Open AccessThe cholesterol‐binding motif of the HIV ‐1 glycoprotein gp41 regulates lateral sorting and oligomerization
Author(s) -
Schwarzer Roland,
Levental Ilya,
Gramatica Andrea,
Scolari Silvia,
Buschmann Volker,
Veit Michael,
Herrmann Andreas
Publication year - 2014
Publication title -
cellular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.542
H-Index - 138
eISSN - 1462-5822
pISSN - 1462-5814
DOI - 10.1111/cmi.12314
Subject(s) - förster resonance energy transfer , lipid raft , biology , chinese hamster ovary cell , microbiology and biotechnology , glycoprotein , raft , gp41 , transmembrane protein , cytoplasm , viral envelope , fluorescence microscope , cell membrane , lipid bilayer , membrane , biochemistry , chemistry , fluorescence , signal transduction , receptor , epitope , genetics , antibody , physics , organic chemistry , quantum mechanics , copolymer , polymer
Summary Enveloped viruses often use membrane lipid rafts to assemble and bud, augment infection and spread efficiently. However, the molecular bases and functional consequences of the partitioning of viral glycoproteins into microdomains remain intriguing questions in virus biology. Here, we measured F oerster resonance energy transfer by fluorescence lifetime imaging microscopy ( FLIM ‐ FRET ) to study the role of distinct membrane proximal regions of the human immunodeficiency virus glycoprotein gp41 for lipid raft partitioning in living C hinese hamster ovary cells ( CHO‐K 1). Gp41 was labelled with a fluorescent protein at the exoplasmic face of the membrane, preventing any interference of the fluorophore with the proposed role of the transmembrane and cytoplasmic domains in lateral organization of gp41. Raft localization was deduced from interaction with an established raft marker, a fluorescently tagged glycophosphatidylinositol anchor and the cholesterol recognition amino acid consensus ( CRAC ) was identified as the crucial lateral sorting determinant in CHO‐K 1 cells. Interestingly, the raft association of gp41 indicates a substantial cell‐to‐cell heterogeneity of the plasma membrane microdomains. In complementary fluorescence polarization microscopy, a distinct CRAC requirement was found for the oligomerization of the gp41 variants. Our data provide further insight into the molecular basis and biological implications of the cholesterol dependent lateral sorting of viral glycoproteins for virus assembly at cellular membranes.