1
|
Lewis HC, Kelnhofer-Millevolte LE, Brinkley MR, Arbach HE, Arnold EA, Sanders S, Bosse JB, Ramachandran S, Avgousti DC. HSV-1 exploits host heterochromatin for nuclear egress. J Cell Biol 2023; 222:e202304106. [PMID: 37516914 PMCID: PMC10373338 DOI: 10.1083/jcb.202304106] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 06/13/2023] [Accepted: 06/14/2023] [Indexed: 07/31/2023] Open
Abstract
Herpes simplex virus (HSV-1) progeny form in the nucleus and exit to successfully infect other cells. Newly formed capsids navigate complex chromatin architecture to reach the inner nuclear membrane (INM) and egress. Here, we demonstrate by transmission electron microscopy (TEM) that HSV-1 capsids traverse heterochromatin associated with trimethylation on histone H3 lysine 27 (H3K27me3) and the histone variant macroH2A1. Through chromatin profiling during infection, we revealed global redistribution of these marks whereby massive host genomic regions bound by macroH2A1 and H3K27me3 correlate with decreased host transcription in active compartments. We found that the loss of these markers resulted in significantly lower viral titers but did not impact viral genome or protein accumulation. Strikingly, we discovered that loss of macroH2A1 or H3K27me3 resulted in nuclear trapping of capsids. Finally, by live-capsid tracking, we quantified this decreased capsid movement. Thus, our work demonstrates that HSV-1 takes advantage of the dynamic nature of host heterochromatin formation during infection for efficient nuclear egress.
Collapse
Affiliation(s)
- Hannah C Lewis
- Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
- Molecular and Cellular Biology, Graduate Program, University of Washington and Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Laurel E Kelnhofer-Millevolte
- Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
- Molecular and Cellular Biology, Graduate Program, University of Washington and Fred Hutchinson Cancer Research Center, Seattle, WA, USA
- UW Medical Scientist Training Program , Seattle, WA, USA
| | - Mia R Brinkley
- Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Hannah E Arbach
- Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Edward A Arnold
- Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
- Microbiology Graduate Program, University of Washington , Seattle, WA, USA
| | - Saskia Sanders
- Institute of Virology, Hannover Medical School , Hannover, Germany
- Leibniz Institute of Virology (LIV) , Hamburg, Germany
- Centre for Structural Systems Biology , Hamburg, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School , Hannover, Germany
| | - Jens B Bosse
- Institute of Virology, Hannover Medical School , Hannover, Germany
- Leibniz Institute of Virology (LIV) , Hamburg, Germany
- Centre for Structural Systems Biology , Hamburg, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School , Hannover, Germany
| | - Srinivas Ramachandran
- RNA Bioscience Initiative, University of Colorado School of Medicine , Aurora, CO, USA
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Daphne C Avgousti
- Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| |
Collapse
|
2
|
Banerjee S, Smith C, Geballe AP, Rothenburg S, Kitzman JO, Brennan G. Gene amplification acts as a molecular foothold to facilitate cross-species adaptation and evasion of multiple antiviral pathways. Virus Evol 2022; 8:veac105. [PMID: 36483110 PMCID: PMC9724558 DOI: 10.1093/ve/veac105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 10/06/2022] [Accepted: 11/08/2022] [Indexed: 11/16/2022] Open
Abstract
Cross-species spillover events are responsible for many of the pandemics in human history including COVID-19; however, the evolutionary mechanisms that enable these events are poorly understood. We have previously modeled this process using a chimeric vaccinia virus expressing the rhesus cytomegalovirus-derived protein kinase R (PKR) antagonist RhTRS1 in place of its native PKR antagonists: E3L and K3L (VACVΔEΔK + RhTRS1). Using this virus, we demonstrated that gene amplification of rhtrs1 occurred early during experimental evolution and was sufficient to fully rescue virus replication in partially resistant African green monkey (AGM) fibroblasts. Notably, this rapid gene amplification also allowed limited virus replication in otherwise completely non-permissive human fibroblasts, suggesting that gene amplification may act as a 'molecular foothold' to facilitate viral adaptation to multiple species. In this study, we demonstrate that there are multiple barriers to VACVΔEΔK + RhTRS1 replication in human cells, mediated by both PKR and ribonuclease L (RNase L). We experimentally evolved three AGM-adapted virus populations in human fibroblasts. Each population adapted to human cells bimodally, via an initial 10-fold increase in replication after only two passages followed by a second 10-fold increase in replication by passage 9. Using our Illumina-based pipeline, we found that some single nucleotide polymorphisms (SNPs) which had evolved during the prior AGM adaptation were rapidly lost, while thirteen single-base substitutions and short indels increased over time, including two SNPs unique to human foreskin fibroblast (HFF)-adapted populations. Many of these changes were associated with components of the viral RNA polymerase, although no variant was shared between all three populations. Taken together, our results demonstrate that rhtrs1 amplification was sufficient to increase viral tropism after passage in an 'intermediate species' and subsequently enabled the virus to adopt different, species-specific adaptive mechanisms to overcome distinct barriers to viral replication in AGM and human cells.
