Infectivities of human and other primate lentiviruses are activated by desialylation of the virion surface.

1996 ◽  
Vol 70 (11) ◽  
pp. 7462-7470 ◽  
Author(s):  
H Hu ◽  
T Shioda ◽  
C Moriya ◽  
X Xin ◽  
M K Hasan ◽  
...  
Keyword(s):  
Primate Lentiviruses ◽  
Virion Surface

scholarly journals The C-terminal domain of feline and bovine SAMHD1 proteins has a crucial role in lentiviral restriction

2020 ◽  
Vol 295 (13) ◽  
pp. 4252-4264 ◽  
Author(s):  
Chu Wang ◽  
Kaikai Zhang ◽  
Lina Meng ◽  
Xin Zhang ◽  
Yanan Song ◽  
...  
Keyword(s):  
Proteasomal Degradation ◽  
Acid Sites ◽  
Accessory Protein ◽  
Restriction Profile ◽  
Biological Functions ◽  
Terminal Domain ◽  
Functional Regions ◽  
Viral Restriction ◽  
Primate Lentiviruses

SAM and HD domain-containing protein 1 (SAMHD1) is a host factor that restricts reverse transcription of lentiviruses such as HIV in myeloid cells and resting T cells through its dNTP triphosphohydrolase (dNTPase) activity. Lentiviruses counteract this restriction by expressing the accessory protein Vpx or Vpr, which targets SAMHD1 for proteasomal degradation. SAMHD1 is conserved among mammals, and the feline and bovine SAMHD1 proteins (fSAM and bSAM) restrict lentiviruses by reducing cellular dNTP concentrations. However, the functional regions of fSAM and bSAM that are required for their biological functions are not well-characterized. Here, to establish alternative models to investigate SAMHD1 in vivo, we studied the restriction profile of fSAM and bSAM against different primate lentiviruses. We found that both fSAM and bSAM strongly restrict primate lentiviruses and that Vpx induces the proteasomal degradation of both fSAM and bSAM. Further investigation identified one and five amino acid sites in the C-terminal domain (CTD) of fSAM and bSAM, respectively, that are required for Vpx-mediated degradation. We also found that the CTD of bSAM is directly involved in mediating bSAM's antiviral activity by regulating dNTPase activity, whereas the CTD of fSAM is not. Our results suggest that the CTDs of fSAM and bSAM have important roles in their antiviral functions. These findings advance our understanding of the mechanism of fSAM- and bSAM-mediated viral restriction and might inform strategies for improving HIV animal models.

Exploitation of plant and archaeal viruses in bionanotechnology

2009 ◽  
Vol 37 (4) ◽  
pp. 665-670 ◽  
Author(s):  
David J. Evans
Keyword(s):  
The Body ◽  
Layer By Layer ◽  
Archaeal Virus ◽  
Sulfolobus Islandicus ◽  
Naturally Occurring ◽  
Archaeal Viruses ◽  
Nanobuilding Blocks ◽  
Multiple Copies ◽  
Site Selective ◽  
Virion Surface

CPMV (cowpea mosaic virus), a plant virus, is a naturally occurring sphere-like nanoparticle, and is used as a synthon and/or template in bionanoscience. The virions formed by CPMV can be regarded as programmable nanobuilding blocks with a diameter of ∼30 nm. A range of molecules have been attached to this viral nanoscaffold, yielding stable nanoparticles that display multiple copies of the desired molecule. It has been shown that, in addition to surface amine groups, surface carboxy groups are also addressable, and a procedure has been developed that enables introduction of reactive thiols at the virion surface that avoids virus aggregation. Furthermore, the virions can be functionalized to form electroactive nanoparticles. Methods for the construction of arrays and multilayers, using a layer-by-layer approach, have been established. As proof of concept, for example, CPMV particles have been immobilized on surfaces and arranged in defined layers. Engineered variants of CPMV can be used as templates for mineralization with, for example, silica to give monodisperse robust silica nanoparticles of ∼32 nm. SIRV2 (Sulfolobus islandicus rod-shaped virus 2), is a robust archaeal virus, resistant to high temperature and low pH. SIRV2 can act as a template for site-selective and spatially controlled chemical modification. Both the ends and the body of the virus, or the ends only, can be chemically addressed; SIRV2 can be regarded as a structurally unique nanobuilding block.

scholarly journals Biological Effect of Muller's Ratchet: Distant Capsid Site Can Affect Picornavirus Protein Processing

2009 ◽  
Vol 83 (13) ◽  
pp. 6748-6756 ◽  
Author(s):  
Cristina Escarmís ◽  
Celia Perales ◽  
Esteban Domingo
Keyword(s):  
Three Dimensional ◽  
Antigenic Site ◽  
Foot And Mouth Disease ◽  
Distance Effect ◽  
Dimensional Structure ◽  
Mouth Disease Virus ◽  
Precursor Proteins ◽  
Biochemical Level ◽  
Capsid Protein Vp1 ◽  
Virion Surface

ABSTRACT Repeated bottleneck passages of RNA viruses result in accumulation of mutations and fitness decrease. Here, we show that clones of foot-and-mouth disease virus (FMDV) subjected to bottleneck passages, in the form of plaque-to-plaque transfers in BHK-21 cells, increased the thermosensitivity of the viral clones. By constructing infectious FMDV clones, we have identified the amino acid substitution M54I in capsid protein VP1 as one of the lesions associated with thermosensitivity. M54I affects processing of precursor P1, as evidenced by decreased production of VP1 and accumulation of VP1 precursor proteins. The defect is enhanced at high temperatures. Residue M54 of VP1 is exposed on the virion surface, and it is close to the B-C loop where an antigenic site of FMDV is located. M54 is not in direct contact with the VP1-VP3 cleavage site, according to the three-dimensional structure of FMDV particles. Models to account for the effect of M54 in processing of the FMDV polyprotein are proposed. In addition to revealing a distance effect in polyprotein processing, these results underline the importance of pursuing at the biochemical level the biological defects that arise when viruses are subjected to multiple bottleneck events.

scholarly journals Mosaic Genomes of the Six Major Primate Lentivirus Lineages Revealed by Phylogenetic Analyses

2003 ◽  
Vol 77 (13) ◽  
pp. 7202-7213 ◽  
Author(s):  
Marco Salemi ◽  
Tulio De Oliveira ◽  
Valerie Courgnaud ◽  
Vincent Moulton ◽  
Barbara Holland ◽  
...  
Keyword(s):  
Phylogenetic Relationships ◽  
Statistical Tests ◽  
Phylogenetic Analyses ◽  
Decomposition Analysis ◽  
Phylogeny Reconstruction ◽  
Origin And Evolution ◽  
Immunodeficiency Virus ◽  
Primate Lentiviruses ◽  
Recombinant Fragments ◽  
Clustering Patterns

ABSTRACT To clarify the origin and evolution of the primate lentiviruses (PLVs), which include human immunodeficiency virus types 1 and 2 as well as their simian relatives, simian immunodeficiency viruses (SIVs), isolated from several host species, we investigated the phylogenetic relationships among the six supposedly nonrecombinant PLV lineages for which the full genome sequences are available. Employing bootscanning as an exploratory tool, we located several regions in the PLV genome that seem to have uncertain or conflicting phylogenetic histories. Phylogeny reconstruction based on distance and maximum-likelihood algorithms followed by a number of statistical tests confirms the existence of at least five putative recombinant fragments in the PLV genome with different clustering patterns. Split decomposition analysis also shows that phylogenetic relationships among PLVs may be better represented by network-based graphs, such as the ones produced by SplitsTree. Our findings not only imply that the six so-called pure PLV lineages have in fact mosaic genomes but also make more unlikely the hypothesis of cospeciation of SIVs and their simian hosts.

scholarly journals The Susceptibility of Primate Lentiviruses to Nucleosides and Vpx during Infection of Dendritic Cells Is Regulated by CA

2015 ◽  
Vol 89 (7) ◽  
pp. 4030-4034 ◽  
Author(s):  
Véronique Barateau ◽  
Xuan-Nhi Nguyen ◽  
Fanny Bourguillault ◽  
Grégory Berger ◽  
Stéphanie Cordeil ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Dendritic Cells ◽  
Simian Immunodeficiency Virus ◽  
Viral Protein ◽  
Immunodeficiency Virus ◽  
Protein X ◽  
Primate Lentiviruses ◽  
Species Specific ◽  
Hiv 1

The block toward human immunodeficiency virus type 1 (HIV-1) infection of dendritic cells (DCs) can be relieved by Vpx (viral protein X), which degrades sterile alpha motif-hydroxylase domain 1 (SAMHD1) or by exogenously added deoxynucleosides (dNs), lending support to the hypothesis that SAMHD1 acts by limiting deoxynucleoside triphosphates (dNTPs). This notion has, however, been questioned. We show that while dNs and Vpx increase the infectivity of HIV-1, only the latter restores the infectivity of a simian immunodeficiency virus of macaques variant, SIVMACΔVpx virus. This distinct behavior seems to map to CA, suggesting that species-specific CA interactors modulate infection of DCs.

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