HIV-1 Vpr induces cell cycle arrest and enhances viral gene expression by depleting CCDC137

SummaryThe HIV-1 Vpr accessory protein induces ubiquitin/proteasome-dependent degradation of many cellular proteins by recruiting them to a cullin4A-DDB1-DCAF1 complex. In so doing, Vpr enhances HIV-1 gene expression and induces (G2/M) cell cycle arrest. However, the identities of Vpr target proteins through which these biological effects are exerted are unknown. We show that a chromosome periphery protein, CCDC137/cPERP-B, is targeted for depletion by HIV-1 Vpr, in a cullin4A-DDB1-DCAF1 dependent manner. CCDC137 depletion caused G2/M cell-cycle arrest, while Vpr-resistant CCDC137 mutants conferred resistance to Vpr-induced G2/M arrest. CCDC137 depletion also recapitulated the ability of Vpr to enhance HIV-1 gene expression, particularly in macrophages. Our findings indicate that Vpr promotes cell-cycle arrest and HIV-1 gene expression through depletion of CCDC137.

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HIV-1 Vpr induces cell cycle arrest and enhances viral gene expression by depleting CCDC137

eLife ◽

10.7554/elife.55806 ◽

2020 ◽

Vol 9 ◽

Cited By ~ 2

Author(s):

Fengwen Zhang ◽

Paul D Bieniasz

Keyword(s):

Gene Expression ◽

Cell Cycle ◽

Cell Cycle Arrest ◽

Biological Effects ◽

Viral Gene Expression ◽

Viral Gene ◽

Dependent Manner ◽

M Cell ◽

Cycle Arrest ◽

Hiv 1

The HIV-1 Vpr accessory protein induces ubiquitin/proteasome-dependent degradation of many cellular proteins by recruiting them to a cullin4A-DDB1-DCAF1 complex. In so doing, Vpr enhances HIV-1 gene expression and induces (G2/M) cell cycle arrest. However, the identities of Vpr target proteins through which these biological effects are exerted are unknown. We show that a chromosome periphery protein, CCDC137/cPERP-B, is targeted for depletion by HIV-1 Vpr, in a cullin4A-DDB1-DCAF1 dependent manner. CCDC137 depletion caused G2/M cellcycle arrest, while Vpr-resistant CCDC137 mutants conferred resistance to Vpr-induced G2/M arrest. CCDC137 depletion also recapitulated the ability of Vpr to enhance HIV-1 gene expression, particularly in macrophages. Our findings indicate that Vpr promotes cell-cycle arrest and HIV-1 gene expression through depletion of CCDC137.

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Author response: HIV-1 Vpr induces cell cycle arrest and enhances viral gene expression by depleting CCDC137

10.7554/elife.55806.sa2 ◽

2020 ◽

Author(s):

Fengwen Zhang ◽

Paul D Bieniasz

Keyword(s):

Gene Expression ◽

Cell Cycle ◽

Cell Cycle Arrest ◽

Viral Gene Expression ◽

Author Response ◽

Viral Gene ◽

Cycle Arrest ◽

Hiv 1

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Decision letter: HIV-1 Vpr induces cell cycle arrest and enhances viral gene expression by depleting CCDC137

10.7554/elife.55806.sa1 ◽

2020 ◽

Author(s):

Vicente Planelles ◽

Michael Emerman

Keyword(s):

Gene Expression ◽

Cell Cycle ◽

Cell Cycle Arrest ◽

Viral Gene Expression ◽

Viral Gene ◽

Cycle Arrest ◽

Hiv 1

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Cell Cycle-Independent Expression of Immediate-Early Gene 3 Results in G1 and G2 Arrest in Murine Cytomegalovirus-Infected Cells

Journal of Virology ◽

10.1128/jvi.01212-08 ◽

2008 ◽

Vol 82 (20) ◽

pp. 10188-10198 ◽

Cited By ~ 27

Author(s):

Lüder Wiebusch ◽

Anke Neuwirth ◽

Linus Grabenhenrich ◽

Sebastian Voigt ◽

Christian Hagemeier

Keyword(s):