Collapse
Affiliation(s)
- Shefali Banerjee
- †Current address for SB: Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, USA
| | | | - Adam P Geballe
- Departments of Human Genetics and Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI 48109, USA,Divisions of Human Biology and Clinical Research, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | | | - Jacob O Kitzman
- Departments of Microbiology and Medicine, University of Washington, Seattle, WA 98195, USA
| | | |
Collapse
|
3
|
Banerjee S, Smith C, Geballe A, Rothenburg S, Kitzman JO, Brennan G. Gene amplification acts as a molecular foothold to facilitate cross-species adaptation and evasion of multiple antiviral pathways. bioRxiv 2022:2022.06.06.494757. [PMID: 35702158 PMCID: PMC9196108 DOI: 10.1101/2022.06.06.494757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Cross-species spillover events are responsible for many of the pandemics in human history including COVID-19; however, the evolutionary mechanisms that enable these events are poorly understood. We have previously modeled this process using a chimeric vaccinia virus expressing the rhesus cytomegalovirus-derived PKR antagonist RhTRS1 in place of its native PKR antagonists; E3L and K3L (VACVΔEΔK+RhTRS1). Using this virus, we demonstrated that gene amplification of rhtrs1 occurred early during experimental evolution and was sufficient to fully rescue virus replication in partially resistant African green monkey (AGM) fibroblasts. Notably, this rapid gene amplification also allowed limited virus replication in otherwise completely non-permissive human fibroblasts, suggesting that gene amplification may act as a "molecular foothold" to facilitate viral adaptation to multiple species. In this study, we demonstrate that there are multiple barriers to VACVΔEΔK+RhTRS1 replication in human cells, mediated by both PKR and RNase L. We experimentally evolved three AGM-adapted virus populations in human fibroblasts. Each population adapted to human cells bimodally, via an initial 10-fold increase in replication after only two passages followed by a second 10-fold increase in replication by passage nine. Using our Illumina-based pipeline, we found that some SNPs which had evolved during the prior AGM adaptation were rapidly lost, while 13 single-base substitutions and short indels increased over time, including two SNPs unique to HFF adapted populations. Many of these changes were associated with components of the viral RNA polymerase, although no variant was shared between all three populations. Taken together, our results demonstrate that rhtrs1 amplification was sufficient to increase viral tropism after passage in an "intermediate species" and subsequently enabled the virus to adopt different, species-specific adaptive mechanisms to overcome distinct barriers to viral replication in AGM and human cells.
Collapse
Affiliation(s)
- Shefali Banerjee
- Department of Medical Microbiology and Immunology, School of Medicine, University of California, Davis, Davis, CA 95616, USA
| | - Cathy Smith
- Departments of Human Genetics and Computational Medicine & Bioinformatics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Adam Geballe
- Divisions of Human Biology and Clinical Research, Fred Hutchinson Cancer Center, Seattle, WA, 98109 USA
- Departments of Microbiology and Medicine, University of Washington, Seattle, WA, 98195, USA
| | - Stefan Rothenburg
- Department of Medical Microbiology and Immunology, School of Medicine, University of California, Davis, Davis, CA 95616, USA
| | - Jacob O Kitzman
- Departments of Human Genetics and Computational Medicine & Bioinformatics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Greg Brennan
- Department of Medical Microbiology and Immunology, School of Medicine, University of California, Davis, Davis, CA 95616, USA
| |
Collapse
|
4
|
Olson AT, Child SJ, Geballe AP. Antagonism of Protein Kinase R by Large DNA Viruses. Pathogens 2022; 11:pathogens11070790. [PMID: 35890034 PMCID: PMC9319463 DOI: 10.3390/pathogens11070790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 07/06/2022] [Accepted: 07/07/2022] [Indexed: 12/02/2022] Open
Abstract
Decades of research on vaccinia virus (VACV) have provided a wealth of insights and tools that have proven to be invaluable in a broad range of studies of molecular virology and pathogenesis. Among the challenges that viruses face are intrinsic host cellular defenses, such as the protein kinase R pathway, which shuts off protein synthesis in response to the dsRNA that accumulates during replication of many viruses. Activation of PKR results in phosphorylation of the α subunit of eukaryotic initiation factor 2 (eIF2α), inhibition of protein synthesis, and limited viral replication. VACV encodes two well-characterized antagonists, E3L and K3L, that can block the PKR pathway and thus enable the virus to replicate efficiently. The use of VACV with a deletion of the dominant factor, E3L, enabled the initial identification of PKR antagonists encoded by human cytomegalovirus (HCMV), a prevalent and medically important virus. Understanding the molecular mechanisms of E3L and K3L function facilitated the dissection of the domains, species-specificity, and evolutionary potential of PKR antagonists encoded by human and nonhuman CMVs. While remaining cognizant of the substantial differences in the molecular virology and replication strategies of VACV and CMVs, this review illustrates how VACV can provide a valuable guide for the study of other experimentally less tractable viruses.
