We are pleased to announce the publication of a study conducted by Nario TOMISHIGE, Yves MELY, and Toshihide KOBAYASHI on how the HIV-1 Gag protein reorganizes lipids in the host plasma membrane.
HIV-1 is enveloped in a membrane derived from the host cell, which is notably enriched in specific lipids such as sphingomyelin (SM) and cholesterol (Chol). This lipid composition is essential for the infectivity of the virus. The formation of new viral particles begins with the binding of the Gag protein to phosphatidylinositol-4,5-bisphosphate (PI(4,5)P₂) present on the inner surface of the plasma membrane.
Using endogenous lipid probes and advanced microscopy techniques, our colleagues show that Gag multimerization induces a reorganization of SM- and cholesterol-rich lipid domains in a manner dependent on membrane curvature.
Two plausible mechanisms are discussed to explain the enrichment of specific lipids in the outer layer of the membrane:
• a process of interdigitation between the bilayer sheets,
• or a cholesterol flip-flop promoted by the presence of Gag.
This study sheds new light on the molecular mechanisms that allow the virus to remodel the host membrane in order to optimize the formation and infectivity of its particles.
Congratulations to the authors.
Link: Selection of Host Plasma Membrane Lipids by HIV-1 Gag Protein. BioEssays: https://doi.org/10.1002/bies.70090
