Cyclophilin A-Dependent Restriction of Human Immunodeficiency Virus Type 1 Capsid Mutants for Infection of Nondividing Cells

Qi, Mingli; Yang, Ruifeng; Aiken, Christopher

doi:10.1128/jvi.01518-08

Cited by 66 publications

(92 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, in the CsA washout assay, this mutant uncoated slower than the wild type. Additionally, A92E mutant virus displays capsid stability similar to that of the wild-type virus, but it uncoats faster in the CsA washout assay (14). While there is often a general correlation between in vitro capsid stability and the rate of uncoating, these data suggest that other factors are involved with uncoating in vivo.…”

Section: Discussionmentioning

confidence: 61%

“…Because CypA can still bind the capsid, these mutants are proposed to alter the response of the virus to cellular CypA binding. In addition, these mutants are impaired for the ability of HIV to infect nondividing cells, indicating that they may have lost the ability to actively transport into the nucleus (14,34). In the CsA washout assay, A92E mutant virus uncoated faster than HIV-GFP with a significantly decreased half-life of uncoating (50 min) compared to the wild-type virus (90 min; Fig.…”

Section: Mutations In P24mentioning

confidence: 99%

“…CA mutations (E45A, N74D, G89V, P90A, A92E, and G94) that are currently actively studied due to their effects on other aspects of HIV replication, including infection of nondividing cells, utilization of nuclear import pathways, and integration site selection (13)(14)(15)(16)(17)(18)(19). Often the effect of these mutations on other steps in viral replication has been proposed to be due to changes in uncoating.…”

Section: Mutations In P24mentioning

confidence: 99%

See 2 more Smart Citations

Identification of Capsid Mutations That Alter the Rate of HIV-1 Uncoating in Infected Cells

Hulme

Kelley

Okocha

et al. 2015

J Virol

View full text Add to dashboard Cite

After viral fusion with the cell membrane, the conical capsid of HIV-1 disassembles by a process called uncoating. We recently utilized the cyclosporine (CsA) washout assay, in which TRIM-CypA-mediated restriction of viral replication is used to detect the state of the viral capsid, to study the kinetics of uncoating in HIV-1-infected cells. Here we have extended this analysis to examine the effects of p24 capsid protein (p24 CA ) mutations and cellular environment on the kinetics of uncoating in infected cells. We found that p24 CA mutations can significantly increase (A92E), delay (E45A and N74D), or have no effect (G94D) on the rate of uncoating and that these alterations are not due to changes in reverse transcription. Inhibition of reverse transcription delayed uncoating kinetics to an extent similar to that of the wild-type virus with all the p24 CA mutant viruses tested. In addition, we observed differences in uncoating in two cell lines, which suggests that the cellular environment can differentially impact the disassembly of wild-type and mutant capsids. Collectively, these experiments suggest that viral and cellular factors are important for the process of uncoating. Finally, these data support the model whereby early steps in reverse transcription facilitate HIV-1 uncoating. IMPORTANCEThe HIV-1 capsid is a cone-shaped structure, composed of the HIV-1-encoded protein p24 CA , which contains the viral RNA and other proteins needed for infection. After the virus enters a target cell, this capsid must disassemble by a process called uncoating. Uncoating is required for HIV-1 infection to progress, but the details of how this process occurs is not known. In this study, we used an in vivo assay to examine the uncoating process in HIV-1-infected cells. We determined that p24 CA mutations could increase or decrease the rate of uncoating and that this rate varied in different cell lines. We also found that reverse transcription of the viral RNA altered the process of uncoating before the p24 CA mutations. Collectively, these experiments provide a better understanding of how viral and cellular factors are involved with a poorly understood step in HIV-1 infection.

show abstract

Section: Discussionmentioning

confidence: 61%

Section: Mutations In P24mentioning

confidence: 99%

Section: Mutations In P24mentioning

confidence: 99%

See 1 more Smart Citation

Identification of Capsid Mutations That Alter the Rate of HIV-1 Uncoating in Infected Cells

