Dataset Information

Critical phosphoprotein elements that regulate polymerase architecture and function in vesicular stomatitis virus.

ABSTRACT: The RNA-dependent RNA polymerase (RdRP) of nonsegmented negative-sense RNA viruses consists of a large catalytic protein (L) and a phosphoprotein cofactor (P). During infection, the RdRP replicates and transcribes the viral genome, which resides inside an oligomer of nucleocapsid protein (N-RNA). The classical view of P as a cofactor for L assigns a primary role of P as a bridge mediating the access of L to the RNA template, whereby its N-terminal domain (P(NTD)) binds L and its C-terminal domain (P(CTD)) binds N-RNA. Recent biochemical and structural studies of a prototype nonsegmented negative-sense RNA virus, vesicular stomatitis virus, suggest a role for P beyond that of a mere physical link: P induces a structural rearrangement in L and stimulates polymerase processivity. In this study, we investigated the critical requirements within P mediating the functional interaction with L to form a fully functional RdRP. We analyzed the correlation between the impact of P on the conformation of L and its activity in RNA synthesis and the consequences of these events on RdRP function. We identified three separable elements of the P(NTD) that are required for inducing the conformational rearrangement of L, stimulating polymerase processivity, and mediating transcription of the N-RNA. The functional interplay between these elements provides insight into the role of P as a dynamic player in the RNA synthesis machine, influencing essential aspects of polymerase structure and function.

SUBMITTER: Rahmeh AA

PROVIDER: S-EPMC3437890 | biostudies-other | 2012 Sep

REPOSITORIES: biostudies-other

ACCESS DATA

Publications

Critical phosphoprotein elements that regulate polymerase architecture and function in vesicular stomatitis virus.

Rahmeh Amal A AA Morin Benjamin B Schenk Andreas D AD Liang Bo B Liang Bo B Heinrich Bianca S BS Brusic Vesna V Walz Thomas T Whelan Sean P J SP

Proceedings of the National Academy of Sciences of the United States of America 20120820 36

The RNA-dependent RNA polymerase (RdRP) of nonsegmented negative-sense RNA viruses consists of a large catalytic protein (L) and a phosphoprotein cofactor (P). During infection, the RdRP replicates and transcribes the viral genome, which resides inside an oligomer of nucleocapsid protein (N-RNA). The classical view of P as a cofactor for L assigns a primary role of P as a bridge mediating the access of L to the RNA template, whereby its N-terminal domain (P(NTD)) binds L and its C-terminal domai ...[more]

PMID: 22908284

Similar Datasets

Project description:UnlabelledViruses have various mechanisms to duplicate their genomes and produce virus-specific mRNAs. Negative-strand RNA viruses encode their own polymerases to perform each of these processes. For the nonsegmented negative-strand RNA viruses, the polymerase is comprised of the large polymerase subunit (L) and the phosphoprotein (P). L proteins from members of the Rhabdoviridae, Paramyxoviridae, and Filoviridae share sequence and predicted secondary structure homology. Here, we present the structure of the N-terminal domain (conserved region I) of the L protein from a rhabdovirus, vesicular stomatitis virus, at 1.8-Å resolution. The strictly and strongly conserved residues in this domain cluster in a single area of the protein. Serial mutation of these residues shows that many of the amino acids are essential for viral transcription but not for mRNA capping. Three-dimensional alignments show that this domain shares structural homology with polymerases from other viral families, including segmented negative-strand RNA and double-stranded RNA (dsRNA) viruses.ImportanceNegative-strand RNA viruses include a diverse set of viral families that infect animals and plants, causing serious illness and economic impact. The members of this group of viruses share a set of functionally conserved proteins that are essential to their replication cycle. Among this set of proteins is the viral polymerase, which performs a unique set of reactions to produce genome- and subgenome-length RNA transcripts. In this article, we study the polymerase of vesicular stomatitis virus, a member of the rhabdoviruses, which has served in the past as a model to study negative-strand RNA virus replication. We have identified a site in the N-terminal domain of the polymerase that is essential to viral transcription and that shares sequence homology with members of the paramyxoviruses and the filoviruses. Newly identified sites such as that described here could prove to be useful targets in the design of new therapeutics against negative-strand RNA viruses.

