scholarly journals Identification of RFPL3 Protein as a Novel E3 Ubiquitin Ligase Modulating the Integration Activity of Human Immunodeficiency Virus, Type 1 Preintegration Complex Using a Microtiter Plate-based Assay

2014 ◽  
Vol 289 (38) ◽  
pp. 26368-26382 ◽  
Author(s):  
Beng Hui Tan ◽  
Yasutsugu Suzuki ◽  
Hirotaka Takahashi ◽  
Pamela Ho Rui Ying ◽  
Chikako Takahashi ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Ubiquitin Ligase ◽  
E3 Ubiquitin Ligase ◽  
Microtiter Plate ◽  
Preintegration Complex ◽  
Immunodeficiency Virus

scholarly journals Regulation of Apobec3F and Human Immunodeficiency Virus Type 1 Vif by Vif-Cul5-ElonB/C E3 Ubiquitin Ligase

2005 ◽  
Vol 79 (15) ◽  
pp. 9579-9587 ◽  
Author(s):  
Bindong Liu ◽  
Phuong Thi Nguyen Sarkis ◽  
Kun Luo ◽  
Yunkai Yu ◽  
Xiao-Fang Yu
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Ubiquitin Ligase ◽  
E3 Ubiquitin Ligase ◽  
E3 Ligase ◽  
Immunodeficiency Virus ◽  
Hiv 1 ◽  
Ligase Function

ABSTRACT The human cytidine deaminase Apobec3F (h-A3F), a protein related to the previously recognized antiviral factor Apobec3G (h-A3G), has antiviral activity against human immunodeficiency virus type 1 (HIV-1) that is suppressed by the viral protein Vif. The mechanism of HIV-1 Vif-mediated suppression of h-A3F is not fully understood. Here, we demonstrate that while h-A3F, like h-A3G, was able to suppress primate lentiviruses other than HIV-1 (simian immunodeficiency virus from African green monkeys [SIVagm] and Rhesus macaques [SIVmac]), the interaction between Vif proteins and h-A3F appeared to differ from that with h-A3G. H-A3F showed no change in its species specificity against HIV-1 or SIVagm Vif when a negatively charged amino acid was replaced with a lysine at position 128, a residue critical for h-A3G recognition by HIV-1 Vif. However, HIV-1 Vif, but not SIVagm Vif, was able to bind h-A3F and induce its polyubiquitination and degradation through the Cul5-containing E3 ubiquitin ligase. Interference with Cul5-E3 ligase function by depletion of Cul5, through RNA interference or overexpression of Cul5 mutants, blocked the ability of HIV-1 Vif to suppress h-A3F. A BC-box mutant of HIV-1 Vif that failed to recruit Cul5-E3 ligase but was still able to interact with h-A3F failed to suppress h-A3F. Interestingly, interference with Cul5-E3 ligase function or overexpression of h-A3F or h-A3G also increased the stability of HIV-1 Vif, suggesting that like the substrate molecules h-A3F and h-A3G, the substrate receptor protein Vif is itself also regulated by Cul5-E3 ligase. Our results indicate that Cul5-E3 ligase appears to be a common pathway hijacked by HIV-1 Vif to defeat both h-A3F and h-A3G. Developing inhibitors to disrupt the interaction between Vif and Cul5-E3 ligase could be therapeutically useful, allowing multiple host antiviral factors to suppress HIV-1.

scholarly journals Human Immunodeficiency Virus Type 1 Vif Induces Cell Cycle Delay via Recruitment of the Same E3 Ubiquitin Ligase Complex That Targets APOBEC3 Proteins for Degradation

2008 ◽  
Vol 82 (18) ◽  
pp. 9265-9272 ◽  
Author(s):  
Jason L. DeHart ◽  
Alberto Bosque ◽  
Reuben S. Harris ◽  
Vicente Planelles
Keyword(s):  
Cell Cycle ◽  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Ubiquitin Ligase ◽  
Cell Cycle Delay ◽  
Immunodeficiency Virus ◽  
Apobec3 Proteins ◽  
Hiv 1

