Poster abstracts
Poster number 55 submitted by Danni Jin
Interaction between Human Glutamyl-Prolyl tRNA synthetase Linker domain and HIV-1 Matrix: Implications for viral infection
Danni Jin, Nathan P. Titkemeier, Alice A. Duchon (Department of Chemistry and Biochemistry, Center for RNA Biology, and Center for Retrovirus Research, The Ohio State University, Columbus, OH 43210), Yiping Zhu (Department of Biochemistry and Molecular Biophysics, Howard Hughes Medical Institute, Columbia University, New York, NY, 10032), Corine St. Gelais (Center for RNA Biology, Center for Retrovirus Research, and Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210), Li Wu (Center for RNA Biology, Center for Retrovirus Research, and Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210), Stephen P. Goff (Department of Biochemistry and Molecular Biophysics, Howard Hughes Medical Institute, Columbia University, New York, NY, 10032), Karin Musier-Forsyth (Department of Chemistry and Biochemistry, Center for RNA Biology, and Center for Retrovirus Research, The Ohio State University, Columbus, OH 43210)
Abstract:
Aminoacyl-tRNA synthetases (AARSs) are part of the cellular translational machinery and primarily function to ligate specific amino acids to cognate tRNAs. Mammalian Glutamyl-Prolyl tRNA Synthetase (EPRS) is a bifunctional AARS with a unique Linker domain between two synthetase domains, which has been shown to be involved in several non-canonical functions. EPRS is a component of the multi-aminoacyl-tRNA synthetase complex (MSC) together with seven other AARSs and three scaffold proteins. The genome of Human Immunodeficiency Virus Type 1 (HIV-1) encodes 15 viral proteins, which interact with host factors that affect viral replication. Based on published studies, many MSC components are included in the interactome of HIV-1 Matrix (MA) protein. We hypothesize that this virus-host interaction contributes to efficient viral infection. Our new data suggest that the expression of EPRS is downregulated in HIV-1 infected cells, and HIV-1 infectivity decreases in 293T cells stably overexpressing the Linker. Preliminary data also show that MA interacts with the MSC through the Linker domain in an RNA-dependent manner, but the specific RNA mediating the interaction is unknown. We are unable to detect an interaction between MA and the purified EPRS Linker in vitro in the absence of RNA, and both proteins interact with many tRNA species with similar affinity. MA mutants that fail to interact with the MSC in cells were identified by alanine-scanning mutagenesis, and viruses expressing these MA mutants are less infectious. Based on these observations, we propose that the Linker domain of EPRS restricts HIV-1 infection, and that the virus has evolved to downregulate this host cell protein.
Keywords: HIV-1, EPRS