The nuclear lamina is a dense network of intermediate filaments beneath the inner nuclear membrane. Composed of A-type lamins (lamin A/C) and B-type lamins (lamins B1 and B2), the nuclear lamina provides a scaffold for the nuclear envelope and chromatin, thereby maintaining the structural integrity of the nucleus. A-type lamins are also found inside the nucleus where they interact with chromatin and participate in gene regulation. Viruses replicating in the cell nucleus have to overcome the nuclear envelope during the initial phase of infection and during the nuclear egress of viral progeny. Here, we focused on the role of lamins in the replication cycle of a dsDNA virus, mouse polyomavirus. We detected accumulation of the major capsid protein VP1 at the nuclear periphery, defects in nuclear lamina staining and different lamin A/C phosphorylation patterns in the late phase of mouse polyomavirus infection, but the nuclear envelope remained intact. An absence of lamin A/C did not affect the formation of replication complexes but did slow virus propagation. Based on our findings, we propose that the nuclear lamina is a scaffold for replication complex formation and that lamin A/C has a crucial role in the early phases of infection with mouse polyomavirus.

• Klíčová slova
• VP1, lamin A/C, lamin B, mouse polyomavirus, viral replication centres,
• MeSH
• buněčné jádro metabolismus   virologie   MeSH
• fosforylace MeSH
• infekce onkogenními viry virologie   patologie   metabolismus   genetika   MeSH
• jaderná lamina * metabolismus   virologie   MeSH
• jaderný obal metabolismus   virologie   MeSH
• lamin typ A * metabolismus   genetika   MeSH
• lamin typ B metabolismus   genetika   MeSH
• myši MeSH
• polyomavirové infekce * virologie   metabolismus   genetika   patologie   MeSH
• Polyomavirus * genetika   patogenita   fyziologie   MeSH
• replikace viru * MeSH
• virové plášťové proteiny metabolismus   genetika   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• lamin typ A * MeSH
• lamin typ B MeSH
• virové plášťové proteiny MeSH
• VP1 protein, polyomavirus MeSH Prohlížeč

We explored how a simple retrovirus, Mason-Pfizer monkey virus (M-PMV) to facilitate its replication process, utilizes DHX15, a cellular RNA helicase, typically engaged in RNA processing. Through advanced genetic engineering techniques, we showed that M-PMV recruits DHX15 by mimicking cellular mechanisms, relocating it from the nucleus to the cytoplasm to aid in viral assembly. This interaction is essential for the correct packaging of the viral genome and critical for its infectivity. Our findings offer unique insights into the mechanisms of viral manipulation of host cellular processes, highlighting a sophisticated strategy that viruses employ to leverage cellular machinery for their replication. This study adds valuable knowledge to the understanding of viral-host interactions but also suggests a common evolutionary history between cellular processes and viral mechanisms. This finding opens a unique perspective on the export mechanism of intron-retaining mRNAs in the packaging of viral genetic information and potentially develop ways to stop it.

• Klíčová slova
• DEAH-box RNA helicase, DHX15, G-patch, gRNA packaging, retrovirus,
• MeSH
• buněčné jádro metabolismus   virologie   MeSH
• DEAD-box RNA-helikasy metabolismus   genetika   MeSH
• genom virový MeSH
• HEK293 buňky MeSH
• lidé MeSH
• Masonův-Pfizerův opičí virus * genetika   metabolismus   fyziologie   MeSH
• replikace viru genetika   fyziologie   MeSH
• RNA virová * metabolismus   genetika   MeSH
• RNA-helikasy metabolismus   genetika   MeSH
• sestavení viru * genetika   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• DEAD-box RNA-helikasy MeSH
• DHX15 protein, human MeSH Prohlížeč
• RNA virová * MeSH
• RNA-helikasy MeSH

During the last two decades, progresses in bioimaging and the development of various strategies to fluorescently label the viral components opened a wide range of possibilities to visualize the early phase of Human Immunodeficiency Virus 1 (HIV-1) life cycle directly in infected cells. After fusion of the viral envelope with the cell membrane, the viral core is released into the cytoplasm and the viral RNA (vRNA) is retro-transcribed into DNA by the reverse transcriptase. During this process, the RNA-based viral complex transforms into a pre-integration complex (PIC), composed of the viral genomic DNA (vDNA) coated with viral and host cellular proteins. The protective capsid shell disassembles during a process called uncoating. The viral genome is transported into the cell nucleus and integrates into the host cell chromatin. Unlike biochemical approaches that provide global data about the whole population of viral particles, imaging techniques enable following individual viruses on a single particle level. In this context, quantitative microscopy has brought original data shedding light on the dynamics of the viral entry into the host cell, the cytoplasmic transport, the nuclear import, and the selection of the integration site. In parallel, multi-color imaging studies have elucidated the mechanism of action of host cell factors implicated in HIV-1 viral cycle progression. In this review, we describe the labeling strategies used for HIV-1 fluorescence imaging and report on the main advancements that imaging studies have brought in the understanding of the infection mechanisms from the viral entry into the host cell until the provirus integration step.

