TY - THES A1 - Lehmann, Christine T1 - Die Bedeutung des Masernvirus Matrix-Proteins für die Virusfreisetzung und zelltypabhängige Unterschiede seines intrazellulären Transports T1 - The role of measles virus matrix protein for virus release and cell type-specific differences in its intracellular transport N2 - Die Morphogenese von Viruspartikeln und deren Freisetzung aus infizierten Zellen sind späte Schritte im viralen Lebenszyklus. Matrix-Proteine (M) negativsträngiger RNA-Viren und Retroviren, bei denen es sich um periphere Membran-assoziierte Proteine handelt, spielen für diese Prozesse eine besonders wichtige Rolle. Im Verlauf der Masernvirus (MV)-Infektion interagiert das M-Protein mit dem viralen Nukleoproteinkomplex im Innern der Viruspartikel einerseits und mit den viralen Glykoproteinen auf der Oberfläche andererseits. Die Bedeutung des MV M-Proteins für die Partikelproduktion und sein intrazellulärer Transport wurden bislang wenig untersucht. In dieser Arbeit konnte gezeigt werden, dass das MV M-Protein in höhermolekularen Komplexe oligomerisiert und transient mono-ubiquitiniert vorliegt. Beide biochemischen Eigenschaften des M-Proteins sind wahrscheinlich für die Partikelentstehung von Bedeutung, wie durch Studien an M-Protein-Orthologen anderer Viren bereits belegt wurde. Das MV M-Protein assoziierte mit Membranen und speziellen Membranmikrodomänen, sogenannten Detergenz-resistenten Membranfraktionen (DRMs), und vermittelte nach transienter Expression in Fibroblasten die Produktion Virus-ähnlicher Partikel (virus-like particles, VLPs). Es ist beschrieben, dass umhüllte Viren präferenziell aus DRMs freigesetzt werden. Die Koexpression des MV-Glykoproteins F erhöhte den Anteil mit DRM-assoziierten M-Proteins um ein Vierfaches, steigerte jedoch, wie auch das H-Protein, die Effizienz der VLP-Freisetzung nicht. Überraschenderweise waren beide jedoch selbst in der Lage VLPs zu induzieren. Die Effizienz der VLP-Produktion war gering und entsprach der der Viruspartikelfreisetzung. Dendritische Zellen (DCs) sind für MV semipermissiv. Obwohl alle viralen Proteine synthetisiert werden, wird kein infektiöses Virus freigesetzt. In dieser Arbeit konnte gezeigt werden, dass die intrazelluläre Lokalisation der M-, H- und N-Proteine dramatisch von der in der produktiv infizierbaren Fibroblastenzelllinie HeLa abweicht. Während in infizierten HeLa-Zellen das M-Protein mit Lamp-1-positiven späten Endosomen kolokalisierte, akkumulierten in DCs alle untersuchten viralen Proteine in einem spät endosomalen Kompartiment, das das Tetraspanin CD81, aber nicht Lamp-1, enthielt und möglicherweise an der MHC-Klasse-II-abhängigen Antigenpräsentation beteiligt ist. N2 - Morphogenesis of viral particles and their release from infected cells are late steps in viral life cycle. Matrix (M) proteins of negative-stranded RNA viruses and retroviruses, which are peripheral membrane-associated proteins, play a crucial role in these processes. During measles virus (MV) infection the M protein interacts both with the viral nucleoprotein complex and viral glycoproteins. So far, little is known about the importance of the MV M protein for particle production and its intracellular transport. This work shows that the MV M protein oligomerises to higher molecular complexes and is transiently mono-ubiquitinated. These biochemical properties of the protein are likely to be of importance for particle formation as has been shown in studies with M protein orthologues of other viruses. The M protein associates with membranes and specialized membrane microdomains, so called detergent-resistant membrane fractions (DRMs), and triggers the production of virus-like particles (VLPs) after transient expression in fibroblasts. It has been described that enveloped viruses preferentially bud from DRMs. Coexpression of the glycoprotein F increased the fraction of M protein associated with DRMs about four-fold, though the efficiency of VLP release was unaffected by coexpressed F and H glycoproteins, respectively. Surprisingly, both glycoproteins individually promoted VLP formation on their own. The efficiency of VLP production was low and corresponded almost exactly to that of viral particles. Dendritic cells (DCs) are semipermissive to MV infection. Though all viral proteins are synthesized, almost no infectious virus is released indicating a block in a late step of the viral life cycle. This work shows that the intracellular localization of M, H and N proteins differs dramatically from that observed in the productively