@phdthesis{Ye2023,
  author    = {Ye, Liqing},
  title     = {RNA-RNA interactions in viral genome packaging},
  doi       = {10.25972/OPUS-29636},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-296361},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {RNA is one of the most abundant macromolecules and plays essential roles in numerous biological processes. This doctoral thesis consists of two projects focusing on RNA structure and RNA-RNA interactions in viral genome packaging. In the first project I developed a method called Functional Analysis of RNA Structure (FARS-seq) to investigate structural features regulating genome dimerization within the HIV-1 5'UTR. Genome dimerization is a conserved feature of retroviral replication and is thought to be a prerequisite for binding to the viral structural protein Pr55Gag during genome packaging. It also plays a role in genome integrity and evolution through recombination, and is linked to a structural switch that may regulate genome packaging and translation within cells. Despite its importance for HIV-1 replication, the RNA signals regulating genome dimerization, and the molecular mechanism leading to the selection of the genome dimer over the monomer for packaging are incompletely understood. The FARS-seq method combines RNA structural information obtained by chemical probing with single nucleotide resolution profiles of RNA function obtained by mutational interference. In this way, we found nucleotides that were critical for dimerization, especially within the well-characterized dimerization motif within stem-loop 1 (SL1). We also found stretches of nucleotides that enhanced genome dimerization upon mutation, suggesting their role in negatively regulating dimerization. A structural analysis identified distinct structural signatures within monomeric and dimeric RNA. The dimeric conformation displayed the canonical transactivation response (TAR), PolyA, primer binding site (PBS), and SL1-SL3 stem-loops, and contained a long range U5-AUG interaction. Unexpectedly, in monomeric RNA, SL1 was reconfigured into long- and short-range base-pairings with PolyA and PBS, respectively. Intriguingly, these base pairings concealed the palindromic sequence needed for dimerization and disrupted the internal loop in SL1 previously shown to contain the major packaging motif for Pr55Gag. We therefore rationally introduced mutations into PolyA and PBS, and showed how these regions regulate genome dimerization, and the binding of Pr55Gag in vitro, as well as genome packaging into virions. These findings give insights into late stages of the HIV-1 life cycle and a mechanistic explanation for the link between RNA dimerization and packaging. In the second project, I developed a proximity ligation and high-throughput sequencing-based method, RNA-RNA seq, which can measure direct (RNA-RNA) and indirect (protein-mediated) interactions. In contrast to existing methods, RNA-RNA seq is not limited by specific protein or RNA baits, nor to a particular crosslinking reagent. The genome of influenza A virus contains eight segments, which assemble into a "7+1" supramolecular complex. However, the molecular details of genome assembly are poorly understood. Our goal is to use RNA-RNA seq to identify the sites of interaction between the eight genomic RNAs of influenza, and to use this information to define the quaternary RNA architecture of the genome. We showed that RNA-RNA seq worked on model substrates, like the HIV-1 Dimerization Initiation Site (DIS) RNA and purified ribosome, as well as influenza A virus infected cells.},
  subject      = {RNS-Viren},
  language  = {en}
}
@article{YeAmbiOlguinNavaetal.2021,
  author    = {Ye, Liqing and Ambi, Uddhav B. and Olguin-Nava, Marco and Gribling-Burrer, Anne-Sophie and Ahmad, Shazeb and Bohn, Patrick and Weber, Melanie M. and Smyth, Redmond P.},
  title     = {RNA structures and their role in selective genome packaging},
  series = {Viruses},
  volume    = {13},
  journal   = {Viruses},
  number    = {9},
  issn      = {1999-4915},
  doi       = {10.3390/v13091788},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-246101},
  year      = {2021},
  abstract  = {To generate infectious viral particles, viruses must specifically select their genomic RNA from milieu that contains a complex mixture of cellular or non-genomic viral RNAs. In this review, we focus on the role of viral encoded RNA structures in genome packaging. We first discuss how packaging signals are constructed from local and long-range base pairings within viral genomes, as well as inter-molecular interactions between viral and host RNAs. Then, how genome packaging is regulated by the biophysical properties of RNA. Finally, we examine the impact of RNA packaging signals on viral evolution.},
  language  = {en}
}