N-p-Tosyl-L-phenylalanine chloromethyl ketone (TPCK) inhibits HIV-1 by suppressing the activity of viral protease

2020 ◽  
Vol 527 (1) ◽  
pp. 167-172
Author(s):  
Jay Trivedi ◽  
Payel Ghosh ◽  
Debashis Mitra
Keyword(s):  
Viral Protease ◽  
Chloromethyl Ketone ◽  
Hiv 1

scholarly journals The HIV-1 Nucleocapsid Regulates Its Own Condensation by Phase-Separated Activity-Enhancing Sequestration of the Viral Protease during Maturation

Viruses ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2312
Author(s):  
Sébastien Lyonnais ◽  
S. Kashif Sadiq ◽  
Cristina Lorca-Oró ◽  
Laure Dufau ◽  
Sara Nieto-Marquez ◽  
...  
Keyword(s):  
Self Assembly ◽  
Rna Binding ◽  
Weak Interactions ◽  
Biological Functions ◽  
Viral Protease ◽  
Virus Maturation ◽  
Sequential Processing ◽  
Rnp Granules ◽  
Crowded Environments ◽  
Hiv 1

A growing number of studies indicate that mRNAs and long ncRNAs can affect protein populations by assembling dynamic ribonucleoprotein (RNP) granules. These phase-separated molecular ‘sponges’, stabilized by quinary (transient and weak) interactions, control proteins involved in numerous biological functions. Retroviruses such as HIV-1 form by self-assembly when their genomic RNA (gRNA) traps Gag and GagPol polyprotein precursors. Infectivity requires extracellular budding of the particle followed by maturation, an ordered processing of ∼2400 Gag and ∼120 GagPol by the viral protease (PR). This leads to a condensed gRNA-NCp7 nucleocapsid and a CAp24-self-assembled capsid surrounding the RNP. The choreography by which all of these components dynamically interact during virus maturation is one of the missing milestones to fully depict the HIV life cycle. Here, we describe how HIV-1 has evolved a dynamic RNP granule with successive weak–strong–moderate quinary NC-gRNA networks during the sequential processing of the GagNC domain. We also reveal two palindromic RNA-binding triads on NC, KxxFxxQ and QxxFxxK, that provide quinary NC-gRNA interactions. Consequently, the nucleocapsid complex appears properly aggregated for capsid reassembly and reverse transcription, mandatory processes for viral infectivity. We show that PR is sequestered within this RNP and drives its maturation/condensation within minutes, this process being most effective at the end of budding. We anticipate such findings will stimulate further investigations of quinary interactions and emergent mechanisms in crowded environments throughout the wide and growing array of RNP granules.

scholarly journals Context Surrounding Processing Sites Is Crucial in Determining Cleavage Rate of a Subset of Processing Sites in HIV-1 Gag and Gag-Pro-Pol Polyprotein Precursors by Viral Protease

2012 ◽  
Vol 287 (16) ◽  
pp. 13279-13290 ◽  
Author(s):  
Sook-Kyung Lee ◽  
Marc Potempa ◽  
Madhavi Kolli ◽  
Ayşegül Özen ◽  
Celia A. Schiffer ◽  
...  
Keyword(s):  
Cleavage Rate ◽  
Viral Protease ◽  
Hiv 1

scholarly journals Mutations in HIV-1 reverse transcriptase cause misfolding and miscleavage by the viral protease

Virology ◽  
2013 ◽  
Vol 444 (1-2) ◽  
pp. 241-249 ◽  
Author(s):  
Linda L. Dunn ◽  
Paul L. Boyer ◽  
Patrick K. Clark ◽  
Stephen H. Hughes
Keyword(s):  
Reverse Transcriptase ◽  
Viral Protease ◽  
Hiv 1

scholarly journals CARD8 inflammasome mediates pyroptosis of HIV-1-infected cells by sensing viral protease activity

2020 ◽  
Author(s):  
Qiankun Wang ◽  
Hongbo Gao ◽  
Kolin M. Clark ◽  
Pengfei Tang ◽  
Gray H. Harlan ◽  
...  
Keyword(s):  
Rapid Evolution ◽  
Mutation Rates ◽  
Host Immune System ◽  
Virus Reactivation ◽  
Viral Protease ◽  
Viral Budding ◽  
Infected Cells ◽  
Latent Hiv ◽  
Hiv 1 ◽  
Recognition Receptor

AbstractHIV-1 has high mutation rates and exists as mutant swarms in the host. Rapid evolution of HIV-1 allows the virus to outpace host immune system, leading to viral persistence. Novel approaches to target immutable components are needed to clear HIV-1 infection. Here we report a pattern-recognition receptor CARD8 that senses enzymatic activity of the HIV-1 protease, which is indispensable for the virus. All subtypes of HIV-1 can be sensed by CARD8 despite substantial viral diversity. HIV-1 evades CARD8 sensing because the viral protease remains inactive in infected cells prior to viral budding. Induction of premature intracellular activation of the viral protease triggers CARD8 inflammasome-mediated pyroptosis of HIV-1-infected cells. This strategy leads to clearance of latent HIV-1 in patient CD4+ T cells after virus reactivation. Taken together, our study identifies CARD8 as an inflammasome sensor of HIV-1 that holds promise as a strategy for clearance of persistent HIV-1 infection.

