The F12-Vif derivative Chim3 inhibits HIV-1 replication in CD4+ T lymphocytes and CD34+-derived macrophages by blocking HIV-1 DNA integration

Blood ◽  
2009 ◽  
Vol 113 (15) ◽  
pp. 3443-3452 ◽  
Author(s):  
Simona Porcellini ◽  
Luca Alberici ◽  
Francesco Gubinelli ◽  
Rossella Lupo ◽  
Clelia Olgiati ◽  
...  

Abstract The viral infectivity factor (Vif) is essential for HIV-1 infectivity and hence is an ideal target for promising anti–HIV-1/AIDS gene therapy. We previously demonstrated that F12-Vif mutant inhibits HIV-1 replication in CD4+ T lymphocytes. Despite macrophage relevance to HIV-1 pathogenesis, most gene therapy studies do not investigate macrophages because of their natural resistance to genetic manipulation. Here, we confirm the F12-Vif antiviral activity also in macrophages differentiated in vitro from transduced CD34+ human stem cells (HSCs). Moreover, we identified the 126- to 170-amino-acid region in the C-terminal half of F12-Vif as responsible for its antiviral function. Indeed, Chim3 protein, containing this 45-amino-acid region embedded in a WT-Vif backbone, is as lethal as F12-Vif against HIV-1. Of major relevance, we demonstrated a dual mechanism of action for Chim3. First, Chim3 functions as a transdominant factor that preserves the antiviral function of the natural restriction factor APOBEC3G (hA3G). Second, Chim3 blocks the early HIV-1 retrotranscript accumulation and thereby HIV-1 DNA integration regardless of the presence of WT-Vif and hA3G. In conclusion, by impairing the early steps of HIV-1 life cycle, Chim3 conceivably endows engineered cells with survival advantage, which is required for the efficient immune reconstitution of patients living with HIV/AIDS.

2020 ◽  
Vol 18 (3) ◽  
pp. 165-171
Author(s):  
Ling Du ◽  
Lina Wang ◽  
Tong Yu ◽  
Ruolei Xin ◽  
Zhefeng Meng

Background: HIV-1 CRF01_AE and CRF07_BC recombinant strains are responsible for more than 80% of new infections in China since the beginning of the 2000s. These two strains may have distinct genetic mutations, which resulted in distinct patterns of pathogenesis related to the viral gene, Vpr. Objective: The amino acid pattern and genetic diversity of Vpr were analyzed and characterized in HIV-1 CRF01_AE and CRF07_BC HIV-1 strains. Methods: The Vpr gene was amplified from extracted viral RNA and DNA sequencing was performed using an ABI3730 analyzer. The positional amino acid composition, genetic variation and distance of Vpr sequence were analyzed by Bio-Edit 7.2 and Mega 6.01 software packages. Results: A total of 162 CRF01_AE and 80 CRF07_BC derived Vpr sequences were obtained by DNA sequencing. CRF01_AE patients showed higher viral load and lower CD4 counts than CRF07_BC patients (P<0.05). Higher genetic distance and more polymorphic amino acids were found in CRF01_AE Vpr than CRF07_BC Vpr (P<0.05). The common conservative amino acid region was identified as 29EAVRHFP35 in both CRF07_BC and CRF01_AE. Of note, the R77Q mutation was found in both the most recently Chinese derived CRF07_BC and CRF01_AE Vpr. Conclusion: CRF01_AE derived Vpr has higher genetic variation and pathogenesis in comparison to the CRF07_BC strain.


2000 ◽  
Vol 182 (16) ◽  
pp. 4628-4631 ◽  
Author(s):  
Mio Ohnuma ◽  
Nobuyuki Fujita ◽  
Akira Ishihama ◽  
Kan Tanaka ◽  
Hideo Takahashi

ABSTRACT ς38 (or ςS, the rpoS gene product) is a sigma subunit of RNA polymerase in Escherichia coli and directs transcription from a number of stationary-phase promoters as well as osmotically inducible promoters. In this study, we analyzed the function of the carboxy-terminal 16-amino-acid region of ς38 (residues 315 to 330), which is well conserved among the rpoS gene products of enteric bacterial species. Truncation of this region was shown to result in the loss of sigma activity in vivo using promoter-lacZ fusion constructs, but the mutant ς38 retained the binding activity in vivo to the core enzyme. The in vitro transcription analysis revealed that the transcription activity of ς38 holoenzyme under high potassium glutamate concentrations was significantly decreased by the truncation of the carboxy-terminal tail element.