• Klíčová slova
• HIV-1, fluorescence microscopy, virus labeling,
• MeSH
• buněčné jádro virologie   MeSH
• fluorescenční mikroskopie MeSH
• HIV infekce virologie   MeSH
• HIV-1 chemie   genetika   fyziologie   MeSH
• integrace viru MeSH
• internalizace viru * MeSH
• lidé MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

Microtubules, part of the cytoskeleton, are indispensable for intracellular movement, cell division, and maintaining cell shape and polarity. In addition, microtubules play an important role in viral infection. In this review, we summarize the role of the microtubules' network during polyomavirus infection. Polyomaviruses usurp microtubules and their motors to travel via early and late acidic endosomes to the endoplasmic reticulum. As shown for SV40, kinesin-1 and microtubules are engaged in the release of partially disassembled virus from the endoplasmic reticulum to the cytosol, and dynein apparently assists in the further disassembly of virions prior to their translocation to the cell nucleus-the place of their replication. Polyomavirus gene products affect the regulation of microtubule dynamics. Early T antigens destabilize microtubules and cause aberrant mitosis. The role of these activities in tumorigenesis has been documented. However, its importance for productive infection remains elusive. On the other hand, in the late phase of infection, the major capsid protein, VP1, of the mouse polyomavirus, counteracts T-antigen-induced destabilization. It physically binds microtubules and stabilizes them. The interaction results in the G2/M block of the cell cycle and prolonged S phase, which is apparently required for successful completion of the viral replication cycle.

• Klíčová slova
• T antigens, VP1 capsid protein, cell cycle block, dynein, kinesin, microtubules, molecular motors, polyomavirus, virus, virus trafficking,
• MeSH
• buněčné jádro virologie   MeSH
• cytosol virologie   MeSH
• endoplazmatické retikulum virologie   MeSH
• endozomy virologie   MeSH
• interakce hostitele a patogenu * MeSH
• lidé MeSH
• mikrotubuly fyziologie   virologie   MeSH
• myši MeSH
• Polyomavirus genetika   patogenita   MeSH
• replikace viru MeSH
• vazba proteinů MeSH
• virové plášťové proteiny genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• virové plášťové proteiny MeSH
• VP1 protein, polyomavirus MeSH Prohlížeč

VP1, the major structural protein of the mouse polyomavirus (MPyV), is the major architectural component of the viral capsid. Its pentamers are able to self-assemble into capsid-like particles and to non-specifically bind DNA. Surface loops of the protein interact with sialic acid of ganglioside receptors. Although the replication cycle of the virus, including virion morphogenesis, proceeds in the cell nucleus, a substantial fraction of the protein is detected in the cytoplasm of late-phase MPyV-infected cells. In this work, we detected VP1 mainly in the cytoplasm of mammalian cells transfected with plasmid expressing VP1. In the cytoplasm, VP1-bound microtubules, including the mitotic spindle, and the interaction of VP1 with microtubules resulted in cell cycle block at the G2/M phase. Furthermore, in the late phase of MPyV infection and in cells expressing VP1, microtubules were found to be hyperacetylated. We then sought to understand how VP1 interacts with microtubules. Dynein is not responsible for the VP1-microtubule association, as neither overexpression of p53/dynamitin nor treatment with ciliobrevin-D (an inhibitor of dynein activity) prevented binding of VP1 to microtubules. A pull-down assay for VP1-interacting proteins identified the heat shock protein 90 (Hsp90) chaperone, and Hsp90 was also detected in the VP1-microtubule complexes. Although Hsp90 is known to be associated with acetylated microtubules, it does not mediate the interaction between VP1 and microtubules. Our study provides insight into the role of the major structural protein in MPyV replication, indicating that VP1 is a multifunctional protein that participates in the regulation of cell cycle progression in MPyV-infected cells.