Collapse
Affiliation(s)
- Annabel T. Olson
- Divisions of Human Biology and Clinical Research, Fred Hutchinson Cancer Center, 1100 Fairview Ave N Seattle, P.O. Box 19024, Seattle, WA 98109, USA; (A.T.O.); (S.J.C.)
- Departments of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - Stephanie J. Child
- Divisions of Human Biology and Clinical Research, Fred Hutchinson Cancer Center, 1100 Fairview Ave N Seattle, P.O. Box 19024, Seattle, WA 98109, USA; (A.T.O.); (S.J.C.)
| | - Adam P. Geballe
- Divisions of Human Biology and Clinical Research, Fred Hutchinson Cancer Center, 1100 Fairview Ave N Seattle, P.O. Box 19024, Seattle, WA 98109, USA; (A.T.O.); (S.J.C.)
- Departments of Microbiology, University of Washington, Seattle, WA 98195, USA
- Departments of Medicine, University of Washington, Seattle, WA 98195, USA
- Correspondence:
| |
Collapse
|
5
|
Phan QV, Bogdanow B, Wyler E, Landthaler M, Liu F, Hagemeier C, Wiebusch L. Engineering, decoding and systems-level characterization of chimpanzee cytomegalovirus. PLoS Pathog 2022; 18:e1010193. [PMID: 34982803 PMCID: PMC8759705 DOI: 10.1371/journal.ppat.1010193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 01/14/2022] [Accepted: 12/09/2021] [Indexed: 11/19/2022] Open
Abstract
The chimpanzee cytomegalovirus (CCMV) is the closest relative of human CMV (HCMV). Because of the high conservation between these two species and the ability of human cells to fully support CCMV replication, CCMV holds great potential as a model system for HCMV. To make the CCMV genome available for precise and rapid gene manipulation techniques, we captured the genomic DNA of CCMV strain Heberling as a bacterial artificial chromosome (BAC). Selected BAC clones were reconstituted to infectious viruses, growing to similar high titers as parental CCMV. DNA sequencing confirmed the integrity of our clones and led to the identification of two polymorphic loci and a deletion-prone region within the CCMV genome. To re-evaluate the CCMV coding potential, we analyzed the viral transcriptome and proteome and identified several novel ORFs, splice variants, and regulatory RNAs. We further characterized the dynamics of CCMV gene expression and found that viral proteins cluster into five distinct temporal classes. In addition, our datasets revealed that the host response to CCMV infection and the de-regulation of cellular pathways are in line with known hallmarks of HCMV infection. In a first functional experiment, we investigated a proposed frameshift mutation in UL128 that was suspected to restrict CCMV's cell tropism. In fact, repair of this frameshift re-established productive CCMV infection in endothelial and epithelial cells, expanding the options of CCMV as an infection model. Thus, BAC-cloned CCMV can serve as a powerful tool for systematic approaches in comparative functional genomics, exploiting the close phylogenetic relationship between CCMV and HCMV.
