scholarly journals Cloning and Sequencing of Defective Particles Derived from the Autonomous Parvovirus Minute Virus of Mice for the Construction of Vectors with Minimal cis-Acting Sequences

2001 ◽  
Vol 75 (3) ◽  
pp. 1284-1293 ◽  
Author(s):  
Nathalie Clément ◽  
Bernard Avalosse ◽  
Karim El Bakkouri ◽  
Thierry Velu ◽  
Annick Brandenburger
Keyword(s):  
Virus Production ◽  
Dna Amplification ◽  
Wild Type ◽  
Nonstructural Proteins ◽  
Helper Plasmid ◽  
Minute Virus Of Mice ◽  
Coding Sequences ◽  
Cis Acting ◽  
Minute Virus ◽  
Helper Plasmids

ABSTRACT The production of wild-type-free stocks of recombinant parvovirus minute virus of mice [MVM(p)] is difficult due to the presence of homologous sequences in vector and helper genomes that cannot easily be eliminated from the overlapping coding sequences. We have therefore cloned and sequenced spontaneously occurring defective particles of MVM(p) with very small genomes to identify the minimalcis-acting sequences required for DNA amplification and virus production. One of them has lost all capsid-coding sequences but is still able to replicate in permissive cells when nonstructural proteins are provided in trans by a helper plasmid. Vectors derived from this particle produce stocks with no detectable wild-type MVM after cotransfection with new, matched, helper plasmids that present no homology downstream from the transgene.

Selective killing of transformed rat cells by minute virus of mice does not require infectious virus production.

1990 ◽  
Vol 64 (1) ◽  
pp. 458-462 ◽  
Author(s):  
E Guetta ◽  
M Mincberg ◽  
S Mousset ◽  
C Bertinchamps ◽  
J Rommelaere ◽  
...  
Keyword(s):  
Infectious Virus ◽  
Virus Production ◽  
Minute Virus Of Mice ◽  
Minute Virus

scholarly journals Opposite Transcriptional Effects of Cyclic AMP-Responsive Elements in Confluent or p27KIP-Overexpressing Cells versus Serum-Starved or Growing Cells

1998 ◽  
Vol 18 (1) ◽  
pp. 409-419 ◽  
Author(s):  
Laurent Deleu ◽  
François Fuks ◽  
Dimitry Spitkovsky ◽  
Rita Hörlein ◽  
Steffen Faisst ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Cycle ◽  
Cyclic Amp ◽  
Dna Amplification ◽  
S Phase ◽  
Host Cells ◽  
Dependent Manner ◽  
Cyclin Dependent Kinase ◽  
Minute Virus Of Mice ◽  
Minute Virus

ABSTRACT The minute virus of mice, an autonomous parvovirus, requires entry of host cells into the S phase of the cell cycle for its DNA to be amplified and its genes expressed. This work focuses on the P4 promoter of this parvovirus, which directs expression of the transcription unit encoding the parvoviral nonstructural polypeptides. These notably include protein NS1, necessary for the S-phase-dependent burst of parvoviral DNA amplification and gene expression. The activity of the P4 promoter is shown to be regulated in a cell cycle-dependent manner. At the G1/S-phase transition, the promoter is activated via a cis-acting DNA element which interacts with phase-specific complexes containing the cellular transcription factor E2F. It is inhibited, on the other hand, in cells arrested in G1 due to contact inhibition. This inhibitory effect is not observed in serum-starved cells. It is mediated in cis by cyclic AMP response elements (CREs). Unlike serum-starved cells, confluent cells accumulate the cyclin-dependent kinase inhibitor p27, suggesting that the switch from CRE-mediated activation to CRE-mediated repression involves the p27 protein. Accordingly, plasmid-driven overexpression of p27 causes down-modulation of promoter P4 in growing cells, depending on the presence of at least two functional CREs. No such effect is observed with two other cyclin-dependent kinase inhibitors, p16 and p21. Given the importance of P4-driven synthesis of protein NS1 in parvoviral DNA amplification and gene expression, the stringent S-phase dependency of promoter P4 is likely a major determinant of the absolute requirement of the minute virus of mice for host cell proliferation.

scholarly journals Resolution of Parvovirus Dimer Junctions Proceeds through a Novel Heterocruciform Intermediate

2003 ◽  
Vol 77 (11) ◽  
pp. 6245-6254 ◽  
Author(s):  
Susan F. Cotmore ◽  
Peter Tattersall
Keyword(s):  
Dna Synthesis ◽  
Crucial Role ◽  
Dna Amplification ◽  
Single Strand ◽  
Minute Virus Of Mice ◽  
Initiator Protein ◽  
Resolution Model ◽  
Minute Virus ◽  
Single Sequence

ABSTRACT The minute virus of mice initiator protein, NS1, excises new copies of the left viral telomere in a single sequence orientation, dubbed flip, during resolution of the junction between monomer genomes in palindromic dimer intermediate duplexes. We examined this reaction in vitro using both 32P-end-labeled linear substrates and similar unlabeled templates labeled by incorporation of [α-32P]TTP during the synthesis. The observed products suggest a resolution model that explains conservation of the hairpin sequence and in which a novel heterocruciform intermediate plays a crucial role. In vitro, NS1 initiates two replication pathways from OriLTC, the single active origin embedded in one arm of the dimer junction. NS1-mediated nicking liberates a base-paired 3′ nucleotide to prime DNA synthesis and, in a reaction we call “read-through synthesis,” forks established while the substrate is a linear duplex synthesize DNA in the flop orientation, leading to DNA amplification but not to junction resolution. Nicking leaves NS1 covalently attached to the 5′ end of the DNA, where it can serve as a 3′-to-5′ helicase, unwinding the NS1-associated strand. In the second pathway, resolution substrates are created when such unwinding induces the palindrome to reconfigure into a cruciform prior to fork assembly. New forks can then synthesize DNA in the flip orientation, copying one cruciform arm and creating a heterocruciform intermediate. Resolution proceeds via hairpin transfer in the extended arm of the heterocruciform, which releases one covalently closed duplex telomere and a partially single-stranded junction intermediate. We suggest that the latter intermediate is finally resolved via an NS1-induced single-strand nick at the otherwise inactive origin, OriLGAA.