Project description:The multidomain polymerase protein (L) of nonsegmented negative-strand (NNS) RNA viruses catalyzes transcription and replication of the virus genome. The N-terminal half of the protein forms a ring-like polymerase structure, while the C-terminal half encoding viral mRNA transcript modifications consists of a flexible appendage with three distinct globular domains. To gain insight into putative transient interactions between L domains during viral RNA synthesis, we exchanged each of the four distinct regions encompassing the appendage region of vesicular stomatitis virus (VSV) Indiana serotype L protein with their counterparts from VSV New Jersey and analyzed effects on virus polymerase activity in a minigenome system. The methyltransferase domain exchange yielded a fully active polymerase protein, which functioned as well as wild-type L in the context of a recombinant virus. Exchange of the downstream C-terminal nonconserved region abolished activity, but coexchanging it with the methyltransferase domain generated a polymerase favoring replicase over transcriptase activity, providing strong evidence of interaction between these two regions. Exchange of the capping enzyme domain or the adjacent nonconserved region thought to function as an "unstructured" linker also abrogated polymerase activity even when either domain was coexchanged with other appendage domains. Further probing of the putative linker segment using in-frame enhanced green fluorescent protein (EGFP) insertions similarly abrogated activity. We discuss the implications of these findings with regard to L protein appendage domain structure and putative domain-domain interactions required for polymerase function.NNS viruses include many well-known human pathogens (e.g., rabies, measles, and Ebola viruses), as well as emerging viral threats (e.g., Nipah and Hendra viruses). These viruses all encode a large L polymerase protein similarly organized into multiple domains that work in concert to enable virus genome transcription and replication. But how the unique L protein carries out the multiplicity of individual steps in these two distinct processes is poorly understood. Using two different approaches, i.e., exchanging individual domains in the C-terminal appendage region of the protein between two closely related VSV serotypes and inserting unrelated protein domains, we shed light on requirements for domain-domain interactions and domain contiguity in polymerase function. These findings further our understanding of the conformational dynamics of NNS L polymerase proteins, which play an essential role in the pathogenic properties of these viruses and represent attractive targets for the development of antiviral measures.

Project description:Vesicular stomatitis Indiana virus (VSIV), formerly known as vesicular stomatitis virus (VSV) Indiana (VSVIND), is a model virus that is exceptionally sensitive to the inhibitory action of interferons (IFNs). Interferons induce an antiviral state by stimulating the expression of hundreds of interferon-stimulated genes (ISGs). These ISGs can constrain viral replication, limit tissue tropism, reduce pathogenicity, and inhibit viral transmission. Since VSIV is used as a backbone for multiple oncolytic and vaccine strategies, understanding how ISGs restrict VSIV not only helps in understanding VSIV-induced pathogenesis but also helps us evaluate and understand the safety and efficacy of VSIV-based therapies. Thus, there is a need to identify and characterize the ISGs that possess anti-VSIV activity. Using arrayed ISG expression screening, we identified TRIM69 as an ISG that potently inhibits VSIV. This inhibition was highly specific as multiple viruses, including influenza A virus, HIV-1, Rift Valley fever virus, and dengue virus, were unaffected by TRIM69. Indeed, just one amino acid substitution in VSIV can govern sensitivity/resistance to TRIM69. Furthermore, TRIM69 is highly divergent in human populations and exhibits signatures of positive selection that are consistent with this gene playing a key role in antiviral immunity. We propose that TRIM69 is an IFN-induced inhibitor of VSIV and speculate that TRIM69 could be important in limiting VSIV pathogenesis and might influence the specificity and/or efficacy of vesiculovirus-based therapies.IMPORTANCE Vesicular stomatitis Indiana virus (VSIV) is a veterinary pathogen that is also used as a backbone for many oncolytic and vaccine strategies. In natural and therapeutic settings, viral infections like VSIV are sensed by the host, and as a result the host cells make proteins that can protect them from viruses. In the case of VSIV, these antiviral proteins constrain viral replication and protect most healthy tissues from virus infection. In order to understand how VSIV causes disease and how healthy tissues are protected from VSIV-based therapies, it is crucial that we identify the proteins that inhibit VSIV. Here, we show that TRIM69 is an antiviral defense that can potently and specifically block VSIV infection.

Dataset Information

Critical phosphoprotein elements that regulate polymerase architecture and function in vesicular stomatitis virus.

Publications

Critical phosphoprotein elements that regulate polymerase architecture and function in vesicular stomatitis virus.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets