◽  
Vol 84 (9) ◽  
pp. 4840-4844 ◽  
Author(s):  
Qiujia Shao ◽  
Yudi Wang ◽  
James E. K. Hildreth ◽  
Bindong Liu

ABSTRACT Proteasomal degradation of APOBEC3G is a critical step for human immunodeficiency virus type 1 (HIV-1) replication. However, the necessity for polyubiquitination of APOBEC3G in this process is still controversial. In this study, we showed that although macaque simian immunodeficiency virus (SIVmac) Vif is more stable than HIV-1 Vif in human cells, SIVmac Vif induces degradation of APBOEC3G as efficiently as HIV-1 Vif. Overexpression of APOBEC3G or lysine-free APOBEC3G stabilized HIV-1 Vif, indicating that APOBEC3G degradation is independent of the degradation of Vif. Furthermore, an in vivo polyubiquitination assay showed that lysine-free APOBEC3G was also polyubiquitinated. These data suggest that polyubiquitination of APOBEC3G, not that of HIV-1 Vif, is crucial for APOBEC3G degradation.


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