Poster abstracts
Poster number 62 submitted by Kira Holton
Cellular Context for mRNA Substrate Selection by Pseudouridine Synthase 7 (PUS7)
Kira Holton (Biological Chemistry, University of Michigan), Brittany Bowman (Biological Chemistry, University of Michigan), Kristin Koutmou (Chemistry, University of Michigan), Chase Weidmann (Biological Chemistry, University of Michigan)
Abstract:
Human pseudouridine synthase (PUS) enzymes isomerize uridine bases to pseudouridine (Ψ) in coding and noncoding RNAs. The PUS enzyme PUS7 is responsible for a large fraction of pseudouridylation events, and altered PUS7 activity is implicated in several diseases. The mechanisms of PUS7-depedent substrate modification and how Ψ contributes to disease pathogenesis are unclear. Without understanding the cellular contexts that direct PUS7 target selection, we cannot predict the functional consequences of PUS7-dependent Ψ in RNA. We hypothesize that distinct RNA structural contexts and protein-RNA interactions drive selection of Ψ sites by PUS7 in cells. We are employing live-cell chemical probing and sequencing technologies to identify these cellular contexts. Preliminary data from interaction network probing in human cells suggest a trend for limited protein-binding at Ψ sites compared to unmodified sites. We will probe these networks in cells that do not express PUS7 to understand the underlying molecular features of PUS7-modified sites in the absence of Ψ. We will similarly chemically probe whether RNA structural motifs are conserved at PUS7-modified sites. We anticipate that the knowledge generated from this research will allow us to predict novel PUS7-dependent Ψ sites and may be suggestive of a novel gene regulatory mechanism based on RNA modifications.
Keywords: Pseudouridine, Live Cell Chemical Probing, PUS7