Gene Expression ◽

Cell Cycle ◽

Cell Cycle Arrest ◽

Viral Gene Expression ◽

Immediate Early Gene ◽

Early Gene ◽

Immediate Early ◽

Viral Gene ◽

Cycle Arrest ◽

Infected Cells

ABSTRACT The infectious cycle of human cytomegalovirus (HCMV) is intricately linked to the host's cell cycle. Viral gene expression can be initiated only in G0/G1 phase. Once expressed, the immediate-early gene product IE2 prevents cellular DNA synthesis, arresting infected cells with a G1 DNA content. This function is required for efficient viral replication in vitro. A prerequisite for addressing its in vivo relevance is the characterization of cell cycle-regulatory activities of CMV species for which animal models have been established. Here, we show that murine CMV (MCMV), like HCMV, has a strong antiproliferative capacity and arrests cells in G1. Unexpectedly, and in contrast to HCMV, MCMV can also block cells that have passed through S phase by arresting them in G2. Moreover, MCMV can also replicate in G2 cells. This is made possible by the cell cycle-independent expression of MCMV immediate-early genes. Transfection experiments show that of several MCMV candidate genes, only immediate-early gene 3 (ie3), the homologue of HCMV IE2, exhibits cell cycle arrest activity. Accordingly, an MCMV ie3 deletion mutant has lost the ability to arrest cells in either G1 or G2. Thus, despite interspecies variations in the cell cycle dependence of viral gene expression, the central theme of HCMV IE2-induced cell cycle arrest is conserved in the murine counterpart, raising the possibility of studying its physiological relevance at the level of the whole organism.

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Pisosterol Induces G2/M Cell Cycle Arrest and Apoptosis via the ATM/ATR Signaling Pathway in Human Glioma Cells

Anti-Cancer Agents in Medicinal Chemistry ◽

10.2174/1871520620666200203160117 ◽

2020 ◽

Vol 20 (6) ◽

pp. 734-750

Author(s):

Wallax A.S. Ferreira ◽

Rommel R. Burbano ◽

Claudia do Ó. Pessoa ◽

Maria L. Harada ◽

Bárbara do Nascimento Borges ◽

...

Keyword(s):

Cell Cycle ◽

Cell Cycle Arrest ◽

Signaling Pathway ◽

Glioma Cell ◽

Molecular Mechanisms ◽

Glioma Cells ◽

Dependent Manner ◽

M Cell ◽

Trypan Blue Exclusion ◽

Cycle Arrest

Background: Pisosterol, a triterpene derived from Pisolithus tinctorius, exhibits potential antitumor activity in various malignancies. However, the molecular mechanisms that mediate the pisosterol-specific effects on glioma cells remain unknown. Objective: This study aimed to evaluate the antitumoral effects of pisosterol on glioma cell lines. Methods: The 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) and trypan blue exclusion assays were used to evaluate the effect of pisosterol on cell proliferation and viability in glioma cells. The effect of pisosterol on the distribution of the cells in the cell cycle was performed by flow cytometry. The expression and methylation pattern of the promoter region of MYC, ATM, BCL2, BMI1, CASP3, CDK1, CDKN1A, CDKN2A, CDKN2B, CHEK1, MDM2, p14ARF and TP53 was analyzed by RT-qPCR, western blotting and bisulfite sequencing PCR (BSP-PCR). Results: Here, it has been reported that pisosterol markedly induced G2/M arrest and apoptosis and decreased the cell viability and proliferation potential of glioma cells in a dose-dependent manner by increasing the expression of ATM, CASP3, CDK1, CDKN1A, CDKN2A, CDKN2B, CHEK1, p14ARF and TP53 and decreasing the expression of MYC, BCL2, BMI1 and MDM2. Pisosterol also triggered both caspase-independent and caspase-dependent apoptotic pathways by regulating the expression of Bcl-2 and activating caspase-3 and p53. Conclusions: It has been, for the first time, confirmed that the ATM/ATR signaling pathway is a critical mechanism for G2/M arrest in pisosterol-induced glioma cell cycle arrest and suggests that this compound might be a promising anticancer candidate for further investigation.

