9r8u
Flag-tag LASV spike acidified to pH 5.0 and re-equilibrated to pH 8.0
Structural highlights
FunctionGLYC_LASSJ Stable signal peptide (SSP) is cleaved but is apparently retained as the third component of the GP complex. The SSP is required for efficient glycoprotein expression, post-translational cleavage of GP1 and GP2, glycoprotein transport to the cell plasma membrane, formation of infectious virus particles, and acid pH-dependent glycoprotein-mediated cell fusion. The GP complex interacts with host glycosylated LAMP1 to mediate efficient infection.[1] Glycoprotein G1 mediates virus attachment to host receptor alpha-dystroglycan DAG1. This attachment induces virion internalization predominantly through clathrin- and caveolin-independent endocytosis. Glycoprotein G2 is a class I viral fusion protein, that directs fusion of viral and host endosomal membranes, leading to delivery of the nucleocapsid into the cytoplasm. Membrane fusion is mediated by irreversable conformational changes induced upon acidification in the endosome (By similarity). Publication Abstract from PubMedLassa virus (LASV) is a devastating human pathogen with no vaccines and limited therapeutics. The LASV class-I spike complex engages target cells via binding its primary host receptor, matriglycan, followed by macropinocytosis and binding of its secondary receptor, lysosomal-associated membrane protein 1 (LAMP1), to trigger virus fusion. This process occurs across multiple pH-dependent steps, but the molecular events remain largely unknown. Through high-resolution structures, we study the pH-induced conformational changes of the spike preceding membrane fusion. We reveal pH-sensitive metal coordination sites that control the integrity of the spike's native state, elucidate a reorganization of the spike's transmembrane region, and provide a mechanism for dissociation from its primary receptor. Using the entry inhibitor ARN-75039, we validate our findings and establish the molecular basis for the binding and function of this investigational drug. These data define the molecular basis for the cell entry of LASV and will promote efforts in combating this virus and potentially related viral pathogens. pH-induced conformational changes and inhibition of the Lassa virus spike complex.,Katz M, Cohen-Dvashi H, Borni S, Ruedas J, Henkel G, McCormack K, Diskin R Cell Host Microbe. 2025 Sep 10;33(9):1577-1588.e7. doi: , 10.1016/j.chom.2025.07.020. Epub 2025 Sep 1. PMID:40897176[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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