scholarly journals The effect of an HIV-1 viral protease inhibitor on staurosporine-induced apoptosis in immortalized mesangial cells

2002 ◽  
Vol 120 (3) ◽  
pp. 81-83 ◽  
Author(s):  
Adrian Pierce Serone ◽  
Simone Mafalda Rodrigues Camargo ◽  
Nestor Schor
Keyword(s):  
Protease Inhibitor ◽  
Mesangial Cells ◽  
Glomerular Sclerosis ◽  
Viral Protease ◽  
Apoptotic Pathway ◽  
Induced Apoptosis ◽  
Late Stages ◽  
Glomerular Extracellular Matrix ◽  
Hiv 1 ◽  
De Medicina

CONTEXT: Progressive glomerular sclerosis is a condition characterized by the accumulation of glomerular extracellular matrix and a decrease in the number of glomerular cells. The mechanisms involved in the progressive loss of glomerular cells are not well understood but may involve the process of apoptosis. The principal mediators for the apoptotic pathway are a class of protease enzymes called caspases. It is not known how other therapeutic protease inhibitors affect the caspase cascade and therefore whether they would be effective in preventing excessive apoptosis in the late stages of progressive glomerular sclerosis. OBJECTIVE: To evaluate whether an inhibitor of the HIV-1 viral protease Ac-Leu-Val-phenylalanine (PI) could inhibit apoptosis in immortalized mesangial cells. DESIGN: Experimental. SETTING: Nephrology Division, Universidade Federal de São Paulo/Escola Paulista de Medicina. PARTICIPANTS: Immortalized mesangial cells. PROCEDURES: Cell culture. MAIN MEASUREMENTS: Viability and rate of apoptosis. RESULTS: Immortalized mesangial cells were treated with staurosporine (at concentrations of 10-100 nM for 8-28 hours) to induce apoptosis. Staurosporine at 10 nM for 8 hours had no effect on viability, but did cause a significant increase in the rate of apoptosis (p = 0.0411, n = 6). Increasing the incubation time elicited a greater increase in the rate of apoptosis (p = 0.0001, n = 6), although there was also a significant decrease in viability (p=0.0002). Increasing the concentration of staurosporine to 100 nM resulted in a marked increase in apoptosis (p <0.0001) but resulted in unacceptable viability (<40%, p <0.0001, n = 6). CONCLUSIONS: Incubation of immortalized mesangial cells with PI (900 nM) alone for 2-24 hours had no effect on cell viability or the rate of apoptosis when compared with vehicle (methanol) controls. Co-incubation of the cells with staurosporine (10 nM) and PI for 24 hours had no significant effect on the rate of apoptosis. Therefore, in immortalized mesangial cells, staurosporine-induced apoptosis was not significantly affected by the HIV-1 viral protease inhibitor Ac-Leu-Val-phenylalanine.

scholarly journals Identification of a Key Target Sequence To Block Human Immunodeficiency Virus Type 1 Replication within thegag-pol Transframe Domain

2000 ◽  
Vol 74 (10) ◽  
pp. 4621-4633 ◽  
Author(s):  
Shizuko Sei ◽  
Quan-en Yang ◽  
Dennis O'Neill ◽  
Kazuhisa Yoshimura ◽  
Kunio Nagashima ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Binding Motif ◽  
Target Sequence ◽  
Viral Protease ◽  
Conserved Sequence ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Although the full sequence of the human immunodeficiency virus type 1 (HIV-1) genome has been known for more than a decade, effective genetic antivirals have yet to be developed. Here we show that, of 22 regions examined, one highly conserved sequence (ACTCTTTGGCAACGA) near the 3′ end of the HIV-1 gag-poltransframe region, encoding viral protease residues 4 to 8 and a C-terminal Vpr-binding motif of p6Gag protein in two different reading frames, can be successfully targeted by an antisense peptide nucleic acid oligomer named PNAPR2. A disrupted translation of gag-pol mRNA induced at the PNAPR2-annealing site resulted in a decreased synthesis of Pr160Gag-Pol polyprotein, hence the viral protease, a predominant expression of Pr55Gag devoid of a fully functional p6Gag protein, and the excessive intracellular cleavage of Gag precursor proteins, hindering the processes of virion assembly. Treatment with PNAPR2abolished virion production by up to 99% in chronically HIV-1-infected H9 cells and in peripheral blood mononuclear cells infected with clinical HIV-1 isolates with the multidrug-resistant phenotype. This particular segment of the gag-pol transframe gene appears to offer a distinctive advantage over other regions in invading viral structural genes and restraining HIV-1 replication in infected cells and may potentially be exploited as a novel antiviral genetic target.

scholarly journals Toxins that are activated by HIV type-1 protease through removal of a signal for degradation by the N-end-rule pathway

