Infection by agnoprotein-negative mutants of polyomavirus JC and SV40 results in the release of virions that are mostly deficient in DNA content

<p>Abstract</p> <p>Background</p> <p>Human polyomavirus JC (JCV) is the etiologic agent of a brain disease, known as progressive multifocal leukoencephalopathy (PML). The JCV genome encodes a small multifunctional phospho-protein, agnoprotein, from the late coding regio...

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Main Authors: Safak Mahmut, White Martyn K, Saribas Abdullah S, Sariyer Ilker K
Format: Article
Language:English
Published: BMC 2011-05-01
Series:Virology Journal
Subjects:
Online Access:http://www.virologyj.com/content/8/1/255
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author Safak Mahmut
White Martyn K
Saribas Abdullah S
Sariyer Ilker K
author_facet Safak Mahmut
White Martyn K
Saribas Abdullah S
Sariyer Ilker K
author_sort Safak Mahmut
collection DOAJ
description <p>Abstract</p> <p>Background</p> <p>Human polyomavirus JC (JCV) is the etiologic agent of a brain disease, known as progressive multifocal leukoencephalopathy (PML). The JCV genome encodes a small multifunctional phospho-protein, agnoprotein, from the late coding region of the virus, whose regulatory functions in viral replication cycle remain elusive. In this work, the functional role of JCV and SV40 agnoproteins in virion release was investigated using a point mutant (Pt) of each virus, where the ATG codon of agnoprotein was mutated to abrogate its expression.</p> <p>Results</p> <p>Analysis of both viral protein expression and replication using Pt mutant of each virus revealed that both processes were substantially down-regulated in the absence of agnoprotein compared to wild-type (WT) virus. Complementation studies in cells, which are constitutively expressing JCV agnoprotein and transfected with the JCV Pt mutant genome, showed an elevation in the level of viral DNA replication near to that observed for WT. Constitutive expression of large T antigen was found to be not sufficient to compensate the loss of agnoprotein for efficient replication of neither JCV nor SV40 in vivo. Examination of the viral release process for both JCV and SV40 Pt mutants showed that viral particles are efficiently released from the infected cells in the absence of agnoprotein but were found to be mostly deficient in viral DNA content.</p> <p>Conclusions</p> <p>The results of this study provide evidence that agnoprotein plays an important role in the polyomavirus JC and SV40 life cycle. Infection by agnoprotein-negative mutants of both viruses results in the release of virions that are mostly deficient in DNA content.</p>
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spelling doaj.art-3487021a69c249da9bd36aed6a2669992022-12-22T03:24:53ZengBMCVirology Journal1743-422X2011-05-018125510.1186/1743-422X-8-255Infection by agnoprotein-negative mutants of polyomavirus JC and SV40 results in the release of virions that are mostly deficient in DNA contentSafak MahmutWhite Martyn KSaribas Abdullah SSariyer Ilker K<p>Abstract</p> <p>Background</p> <p>Human polyomavirus JC (JCV) is the etiologic agent of a brain disease, known as progressive multifocal leukoencephalopathy (PML). The JCV genome encodes a small multifunctional phospho-protein, agnoprotein, from the late coding region of the virus, whose regulatory functions in viral replication cycle remain elusive. In this work, the functional role of JCV and SV40 agnoproteins in virion release was investigated using a point mutant (Pt) of each virus, where the ATG codon of agnoprotein was mutated to abrogate its expression.</p> <p>Results</p> <p>Analysis of both viral protein expression and replication using Pt mutant of each virus revealed that both processes were substantially down-regulated in the absence of agnoprotein compared to wild-type (WT) virus. Complementation studies in cells, which are constitutively expressing JCV agnoprotein and transfected with the JCV Pt mutant genome, showed an elevation in the level of viral DNA replication near to that observed for WT. Constitutive expression of large T antigen was found to be not sufficient to compensate the loss of agnoprotein for efficient replication of neither JCV nor SV40 in vivo. Examination of the viral release process for both JCV and SV40 Pt mutants showed that viral particles are efficiently released from the infected cells in the absence of agnoprotein but were found to be mostly deficient in viral DNA content.</p> <p>Conclusions</p> <p>The results of this study provide evidence that agnoprotein plays an important role in the polyomavirus JC and SV40 life cycle. Infection by agnoprotein-negative mutants of both viruses results in the release of virions that are mostly deficient in DNA content.</p>http://www.virologyj.com/content/8/1/255JC virusBK virusSV40replicationtranscriptionvirion release
spellingShingle Safak Mahmut
White Martyn K
Saribas Abdullah S
Sariyer Ilker K
Infection by agnoprotein-negative mutants of polyomavirus JC and SV40 results in the release of virions that are mostly deficient in DNA content
Virology Journal
JC virus
BK virus
SV40
replication
transcription
virion release
title Infection by agnoprotein-negative mutants of polyomavirus JC and SV40 results in the release of virions that are mostly deficient in DNA content
title_full Infection by agnoprotein-negative mutants of polyomavirus JC and SV40 results in the release of virions that are mostly deficient in DNA content
title_fullStr Infection by agnoprotein-negative mutants of polyomavirus JC and SV40 results in the release of virions that are mostly deficient in DNA content
title_full_unstemmed Infection by agnoprotein-negative mutants of polyomavirus JC and SV40 results in the release of virions that are mostly deficient in DNA content
title_short Infection by agnoprotein-negative mutants of polyomavirus JC and SV40 results in the release of virions that are mostly deficient in DNA content
title_sort infection by agnoprotein negative mutants of polyomavirus jc and sv40 results in the release of virions that are mostly deficient in dna content
topic JC virus
BK virus
SV40
replication
transcription
virion release
url http://www.virologyj.com/content/8/1/255
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