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SMBA1, a Bax Activator, Induces Cell Cycle Arrest and Apoptosis in Malignant Glioma Cells

Pharmacology ◽

10.1159/000500292 ◽

2019 ◽

Vol 105 (3-4) ◽

pp. 164-172

Author(s):

Shuangbo Fan ◽

Qian Xu ◽

Liang Wang ◽

Yulin Wan ◽

Sheng Qiu

Keyword(s):

Cell Cycle ◽

Cell Cycle Arrest ◽

Biological Effects ◽

Cyclin B1 ◽

Dependent Manner ◽

Apoptosis Pathway ◽

Cycle Arrest ◽

Intrinsic Apoptosis Pathway ◽

Induced Apoptosis ◽

Dose Dependent

SMBA1 (small-molecule Bax agonists 1), a small molecular activator of Bax, is a potential anti-tumour agent. In the present study, we investigated the biological effects of SMBA1 on glioblastoma (GBM) cells. SMBA1 reduced the viabilities of U87MG, U251 and T98G cells in a time- and dose-dependent manner. Moreover, treatment with SMBA1 induced cell cycle arrest at the G2/M phase transition, accompanied by the downregulation of Cdc25c and cyclin B1 and the upregulation of p21. SMBA1 also induced apoptosis of GBM cells in a dose-dependent manner. Mechanistically, SMBA1 induced apoptosis via the intrinsic pathway. Silencing of Bax or ectopic expression of Bcl-2 significantly inhibited SMBA1-induced apoptosis. Moreover, SMBA1 inhibited the growth of U87MG xenograft tumours in vivo. Overall, SMBA1 shows anti-proliferative effects against GBM cells through activation of the intrinsic apoptosis pathway.

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Antagonism of PP2A is an independent and conserved function of HIV-1 Vif and causes cell cycle arrest

10.1101/825752 ◽

2019 ◽

Author(s):

Sara Marelli ◽

James C Williamson ◽

Anna V Protasio ◽

Adi Naamati ◽

Edward JD Greenwood ◽

...

Keyword(s):

Cell Cycle ◽

Cell Cycle Arrest ◽

Cell Cycle Progression ◽

M Cell ◽

Regulatory Subunits ◽

Cycle Arrest ◽

Identify Amino Acid ◽

Necessary And Sufficient ◽

Hiv 1

AbstractThe seminal description of cellular restriction factor APOBEC3G and its antagonism by HIV-1 Vif has underpinned two decades of research on the host-virus interaction. As well as APOBEC3G and its homologues, however, we have recently discovered that Vif is also able to degrade the PPP2R5 family of regulatory subunits of key cellular phosphatase PP2A (PPP2R5A-E) (Greenwood et al., 2016; Naamati et al., 2019). We now identify amino acid polymorphisms at positions 31 and 128 of HIV-1 Vif which selectively regulate the degradation of PPP2R5 family proteins. These residues covary across HIV-1 viruses in vivo, favouring depletion of PPP2R5A-E. Through analysis of point mutants and naturally occurring Vif variants, we further show that degradation of PPP2R5 family subunits is both necessary and sufficient for Vif-dependent G2/M cell cycle arrest. Antagonism of PP2A by HIV-1 Vif is therefore independent of APOBEC3 family proteins, and regulates cell cycle progression in HIV-infected cells.

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PI3KCA and PIM Inhibitors in Peripheral T-Cell Lymphomas

Blood ◽

10.1182/blood.v116.21.4917.4917 ◽

2010 ◽

Vol 116 (21) ◽

pp. 4917-4917

Author(s):

Esperanza Martin-Sanchez ◽

Socorro M. Rodriguez-Pinilla ◽

Luis Lombardia ◽

Margarita Sanchez-Beato ◽

Beatriz Dominguez-Gonzalez ◽

...

Keyword(s):