1999 ◽  
Vol 343 (1) ◽  
pp. 199-207 ◽  
Author(s):  
Pål Ø. FALNES ◽  
Reinhold WELKER ◽  
Hans-Georg KRÄUSSLICH ◽  
Sjur OLSNES
Keyword(s):  
Protein Synthesis ◽  
Diphtheria Toxin ◽  
Mammalian Cells ◽  
Cellular Protein ◽  
Viral Protease ◽  
Infected Cells ◽  
Hiv Type 1 ◽  
Hiv 1 ◽  
Cellular Protein Synthesis

Diphtheria toxin enters the cytosol of mammalian cells where it inhibits cellular protein synthesis, leading to cell death. Recently we found that the addition of a signal for N-end-rule-mediated protein degradation to diphtheria toxin substantially reduced its intracellular stability and toxicity. These results prompted us to construct a toxin containing a degradation signal that is removable through the action of a viral protease. In principle, such a toxin would be preferentially stabilized, and thus activated, in cells expressing the viral protease in the cytosol, i.e. virus-infected cells, thereby providing a specific eradication of these cells. In the present work we describe the construction of toxins that contain a signal for N-end-rule-mediated degradation just upstream of a cleavage site for the protease from HIV type 1 (HIV-1 PR). We show that the toxins are cleaved by HIV-1 PR exclusively at the introduced sites, and thereby are converted from unstable to stable proteins. Furthermore, this cleavage substantially increased the ability of the toxins to inhibit cellular protein synthesis. However, the toxins were unable to selectively eradicate HIV-1-infected cells, apparently due to low cytosolic HIV-1 PR activity, since we could not detect cleavage of the toxins by HIV-1 PR in infected cells. Alternative strategies for the construction of toxins that can specifically be activated by viral proteases are discussed.

scholarly journals Structure–function analysis of the ribosomal frameshifting signal of two human immunodeficiency virus type 1 isolates with increased resistance to viral protease inhibitors

2007 ◽  
Vol 88 (1) ◽  
pp. 226-235 ◽  
Author(s):  
Roseanne Girnary ◽  
Louise King ◽  
Laurence Robinson ◽  
Robert Elston ◽  
Ian Brierley
Keyword(s):  
Human Immunodeficiency Virus ◽  
Protease Inhibitors ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Ribosomal Frameshift ◽  
Viral Protease ◽  
Immunodeficiency Virus ◽  
Slippery Sequence ◽  
Hiv 1

Expression of the pol-encoded proteins of human immunodeficiency virus type 1 (HIV-1) requires a programmed –1 ribosomal frameshift at the junction of the gag and pol coding sequences. Frameshifting takes place at a heptanucleotide slippery sequence, UUUUUUA, and is enhanced by a stimulatory RNA structure located immediately downstream. In patients undergoing viral protease (PR) inhibitor therapy, a p1/p6gag L449F cleavage site (CS) mutation is often observed in resistant isolates and frequently generates, at the nucleotide sequence level, a homopolymeric and potentially slippery sequence (UUUUCUU to UUUUUUU). The mutation is located within the stimulatory RNA downstream of the authentic slippery sequence and could act to augment levels of pol-encoded enzymes to counteract the PR deficit. Here, RNA secondary structure probing was employed to investigate the structure of a CS-containing frameshift signal, and the effect of this mutation on ribosomal frameshift efficiency in vitro and in tissue culture cells was determined. A second mutation, a GGG insertion in the loop of the stimulatory RNA that could conceivably lead to resistance by enhancing the activity of the structure, was also tested. It was found, however, that the CS and GGG mutations had only a very modest effect on the structure and activity of the HIV-1 frameshift signal. Thus the increased resistance to viral protease inhibitors seen with HIV-1 isolates containing mutations in the frameshifting signal is unlikely to be accounted for solely by enhancement of frameshift efficiency.

A catalogue of putative HIV-1 protease host cell substrates

2012 ◽  
Vol 393 (9) ◽  
pp. 915-931 ◽  
Author(s):  
Francis Impens ◽  
Evy Timmerman ◽  
An Staes ◽  
Kathleen Moens ◽  
Kevin K. Ariën ◽  
...  
Keyword(s):  
Large Scale ◽  
Viral Protease ◽  
Peptide Substrates ◽  
Immunodeficiency Virus ◽  
Interaction Partners ◽  
Unbiased Manner ◽  
Human Proteins ◽  
Wide Scale ◽  
Hiv 1

Abstract Processing of human immunodeficiency virus (HIV) proteins by the HIV-1 protease is essential for HIV infectivity. In addition, several studies have revealed cleavage of human proteins by this viral protease during infection; however, no large-scale HIV-1 protease degradomics study has yet been performed. To identify putative host substrates in an unbiased manner and on a proteome-wide scale, we used positional proteomics to identify peptides reporting protein processing by the HIV-1 protease, and a catalogue of over 120 cellular HIV-1 protease substrates processed in vitro was generated. This catalogue includes previously reported substrates as well as recently described interaction partners of HIV-1 proteins. Cleavage site alignments revealed a specificity profile in good correlation with previous studies, even though the ELLE consensus motif was not cleaved efficiently when incorporated into peptide substrates due to subsite cooperativity. Our results are further discussed in the context of HIV-1 infection and the complex substrate recognition by the viral protease.

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