Liou, G.-G. | Search bioRxiv

bioRxiv2020

A self-assembled protein nanoparticle serving as a one-shot vaccine carrier

In this paper, we are exploring the role of an amphipathic helical peptide in mediating the self-assembly of a fusion protein into a protein nanoparticle and the application of the nanoparticle as a one-shot vaccine carrier. Out of several candidates, an amphipathic helical peptide derived from M2 protein of type A influenza virus is found to stimulate high antigenicity when fused to a fluorescent protein genetically. This fusion protein was found to form protein nanoparticle spontaneously when expressed and purified protein stimulates long-lasting antibody responses in single immunization. Through modeling peptide structure and nanoparticle assembly, we have improved this vaccine carrier in complex stability. The revised vaccine carrier is able to stimulate constant antibody titer to a heterologous antigen for at least six months in single immunization. The immune response against a heterologous antigen can be boosted further by additional immunization in spite of high immune responses to carrier protein.

immunology↗

bioRxiv2020

Dynamin-2 regulates synaptic podosome maturation to facilitate neuromuscular junction development

Neuromuscular junctions (NMJs) govern rapid and efficient neuronal communication with muscle cells, which relies on the proper architecture of specialized postsynaptic compartments. However, the intrinsic mechanism in muscle cells contributing to elaborate NMJ development has been unclear. In this study, we reveal that the GTPase dynamin-2 (Dyn2), best-known for catalyzing synaptic vesicle endocytosis at the presynaptic membrane, is also involved in postsynaptic morphogenesis. We demonstrate that Dyn2 is enriched in the postsynaptic membrane of muscle cells and is involved in the maturation of neurotransmitter receptor clusters via its actin bundling ability. Dyn2 functions as a molecular girdle to regulate synaptic podosome turnover and promote morphogenesis of the postsynaptic apparatus. In Drosophila NMJs, Dyn2 is required to organize the postsynaptic actin cytoskeleton and to mediate its electrophysiological activities. Mechanistically, the actin binding, self-assembly, GTP hydrolysis ability, and Y597 phosphorylation of Dyn2 all regulate its actin bundling activity. Together, our study uncovers a role for Dyn2 in cytoskeleton remodeling and organization at the postsynaptic membrane of NMJs.

molecular biology↗