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Principal Investigator: Brian Geiss
Organization: COLORADO STATE UNIVERSITY
Fiscal Year: 2020
Award: $407,060
Funding agency: National Institute of Allergy and Infectious Diseases
SARS-CoV-2 must cap and methylate its mRNAs to ensure their stability, translatability, and avoid
detection by host innate immune mechanism as non-self transcripts. The process of RNA capping, therefore,
is pivotal to the success of a SARS-CoV-2 infection. It also represents a key contributor to the molecular
mechanisms of pathogenesis as well as a very attractive target for the development of antiviral therapeutics.
However, there are three key knowledge gaps that have slowed progress in our understanding of this
important area of coronavirus molecular biology that will be addressed in this proposal. First, the identity of the
guanylyltransferase (GTase), the centerpiece of the viral RNA capping machinery that transfers GTP to the 5'
end of the nascent transcript, is unknown. We will use a two-pronged strategy of complementary molecular
and biochemical approaches to address this glaring gap in our understanding of SARS-CoV-2 mRNA capping
mechanisms, laying the foundation for the development of capping-targeted antivirals. Second, while RNA
capping is a regulated process and uncapped RNAs play an influential role in the biology of other positive
sense RNA viral infections, it is not known if RNA capping is a regulated or a default event in coronaviruses.
We will determine if uncapped RNAs are produced by SARS-CoV-2 in order to establish the foundation for a
role of regulated capping and non-coding viral transcripts in SARS-CoV-2 infections. Finally, every cellular
mRNA that begins with a terminal adenosine has that residue 2'O methylated at the ribose ring as well as N6
methylated on the adenosine base (m6Am). The strong conservation of this m6Am modification indicates its
importance in cell biology, an assertation recently confirmed with data suggesting that the modification
increases translatability and facilitates recognition of the transcript as `self'. Interestingly, SARS-CoV-2 and
other coronaviruses all initiate their transcripts with an A residue, but it is not known whether that A residue
contains an m6A modification. In the final part of this project, we will determine the m6A modification status of
the terminal 5' A residue of SARS-CoV-2 mRNAs and investigate the role that the modification (or lack thereof)
plays in the biology of coronaviral transcripts. Collectively these studies will provide important new insights into
the molecular biology of SARS-CoV-2 and open up avenues for the development of broad-spectrum anti-
coronaviral therapeutics.
Terms: <2019 novel coronavirus><2019-nCoV><5' Capped RNA><5' mRNA Cap Structure><Address><Adenosine><Antiviral Agents><Antiviral Drugs><Antivirals><Area><Attention><Biochemical><Biological><Biology><Cell Body><Cell Function><Cell Process><Cell physiology><Cells><Cellular Function><Cellular Physiology><Cellular Process><Cellular biology><Coronaviridae><Coronavirus><D-Ribose><DNA Molecular Biology><DNA Polymerase II><DNA Polymerase epsilon><DNA-Dependent DNA Polymerase II><Data><Defense Mechanisms><Detection><Development><EC 2.7.7><Ensure><Enzyme Gene><Enzymes><Event><Family><Foundations><Functional RNA><Future><GTP><Gene Expression><Gene Transcription><Generations><Genetic Transcription><Genetic Translation><Genome><Genomics><Glare><Guanosine><Guanosine Triphosphate><Immune Precipitation><Immune Surveillance><Immunologic Surveillance><Immunologic Surveillances><Immunological Surveillance><Immunological Surveillances><Immunoprecipitation><Immunosurveillance><Infection><Influentials><Knowledge><L-Lysine><Label><Lysine><Mass Photometry/Spectrum Analysis><Mass Spectrometry><Mass Spectroscopy><Mass Spectrum><Mass Spectrum Analyses><Mass Spectrum Analysis><Messenger RNA><Methylation><Modification><Molecular><Molecular Biology><Mutation Analysis><Non-Coding><Non-Coding RNA><Non-Polyadenylated RNA><Non-translated RNA><Noncoding RNA><Nontranslated RNA><ORFs><Open Reading Frames><Pathogenesis><Play><Pol II><Process><Property><Protein Coding Region><Proteins><RNA><RNA Caps><RNA Expression><RNA Gene Products><RNA Stability><RNA Virus Infections><RNA Viruses><RNA metabolism><RNA methylation><RNA replication><RNA viral infection><Regulation><Replication Unit><Replicon><Ribonucleic Acid><Ribose><Role><SARS Virus><SARS corona virus><SARS coronavirus><SARS-Associated Coronavirus><SARS-CoV><SARS-CoV-2><SARS-CoV2><SARS-Related Coronavirus><SARS-associated coronavirus 2><SARS-coronavirus-2><SARS-related coronavirus 2><Severe Acute Respiratory Syndrome Virus><Severe Acute Respiratory Syndrome corona virus><Severe Acute Respiratory Syndrome coronavirus><Severe acute respiratory syndrome coronavirus 2><Structure><Subcellular Process><System><Therapeutic><Transcript><Transcription><Transfection><Translation Initiation><Untranslated RNA><Viral><Viral Diseases><Viral Gene Products><Viral Gene Proteins><Viral Genes><Viral Pathogenesis><Viral Proteins><Virus><Virus Diseases><Virus Replication><Work><Wuhan coronavirus><anti-viral agents><anti-viral drugs><anti-virals><base><cell biology><corona virus><develop a vaccine><development of a vaccine><developmental><drug development><guanylyltransferase><innate immune mechanisms><innate immune sensing><insight><mRNA><mRNA Stability><mRNA Translation><mRNA capping><new drug treatments><new drugs><new therapeutics><new therapy><new vaccines><next generation therapeutics><next generation vaccines><noncoding><novel><novel drug treatments><novel drugs><novel therapeutics><novel therapy><novel vaccines><nucleotidyltransferase><psychological defense mechanism><severe acute respiratory syndrome-CoV><social role><success><therapeutic agent development><therapeutic development><vaccine development><vaccine formulation><viral RNA><viral infection><viral multiplication><viral replication><virus RNA><virus host interaction><virus infection><virus multiplication><virus pathogenesis><virus protein><virus-induced disease>