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) Vif recruits a Cullin 5 ubiquitin ligase that targets APOBEC3 proteins for degradation. Recently, Vif has also been shown to induce cell cycle disturbance in G2. We show that in contrast to the expression of Vpr, the expression of Vif does not preclude cell division, and therefore, Vif causes delay and not arrest in G2. We also demonstrate that the interaction of Vif with the ubiquitin ligase is required for cell cycle disruption, as was previously shown for HIV-1 Vpr. The presence of APOBEC3 D/E, F, and G had no influence on Vif-induced alteration of the cell cycle. We conclude that cell cycle delay by Vif is a result of ubiquitination and degradation of a cellular protein that is different from the known APOBEC3 family members.

scholarly journals Lys-34, Dispensable for Integrase Catalysis, Is Required for Preintegration Complex Function and Human Immunodeficiency Virus Type 1 Replication

2005 ◽  
Vol 79 (19) ◽  
pp. 12584-12591 ◽  
Author(s):  
Richard Lu ◽  
Nick Vandegraaff ◽  
Peter Cherepanov ◽  
Alan Engelman
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Complex Function ◽  
Wild Type ◽  
Preintegration Complex ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Retroviral integrases (INs) function in the context of preintegration complexes (PICs). Two conserved Lys residues in the N-terminal domain of human immunodeficiency virus type 1 (HIV-1) IN were analyzed here for their roles in integration and virus replication. Whereas HIV-1K46A grew like the wild type, HIV-1K34A was dead. Yet recombinant INK34A protein functioned in in vitro integration assays, and Vpr-INK34A efficiently transcomplemented the infectivity defect of an IN active site mutant virus in cells. HIV-1K34A was therefore similar to a number of previously characterized mutant viruses that failed to replicate despite encoding catalytically competent IN. To directly analyze mutant PIC function, a sensitive PCR-based integration assay was developed. HIV-1K34A and related mutants failed to support detectable levels (<1% of wild type) of integration. We therefore concluded that mutations like K34A disrupted higher-order interactions important for PIC function/maturation compared to the innate catalytic activity of IN enzyme.

scholarly journals Evidence for a Functional Link between Uncoating of the Human Immunodeficiency Virus Type 1 Core and Nuclear Import of the Viral Preintegration Complex

2006 ◽  
Vol 80 (8) ◽  
pp. 3712-3720 ◽  
Author(s):  
David J. Dismuke ◽  
Christopher Aiken
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Viral Dna ◽  
Preintegration Complex ◽  
Viral Core ◽  
Immunodeficiency Virus ◽  
Infected Cells ◽  
Hiv 1

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) particles begin their replication upon fusion with the plasma membrane of target cells and release of the viral core into the host cell cytoplasm. Soon thereafter, the viral capsid, which is composed of a polymer of the CA protein, disassociates from the internal ribonucleoprotein complex. While this disassembly process remains poorly understood, the available evidence indicates that proper uncoating of the core is a key step in infection. Defects in uncoating most often lead to a failure of the virus to undergo reverse transcription, resulting in an inability to form a functional viral preintegration complex (PIC). In a previous study, we reported that an HIV-1 mutant containing two substitutions in CA (Q63A/67A) was unusual in that it was poorly infectious yet synthesized normal levels of viral DNA. Here we report that this mutant is impaired for nuclear entry. Quantitative analysis of viral DNA synthesis from infected cells by Southern blotting and real-time PCR revealed that the Q63A/Q67A mutant is impaired in the synthesis of one-long terminal repeat (1-LTR) and 2-LTR circles. Isolation of PICs from acutely infected cells revealed that the Q63A/Q67A mutant produces protein-DNA complexes similar to wild-type in yield and overall composition, but these PICs contained elevated levels of CA and were impaired for integration in vitro. These results demonstrate that mutations in CA can have deleterious effects on both nuclear targeting and integration, suggesting that these steps in the HIV-1 life cycle are dependent on proper uncoating of the viral core.

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