Project description:This project describes the protein composition of the Cafeteria roenbergensis virus (CroV, strain BV-PW1: TaxID 693272) particle, a giant marine DNA virus that infects the heterotrophic nanoflagellate microeukaryote C. roenbergensis. CroV is a member of the Nucleo-Cytoplasmic Large DNA Virus clade and related to Acanthamoeba polyphaga mimivirus. CroV possesses a DNA genome of ~730 kilobase pairs that encodes 544 predicted proteins. We analyzed the protein composition of purified CroV particles by liquid chromatography - tandem mass spectrometry (LC-MS/MS) and identified 141 virion-associated CroV proteins. Predicted functions could be assigned to 37% of these proteins, which include structural proteins as well as enzymes for transcription, DNA repair, redox reactions and protein modification. Homologs of 36 CroV virion proteins have previously been found in the virion of Acanthamoeba polyphaga mimivirus. This study shows that giant DNA virus particles contain more than one hundred viral proteins that include specific enzymatic functions.
Project description:A general means of viral attenuation involves the extensive recoding of synonymous codons in the viral genome. The mechanistic underpinnings of this approach remain unclear, however. Using quantitative proteomics and RNA sequencing, we explore the molecular basis of attenuation in a strain of bacteriophage T7 whose major capsid gene was engineered to carry 182 suboptimal codons. We do not detect transcriptional effects from recoding. Proteomic observations reveal that translation is halved for the recoded major capsid gene, and a more modest reduction applies to several co-expressed downstream genes. We observe no changes in protein abundances of other co-expressed genes that are encoded upstream. Viral burst size, like capsid protein abundance, is also decreased by half. Together, these observations suggest that, in this virus, reduced translation of an essential polycistronic transcript and diminished virion assembly form the molecular basis of attenuation.
Project description:WT and GSDMD KO mice were infected with 50 TCID50 influenza virus strain PR8. 7 days post infection, RNA was extracted from lung tissue using TRIzol. RNA library preparation and sequencing was performed by Genewiz.
Project description:To obtain the site-by-site methylation landscape of the infectious spleen and kidney necrosis virus (ISKNV) genome, whole-genome bisulfite sequencing (WGBS) was performed on an ISKNV strain from 3 duplicate samples.
Project description:<p>Tick-borne encephalitis virus is an enveloped, pathogenic, RNA virus in the family Flaviviridae, genus Flavivirus. Viral particles are formed when the nucleocapsid, consisting of an RNA genome and multiple copies of the capsid protein, buds through the endoplasmic reticulum membrane and acquires the viral envelope and the associated proteins. The coordination of the nucleocapsid components to the sites of assembly and budding are poorly understood. Here, we investigate nucleocapsid assembly by characterizing the interactions of the wild-type and truncated capsid proteins with membranes by using biophysical methods and model membrane systems. We show that capsid protein initially binds membranes via electrostatic interactions with negatively-charged lipids which is followed by membrane insertion. Additionally, we show that membrane-bound capsid protein can recruit viral genomic RNA. We confirm the biological relevance of the biophysical findings by using mass spectrometry to show that purified virions contain negatively-charged lipids. Our results suggest that nucleocapsid assembly is coordinated by negatively-charged membrane patches on the endoplasmic reticulum and that the capsid protein mediates direct contacts between the nucleocapsid and the membrane.</p>
