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The polypyrimidine tract-binding protein is required for efficient dengue virus propagation and associates with the viral replication machinery.

ABSTRACT: The polypyrimidine tract-binding protein (PTB) functions primarily as an IRES trans-acting factor in the propagation of hepatitis C virus and picornaviruses. PTB interacts with secondary structures within the 3'- and 5'-untranslated regions of these viral genomes to mediate efficient IRES-mediated viral translation. PTB has also been reported to bind to the untranslated region of the single-stranded RNA dengue virus (DENV), suggesting a similar function for PTB in flaviviruses. Indeed small interfering RNA-mediated PTB knockdown inhibited the production of infectious DENV, and this inhibition was specific to PTB knockdown and not due to a nonspecific anti-viral state. In fact, PTB depletion did not inhibit the production infectious yellow fever virus, another flavivirus. Nevertheless, whereas PTB knockdown led to a significant decrease in the accumulation of DENV viral RNAs, it did not impair translation. Moreover, PTB was shown to interact with the DENV nonstructural 4A protein, a known component of the viral replication complex, and with the DENV genome during infection. These data suggest that PTB interacts with the replication complex of DENV and is acting at the level of viral RNA replication.

SUBMITTER: Anwar A

PROVIDER: S-EPMC2719340 | biostudies-literature | 2009 Jun

REPOSITORIES: biostudies-literature

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The polypyrimidine tract-binding protein is required for efficient dengue virus propagation and associates with the viral replication machinery.

Anwar Azlinda A Leong K M KM Ng Mary L ML Chu Justin J H JJH Garcia-Blanco Mariano A MA

The Journal of biological chemistry 20090420 25

The polypyrimidine tract-binding protein (PTB) functions primarily as an IRES trans-acting factor in the propagation of hepatitis C virus and picornaviruses. PTB interacts with secondary structures within the 3'- and 5'-untranslated regions of these viral genomes to mediate efficient IRES-mediated viral translation. PTB has also been reported to bind to the untranslated region of the single-stranded RNA dengue virus (DENV), suggesting a similar function for PTB in flaviviruses. Indeed small inte ...[more]

PMID: 19380576

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Project description:Human parvovirus B19 (B19V) infection of human erythroid progenitor cells (EPCs) induces a DNA damage response and cell cycle arrest at late S phase, which facilitates viral DNA replication. However, it is not clear exactly which cellular factors are employed by this single-stranded DNA virus. Here, we used microarrays to systematically analyze the dynamic transcriptome of EPCs infected with B19V. We found that DNA metabolism, DNA replication, DNA repair, DNA damage response, cell cycle, and cell cycle arrest pathways were significantly regulated after B19V infection. Confocal microscopy analyses revealed that most cellular DNA replication proteins were recruited to the centers of viral DNA replication, but not the DNA repair DNA polymerases. Our results suggest that DNA replication polymerase ? and polymerase ? are responsible for B19V DNA replication by knocking down its expression in EPCs. We further showed that although RPA32 is essential for B19V DNA replication and the phosphorylated forms of RPA32 colocalized with the replicating viral genomes, RPA32 phosphorylation was not necessary for B19V DNA replication. Thus, this report provides evidence that B19V uses the cellular DNA replication machinery for viral DNA replication.IMPORTANCE Human parvovirus B19 (B19V) infection can cause transient aplastic crisis, persistent viremia, and pure red cell aplasia. In fetuses, B19V infection can result in nonimmune hydrops fetalis and fetal death. These clinical manifestations of B19V infection are a direct outcome of the death of human erythroid progenitors that host B19V replication. B19V infection induces a DNA damage response that is important for cell cycle arrest at late S phase. Here, we analyzed dynamic changes in cellular gene expression and found that DNA metabolic processes are tightly regulated during B19V infection. Although genes involved in cellular DNA replication were downregulated overall, the cellular DNA replication machinery was tightly associated with the replicating single-stranded DNA viral genome and played a critical role in viral DNA replication. In contrast, the DNA damage response-induced phosphorylated forms of RPA32 were dispensable for viral DNA replication.

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Dataset Information

The polypyrimidine tract-binding protein is required for efficient dengue virus propagation and associates with the viral replication machinery.

Publications

The polypyrimidine tract-binding protein is required for efficient dengue virus propagation and associates with the viral replication machinery.

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