• Klíčová slova
• VP1, cell cycle arrest, chaperone Hsp90, microtubules, mouse polyomavirus,
• MeSH
• acetylace MeSH
• buněčné jádro metabolismus   virologie   MeSH
• buňky NIH 3T3 MeSH
• cytoplazma metabolismus   virologie   MeSH
• epitelové buňky metabolismus   virologie   MeSH
• exprese genu MeSH
• HEK293 buňky MeSH
• HeLa buňky MeSH
• interakce hostitele a patogenu MeSH
• kontrolní body fáze G2 buněčného cyklu MeSH
• lidé MeSH
• mikrotubuly metabolismus   virologie   MeSH
• mléčné žlázy zvířat metabolismus   virologie   MeSH
• myši MeSH
• plazmidy chemie   metabolismus   MeSH
• Polyomavirus genetika   metabolismus   MeSH
• proteiny tepelného šoku HSP90 genetika   metabolismus   MeSH
• transfekce MeSH
• vazba proteinů MeSH
• virion genetika   metabolismus   MeSH
• virové plášťové proteiny genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• proteiny tepelného šoku HSP90 MeSH
• virové plášťové proteiny MeSH
• VP1 protein, polyomavirus MeSH Prohlížeč

There is still a considerable need for development of new tools and methods detecting specific viral proteins for the diagnosis and pathogenesis study of the Yellow fever virus (YFV). This study aimed to develop and characterize polyclonal peptide antisera for detection of YFV-C and -NS1 proteins. The antisera were used further to investigate NS1 protein expression during YFV infection in mammalian cells. YFV target proteins were detected by all antisera in western blot and immunofluorescence assays. No cross-reactivity was observed with Dengue virus, West Nile virus, Tick-borne encephalitis virus and Japanese encephalitis virus. Nuclear localization of the YFV-C protein was demonstrated for the first time. Experiments investigating NS1 expression suggested a potential use of the YFV-NS1 antisera for development of diagnostic approaches targeting the secreted form of the NS1 protein. The antisera described in this study offer new possibilities for use in YFV research and for the development of novel diagnostic tests.

• Klíčová slova
• Capsid protein, NS1 protein, Peptide antisera, Yellow fever virus,
• MeSH
• antigeny virové analýza   imunologie   metabolismus   MeSH
• buněčné jádro chemie   virologie   MeSH
• Cercopithecus aethiops MeSH
• diagnostické testy rutinní metody   MeSH
• fluorescenční protilátková technika MeSH
• králíci MeSH
• morčata MeSH
• peptidy izolace a purifikace   metabolismus   MeSH
• protilátky virové imunologie   izolace a purifikace   metabolismus   MeSH
• senzitivita a specificita MeSH
• Vero buňky MeSH
• virologie metody   MeSH
• virové nestrukturální proteiny analýza   imunologie   metabolismus   MeSH
• virové plášťové proteiny analýza   imunologie   metabolismus   MeSH
• virus žluté zimnice imunologie   izolace a purifikace   MeSH
• western blotting MeSH
• zkřížené reakce MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• morčata MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antigeny virové MeSH
• NS1 protein, Flavivirus MeSH Prohlížeč
• peptidy MeSH
• protilátky virové MeSH
• virové nestrukturální proteiny MeSH
• virové plášťové proteiny MeSH

To get access to the replication site, small non-enveloped DNA viruses have to cross the cell membrane using a limited number of capsid proteins, which also protect the viral genome in the extracellular environment. Most of DNA viruses have to reach the nucleus to replicate. The capsid proteins involved in transmembrane penetration are exposed or released during endosomal trafficking of the virus. Subsequently, the conserved domains of capsid proteins interact with cellular membranes and ensure their efficient permeabilization. This review summarizes our current knowledge concerning the role of capsid proteins of small non-enveloped DNA viruses in intracellular membrane perturbation in the early stages of infection.

• MeSH
• Adenoviridae fyziologie   MeSH
• buněčná membrána metabolismus   virologie   MeSH
• buněčné jádro metabolismus   virologie   MeSH
• endozomy metabolismus   virologie   MeSH
• eukaryotické buňky metabolismus   virologie   MeSH
• interakce hostitele a patogenu MeSH
• internalizace viru * MeSH
• lidé MeSH
• Papillomaviridae fyziologie   MeSH
• Parvoviridae fyziologie   MeSH
• Polyomaviridae fyziologie   MeSH
• replikace viru MeSH
• transport proteinů MeSH
• vazba proteinů MeSH
• virové plášťové proteiny chemie   metabolismus   MeSH
• virové receptory metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• virové plášťové proteiny MeSH
• virové receptory MeSH

Lamins are the best characterized cytoskeletal components of the cell nucleus that help to maintain the nuclear shape and participate in diverse nuclear processes including replication or transcription. Nuclear actin is now widely accepted to be another cytoskeletal protein present in the nucleus that fulfills important functions in the gene expression. Some viruses replicating in the nucleus evolved the ability to interact with and probably utilize nuclear actin for their replication, e.g., for the assembly and transport of capsids or mRNA export. On the other hand, lamins play a role in the propagation of other viruses since nuclear lamina may represent a barrier for virions entering or escaping the nucleus. This review will summarize the current knowledge about the roles of nuclear actin and lamins in viral infections.

