Biophysical Society Thematic Meeting| Padova 2019

Quantitative Aspects of Membrane Fusion and Fission

Poster Abstracts

4-POS Board 4 TARGETING THE HENDRA VIRUS FUSION PROTEIN TRANSMEMBRANE DOMAIN TO INHIBIT VIRAL MEMBRANE FUSION Chelsea Barrett 1 ; Stacy R Webb 1 ; Rebecca Dutch 1 ; 1 University of Kentucky, Molecular and Cellular Biochemistry, Lexington, Kentucky, USA Enveloped viruses utilize surface glycoproteins to attach to host cells and initiate fusion of the viral envelope with the host cell membrane. Hendra virus, a highly pathogenic, zoonotic, enveloped virus in the family Paramyxoviridae , uses two surface proteins, the attachment protein (G) and the fusion protein (F), to carry out binding and viral entry. The F protein is synthesized as a trimer in a pre-fusion meta-stable conformation that, upon receipt of a triggering signal, undergoes a large, essentially irreversible, conformational change that drives fusion of the virus and host cell membranes. Previous research has demonstrated that the transmembrane domain (TMD) of F plays a key role in the protein’s trimeric association and overall protein stability, including stability of the pre-fusion conformation. To characterize the effect of disrupting these TMD interactions on the fusion process, exogenous Hendra F TM constructs were created containing the full TM domain and limited adjacent sequences. When these TM constructs were co-expressed with the full length Hendra F protein, a significant reduction in the expression and stability of the full length protein was observed. Furthermore, the F protein had a significantly impaired ability to facilitate viral and host cell membrane fusion when the TM constructs were present. In contrast, when the Hendra TM constructs were co-expressed with Parainfluenza Virus 5 (PIV5) F, another member of Paramyxoviridae , no decrease in PIV5 F expression or fusion activity was observed, suggesting the protein disruption by the TM constructs occurs in a sequence specific manner. These results when taken together, demonstrate that TMD interactions can be targeted to disrupt protein function and ultimately viral entry, even after the protein has trafficked to the viral membrane.

53