scholarly journals A DNA-origami nuclear pore mimic reveals nuclear entry mechanisms of HIV-1 capsid

2020 ◽  
Author(s):  
Qi Shen ◽  
Chaoyi Xu ◽  
Sooin Jang ◽  
Qiancheng Xiong ◽  
Swapnil C. Devarkar ◽  
...  
Keyword(s):  
Nuclear Pore Complex ◽  
Nuclear Import ◽  
Dna Origami ◽  
Nuclear Pore ◽  
Nuclear Entry ◽  
Cellular Factors ◽  
Immunodeficiency Virus ◽  
Hiv 1 ◽  
Human Immunodeficiency Virus 1

SummaryThe capsid of human immunodeficiency virus 1 (HIV-1) plays a pivotal role in viral nuclear import, but the mechanism by which the viral core passages the nuclear pore complex (NPC) is poorly understood. Here, we use DNA-origami mimics of the NPC, termed NuPODs (NucleoPorins Organized by DNA), to reveal the mechanistic underpinnings of HIV-1 capsid nuclear entry. We found that trimeric interface formed via three capsid protein hexamers is targeted by a triple-arginine (RRR) motif but not the canonical phenylalanine-glycine (FG) motif of NUP153. As NUP153 is located on the nuclear face of the NPC, this result implies that the assembled capsid must cross the NPC in vivo. This hypothesis is corroborated by our observations of tubular capsid assemblies penetrating through NUP153 NuPODs. NUP153 prefers to bind highly curved capsid assemblies including those found at the tips of viral cores, thereby facilitating capsid insertion into the NPC. Furthermore, a balance of capsid stabilization by NUP153 and deformation by CPSF6, along with other cellular factors, may allow for the intact capsid to pass NPCs of various sizes. The NuPOD system serves as a unique tool for unraveling the previously elusive mechanisms of nuclear import of HIV-1 and other viruses.

scholarly journals SUN1 Regulates HIV-1 Nuclear Import in a Manner Dependent on the Interaction between the Viral Capsid and Cellular Cyclophilin A

2018 ◽  
Vol 92 (13) ◽  
pp. e00229-18 ◽  
Author(s):  
Xinlong Luo ◽  
Wei Yang ◽  
Guangxia Gao
Keyword(s):  
Nuclear Pore Complex ◽  
Nuclear Import ◽  
Leukemia Virus ◽  
Cyclophilin A ◽  
Cellular Protein ◽  
Wild Type Virus ◽  
Nuclear Pore ◽  
Nuclear Entry ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACTHuman immunodeficiency virus type 1 (HIV-1) can infect nondividing cells via passing through the nuclear pore complex. The nuclear membrane-imbedded protein SUN2 was recently reported to be involved in the nuclear import of HIV-1. Whether SUN1, which shares many functional similarities with SUN2, is involved in this process remained to be explored. Here we report that overexpression of SUN1 specifically inhibited infection by HIV-1 but not that by simian immunodeficiency virus (SIV) or murine leukemia virus (MLV). Overexpression of SUN1 did not affect reverse transcription but led to reduced accumulation of the 2-long-terminal-repeat (2-LTR) circular DNA and integrated viral DNA, suggesting a block in the process of nuclear import. HIV-1 CA was mapped as a determinant for viral sensitivity to SUN1. Treatment of SUN1-expressing cells with cyclosporine (CsA) significantly reduced the sensitivity of the virus to SUN1, and an HIV-1 mutant containing CA-G89A, which does not interact with cyclophilin A (CypA), was resistant to SUN1 overexpression. Downregulation of endogenous SUN1 inhibited the nuclear entry of the wild-type virus but not that of the G89A mutant. These results indicate that SUN1 participates in the HIV-1 nuclear entry process in a manner dependent on the interaction of CA with CypA.IMPORTANCEHIV-1 infects both dividing and nondividing cells. The viral preintegration complex (PIC) can enter the nucleus through the nuclear pore complex. It has been well known that the viral protein CA plays an important role in determining the pathways by which the PIC enters the nucleus. In addition, the interaction between CA and the cellular protein CypA has been reported to be important in the selection of nuclear entry pathways, though the underlying mechanisms are not very clear. Here we show that both SUN1 overexpression and downregulation inhibited HIV-1 nuclear entry. CA played an important role in determining the sensitivity of the virus to SUN1: the regulatory activity of SUN1 toward HIV-1 relied on the interaction between CA and CypA. These results help to explain how SUN1 is involved in the HIV-1 nuclear entry process.