Hulme

Kelley

Okocha

et al. 2015

J Virol

View full text Add to dashboard Cite

show abstract

“…In T lymphocytes, CypA stabilizes the HIV-1 capsid and promotes infection (5). The CypA domain of the nuclear pore protein Nup358 has been reported to be important for proper nuclear targeting of HIV-1 preintegration complexes (5,16,(20)(21)(22)(23)(24).…”

mentioning

confidence: 99%

“…TRIM5␣ is a protein that mediates the premature, deleterious disassembly of the capsid and therefore acts as a restriction factor (19). The prolyl cis-trans isomerase cyclophilin A (CypA) binds the HIV-1 capsid and modulates capsid stability in either a positive or negative manner, depending on the type of infected cell and the sequence of the helix 4/5 loop (CypA-binding loop) of the capsid protein (CA) (5,16,(20)(21)(22)(23)(24). In T lymphocytes, CypA stabilizes the HIV-1 capsid and promotes infection (5).…”

mentioning

confidence: 99%

Enhanced Autointegration in Hyperstable Simian Immunodeficiency Virus Capsid Mutants Blocked after Reverse Transcription

Tipper

Sodroski

2013

J Virol

View full text Add to dashboard Cite

cAfter entering a host cell, retroviruses such as simian immunodeficiency virus (SIV) uncoat, disassembling the viral capsid. Rates of uncoating that are too high and too low can be detrimental to the efficiency of infection. Rapid uncoating typically leads to blocks in reverse transcription, but the basis for replication defects associated with slow uncoating is less clear. Here we characterize the phenotypes of two SIVmac239 mutants with changes, A87E and A87D, in the helix 4/5 loop of the capsid protein. These mutant viruses exhibited normal capsid morphology but were significantly attenuated for infectivity. The infectivity of wild-type and mutant SIVmac239 was not decreased by aphidicolin-induced growth arrest of the target cells. In the cytosol of infected cells, the A87E and A87D capsids remained in particulate form longer than the wild-type SIVmac239 capsid, suggesting that the mutants uncoat more slowly than the wild-type capsid. Both mutants exhibited much higher levels of autointegrated DNA forms than wild-type SIVmac239. Thus, some changes in the helix 4/5 loop of the SIVmac239 capsid protein result in capsid hyperstability and an increase in autointegration.

show abstract

Effect of internal cleavage site mutations in human immunodeficiency virus type 1 capsid protein on its structure and function

et al. 2016

View full text Add to dashboard Cite

The capsid protein of the human immunodeficiency virus type 1 has been found to be a substrate of the retroviral protease in vitro , and its processing was predicted to be strongly dependent on a pH ‐induced conformational change. Several protease cleavage sites have been identified within the capsid protein, but the importance of its cleavage by the viral protease at the early phase of infection is controversial. To confirm the relevance of this process, we aimed to design, produce, and characterize mutant capsid proteins, in which the protein susceptibility toward HIV ‐1 protease is altered without affecting other steps of the viral life cycle. Our results indicate that while the introduced mutations changed the cleavage rate at the mutated sites of the capsid protein by HIV ‐1 protease, some of them caused only negligible or moderate structural changes (A78V, L189F, and L189I). However, the effects of other mutations (W23A, A77P, and L189P) were dramatic, as assessed by secondary structure determination or cyclophilin A‐binding assay. Based on our observations, the L189F mutant capsid remains structurally and functionally unchanged and may therefore be the best candidate for use in studies aimed at better understanding the role of the protease in the early postentry events of viral infection or retrovirus‐mediated gene transduction.

show abstract

Cyclophilin A-Dependent Restriction of Human Immunodeficiency Virus Type 1 Capsid Mutants for Infection of Nondividing Cells

Cited by 66 publications

References 57 publications

Identification of Capsid Mutations That Alter the Rate of HIV-1 Uncoating in Infected Cells

Identification of Capsid Mutations That Alter the Rate of HIV-1 Uncoating in Infected Cells

Enhanced Autointegration in Hyperstable Simian Immunodeficiency Virus Capsid Mutants Blocked after Reverse Transcription

Effect of internal cleavage site mutations in human immunodeficiency virus type 1 capsid protein on its structure and function

Contact Info

Product

Resources

About