Collapse
Affiliation(s)
- Quang Vinh Phan
- Department of Pediatric Oncology/Hematology, Charité—Universitätsmedizin Berlin, Berlin, Germany
| | - Boris Bogdanow
- Department of Structural Biology, Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany
| | - Emanuel Wyler
- Berlin Institute for Medical Systems Biology, Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - Markus Landthaler
- Berlin Institute for Medical Systems Biology, Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - Fan Liu
- Department of Structural Biology, Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany
| | - Christian Hagemeier
- Department of Pediatric Oncology/Hematology, Charité—Universitätsmedizin Berlin, Berlin, Germany
| | - Lüder Wiebusch
- Department of Pediatric Oncology/Hematology, Charité—Universitätsmedizin Berlin, Berlin, Germany
| |
Collapse
|
6
|
Lin YT, Chau LF, Coutts H, Mahmoudi M, Drampa V, Lee CH, Brown A, Hughes DJ, Grey F. Does the Zinc Finger Antiviral Protein (ZAP) Shape the Evolution of Herpesvirus Genomes? Viruses 2021; 13:1857. [PMID: 34578438 PMCID: PMC8473364 DOI: 10.3390/v13091857] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 09/12/2021] [Accepted: 09/13/2021] [Indexed: 01/02/2023] Open
Abstract
An evolutionary arms race occurs between viruses and hosts. Hosts have developed an array of antiviral mechanisms aimed at inhibiting replication and spread of viruses, reducing their fitness, and ultimately minimising pathogenic effects. In turn, viruses have evolved sophisticated counter-measures that mediate evasion of host defence mechanisms. A key aspect of host defences is the ability to differentiate between self and non-self. Previous studies have demonstrated significant suppression of CpG and UpA dinucleotide frequencies in the coding regions of RNA and small DNA viruses. Artificially increasing these dinucleotide frequencies results in a substantial attenuation of virus replication, suggesting dinucleotide bias could facilitate recognition of non-self RNA. The interferon-inducible gene, zinc finger antiviral protein (ZAP) is the host factor responsible for sensing CpG dinucleotides in viral RNA and restricting RNA viruses through direct binding and degradation of the target RNA. Herpesviruses are large DNA viruses that comprise three subfamilies, alpha, beta and gamma, which display divergent CpG dinucleotide patterns within their genomes. ZAP has recently been shown to act as a host restriction factor against human cytomegalovirus (HCMV), a beta-herpesvirus, which in turn evades ZAP detection by suppressing CpG levels in the major immediate-early transcript IE1, one of the first genes expressed by the virus. While suppression of CpG dinucleotides allows evasion of ZAP targeting, synonymous changes in nucleotide composition that cause genome biases, such as low GC content, can cause inefficient gene expression, especially in unspliced transcripts. To maintain compact genomes, the majority of herpesvirus transcripts are unspliced. Here we discuss how the conflicting pressures of ZAP evasion, the need to maintain compact genomes through the use of unspliced transcripts and maintaining efficient gene expression may have shaped the evolution of herpesvirus genomes, leading to characteristic CpG dinucleotide patterns.
Collapse
Affiliation(s)
- Yao-Tang Lin
- Division of Infection and Immunity, The Roslin Institute, University of Edinburgh, Easter Bush, Edinburgh EH25 9RG, UK; (Y.-T.L.); (L.-F.C.); (H.C.); (M.M.); (V.D.); (C.-H.L.); (A.B.)
| | - Long-Fung Chau
- Division of Infection and Immunity, The Roslin Institute, University of Edinburgh, Easter Bush, Edinburgh EH25 9RG, UK; (Y.-T.L.); (L.-F.C.); (H.C.); (M.M.); (V.D.); (C.-H.L.); (A.B.)
| | - Hannah Coutts
- Division of Infection and Immunity, The Roslin Institute, University of Edinburgh, Easter Bush, Edinburgh EH25 9RG, UK; (Y.-T.L.); (L.-F.C.); (H.C.); (M.M.); (V.D.); (C.-H.L.); (A.B.)
| | - Matin Mahmoudi
- Division of Infection and Immunity, The Roslin Institute, University of Edinburgh, Easter Bush, Edinburgh EH25 9RG, UK; (Y.-T.L.); (L.-F.C.); (H.C.); (M.M.); (V.D.); (C.-H.L.); (A.B.)
| | - Vayalena Drampa
- Division of Infection and Immunity, The Roslin Institute, University of Edinburgh, Easter Bush, Edinburgh EH25 9RG, UK; (Y.-T.L.); (L.-F.C.); (H.C.); (M.M.); (V.D.); (C.-H.L.); (A.B.)
| | - Chen-Hsuin Lee
- Division of Infection and Immunity, The Roslin Institute, University of Edinburgh, Easter Bush, Edinburgh EH25 9RG, UK; (Y.-T.L.); (L.-F.C.); (H.C.); (M.M.); (V.D.); (C.-H.L.); (A.B.)
| | - Alex Brown
- Division of Infection and Immunity, The Roslin Institute, University of Edinburgh, Easter Bush, Edinburgh EH25 9RG, UK; (Y.-T.L.); (L.-F.C.); (H.C.); (M.M.); (V.D.); (C.-H.L.); (A.B.)
