Isolation of poliovirus 2C mutants defective in viral RNA synthesis

Li, Jing-Po; Baltimore, David

doi:10.1128/jvi.62.11.4016-4021.1988

Cited by 119 publications

(85 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Postdamage rehabilitation may involve one or more intermediates exhibiting different levels of fitness. Thus, a 12-nt insert in the 2C coding region of poliovirus RNA resulted in the acquisition of a ts phenotype (366). A pseudorevertant able to grow efficiently at the supra-optimal temperature was shown to have two second-site substitutions in 2C.…”

Section: Rehabilitation After Adverse Changes In Viral Proteinsmentioning

confidence: 99%

Emergency Services of Viral RNAs: Repair and Remodeling

Agol

Gmyl

2018

Microbiol Mol Biol Rev

View full text Add to dashboard Cite

Reproduction of RNA viruses is typically error-prone due to the infidelity of their replicative machinery and the usual lack of proofreading mechanisms. The error rates may be close to those that kill the virus. Consequently, populations of RNA viruses are represented by heterogeneous sets of genomes with various levels of fitness. This is especially consequential when viruses encounter various bottlenecks and new infections are initiated by a single or few deviating genomes. Nevertheless, RNA viruses are able to maintain their identity by conservation of major functional elements. This conservatism stems from genetic robustness or mutational tolerance, which is largely due to the functional degeneracy of many protein and RNA elements as well as to negative selection. Another relevant mechanism is the capacity to restore fitness after genetic damages, also based on replicative infidelity. Conversely, error-prone replication is a major tool that ensures viral evolvability. The potential for changes in debilitated genomes is much higher in small populations, because in the absence of stronger competitors low-fit genomes have a choice of various trajectories to wander along fitness landscapes. Thus, low-fit populations are inherently unstable, and it may be said that to run ahead it is useful to stumble. In this report, focusing on picornaviruses and also considering data from other RNA viruses, we review the biological relevance and mechanisms of various alterations of viral RNA genomes as well as pathways and mechanisms of rehabilitation after loss of fitness. The relationships among mutational robustness, resilience, and evolvability of viral RNA genomes are discussed.

show abstract

Section: Rehabilitation After Adverse Changes In Viral Proteinsmentioning

confidence: 99%

Emergency Services of Viral RNAs: Repair and Remodeling

Agol

Gmyl

2018

Microbiol Mol Biol Rev

View full text Add to dashboard Cite

show abstract

“…Trans-complementation can impact the emergence of drug-resistance [2][3][4]. Given that transcomplementation of NS5B is linked to the function of upstream NS3-5A genes, we hypothesized that NS5B activity would segregate with sensitivity to an HCV-specific direct acting antiviral compound targeting an upstream gene product.…”

Section: Ns5b Activity Segregates With a Dcv-sensitive Ns5a Activitymentioning

confidence: 99%

“…The low-fidelity of RNA virus replication gives rise to swarms of mutant variants [1], which can genetically interact with one another. Mutant viruses may complement or inhibit one another in trans, with important consequences on virus evolution, pathogenesis, and the emergence of drug-resistance [2][3][4][5]. For instance, subgenomic (i.e.…”

Section: Introductionmentioning

confidence: 99%

Hepatitis C Virus RNA Replication Depends on Specific Cis- and Trans-Acting Activities of Viral Nonstructural Proteins

et al. 2015

View full text Add to dashboard Cite

Many positive-strand RNA viruses encode genes that can function in trans, whereas other genes are required in cis for genome replication. The mechanisms underlying trans- and cis-preferences are not fully understood. Here, we evaluate this concept for hepatitis C virus (HCV), an important cause of chronic liver disease and member of the Flaviviridae family. HCV encodes five nonstructural (NS) genes that are required for RNA replication. To date, only two of these genes, NS4B and NS5A, have been trans-complemented, leading to suggestions that other replicase genes work only in cis. We describe a new quantitative system to measure the cis- and trans-requirements for HCV NS gene function in RNA replication and identify several lethal mutations in the NS3, NS4A, NS4B, NS5A, and NS5B genes that can be complemented in trans, alone or in combination, by expressing the NS3–5B polyprotein from a synthetic mRNA. Although NS5B RNA binding and polymerase activities can be supplied in trans, NS5B protein expression was required in cis, indicating that NS5B has a cis-acting role in replicase assembly distinct from its known enzymatic activity. Furthermore, the RNA binding and NTPase activities of the NS3 helicase domain were required in cis, suggesting that these activities play an essential role in RNA template selection. A comprehensive complementation group analysis revealed functional linkages between NS3-4A and NS4B and between NS5B and the upstream NS3–5A genes. Finally, NS5B polymerase activity segregated with a daclatasvir-sensitive NS5A activity, which could explain the synergy of this antiviral compound with nucleoside analogs in patients. Together, these studies define several new aspects of HCV replicase structure-function, help to explain the potency of HCV-specific combination therapies, and provide an experimental framework for the study of cis- and trans-acting activities in positive-strand RNA virus replication more generally.

show abstract

“…However, because 3DPol is a primer-dependent enzyme (Flanegan and Baltimore, 1977; Van Dyke and Flanegan, 1980), several other viral factors (proteins and RNA structures), as well as cellular factors, are likely to participate in the initiation of RNA synthesis. Genetic analysis has implicated most of the non-structural viral proteins in RNA synthesis (Bernstein et al, 1986;Kuhn et al, 1988;Li and Baltimore, 1988;Burns et al, 1989; Giachetti and Semler, 1991), but few cellular components or mechanisms have been identified.…”

Section: Introductionmentioning

confidence: 99%

Replication of poliovirus in Xenopus oocytes requires two human factors.

Gamarnik

Andino

1996

The EMBO Journal

View full text Add to dashboard Cite

We described a novel system to study poliovirus replication in Xenopus oocytes. Poliovirus RNA microinjected into Xenopus oocyte initiates a complete cycle of viral replication, yielding a high level of infectious viruses. Two distinct HeLa cell activities are required, one involved in initiation of translation and the other in RNA synthesis. The translation factor is a large cytoplasmic protein or complex, which is specifically used for initiation of poliovirus translation. The replication factor is required at early stages of RNA synthesis. Formation of infectious poliovirus is highly temperature dependent. At temperatures below 27 degrees C, capsid assembly appears to be impaired. The oocyte system described here could be useful in identifying and characterizing viral and cellular factors involved in virus replication.

show abstract

Isolation of poliovirus 2C mutants defective in viral RNA synthesis

Cited by 119 publications

References 36 publications

Emergency Services of Viral RNAs: Repair and Remodeling

Emergency Services of Viral RNAs: Repair and Remodeling

Hepatitis C Virus RNA Replication Depends on Specific Cis- and Trans-Acting Activities of Viral Nonstructural Proteins

Replication of poliovirus in Xenopus oocytes requires two human factors.

Contact Info

Product

Resources

About