scholarly journals Simple kinetic relationships and nonspecific competition govern nuclear import rates in vivo

2006 ◽  
Vol 175 (4) ◽  
pp. 579-593 ◽  
Author(s):  
Benjamin L. Timney ◽  
Jaclyn Tetenbaum-Novatt ◽  
Diana S. Agate ◽  
Rosemary Williams ◽  
Wenzhu Zhang ◽  
...  
Keyword(s):  
Nuclear Localization ◽  
Nuclear Pore Complex ◽  
Nuclear Import ◽  
Yeast Cells ◽  
Limiting Factor ◽  
Nuclear Pore ◽  
Nuclear Localization Signals ◽  
The Poor ◽  
Cytoplasmic Proteins

Many cargoes destined for nuclear import carry nuclear localization signals that are recognized by karyopherins (Kaps). We present methods to quantitate import rates and measure Kap and cargo concentrations in single yeast cells in vivo, providing new insights into import kinetics. By systematically manipulating the amounts, types, and affinities of Kaps and cargos, we show that import rates in vivo are simply governed by the concentrations of Kaps and their cargo and the affinity between them. These rates fit to a straightforward pump–leak model for the import process. Unexpectedly, we deduced that the main limiting factor for import is the poor ability of Kaps and cargos to find each other in the cytoplasm in a background of overwhelming nonspecific competition, rather than other more obvious candidates such as the nuclear pore complex and Ran. It is likely that most of every import round is taken up by Kaps and nuclear localization signals sampling other cytoplasmic proteins as they locate each other in the cytoplasm.

scholarly journals Disseminated human immunodeficiency virus 1 (HIV-1) infection in SCID-hu mice after peripheral inoculation with HIV-1.

1994 ◽  
Vol 179 (2) ◽  
pp. 513-522 ◽  
Author(s):  
T R Kollmann ◽  
M Pettoello-Mantovani ◽  
X Zhuang ◽  
A Kim ◽  
M Hachamovitch ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
Lymph Nodes ◽  
Peripheral Blood ◽  
Interleukin 2 ◽  
Human T Cells ◽  
Immunodeficiency Virus ◽  
Hiv 1 ◽  
Human Immunodeficiency Virus 1