scholarly journals The Expression Strategy of Goose Parvovirus Exhibits Features of both the Dependovirus and Parvovirus Genera

2005 ◽  
Vol 79 (17) ◽  
pp. 11035-11044 ◽  
Author(s):  
Jianming Qiu ◽  
Fang Cheng ◽  
Yuko Yoto ◽  
Zoltán Zádori ◽  
David Pintel
Keyword(s):  
High Efficiency ◽  
Nonstructural Protein ◽  
Nonstructural Proteins ◽  
Coding Region ◽  
Minute Virus Of Mice ◽  
Adeno Associated Virus ◽  
Goose Parvovirus ◽  
Minute Virus ◽  
The Right ◽  
A Site

ABSTRACT The RNA transcription profile of the goose parvovirus (GPV) was determined, and it is a surprising hybrid of features of the Parvovirus and Dependovirus genera of the Parvovirinae subfamily of the Parvoviridae. Similar to the Dependovirus adeno-associated virus type 5, RNAs transcribed from the GPV upstream P9 promoter, which encode the viral nonstructural proteins, were polyadenylated at a high efficiency at a polyadenylation site [(pA)p] located within an intron in the center of the genome. Efficient usage of (pA)p required a downstream element that overlaps with the polypyrimidine tract of the A2 3′ splice site of the central intron. An upstream element required for efficient use of (pA)p was also identified. RNAs transcribed from the P42 promoter, presumed to encode the viral capsid proteins, primarily extended through (pA)p and were polyadenylated at a site, (pA)d, located at the right end of the genome and ultimately spliced at a high efficiency. No promoter analogous to the Dependovirus P19 promoter was detected; however, similar to minute virus of mice and other members of the Parvovirus genus, a significant portion of pre-mRNAs generated from the P9 promoter were additionally spliced within the putative GPV Rep1 coding region and likely encode an additional, smaller, nonstructural protein. Also similar to members of the Parvovirus genus, detectable activity of the GPV P42 promoter was highly dependent on transactivation by the GPV Rep1 protein in a manner dependent on binding to a cis-element located in the P42 promoter.

scholarly journals Minute virus of mice small non-structural protein NS2 localizes within, but is not required for the formation of, Smn-associated autonomous parvovirus-associated replication bodies

2005 ◽  
Vol 86 (4) ◽  
pp. 1009-1014 ◽  
Author(s):  
Philip J. Young ◽  
Ann Newman ◽  
Klaus T. Jensen ◽  
Lisa R. Burger ◽  
David J. Pintel ◽  
...  
Keyword(s):  
Virus Replication ◽  
Survival Motor Neuron ◽  
Structural Proteins ◽  
Temporal Delay ◽  
Structural Protein ◽  
Wild Type ◽  
Minute Virus Of Mice ◽  
Minute Virus ◽  
Nuclear Structures

The non-structural proteins NS1 and NS2 of the parvovirus minute virus of mice (MVM) are required for efficient virus replication. It has previously been shown that NS1 and NS2 interact and colocalize with the survival motor neuron (Smn) gene product in novel nuclear structures that are formed late in infection, termed Smn-associated APAR (autonomous parvovirus-associated replication) bodies (SAABs). It is not clear what molecular viral intermediate(s) contribute to SAAB formation. The current results address the role of NS2 in SAAB formation. In highly synchronized wild-type MVM infection of murine A92L cells, NS2 colocalizes with Smn and other SAAB constituents. An MVM mutant that does not produce NS2 still generates SAABS, albeit with a temporal delay. The lag in SAAB formation seen in the absence of NS2 is probably related to the temporal delay in virus replication, suggesting that, whilst NS2 is required for efficient viral infection, it is dispensable for SAAB formation.

scholarly journals Interaction between Parvovirus NS2 Protein and Nuclear Export Factor Crm1 Is Important for Viral Egress from the Nucleus of Murine Cells

2002 ◽  
Vol 76 (7) ◽  
pp. 3257-3266 ◽  
Author(s):  
Cathy L. Miller ◽  
David J. Pintel
Keyword(s):  
Viral Infection ◽  
Nuclear Export ◽  
Null Mutant ◽  
Wild Type ◽  
Single Stranded Dna ◽  
Minute Virus Of Mice ◽  
Export Pathway ◽  
Viral Egress ◽  
Late Step ◽  
Minute Virus

ABSTRACT A mutation that disrupts the interaction between the NS2 protein of minute virus of mice and the nuclear export factor Crm1 results in a block to egress of mutant-generated full virions from the nucleus of infected murine cells. These mutants produce wild-type levels of monomer and dimer replicative DNA forms but are impaired in their ability to generate progeny single-stranded DNA in restrictive murine cells in the first round of infection. The NS2-Crm1 interaction mutant can be distinguished phenotypically from an NS2-null mutant and reveals a role for the Crm1-mediated export pathway at a late step in viral infection.

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