infectable fibroblast HeLa cell line. While in infected HeLa cells the M protein colocalized with Lamp-1-positive late endosomes, in DCs all investigated viral proteins accumulated in a Lamp-1-negative late endosomal compartment that contained the tetraspanin CD81, which is potentially involved in MHC class II-loading and antigen presentation. KW - Masernvirus KW - Virulenz KW - Matrixproteine KW - Dendritische Zelle KW - Virologie KW - Masernvirus KW - Matrix-Protein KW - dentritische Zellen KW - virology KW - measles virus KW - matrix protein KW - dendritic cells Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-22107 ER - TY - JOUR A1 - Goettsch, Winfried A1 - Beerenwinkel, Niko A1 - Deng, Li A1 - Dölken, Lars A1 - Dutilh, Bas E. A1 - Erhard, Florian A1 - Kaderali, Lars A1 - Kleist, Max von A1 - Marquet, Roland A1 - Matthijnssens, Jelle A1 - McCallin, Shawna A1 - McMahon, Dino A1 - Rattei, Thomas A1 - Van Rij, Ronald P. A1 - Robertson, David L. A1 - Schwemmle, Martin A1 - Stern-Ginossar, Noam A1 - Marz, Manja T1 - ITN—VIROINF: Understanding (harmful) virus-host interactions by linking virology and bioinformatics JF - Viruses N2 - Many recent studies highlight the fundamental importance of viruses. Besides their important role as human and animal pathogens, their beneficial, commensal or harmful functions are poorly understood. By developing and applying tailored bioinformatical tools in important virological models, the Marie Skłodowska-Curie Initiative International Training Network VIROINF will provide a better understanding of viruses and the interaction with their hosts. This will open the door to validate methods of improving viral growth, morphogenesis and development, as well as to control strategies against unwanted microorganisms. The key feature of VIROINF is its interdisciplinary nature, which brings together virologists and bioinformaticians to achieve common goals. KW - bioinformatic KW - virus KW - virology KW - virus host interaction Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-236687 SN - 1999-4915 VL - 13 IS - 5 ER - TY - JOUR A1 - Lodha, Manivel A1 - Muchsin, Ihsan A1 - Jürges, Christopher A1 - Juranic Lisnic, Vanda A1 - L’Hernault, Anne A1 - Rutkowski, Andrzej J. A1 - Prusty, Bhupesh K. A1 - Grothey, Arnhild A1 - Milic, Andrea A1 - Hennig, Thomas A1 - Jonjic, Stipan A1 - Friedel, Caroline C. A1 - Erhard, Florian A1 - Dölken, Lars T1 - Decoding murine cytomegalovirus JF - PLOS Pathogens N2 - The genomes of both human cytomegalovirus (HCMV) and murine cytomegalovirus (MCMV) were first sequenced over 20 years ago. Similar to HCMV, the MCMV genome had initially been proposed to harbor ≈170 open reading frames (ORFs). More recently, omics approaches revealed HCMV gene expression to be substantially more complex comprising several hundred viral ORFs. Here, we provide a state-of-the art reannotation of lytic MCMV gene expression based on integrative analysis of a large set of omics data. Our data reveal 365 viral transcription start sites (TiSS) that give rise to 380 and 454 viral transcripts and ORFs, respectively. The latter include 200 small ORFs, some of which represented the most highly expressed viral gene products. By combining TiSS profiling with metabolic RNA labelling and chemical nucleotide conversion sequencing (dSLAM-seq), we provide a detailed picture of the expression kinetics of viral transcription. This not only resulted in the identification of a novel MCMV immediate early transcript encoding the m166.5 ORF, which we termed ie4, but also revealed a group of well-expressed viral transcripts that are induced later than canonical true late genes and contain an initiator element (Inr) but no TATA- or TATT-box in their core promoters. We show that viral upstream ORFs (uORFs) tune gene expression of longer viral ORFs expressed in cis at translational level. Finally, we identify a truncated isoform of the viral NK-cell immune evasin m145 arising from a viral TiSS downstream of the canonical m145 mRNA. Despite being ≈5-fold more abundantly expressed than the canonical m145 protein it was not required for downregulating the NK cell ligand, MULT-I. In summary, our work will pave the way for future mechanistic studies on previously unknown cytomegalovirus gene products in an important virus animal model. KW - virology KW - genetics KW - molecular biology KW - immunology KW - microbiology KW - parasitology KW - murine cytomegalovirus (MCMV) Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-350480 SN - 1553-7374 VL - 19 IS - 5 ER -