A small animal model that could be infected with human immunodeficiency virus 1 (HIV-1) after peripheral inoculation would greatly facilitate the study of the pathophysiology of acute HIV-1 infection. The utility of SCID mice implanted with human fetal thymus and liver (SCID-hu mice) for studying peripheral HIV-1 infection in vivo has been hampered by the requirement for direct intraimplant injection of HIV-1 and the continued restriction of the resultant HIV-1 infection to the human thymus and liver (hu-thy/liv) implant. This may have been due to the very low numbers of human T cells present in the SCID-hu mouse peripheral lymphoid compartment. Since the degree of the peripheral reconstitution of SCID-hu mice with human T cells may be a function of the hu-thy/liv implant size, we increased the quantity of hu-thy/liv tissue implanted under the renal capsule and implanted hu-thy/liv tissue under the capsules of both kidneys. This resulted in SCID-hu mice in which significant numbers of human T cells were detected in the peripheral blood, spleens, and lymph nodes. After intraimplant injection of HIV-1 into these modified SCID-hu mice, significant HIV-1 infection was detected by quantitative coculture not only in the hu-thy/liv implant, but also in the spleen and peripheral blood. This indicated that HIV-1 infection can spread from the thymus to the peripheral lymphoid compartment. More importantly, a similar degree of infection of the hu-thy/liv implant and peripheral lymphoid compartment occurred after peripheral intraperitoneal inoculation with HIV-1. Active viral replication was indicated by the detection of HIV-1 gag DNA, HIV-1 gag RNA, and spliced tat/rev RNA in the hu-thy/liv implants, peripheral blood mononuclear cells (PBMC), spleens, and lymph nodes of these HIV-1-infected SCID-hu mice. As a first step in using our modified SCID-hu mouse model to investigate the pathophysiological consequences of HIV-1 infection, the effect of HIV-1 infection on the expression of human cytokines shown to enhance HIV-1 replication was examined. Significantly more of the HIV-1-infected SCID-hu mice expressed mRNA for human tumor necrosis factors alpha and beta, and interleukin 2 in their spleens, lymph nodes, and PBMC than did uninfected SCID-hu mice. This suggested that HIV-1 infection in vivo can stimulate the expression of cytokine mRNA by human T cells.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Identification and culture of Kaposi's sarcoma-like spindle cells from the peripheral blood of human immunodeficiency virus-1-infected individuals and normal controls [see comments]

Blood ◽  
1994 ◽  
Vol 84 (8) ◽  
pp. 2711-2720 ◽  
Author(s):  
PJ Browning ◽  
JM Sechler ◽  
M Kaplan ◽  
RH Washington ◽  
R Gendelman ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
High Risk ◽  
Peripheral Blood ◽  
Vascular Endothelial Cells ◽  
Peripheral Blood Mononuclear ◽  
Spindle Cells ◽  
Immunodeficiency Virus ◽  
Hiv 1 ◽  
Human Immunodeficiency Virus 1

We examined 26 patients with human immunodeficiency virus-1 (HIV-1)- associated Kaposi′s sarcoma (KS), and 76 HIV-1-infected (HIV-1+) people without KS or uninfected (HIV-1-) controls for the presence of circulating KS-like spindle cells. Adherent cells that had spindle morphology and several characteristics of spindle cells of KS lesions (KS cells) were identified in the peripheral blood mononuclear cell fraction only after culture in the presence of conditioned medium (CM) from activated lymphocytes. The peripheral blood-derived spindle cells (PBsc) expressed a variety of endothelial cell markers, such as Ulex europaeus I lectin, EN4, EN2/3, EN7/44, CD13, CD34, CD36, CD54, ELAM-1, and HLA-DR. However, they were negative for CD2, CD19, PaIE, and factor VIII-related antigen. The PBsc produced angiogenic factors as evidenced by the ability of CM from these cells to promote growth of normal vascular endothelial cells. In addition, subcutaneously injected PBsc stimulated angiogenesis in vivo in athymic nude mice. We determined that the number of PBsc grown from the peripheral blood of HIV-1+ patients with KS or at high risk to develop KS were increased by 78- fold (P = .0001) and 18-fold (P = .005), respectively, when compared with HIV-1- controls. The number of spindle cells cultured from the HIV- 1+ patients at low risk for developing KS, eg, HIV-1+ injection drug users, showed no statistical increase when compared with HIV-1- controls. The presence of increased PBsc with characteristics of KS cells in HIV-1+ KS patients or patients at high risk for developing KS gives insights into the origin of KS cells and may explain the multifocal nature of the disease. In addition, this may be useful in predicting the risk of KS development.

scholarly journals Human Immunodeficiency Virus-1 Infection Interrupts Thymopoiesis and Multilineage Hematopoiesis In Vivo