Gene Expression ◽

Cell Cycle ◽

T Cell ◽

Cell Cycle Arrest ◽

Cell Lines ◽

Gene Expression Signature ◽

Dependent Manner ◽

Expression Signature ◽

Cycle Arrest ◽

T Cell Lymphomas

Abstract Abstract 4917 T-cell lymphomas (TCL) are a heterogeneous group of aggressive malignancies lacking specific and efficient therapy. Unfortunately, there are neither animal models nor representative cell lines for most TCL types, making functional and pharmacogenomics studies even more difficult. PI3K and PIM are kinases involved in cell proliferation, frequently altered in human cancer that seems to play a critical role in T-cell development and activation. Genomic studies have identified PIK3CD subunit to be significantly associated with in activation of CD40, NF-kB and TCR-pathways. The aim of this project is to determine the efficiency of PI3K inhibitors (PI3Ki) and PIM inhibitors (PIMi) in TCL, looking for biomarkers of their mechanism of action and to identify markers that could identify responders from non-responders. Twenty PTCL and seven reactive lymph nodes were studied using gene expression microarrays. We performed an in silico analysis using the Connectivity Map program to identify drugs that could potentially reverse PTCL gene expression signature. Among them, several PI3K/mTOR inhibitors were found. A panel of 6 TCL cell lines belonging to different TCL subgroups were treated with 3 PI3Ki (LY294002, ETP-45658, GDC-0941) and one PIMi (ETP-39010). Functional studies were also done to establish the role of each of the targeted genes. In vitro studies showed that PI3Ki induced G1 cell cycle arrest in all cell lines, and apoptosis in a portion of them, in a time/dose-dependent manner. We also observed a decrease in the levels of pAKT(S473), pGSK3B(S9) and p-p70S6K(T389) after treatment. In addition, both the analysis of the PTCL gene expression signature as well as western blot studies on TCL cell lines has shown overexpression of PIM family genes, A decrease in cell viability, and a strong induction of apoptosis in all cell lines was seen after PIM inhibition, without cell cycle arrest. Several diagnostic and pharmacodynamic biomarkers of PIMi have been identified at the mRNA and protein level in both cell lines In conclusion, our results indicate that PI3Ki and PIMi are effective therapeutic approaches for TCLs, identifying potential markers for patient's stratification and pharmacodynamic assessment. Disclosures: No relevant conflicts of interest to declare.

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HIV-1 Vif's Capacity To Manipulate the Cell Cycle Is Species Specific

Journal of Virology ◽

10.1128/jvi.02102-17 ◽

2018 ◽

Vol 92 (7) ◽

Cited By ~ 5

Author(s):

Edward L. Evans ◽

Jordan T. Becker ◽

Stephanie L. Fricke ◽

Kishan Patel ◽

Nathan M. Sherer

Keyword(s):

Cell Cycle ◽

Cell Cycle Arrest ◽

M Cell ◽

Cyclin T1 ◽

Cytopathic Effects ◽

Cycle Arrest ◽

Mouse Cells ◽

Species Specific ◽

Hiv 1 ◽

Human Specific

ABSTRACTCells derived from mice and other rodents exhibit profound blocks to HIV-1 virion production, reflecting species-specific incompatibilities between viral Tat and Rev proteins and essential host factors cyclin T1 (CCNT1) and exportin-1 (XPO1, also known as CRM1), respectively. To determine if mouse cell blocks other than CCNT1 and XPO1 affect HIV's postintegration stages, we studied HIV-1NL4-3gene expression in mouse NIH 3T3 cells modified to constitutively express HIV-1-compatible versions of CCNT1 and XPO1 (3T3.CX cells). 3T3.CX cells supported both Rev-independent and Rev-dependent viral gene expression and produced relatively robust levels of virus particles, confirming that CCNT1 and XPO1 represent the predominant blocks to these stages. Unexpectedly, however, 3T3.CX cells were remarkably resistant to virus-induced cytopathic effects observed in human cell lines, which we mapped to the viral protein Vif and its apparent species-specific capacity to induce G2/M cell cycle arrest. Vif was able to mediate rapid degradation of human APOBEC3G and the PPP2R5D regulatory B56 subunit of the PP2A phosphatase holoenzyme in mouse cells, thus demonstrating that VifNL4-3's modulation of the cell cycle can be functionally uncoupled from some of its other defined roles in CUL5-dependent protein degradation. Vif was also unable to induce G2/M cell cycle arrest in other nonhuman cell types, including cells derived from nonhuman primates, leading us to propose that one or more human-specific cofactors underpin Vif's ability to modulate the cell cycle.IMPORTANCECells derived from mice and other rodents exhibit profound blocks to HIV-1 replication, thus hindering the development of a low-cost small-animal model for studying HIV/AIDS. Here, we engineered otherwise-nonpermissive mouse cells to express HIV-1-compatible versions of two species-specific host dependency factors, cyclin T1 (CCNT1) and exportin-1 (XPO1) (3T3.CX cells). We show that 3T3.CX cells rescue HIV-1 particle production but, unexpectedly, are completely resistant to virus-induced cytopathic effects. We mapped these effects to the viral accessory protein Vif, which induces a prolonged G2/M cell cycle arrest followed by apoptosis in human cells. Combined, our results indicate that one or more additional human-specific cofactors govern HIV-1's capacity to modulate the cell cycle, with potential relevance to viral pathogenesis in people and existing animal models.

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