|
Basic Characteristics of Mutations
|
|
Mutation Site
|
R85A |
|
Mutation Site Sentence
|
These include HIV-1 W54R/HIV-2 L59A Vpr mutants, which block the ability of HIV-1 Vpr to recruit and degrade the DNA glycosylase UNG2;HIV-1 Q65R/HIV-2 Q70R Vpr, which renders Vpr unable to properly localize, multimerize, or recruit known host proteins, such as the Cul4ADCAF1 complex or UNG2 and, therefore, is largely functionally dead;HIV-1 S79A/HIV-2 S84A mutants, which render Vpr unable to cause cell cycle arrest or interact with TAK1 to activate canonical NF-kappaB;and HIV-1 R80A/HIV-2 R85A Vpr mutants, which can still interact with Cul4ADCAF1 and degrade TET2 but do not cause cell cycle arrest, presumably due to the requirement of an additional unknown host protein(s). |
|
Mutation Level
|
Amino acid level |
|
Mutation Type
|
Nonsynonymous substitution |
|
Gene/Protein/Region
|
Vpr |
|
Standardized Encoding Gene
|
Vpr
|
|
Genotype/Subtype
|
HIV-1 A;B;divergent |
|
Viral Reference
|
-
|
|
Functional Impact and Mechanisms
|
|
Disease
|
HIV Infections
|
|
Immune
|
- |
|
Target Gene
|
-
|
|
Clinical and Epidemiological Correlations
|
|
Clinical Information
|
- |
|
Treatment
|
- |
|
Location
|
- |
|
Literature Information
|
|
PMID
|
32753492
|
|
Title
|
HIV Vpr Modulates the Host DNA Damage Response at Two Independent Steps to Damage DNA and Repress Double-Strand DNA Break Repair
|
|
Author
|
Li D,Lopez A,Sandoval C,Nichols Doyle R,Fregoso OI
|
|
Journal
|
mBio
|
|
Journal Info
|
2020 Aug 4;11(4):e00940-20
|
|
Abstract
|
The DNA damage response (DDR) is a signaling cascade that is vital to ensuring the fidelity of the host genome in the presence of genotoxic stress. Growing evidence has emphasized the importance of both activation and repression of the host DDR by diverse DNA and RNA viruses. Previous work has shown that HIV-1 is also capable of engaging the host DDR, primarily through the conserved accessory protein Vpr. However, the extent of this engagement has remained unclear. Here, we show that HIV-1 and HIV-2 Vpr directly induce DNA damage and stall DNA replication, leading to the activation of several markers of double- and single-strand DNA breaks. Despite causing damage and activating the DDR, we found that Vpr represses the repair of double-strand breaks (DSB) by inhibiting homologous recombination (HR) and nonhomologous end joining (NHEJ). Mutational analyses of Vpr revealed that DNA damage and DDR activation are independent from repression of HR and Vpr-mediated cell cycle arrest. Moreover, we show that repression of HR does not require cell cycle arrest but instead may precede this long-standing enigmatic Vpr phenotype. Together, our data uncover that Vpr globally modulates the host DDR at at least two independent steps, offering novel insight into the primary functions of lentiviral Vpr and the roles of the DNA damage response in lentiviral replication.IMPORTANCE The DNA damage response (DDR) is a signaling cascade that safeguards the genome from genotoxic agents, including human pathogens. However, the DDR has also been utilized by many pathogens, such as human immunodeficiency virus (HIV), to enhance infection. To properly treat HIV-positive individuals, we must understand how the virus usurps our own cellular processes. Here, we have found that an important yet poorly understood gene in HIV, Vpr, targets the DDR at two unique steps: it causes damage and activates DDR signaling, and it represses the ability of cells to repair this damage, which we hypothesize is central to the primary function of Vpr. In clarifying these important functions of Vpr, our work highlights the multiple ways human pathogens engage the DDR and further suggests that modulation of the DDR is a novel way to help in the fight against HIV.
|
|
Sequence Data
|
-
|
|
|