Blood ◽  
1998 ◽  
Vol 91 (8) ◽  
pp. 2672-2678 ◽  
Author(s):  
Morgan Jenkins ◽  
Mary Beth Hanley ◽  
Mary Beth Moreno ◽  
Eric Wieder ◽  
Joseph M. McCune
Keyword(s):  
Human Immunodeficiency Virus ◽  
Progenitor Cells ◽  
Hematopoietic Progenitor Cells ◽  
Hematopoietic Progenitors ◽  
Hematopoietic Progenitor ◽  
Immunodeficiency Virus ◽  
Hiv 1 ◽  
Human Immunodeficiency Virus 1

It is still uncertain whether multilineage hematopoietic progenitor cells are affected by human immunodeficiency virus-1 (HIV-1) infection in vivo. The SCID-hu Thy/Liv model is permissive of long-term multilineage human hematopoiesis, including T lymphopoiesis. This model was used to investigate the effects of HIV-1 infection on early hematopoietic progenitor function. We found that both lineage-restricted and multilineage hematopoietic progenitors were depleted from grafts infected with either a molecular clone or a primary isolate of HIV-1. Depletion of hematopoietic progenitors (including CD34+ cells, colony-forming units in methylcellulose, and long-term culture-initiating cells) occurred several days before the onset of thymocyte depletion, indicating that the subsequent rapid decline in thymocyte numbers was due at least in part to loss of thymocyte progenitors. HIV-1 proviral genomes were not detected at high frequency in hematopoietic cells earlier than the intrathymic T-progenitor cell stage, despite the depletion of such cells in infected grafts. Proviral genomes were also not detected in colonies derived from progenitor cells from infected grafts. These data demonstrate that HIV-1 infection interrupts both lineage-restricted and multilineage hematopoiesis in vivo and suggest that depletion of early hematopoietic progenitor cells occurs in the absence of direct viral infection.

scholarly journals Identification and culture of Kaposi's sarcoma-like spindle cells from the peripheral blood of human immunodeficiency virus-1-infected individuals and normal controls [see comments]

Blood ◽  
1994 ◽  
Vol 84 (8) ◽  
pp. 2711-2720 ◽  
Author(s):  
PJ Browning ◽  
JM Sechler ◽  
M Kaplan ◽  
RH Washington ◽  
R Gendelman ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
High Risk ◽  
Peripheral Blood ◽  
Vascular Endothelial Cells ◽  
Peripheral Blood Mononuclear ◽  
Spindle Cells ◽  
Immunodeficiency Virus ◽  
Hiv 1 ◽  
Human Immunodeficiency Virus 1

Abstract We examined 26 patients with human immunodeficiency virus-1 (HIV-1)- associated Kaposi′s sarcoma (KS), and 76 HIV-1-infected (HIV-1+) people without KS or uninfected (HIV-1-) controls for the presence of circulating KS-like spindle cells. Adherent cells that had spindle morphology and several characteristics of spindle cells of KS lesions (KS cells) were identified in the peripheral blood mononuclear cell fraction only after culture in the presence of conditioned medium (CM) from activated lymphocytes. The peripheral blood-derived spindle cells (PBsc) expressed a variety of endothelial cell markers, such as Ulex europaeus I lectin, EN4, EN2/3, EN7/44, CD13, CD34, CD36, CD54, ELAM-1, and HLA-DR. However, they were negative for CD2, CD19, PaIE, and factor VIII-related antigen. The PBsc produced angiogenic factors as evidenced by the ability of CM from these cells to promote growth of normal vascular endothelial cells. In addition, subcutaneously injected PBsc stimulated angiogenesis in vivo in athymic nude mice. We determined that the number of PBsc grown from the peripheral blood of HIV-1+ patients with KS or at high risk to develop KS were increased by 78- fold (P = .0001) and 18-fold (P = .005), respectively, when compared with HIV-1- controls. The number of spindle cells cultured from the HIV- 1+ patients at low risk for developing KS, eg, HIV-1+ injection drug users, showed no statistical increase when compared with HIV-1- controls. The presence of increased PBsc with characteristics of KS cells in HIV-1+ KS patients or patients at high risk for developing KS gives insights into the origin of KS cells and may explain the multifocal nature of the disease. In addition, this may be useful in predicting the risk of KS development.