| | - David J. Hughes
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, St Andrews KY16 9ST, UK;
| | - Finn Grey
- Division of Infection and Immunity, The Roslin Institute, University of Edinburgh, Easter Bush, Edinburgh EH25 9RG, UK; (Y.-T.L.); (L.-F.C.); (H.C.); (M.M.); (V.D.); (C.-H.L.); (A.B.)
| |
Collapse
|
7
|
Schweininger J, Scherer M, Rothemund F, Schilling EM, Wörz S, Stamminger T, Muller YA. Cytomegalovirus immediate-early 1 proteins form a structurally distinct protein class with adaptations determining cross-species barriers. PLoS Pathog 2021; 17:e1009863. [PMID: 34370791 PMCID: PMC8376021 DOI: 10.1371/journal.ppat.1009863] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 08/19/2021] [Accepted: 08/03/2021] [Indexed: 01/12/2023] Open
Abstract
Restriction factors are potent antiviral proteins that constitute a first line of intracellular defense by blocking viral replication and spread. During co-evolution, however, viruses have developed antagonistic proteins to modulate or degrade the restriction factors of their host. To ensure the success of lytic replication, the herpesvirus human cytomegalovirus (HCMV) expresses the immediate-early protein IE1, which acts as an antagonist of antiviral, subnuclear structures termed PML nuclear bodies (PML-NBs). IE1 interacts directly with PML, the key protein of PML-NBs, through its core domain and disrupts the dot-like multiprotein complexes thereby abrogating the antiviral effects. Here we present the crystal structures of the human and rat cytomegalovirus core domain (IE1CORE). We found that IE1CORE domains, also including the previously characterized IE1CORE of rhesus CMV, form a distinct class of proteins that are characterized by a highly similar and unique tertiary fold and quaternary assembly. This contrasts to a marked amino acid sequence diversity suggesting that strong positive selection evolved a conserved fold, while immune selection pressure may have fostered sequence divergence of IE1. At the same time, we detected specific differences in the helix arrangements of primate versus rodent IE1CORE structures. Functional characterization revealed a conserved mechanism of PML-NB disruption, however, primate and rodent IE1 proteins were only effective in cells of the natural host species but not during cross-species infection. Remarkably, we observed that expression of HCMV IE1 allows rat cytomegalovirus replication in human cells. We conclude that cytomegaloviruses have evolved a distinct protein tertiary structure of IE1 to effectively bind and inactivate an important cellular restriction factor. Furthermore, our data show that the IE1 fold has been adapted to maximize the efficacy of PML targeting in a species-specific manner and support the concept that the PML-NBs-based intrinsic defense constitutes a barrier to cross-species transmission of HCMV. Cytomegaloviruses have evolved in very close association with their hosts resulting in a highly species-specific replication. Cell-intrinsic proteins, known as restriction factors, constitute important barriers for cross-species infection of viruses. All cytomegaloviruses characterized so far express an abundant immediate-early protein, termed IE1, that binds to the cellular restriction factor promyelocytic leukemia protein (PML) and antagonizes its repressive activity on viral gene expression. Here, we present the crystal structures of the PML-binding domains of rat and human cytomegalovirus IE1. Despite low amino-acid sequence identity both proteins share a highly similar and unique fold forming a distinct protein class. Functional characterization revealed a common mechanism of PML antagonization. However, we also detected that the respective IE1 proteins only interact with PML proteins of the natural host species. Interestingly, expression of HCMV IE1 allows rat cytomegalovirus infection in human cells. This indicates that the cellular restriction factor PML forms an important barrier for cross-species infection of cytomegaloviruses that might be overcome by adaptation of IE1 protein function. Our data suggest that the cytomegalovirus IE1 structure represents an evolutionary optimized protein fold targeting PML proteins via coiled-coil interactions.
Collapse
Affiliation(s)
- Johannes Schweininger
- Division of Biotechnology, Department of Biology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Myriam Scherer
- Institute of Virology, Ulm University Medical Center, Ulm, Germany
| | | | | | - Sonja Wörz
- Institute of Virology, Ulm University Medical Center, Ulm, Germany
| | - Thomas Stamminger
- Institute of Virology, Ulm University Medical Center, Ulm, Germany
- * E-mail: (TS); (YAM)
| | - Yves A. Muller
- Division of Biotechnology, Department of Biology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
- * E-mail: (TS); (YAM)
| |
Collapse
|