• Klíčová slova
• viruses, cytoskeleton, lamin, nuclear actin, nuclear lamina, nucleus,
• MeSH
• aktiny metabolismus   MeSH
• Baculoviridae metabolismus   patogenita   MeSH
• buněčné jádro metabolismus   virologie   MeSH
• cytoskelet MeSH
• Herpesviridae metabolismus   patogenita   MeSH
• herpetické infekce metabolismus   patologie   virologie   MeSH
• laminy metabolismus   MeSH
• lidé MeSH
• replikace viru * MeSH
• Retroviridae metabolismus   patogenita   MeSH
• retrovirové infekce metabolismus   patologie   virologie   MeSH
• sestavení viru * MeSH
• virové nemoci metabolismus   virologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• aktiny MeSH
• laminy MeSH

A double infection of Daphne mosaic virus (DapMV) and an associated bacilliform virus was observed in the samples of diseased Daphne mezereum shrubs that showed mosaic patterns, precocious leaves reddening, defoliation, repeated flowering with subsequent declining. Extensive aggregations of bacilliform particles (166-370 x 65 nm and 169-233 x 68-78 nm) occurred in the nucleus or perinuclear space of root and leaf tissues suggesting that the virus might belong to the genus Nucleorhabdovirus, family Rhabdoviridae. However, the single bacilliform virions appeared occasionally in the cytoplasm of the leaf cells. We supposed that occurrence of the mixed virus infection could be the cause of D. mezereum decline in the Czech Republic.

• MeSH
• buněčné jádro ultrastruktura   virologie   MeSH
• Daphne virologie   MeSH
• kořeny rostlin ultrastruktura   virologie   MeSH
• listy rostlin ultrastruktura   virologie   MeSH
• nemoci rostlin virologie   MeSH
• rostlinné viry izolace a purifikace   ultrastruktura   MeSH
• transmisní elektronová mikroskopie MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH

Mouse polyomavirus enters host cells internalized, similar to simian virus 40 (SV40), in smooth monopinocytic vesicles, the movement of which is associated with transient actin disorganization. The major capsid protein (VP1) of the incoming polyomavirus accumulates on membranes around the cell nucleus. Here we show that unlike SV40, mouse polyomavirus infection is not substantially inhibited by brefeldin A, and colocalization of VP1 with beta-COP during early stages of polyomavirus infection in mouse fibroblasts was observed only rarely. Thus, these viruses obviously use different traffic routes from the plasma membrane toward the cell nucleus. At approximately 3 h postinfection, a part of VP1 colocalized with the endoplasmic reticulum marker BiP, and a subpopulation of virus was found in perinuclear areas associated with Rab11 GTPase and colocalized with transferrin, a marker of recycling endosomes. Earlier postinfection, a minor subpopulation of virions was found to be associated with Rab5, known to be connected with early endosomes, but the cell entry of virus was slower than that of transferrin or cholera toxin B-fragment. Neither Rab7, a marker of late endosomes, nor LAMP-2 lysosomal glycoprotein was found to colocalize with polyomavirus. In situ hybridization with polyomavirus genome-specific fluorescent probes clearly demonstrated that, regardless of the multiplicity of infection, only a few virions delivered their genomic DNA into the cell nucleus, while the majority of viral genomes (and VP1) moved back from the proximity of the nucleus to the cytosol, apparently for their degradation.

• MeSH
• biologický transport MeSH
• brefeldin A farmakologie   MeSH
• buněčné jádro virologie   MeSH
• chaperon endoplazmatického retikula BiP MeSH
• COP-vezikuly fyziologie   MeSH
• endozomy virologie   MeSH
• lyzozomy virologie   MeSH
• molekulární chaperony analýza   MeSH
• myši MeSH
• obalový protein analýza   MeSH
• Polyomavirus fyziologie   MeSH
• proteiny teplotního šoku * MeSH
• Rab proteiny vázající GTP analýza   MeSH
• Rab5 proteiny vázající GTP analýza   MeSH
• transportní proteiny analýza   MeSH
• virion fyziologie   MeSH
• virové plášťové proteiny analýza   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• brefeldin A MeSH
• chaperon endoplazmatického retikula BiP MeSH
• molekulární chaperony MeSH
• obalový protein MeSH
• proteiny teplotního šoku * MeSH
• Rab proteiny vázající GTP MeSH
• Rab5 proteiny vázající GTP MeSH
• Rab6 protein MeSH Prohlížeč
• transportní proteiny MeSH
• virové plášťové proteiny MeSH