scholarly journals Cone-shaped HIV-1 capsids are transported through intact nuclear pores

2020 ◽  
Author(s):  
Vojtech Zila ◽  
Erica Margiotta ◽  
Beata Turonova ◽  
Thorsten G. Müller ◽  
Christian E. Zimmerli ◽  
...  
Keyword(s):  
Nuclear Import ◽  
Light And Electron Microscopy ◽  
Productive Infection ◽  
Nuclear Pore ◽  
Major Health ◽  
Replication Complex ◽  
Empty Capsid ◽  
Immunodeficiency Virus ◽  
Subtomogram Averaging ◽  
Hiv 1

AbstractHuman immunodeficiency virus (HIV-1) remains a major health threat. Viral capsid uncoating and nuclear import of the viral genome are critical for productive infection. The size of the HIV-1 capsid is generally believed to exceed the diameter of the nuclear pore complex (NPC), indicating that capsid uncoating has to occur prior to nuclear import. Here, we combined correlative light and electron microscopy with subtomogram averaging to capture the structural status of reverse transcription-competent HIV-1 complexes in infected T cells. We demonstrate that the diameter of the NPC in cellulo is sufficient for the import of apparently intact, coneshaped capsids. Subsequent to nuclear import, we detected disrupted and empty capsid fragments, indicating that uncoating of the replication complex occurs by breaking the capsid open, and not by disassembly into individual subunits. Our data directly visualize a key step in HIV-1 replication and enhance our mechanistic understanding of the viral life cycle.

scholarly journals Author response: HIV-1 nuclear import in macrophages is regulated by CPSF6-capsid interactions at the nuclear pore complex

2018 ◽  
Author(s):  
David Alejandro Bejarano ◽  
Ke Peng ◽  
Vibor Laketa ◽  
Kathleen Börner ◽  
K Laurence Jost ◽  
...  
Keyword(s):  
Nuclear Pore Complex ◽  
Nuclear Import ◽  
Author Response ◽  
Nuclear Pore ◽  
Hiv 1

scholarly journals Inhibition of productive human immunodeficiency virus-1 infection by cobalamins

Blood ◽  
1995 ◽  
Vol 86 (4) ◽  
pp. 1281-1287 ◽  
Author(s):  
JB Weinberg ◽  
DL Sauls ◽  
MA Misukonis ◽  
DC Shugars
Keyword(s):  
Human Immunodeficiency Virus ◽  
Blood Monocytes ◽  
Inhibitory Effects ◽  
Immunodeficiency Virus ◽  
Normal Human ◽  
Enzyme Cofactors ◽  
Hiv 1 ◽  
Human Immunodeficiency Virus 1

Various cobalamins act as important enzyme cofactors and modulate cellular function. We investigated cobalamins for their abilities to modify productive human immunodeficiency virus-1 (HIV-1) infection of hematopoietic cells in vitro. We show that hydroxocobalamin (OH-Cbl), methylcobalamin (Me-Cbl), and adenosylcobalamin Ado-Cbl (Ado-Cbl) inhibit HIV-1 infection of normal human blood monocytes and lymphocytes. The inhibitory effects were noted when analyzing the monocytotropic strains HIV-1-BaL and HIV-1-ADA as well as the lymphocytotropic strain HIV-1-LAI. Cobalamins did not modify binding of gp120 to CD4 or block early steps in viral life cycle, inhibit reverse transcriptase, inhibit induction of HIV-1 expression from cells with established or latent infection, or modify monocyte interferon-alpha production. Because of the ability to achieve high blood and tissue levels of cobalamins in vivo and the general lack of toxicity, cobalamins should be considered as potentially useful agents for the treatment of HIV-1 infection.

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