1994 ◽  
Vol 14 (4) ◽  
pp. 2755-2766 ◽  
Author(s):  
D G Overdier ◽  
A Porcella ◽  
R H Costa

Three distinct hepatocyte nuclear factor 3 (HNF-3) proteins (HNF-3 alpha, -3 beta, and -3 gamma) are known to regulate the transcription of liver-specific genes. The HNF-3 proteins bind to DNA as a monomer through a modified helix-turn-helix, known as the winged helix motif, which is also utilized by a number of developmental regulators, including the Drosophila homeotic forkhead (fkh) protein. We have previously described the isolation, from rodent tissue, of an extensive family of tissue-specific HNF-3/fkh homolog (HFH) genes sharing homology in their winged helix motifs. In this report, we have determined the preferred DNA-binding consensus sequence for the HNF-3 beta protein as well as for two divergent family members, HFH-1 and HFH-2. We show that these HNF-3/fkh proteins bind to distinct DNA sites and that the specificity of protein recognition is dependent on subtle nucleotide alterations in the site. The HNF-3, HFH-1, and HFH-2 consensus binding sequences were also used to search DNA regulatory regions to identify potential target genes. Furthermore, an analysis of the DNA-binding properties of a series of HFH-1/HNF-3 beta protein chimeras has allowed us to identify a 20-amino-acid region, located adjacent to the DNA recognition helix, which contributes to DNA-binding specificity. These sequences are not involved in base-specific contacts and include residues which diverge within the HNF-3/fkh family. Replacement of this 20-amino-acid region in HNF-3 beta with corresponding residues from HFH-1 enabled the HNF-3 beta recognition helix to bind only HFH-1-specific DNA-binding sites. We propose a model in which this 20-amino-acid flanking region influences the DNA-binding properties of the recognition helix.


1998 ◽  
Vol 9 (5) ◽  
pp. 1221-1233 ◽  
Author(s):  
Takeshi Fujiwara ◽  
Kazuma Tanaka ◽  
Akihisa Mino ◽  
Mitsuhiro Kikyo ◽  
Kazuo Takahashi ◽  
...  

Rho1p is a yeast homolog of mammalian RhoA small GTP-binding protein. Rho1p is localized at the growth sites and required for bud formation. We have recently shown that Bni1p is a potential target of Rho1p and that Bni1p regulates reorganization of the actin cytoskeleton through interactions with profilin, an actin monomer-binding protein. Using the yeast two-hybrid screening system, we cloned a gene encoding a protein that interacted with Bni1p. This protein, Spa2p, was known to be localized at the bud tip and to be implicated in the establishment of cell polarity. The C-terminal 254 amino acid region of Spa2p, Spa2p(1213–1466), directly bound to a 162-amino acid region of Bni1p, Bni1p(826–987). Genetic analyses revealed that both thebni1 and spa2 mutations showed synthetic lethal interactions with mutations in the genes encoding components of the Pkc1p-mitogen-activated protein kinase pathway, in which Pkc1p is another target of Rho1p. Immunofluorescence microscopic analysis showed that Bni1p was localized at the bud tip in wild-type cells. However, in the spa2 mutant, Bni1p was not localized at the bud tip and instead localized diffusely in the cytoplasm. A mutant Bni1p, which lacked the Rho1p-binding region, also failed to be localized at the bud tip. These results indicate that both Rho1p and Spa2p are involved in the localization of Bni1p at the growth sites where Rho1p regulates reorganization of the actin cytoskeleton through Bni1p.


1989 ◽  
Vol 208 (3) ◽  
pp. 429-443 ◽  
Author(s):  
Patrice Mellot ◽  
Yves Mechulam ◽  
Daniel Le Corre ◽  
Sylvain Blanquet ◽  
Guy Fayat

Biochemistry ◽  
2008 ◽  
Vol 47 (26) ◽  
pp. 6840-6850 ◽  
Author(s):  
Melissa A. Barhoover ◽  
Tivadar Orban ◽  
Daniel O. Beck ◽  
Michael A. Bukys ◽  
Michael Kalafatis

2017 ◽  
Author(s):  
Annick Guiseppi ◽  
Juan Jesus Vicente ◽  
Julien Herrou ◽  
Deborah Byrne ◽  
Aurelie Barneoud ◽  
...  

ABSTRACTChemosensory systems are highly organized signaling pathways that allow bacteria to adapt to environmental changes. The Frz chemosensory system from M. xanthus possesses two CheW-like proteins, FrzA (the core CheW) and FrzB. We found that FrzB does not interact with FrzE (the cognate CheA) as it lacks the amino acid region responsible for this interaction. FrzB, instead, acts upstream of FrzCD in the regulation of M. xanthus chemotaxis behaviors and activates the Frz pathway by allowing the formation and distribution of multiple chemosensory clusters on the nucleoid. These results, together, show that the lack of the CheA-interacting region in FrzB confers new functions to this small protein.AUTHOR SUMMARYChemosensory systems are signaling complexes that are widespread in bacteria and allow the modulation of different cellular functions, such as taxis and development, in response to the environment. We show that the Myxococcus xanthus FrzB is a divergent CheW lacking the region involved in the interaction with the histidine kinase FrzE. Instead, it acts upstream of FrzCD to allow the formation of multiple distributed Frz chemosensory arrays at the nucleoid. The loss of the CheA-interacting region in FrzB might have been selected to confer plasticity to nucleoid-associated chemosensory systems. By unraveling a new accessory protein and its function, this work opens new insights into the knowledge of the regulatory potentials of bacterial chemosensory systems.


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